MatraSport Forum

Each model => Bagheera => Topic started by: andyowl on July 23, 2009, 08:36:12 am



Title: Supercharging a Bagheera
Post by: andyowl on July 23, 2009, 08:36:12 am
The realisation that our competition Bagheera does not have enough power for the straights and the fast curves confirms what many have said from the beginning, that Bagheeras need more power!

Following experience in 1968/9/70 with a Shorrock Supercharged Vauxhall Viva HB I have always thought about fitting a "Blower" to a 1442cc Bagheera. It is such a quick and relatively easy way of gaining up to 50% more power without spending huge sums on engine tuning. The car was used during the week to go selling my employer's engineering products in the North of England but without the blower connected. At the weekend I would re-connect the blower and go rallying in the wonderful Lancashire and Yorkshire hills. Happy Days......

In 1977 I discovered the Matra Bagheera and found out what motoring happiness was really about! Eventually even I had to agree that Baggys could use more power but he was used as a working car and I didn't have time to play. I had a business to run! A future project for when I retired!

With that in mind I purchased, during the '90s, two superchargers. The smaller is a Shorrock "Rotary Vane" blower intended for a 1600cc Ford Cortina complete with a 2" (50mm) SU carburettor. The other is a Wade "Double Helix" blower intended for a 3500cc Rover/Chevrolet V8 installed in a drag racer but purchased without a carb. A large USA Holley carb was recommended!

So now is the time to add "doing" to all the "thinking"!

Yesterday I took from the garage roof space the smaller Shorrock blower and blew off the dust (lots of it!). Everything seems to be there and everything is still free and smooth. The WD40 I had sprayed inside and outside the casing has done a good job while the clothes I plugged the apertures with have prevented ingress of "foreign bodies" such as bugs, moths and mice! A good start! See the pictures below..

The most likely space in the Baggy engine compartment is on the left side above the gearbox although there may be space on the right side with the rear of the blower located above and behind the right side tyre. The "boot" space is also a possibility but that would mean drastic surgery and a lot of metalwork. I have decided to try the gearbox space first.

Concept: Mount the blower on the left over the gear linkage close to and supported by the rear bulkhead rather than by the engine itself (which is the normal way). The drive can be by a cross shaft from the pulley system on the right side of the engine. The carb is a problem with the horizontal SU carb not the ideal configuration. Sucking air from the space above the engine cover would be good or better still from the outside air which should be nice and cool.

The blower is driven by twin "vee" belts from a modified crankshaft pulley. An additional two pulleys have to be added to the standard Simca/Matra pulley to provide the drive and I think there is enough space to add these and allow the belts to pass below the right side engine mounting to the driven pulleys, see the last picture.

Time to cut some metal! Watch this space!

All thoughts and ideas are very welcome! This is time for "silly suggestions". Nothing will be rejected.

Andy


Title: Re: Supercharging a Bagheera
Post by: Fred on July 24, 2009, 12:20:52 am
Great thread Andy, I especially liked this bit (in bold):

Following experience in 1968/9/70 with a Shorrock Supercharged Vauxhall Viva HB I have always thought about fitting a "Blower" to a 1442cc Bagheera.  The car was used during the week to go selling my employer's engineering products in the North of England but without the blower connected. At the weekend I would re-connect the blower and go rallying in the wonderful Lancashire and Yorkshire hills. Happy Days......

I'll be watching this one with interest!  ;)


Title: Re: Supercharging a Bagheera
Post by: Spyros on July 28, 2009, 10:54:18 pm
Andy,

I don't remember how it was done. But on SimcaCG, they did supercharge (Constantion supercharger) a similar version of our engine (1200 cc)
I can't say if it was only due to the supercharger but the power grew from 85 to 120 hp.
I presume this value should be possible


Title: Re: Supercharging a Bagheera
Post by: andyowl on July 29, 2009, 08:21:13 am
At Prescott I met Gerard Magro who owns a Supercharged CG-Simca. We did not get much time to talk but he offered to tell me what was done to the car. I expect to see him again at Etretat and maybe I should try to see the CG.

He has won the "Classements Scratch" for the last three years in the CG548 Spyder at Etretat!

Thank you for the reminder.

Andy


Title: Re: Supercharging a Bagheera
Post by: Jacobosterlindh on July 29, 2009, 12:51:56 pm
seen this?
(http://nsm01.casimages.com/img/2008/11/01/081101034009451312689488.jpg)
(http://nsm01.casimages.com/img/2008/11/01/081101034011451312689489.jpg)


Title: Re: Supercharging a Bagheera
Post by: JL on July 29, 2009, 02:28:33 pm
This must be a Simca 1000 setup where you have loads of room in the engine bay. I am not keen on the blow off valve venting air fuel mixture into the engine bay but an interesting setup nevertheless.

John


Title: Re: Supercharging a Bagheera
Post by: andyowl on July 29, 2009, 03:31:59 pm
Yes thank you, I have seen this thread and followed it with interest. Nice engineering and colours!

But, as someone else has said, I don't think it is a Bagheera engine bay. The distributor location is unusual and the rocker cover is not the same. Loads of space where the DCOE carb is located which I think is where the Bagheera fuel tank is fitted.

Thanks anyway.

Andy

PS I you think Bagheera spares are sometimes expensive try this..
Lamborghini Urraco, 33 years old, replacement clutch pressure plate, if you can find one, is £2,000. This does not include the friction disc nor the release bearing which are an extra £750. Time to go into manufacture I think. Plus freight and VAT of course. Anyone know a good clutch repairer?

AMO


Title: Re: Supercharging a Bagheera
Post by: andyowl on August 17, 2009, 08:16:31 pm
I attended an open air car show, Retro-Rides,  at the Haynes Motor Museum yesterday near Taunton in Somerset.  Baggy Joe was one of the Simca Club UK exhibits and attracted great interest.

Also there was the Simca 1100SR with a supercharger fitted. Very interesting but not very revealing as to the detail as the owner, Mick Ward - editor and competition secretary of the Simca Club UK - has had the car for only a short time and all the work was done by the previous owner. The boost is only 4-6psi (0.3-0.4bar) but he says it is still great fun to drive and drove the car from his home to the show and back again all in one day, around 680km! Well done. He has lent me two books on supercharging and I have some serious reading to do.

Another exhibitor had a supercharged and Nitrous Oxide injected Fiat Merea estate car there (I think that was the model). Nitrous Oxide seems to be a miracle additive and relatively simple to fit. The bad news is that it is not allowed in Sprints and Hill Climbs. Drag Racers use it extensively, but I think I will have to save that idea for a road car! Google "Nitrous Oxide" to get a flavour of what can be achieved.

Another exhibitor was a "Rolling Road" or "Dynamometer" operator offering to test your car and provide a paper (graphic) report of the results for £35 (38Euro). I'll report on that in a separate post as I need to check on the conversion factors for "BHP" to "DIN kW". Either way, Baggy Joe had more power at the wheels (and at the flywheel) that I remember the book saying! Good news!

Andy


Title: Re: Supercharging a Bagheera
Post by: Lanng on October 07, 2009, 12:55:01 pm
I found this on the www - if anyone wants to follow up on the thread.

http://www.bcsc.co.uk/info/superch.html - Shorrock Supercharger Catalogue
http://www.mg-tabc.org/supercharger/Shorrock_ABC.pdf - some basics
http://www.shorrocksuperchargers.co.uk/ - more technical data

/// Lanng


Title: Re: Supercharging a Bagheera
Post by: andyowl on October 08, 2009, 10:38:49 am
Thanks for these sites. I have followed them up as follows:-

http://www.bcsc.co.uk/info/superch.html - Shorrock Supercharger Catalogue. Useful information but the phone numbers no longer work and emails have not been answered.

http://www.mg-tabc.org/supercharger/Shorrock_ABC.pdf - some basics. I cannot get this site to open. Did you succeed?

http://www.shorrocksuperchargers.co.uk/ - more technical data. This one is sad too. The author Ian Bishop died of cancer in June this year. The site was designed by his friend as a memorial to his enthusiasm and he would like to find someone to take over the work. I have registered an interest with the site designer and said I would like to contribute when I have some data from my own Shorrock Project.

I am now committed to have our competition Matra-Simca-Shorrock Bagheera on the Matra Club stand at the National Exhibition Centre Classic Car show in November and have offered rides to club members at our December meeting in Kent. We are hoping to have several Matra competition cars there (RB Djet, Murena 2.2 Sprint/Hill Climb, Murena-Zetec conversion, Murena 1.6, and two Bagheeras). 

No going back now!

All Matristi are of course very welcome to join us at both events! More info follows soon

Andy Owler



Title: Re: Supercharging a Bagheera
Post by: Lanng on October 08, 2009, 11:07:11 am
Hi Andy

No prob with the http://www.mg-tabc.org/supercharger/Shorrock_ABC.pdf - I downloaded it, so drop me an email and I will send you the pdf.
Sorry to hear about Mr. Bishop - and kudos for following up on his work.

Looking forward to hear more about the supercharger project.

Quick question - As I understand; the large Shorrock supercharger works best between 3500rpm and 5000rpm. Is the not going to be an issue with the Bagherra engiens as they are high rpm based? and is it possible to get the charger to kick in at lower rpm. Reason for asking is my Saab 900 T16S (1991) has the "new" mitsu turbo on it which starts at 2500rpm and dies at 4000rpm - its a quick spooling turbo but loosing all the power at 4000rpm and only having a 1500rpm boost window is a bit small for my liking. AND if the Bagheerra Shorrock get the same "turbo kick" as the old Saab - its going to be REALLY fun to drive :)

/// Lanng


Title: Re: Supercharging a Bagheera
Post by: Anders Dinsen on October 08, 2009, 11:54:05 am
If you are going for a new installation, don't forget one of the current leading supercharger companies, Rotrex. Based in Herlev, Denmark - my back garden ;)
Their units are very small.

http://www.supercharger-experience.com/

Yes, they have supercharged the Koenigsegg!

/Anders


Title: Re: Supercharging a Bagheera
Post by: andyowl on October 09, 2009, 10:39:58 am
Lanng.. Thank you for the offer of a copy of the "ABC" file. I tried the link in your posting and it worked fine! Interesting stuff!

Maximum blower speed..
There are various figures quoted for the maximum advised RPM for the larger Shorrock and I have not yet decided which to use. I have an Allard-Shorrock original data sheet which gives, for the C148B blower which I already have, a maximum short duration RPM of 6500 and a sustained RPM of 4750. If I use the same diameter pulley on the crankshaft and on the blower i.e. 1:1 ratio this is not so different to the normal Bagheera engine speeds.  Remember that I am doing short duration events such as Sprints and Hill Climbs where the time spent "cruising" at maximum speed is relatively short. Better accelleration is what I need.

When I used a Shorrock blower on my "everyday" car (a 1966 Vauxhall Viva) the problems occured when I went quickly on motorways. The pistons overheated and melted (several times). Around towns or rallying on minor roads the overheating was much reduced and I don't remember any piston failures in those circumstances. I'm hoping that the same will apply on the Bagheera. Stuck in traffic jams around Manchester was also a problem as the lubricating oil being injected into the blower often contaminated the plugs causing mis-firing. Waiting in line to start the Sprint or climb the hill sounds very like a traffic jam and I have a plan to inject oil only when the blower raises the intake pressure above atmospheric pressure i.e. when the engine is working hard and capable of burning off the oil.

I appreciate that modern blowers are smaller and lighter. If/when I destroy the blower I have I will certainly look around for alternatives but at the moment I want to try the device I already have and think that I understand.

Andy Owler


Title: Re: Supercharging a Bagheera
Post by: Lanng on October 09, 2009, 02:20:08 pm
Hi Andy und Anders

The idea was to find a Bagherra and use it for Classic Hill Climb, Classic Rally etc etc. So because of the underpowered engine in the Bagherra the supercharger sounded like the way to go - as regulations requires "old school" mods in order to pass.

However because of resent personal events everything has been put on hold  - so no Classic Hill Climb or Bagherra this year :(  I even got acces to a nice warm garage with all the tools you could ever need for free.  :'(

To Andy - who about changing the compression and use a waterjet injection system. Saab used them on the Saab 900 Turbo (1987-1989; I think) and you can still get the AquaMist system for 500£ in Sweden. I know this relates more to detonation in the combustion chamber - but if it works on a turbo why not on a SuperCharger.

/// Lanng


Title: Re: Supercharging a Bagheera
Post by: Anders Dinsen on October 09, 2009, 07:59:41 pm
I appreciate that modern blowers are smaller and lighter. If/when I destroy the blower I have I will certainly look around for alternatives but at the moment I want to try the device I already have and think that I understand.

My comment was not raised towards you, Andy, I'm sure you have an excellent blower there, but if people "just" want to tune their engine, a modern blower should be considered.

The idea was to find a Bagherra and use it for Classic Hill Climb, Classic Rally etc etc. So because of the underpowered engine in the Bagherra the supercharger sounded like the way to go - as regulations requires "old school" mods in order to pass.

Old school yes, but as I read the hill climb rules here, they have to be homologated too. Or am I missing something there?

Quote
However because of resent personal events everything has been put on hold  - so no Classic Hill Climb or Bagherra this year :(  I even got acces to a nice warm garage with all the tools you could ever need for free.  :'(

Sorry to hear that. If you decide to scrap the idea completely, then I think we're all happy you shared the idea with us and stimulated the discussion! But I hope it works out in the end!

/Anders


Title: Re: Supercharging a Bagheera
Post by: andyowl on October 10, 2009, 09:01:05 am
Lanng wrote..
 what about changing the compression ..

I have heard that the Rancho had a lower compression ratio than the Bagheera and I wonderd about fitting those pistons. I did some calculations about how thick would the cylinder head gasket have to be to reduce the comp ratio enough. "Quite thick" was the result!

....and use a waterjet injection system. Saab used them on the Saab 900 Turbo (1987-1989; I think) and you can still get the AquaMist system for 500£ in Sweden. I know this relates more to detonation in the combustion chamber - but if it works on a turbo why not on a SuperCharger.

I have heard about the water injection system but know very little. How does it work? What sort of pump and nozzles? When does it inject the water? Maybe the same time as my intermittant lubrication system?

What about the electronic detonation detection devices? They reduce the igntion advance I understand.

Such a lot to learn! Fitting the blower itself seems relatively easy!

Andy Owler


Title: Re: Supercharging a Bagheera
Post by: Spyros on October 10, 2009, 09:38:21 am
Lanng,
I would avoid saying that the Bagheera was underpowered. You need to compare the power/liter to other period cars.
You'll see that when the car was issued in 1973, in was not bad.
Simply, the weight is too high, the engine is too small and the design of the car let you believe that you miss 100 pk.

If you compare the Matra Bagheera 1.3 and the Ligier JS2, the power/liter ratio is the same.
The Bagheera has a 1290 cc engine, the ligier has a 2950 cc maserati engine

Andy,
If you want to decrease the compression, I have 2 easy solution for you.
1) Remember Marcel Morel and his compressed Murena.
He used a 1100 cc engine. Why ?
Just a simple calculation. The cylinder head volume is kept the same (24 cc for the post 75 one and 20 for the early one)
If you decrease the bore, you loose compression.
So, use a 1100 as a basis but with the 70 rods
2) Because of my 16V engines, I need to have custom built head gasket.
They are currently being made, in coper.
You can choose the thickness, even very thick


Title: Re: Supercharging a Bagheera
Post by: andyowl on October 29, 2009, 12:11:09 am
May I ask your advice please? (I have also posted this question in the Rancho section)..

I read that the Rancho had a lower compression ratio than the Bagheera with the same 1442cc engine. Someone told me that they achieved the lower compression by the use of a different piston height. Any advice would be very welcome.

I am tempted to fit the ex-Murena engine I already have but I need to do it quickly so as to have the blown car at NEC on November 13th.

Was there also a low comp 1600 engine perhaps on a Simca commercial vehicle?

They have said that the 1600 engine is not as strong as the smaller capacities particularly at high revs, but my Shorrock blower does not need to rev too hard and has a 6500rpm limit.


Andy Owler


Title: Re: Supercharging a Bagheera
Post by: andyowl on October 30, 2009, 12:09:41 am
Update today...

Thanks for the responses. I have made some progress today although I have not yet spoken to a man who might supply Rancho pistons!

I have the contact details of a man who can supply thick cylinder head gaskets. I'll call him tomorrow.

Several members have warned me that the 1600 engine is not very strong partially due to the non-symmetrical cylinder layout and crankshaft.

I am moving to the conclusion that I should stay with the 1442cc engine with Rancho pistons but with the stroke of 78mm reduced by crankshaft grinding to 77.2mm. This will give a reduced capacity of 1427cc and this when multiplied by the "forced induction factor" of x1.4 will give me a nominal capacity of 1995cc. This will satisfy the competition requirement to remain, after fitting the blower, within the original "Class" of 1401-2000cc. The reduced stroke will also reduce the compression ratio and any further reduction can be achieved by the use of a "decompression gasket".

The "decompression gasket" will cost about 120Euro and take 2 weeks to make. Specially made forged competition pistons are about 150Euro each (so Rancho pistons sound a good idea if they can be found!)

The design is coming together!

Keep the suggestions coming please.

Thanks

Andy Owler


Title: Re: Supercharging a Bagheera
Post by: Spyros on October 30, 2009, 01:14:37 pm
This is far too complicated Andy,

Just take a 1290 cc engine.
Rebore it to fit the murena pistons.
And (80.6 X 70)  ... you get the 1428 cc engine.

Now about the gasket, I can have them made on order in coper, the thickness you want, for 50 €.
I had some special gasket made and they are very nice.
The postage cost will be cheaper than the 120 €.
If you need, drop me a mail  ;)

By the way, who is making your 150€ gaskets ?

And yes, there was 2 compression ratio for the 1600 cc engine


Title: Re: Supercharging a Bagheera
Post by: Spyros on October 30, 2009, 04:28:03 pm
So 70 mm stroke = high revs  :)
Non equidistant engine = presumably more resistant at high revs
No crankshaft grinding with special hard to find bearings


Title: Re: Supercharging a Bagheera
Post by: andyowl on October 30, 2009, 04:41:41 pm
Thanks for the idea of Murena pistons in a bored out 1293 cc engine. Not a combination I had considered!

I have been researching sources of pistons since I read your first posting but I have not checked the obvious sources such as Matra Magic etc. I need also the cost of boring out the block.

I already have the 1293cc engine to use.

Keep thinking!

Andy

PS This has decided me to go ahead with the standard 1442 existing engine for trial purposes rather than wait for special gaskets etc to arrive.

On with the boiler suit again! I wonder what the record is for changing a cylinder head gasket?

Andy


Title: Re: Supercharging a Bagheera
Post by: JL on October 30, 2009, 05:26:47 pm
Andy
Do you know how many cc's you need to get a sensible compression ratio?
John


Title: Re: Supercharging a Bagheera
Post by: andyowl on October 30, 2009, 05:35:51 pm
JL asked...How many ccs do we need for the lowered compression ratio?

I did some calculations a little while ago and from memory I needed an extra gasket of around 1.2mm thick (plus the standard gasket). That was probably based on a 1.6 Murena engine and 8.0:1 compression ratio.

What's on your mind?

Andy


Title: Re: Supercharging a Bagheera
Post by: Lanng on October 31, 2009, 01:41:57 am
Hi Andy

Sorry for the AquaMist delay. Got some links for you:

Seller stuff (description and prices)
http://www.aquamist.co.uk/
http://www.rotorsportsracing.com/performancetuning/water_injection.htm
http://www.partsforsaabs.com/default.php?cPath=28_183 === Saab parts seller

Installed in various Saab´s:
http://www.saab9000.com/procedures/performance/waterinjection.php === Installation on a Saab 9000 Turbo

http://www.nysocphotos.com/gallery/5650646_PYxc6/3/347602870_Gd27M#593457632_RigXQ === Fitting an a Saab 900 turbo; please note that its 4 pages with Saab installation guide shown - it might help, it might not...

http://www.netma.fi/jouko/saab/performance.html === A bit more detailed on installing on a Saab 900 Turbo

I know its a lot of links - but I was not sure how to help you the best way.

/// Lanng


Title: Re: Supercharging a Bagheera
Post by: andyowl on October 31, 2009, 08:45:17 am
Lanng,

That's magnificent, thank you so much!

I have spent the last hour just in the AquaMist site alone.

Fitting the blower in Baggy today! off to work.

Andy


Title: Re: Supercharging a Bagheera
Post by: JL on October 31, 2009, 08:43:46 pm
Andy
If you only require that sort of capacity, you could probably deck the piston crowns and open up the cylinder head to get it along with the advantage of better breathing.
Regards
John


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 01, 2009, 09:06:07 am
JL said ... "..deck the pistons...". Do you mean remove some metal from the top of the pistons to get extra volume in the combustion chamber? That is not something I had considered. I wonder how much can be removed with harming the strength of the piston crown? Someone suggested that is how they made the Rancho low compression pistons.

Spyros said... "use Murena pistons in a bored-out 1293 block with a 70mm crankshaft." I've been thinking about this very neat solution which will give me exactly 2000cc after the "blower factor" but will this not have the same problems as Simca found in that there is not enough metal left between the cylinders? They went to (as I understand it) unevenly spaced cylinders and a different crankshaft. Could one use a 1.6 unevenly spaced crankshaft in the 1293 block?  Hummmm. Perhaps I should take some measurements of our 1442 block when I take the head off to replace the gasket.

My thoughts yesterday of setting a new record for changing the head gasket have been set aside while we fit the blower. There is so much more space to work when the carbs and rocker cover have been removed.

Pictures will follow shortly. Now back to work!

Andy


Title: Re: Supercharging a Bagheera
Post by: JL on November 01, 2009, 11:26:28 am
Hi Andy
Decking the pistons on a race engine (machining the crowns so that they all sit the same distance below the top of the block) is done to give you a balanced combustion chamber capacity which all helps smoother running etc and I seem to remember that there is plenty of meat on the piston crowns for machining - I also used to check the chambers in the head as well.
Using a short stroke bored out 1294cc is a good way to go and if there is any doubt on block wall thickness just have some liners pressed in.
The other thought is that you are now starting to spend enough money to make it worth thinking about having a set of custom pistons made.
Regards
John


Title: Re: Supercharging a Bagheera
Post by: Spyros on November 01, 2009, 11:52:59 am
I agree with JL.
If there is not enough meat you can decide to press liners in.
But according to my calculation, you can use standard 80.6 pistons (Murena, Solara 1.6) or even the first reparation bore (+0.1)
It is with the second reparation bore that you'll have issues.

Also, I don't understand why they produced the first reparation bore since if a 1590 engine is worn, you don't rmove enough by boring it this size. This means that you don't interfeer with Murena restorers. They can't use these pistons.

Still a consideration about the pistons tops :
The 80.6 pistons (murenas & associated) are different from the previous ones: more hollow on the top.
That would help lowering your compression.
I'll try to find back the difference. I mesured it once.
However, the previous pistons seems more resistant than these.
3 years ago, I posted on this : http://www.bagheera-cafe.com/viewtopic.php?t=581&highlight=pistons (http://www.bagheera-cafe.com/viewtopic.php?t=581&highlight=pistons)

Good luck Andy. We are with you  ;)


Title: Re: Supercharging a Bagheera
Post by: suffolkpete on November 01, 2009, 12:57:35 pm
Quote
Could one use a 1.6 unevenly spaced crankshaft in the 1293 block?
Surely you'll just end up with 1592cc if you do that.  If  the 1.6 bore centres are different from the other blocks, I don't see how Spyros's idea, ingenious though it is, can be made to work.  Pity. such an oversquare engine would probably be very free-revving.


Title: Re: Supercharging a Bagheera
Post by: Spyros on November 01, 2009, 10:52:25 pm
Quote
Could one use a 1.6 unevenly spaced crankshaft in the 1293 block?
Surely you'll just end up with 1592cc if you do that.  If  the 1.6 bore centres are different from the other blocks, I don't see how Spyros's idea, ingenious though it is, can be made to work.  Pity. such an oversquare engine would probably be very free-revving.

No you can't use that crankshaft. No you won't get a 1592.

And sorry Pete, but this idea is not new.
Simply, up to know, the people who used the 1.6 piston also wanted to get this volume and so used the 1442 as a base.
Same stroke as the 1.6, so same volume.
Several people did it.

Here however, the idea is to use it on a shorter stroke engine. So not wanting the big volume.
Someone did it too, years ago.
Marcel Morel. He supercharge a Simca engine and since he wanted to compete in the 1600 class, he started also with a smaller engine. A 1100 cc. Why ? The stroke : 65.


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 02, 2009, 09:56:03 am
What a team! Thanks for all the thinking time!

Pictures from yesterday..

We have the blower bolted in and the general layout decided. I now know where the transfer shaft will go and I'm off to the bearing, belt, pulley and universal joint man this morning to order the parts.

I have spoken to the "Thick Head Gasket" man who is actually a "Decompression plate" man. He is quoting around 8 days for delivery and about the same price as I mentioned earlier. I will send him a new head gasket as a pattern today. The cylinder head is off and the engine looks in very good condition. I will check the valves and reassemble it with the decomp' plate when available.

We have taken the crankshaft pulley off ready to have the new pulley fitted. We made a special tool to stop the pulley rotating while we turned the securing bolt. Think of a long pair of scissors with M10 bolts welded on the tips of the blades. They go in the 10mm holes in the pulley and the handles of the "scissors" rest on the ground.

The old mechanical petrol pump is off and a blanking plate made to fill the hole. The new electric petrol pump will go close to the top of the tank.

This might actually happen!

We are using the existing 1442cc engine for the moment while we decide, with your help, which of the capacity options is easiest. The way the discussion is going suggests that re-grinding the crank-pins to give a 77mm stroke rather than the present 78mm might still be the easiest option. Finding (or making) shell bearings for 77mm will be the next problem!

Thanks again
Andy


Title: Re: Supercharging a Bagheera
Post by: suffolkpete on November 03, 2009, 07:01:08 pm
Quote
Could one use a 1.6 unevenly spaced crankshaft in the 1293 block?
I've just been reading the manual and I notice that, on the 1.6 at any rate, the piston centres are not in line with the con rod centres and that on the 1.6 two of the pistons have the opposite orientation to the other two, whereas on the smaller engines they all face the same way.  Perhaps this is how they obtain the uneven spacing, not by using an unevenly spaced crankshaft.  Would this mean that you could use a 1294 crank in a standard 1592 block, rather than trying to bore out a 1442?


Title: Re: Supercharging a Bagheera
Post by: Spyros on November 03, 2009, 10:09:17 pm
Pete,

The block you are speaking about are different.

The 1294 cranckshaft goes with a 1294 block
A 1440 or a 1590 block is about 1.5 cm taller. That's why it will not be possible to mix the taller engine part with the shorter one.
If you think about machining the top of the block, you can only remove about 1mm. After about 5, you are down in the water channels.

That's another argument for Andy to start with a 1290 cc engine : smaller push rods = less flexible = less weight and load on the valves = higher revs ! (again)

1440 and 1590 engines are also different and even between 1590 cc engines you have different types of blocks. The main difference for us, Bagheerian is that in order to fit (keep) our gearbox, you need to reposition 2 of the holding holes.

About the pistons, the 1590 cc pistons are not purely symetric. But, between the internal side of the pistons and the sides of the conrods, you have a play of 3,2 mm. Which let you recenter the conrod without problem.

If you want to start with a 1590 block, you will anyway start with a worn engine, and so also have to rebore it. Isn't it ?
Then, you will realize that you need a minimum of +0.4 overbore. Try to find them.
This only leave you to play with pistons of another french make that you'll have to adapt.
But then, it will give an even bigger cylinder capacity which is not what Andy want if he needs to stay in the same class


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 04, 2009, 12:15:49 am
Surprising developments....

When, on Sunday, I took the head off the current engine after I found that the engine was hard to start and was running very rough (after our track-day last week) I find that the cylinders are 80.6mm bore! Someone has already fitted a 1.6 engine! The cylinders are evenly spaced with around 9mm between each bore. The 1442 head gasket is assymetrical with a much larger gap between cylinders 2 and 3. The 1442 head gasket fits the head but does NOT fit the block! Maybe I have a 1442cc head on the 1592cc block?

The gasket metal ring in between 2 and 3 was not resting on the block metal. On the outer edges of #4 it was also not resting on the metal of the block. Hence the leak perhaps. The extreme activity at the trackday, plus the slight over-heating caused the gasket to leak I think.

I confess also that I did not check the valve clearences before I took the head off. It is possible that there was no valve clearence and maybe the valves became burnt at the track-day.

I have not had time yet to take the valves out - I have been busy again on the blower installation.

Either way I have ordered a Solara head gasket and I will report back on what we find. The Decomp Gasket man is waiting for a gasket to copy and I do not expect to receive it until Thursday. It was only while checking the 1442 head gasket I was going to send him that I noticed it did not fit the block! I do get some things right!

The capacity reduction to 1427cc will have to wait! 1592cc x 1.4 blower factor = 2.2 litres. Murenas better watch out! 

Andy


Title: Re: Supercharging a Bagheera
Post by: suffolkpete on November 04, 2009, 08:54:24 am
Quote
The cylinders are evenly spaced with around 9mm between each bore.
That prompted me to go out and measure the 1.6 engine I am currently rebuilding and the bores are indeed evenly spaced.  So all that business about asymmetric pistons is to make the cylinders evenly spaced and the smaller engines are uneven, presumably to make room for the centre main bearing.  I suppose the bores 1/2 & 3/4 were too close together to bore out the 1.4  make 1.6, so they had to resort to the asymmetric pistons to even out the spacing. Fascinating!


Title: Re: Supercharging a Bagheera
Post by: Spyros on November 04, 2009, 09:35:53 am
So all that business about asymmetric pistons is to make the cylinders evenly spaced and the smaller engines are uneven, presumably to make room for the centre main bearing.
Not really. On the uneven engine, in between cylinder 2 & 3, there is a water jacket.
This had to go to leave room for even spacing

Quote
  I suppose the bores 1/2 & 3/4 were too close together to bore out the 1.4  make 1.6, so they had to resort to the asymmetric pistons to even out the spacing. Fascinating!
They were not too close but the marging left would have mean no room for a rebore and potentialy a percentage of engines that could not have been fit for the bore.
Looking at all the evolution between the 1000 cc engine to the 1590 is indeed fascinating.

Andy,
There are no 1590 cc heads. These heads are identical to the 1440 cc engine  ::)



Title: Re: Supercharging a Bagheera
Post by: andyowl on November 04, 2009, 01:55:44 pm
Spyros wrote...There are no 1590 cc heads. These heads are identical to the 1440 cc engine.

Thanks for that. I will not now need to take off the head from my Murena 1.6 engine!

It has always puzzled me that people claim that the Murena 1.6 engine was not much more powerful than the 1.4 Bagheera engine even with twin DCNF carbs fitted. Surely an extra 10% capacity should give around 8% more power? Why bother otherwise?

What can be done to the 1.4/1.6 head to improve it? Gas flowing would be a start but how much can be removed? Is there any experience out there?

The inlet ports look quite generous but the exhaust ports are skinny. Hard to see how the valves could be enlarged. They are very cose together.

I think I read somewhere that one should remove any sharp edges in the combustion chamber on a blown engine to minimise the risk of excessively hot corners causing pre-ignition. It would also make a small reduction in compression ratio. Probably worth a try while I have the head off.

Andy



Title: Re: Supercharging a Bagheera
Post by: Spyros on November 04, 2009, 02:11:55 pm
The torque of the 1.6 engine is much better.

If you want to fit bigger valves, you are limited by the space in between.
Except if you fit excentric valves guides.
In UK, you should have some facilities to find those for BL types of engines (BMC A, B or Standard). Moss had a special catalog for these

For the exhaust port, I would avoid to open it too much.
The scale at the exit of the head is there to prevent exhaust gas to go back into the compression chamber.
I would work on a better exhaust instead (I also have a DXF for the flange)

If you want to gas flow the inlets, start by matching the carbs, inlet manifold and head. Then, think about the holes for the push rods. It is easy to go too far and to end up into these holes.
I was thinking that gas flowing was more important for normaly aspirated engines ?


Title: Re: Supercharging a Bagheera
Post by: suffolkpete on November 04, 2009, 09:05:02 pm
Quote
1592cc x 1.4 blower factor = 2.2 litres. Murenas better watch out!
Before you get too carried away, are you sure the gearbox can take the power? Reading the other threads on this forum they seem a little fragile  ;)

Peter (Murena owner)


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 05, 2009, 07:54:45 am
suffolkpete wrote.....Can it take the power, gearboxes seem a little fragile ?....

"I don't know" is the straight answer. I am working on the principle that the gearbox takes the 1.6 Murena power and most manufacturers build in a factor of safety which is unlikely to be less than 1.5. I'm looking to gain 50% in power which may therefore be OK. I don't know of any other way of finding out than trying it. How I drive it probably has as much influence on its survival as the outright power it transmits. I seem to be reasonably gentle with my cars and the recent broken diff was the first time I have knowingly broken anything (and I am not convinced that it was something I did then!).

I also have several used gearboxes in the loft which will act as back-up. The one in use now is a Talbot recon unit and just out of the wrapping paper.

Fingers crossed!

Andy


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 05, 2009, 08:04:35 am
What have I got in there?

Last night I checked the bore and stroke of the existing engine. Bore is certainly 80.6mm and the stroke seems to be 77.9mm. Both are as accurate as I can get with a non-digital vernier. It seems we have a Murena/Solara block of around 1590cc. In very good condition too.

I will take the head apart shortly and check out the valves etc. They might not be so good!

I was surprised to find at "top dead centre" that the tops of the pistons are 1.5mm below the top of the block, not flush with the top. Is this normal?

The pistons have slight recesses machined into their tops, I presume for the inlet and exhaust valves. Also normal? I don't have a Murena or Solara workshop manual. Maybe I should buy one!

Watch this space (I know you are and I take great encouragement from that. Thanks!)

Andy


Title: Re: Supercharging a Bagheera
Post by: Spyros on November 05, 2009, 08:49:49 pm
Hi Andy,

Yes, this is normal.
If you increase a bore, you have more volume and since the cylinder head are kept the same, the compression ratio is increased. I suppose that this is the way Talbot managed to keep the compression ratio to acceptable level.

I checked a 1.6 and a 1.2 engine that I have currently in work.
The 1590 have the pistons 1.5 mm below the top (It's currently a trial fit to take the VW valves prints and I'll machine the top of the block because I need to built up the compression ratio)
The 1200 have the pistons less than 0.5 mm below.

Regards,
Spyros


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 14, 2009, 08:08:54 pm
Well, Baggy Joe made it to the NEC with the blower and all its drive shafts and pulleys in place. It is non-working and shown as a "work-in-progress". The grand design we had built on Sunday had to be modified as the support for the tensioning pulley and arm collided with the head!

I received back the cylinder head from the machine shop on Tuesday and spent most of Wednesday cleaning it and fitting it onto the block. There are no valves yet in place although they have been ground in and the seats recut. The head was slightly bent and it has been lightly skimmed.  This implied that the combustion chambers were of smaller capacity than usual and he measured the volume using oil and a pipette. The answer was that the combustion chambers are now 20mL each. I measured the volume above the piston at top-dead-centre and concluded it was 18mL. I gave these figures to the man making the de-compression plate and he calculated again the thickness of the de-comp plate. We are targeting a compression ratio of 8.4:1 being the Shorrock recommendation for competition and fast road work. The required thickness is now 2mm.  The plate arrived on Thursday morning a few minutes before I left for NEC. Good timing all round!

I have not seen the completed Matra stand but on the left we have the Greig Dalgleish beautifully restored Bagheera S1 in pale blue, then Baggy Joe low and scruffy in bright yellow but very much looking like a serious competition car (well I would say that wouldn't I?), then a newly restored and very pretty Rene Bonnet Djet (from the Bowman father and sons team) in silver with black stripes, the Tim Boyes Murena with the Ford Zetec 2Litre engine transplant also in bright yellow and finally the dark red 16L Murena from Titus. What a line-up!

See you on Sunday perhaps?

Andy Owler


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 24, 2009, 08:35:43 pm
Back on the blower project with 11 days to go before he has to be running for the December 6th MECUK meeting!

I have fitted all the valves to the head and the inlet manifold is bolted on. Much of the time has been taken doing preparation work such as cleaning threads, finding new (stainless) nuts and making sure I have everything necessary to just "throw it together". It does seem to be progressing well and I hope to have the head back on the engine tomorrow (Wednesday). Then it is all the "minor" things like the carb and extending the old throttle and choke cables to the new linkages, connecting the two vaccum connections to the same vacuum point between the carb output and the blower suction. The blower gauge needs to go onto the inlet box where it will read the actual pressure being generated.

But what about the ignition system and its automatic Advance/Retard mechanism?

I put the question this evening to Mick Ward of the Simca Club who is running a supercharged Simca Rallye 1100. (I think)....

...Brain picking again if I may...

I haven't yet studied my (and your) books on the subject of ignition advance with the blower but your first thoughts would be appreciated..

A standard engine, if I have got the concept right, has its tickover ignition setting according to the book. This is when the inlet manifold vacuum is at its highest. When the throttle is opened, engine speed increases and manifold vacuum decreases. The auto-advance/retard diaphragm increases the advance to give the flame time to get established just as the piston gets to TDC. In a sense this is necessary also for the blown engine except that too much advance can cause destructive detonation. So maybe the mechanism to advance the spark needs to have a maximum limit at perhaps lower revs? Do you have any experience of how one would achieve this with the rather basic distributors we use?

How about:- Disconnect the auto A/R system and set the advance to suit the max power situation and forget about the tickover?

Alternatively mess with the dizzy springs to get a different curve.

I have been recommended by the guy who made the decompression plate to a USA company called "MSD" (I think). They make a sophisticated electronic ignition package designed for Blown engines where the driver can select an advance curve while on the move. It also responds to actual manifold pressure and adjusts itself. Sexy stuff but expensive too. I have yet to ask Lumenition whether they have anything similar.

Makes my brain hurt, all this thinking!

Andy Owler


Title: Re: Supercharging a Bagheera
Post by: Spyros on November 25, 2009, 08:43:07 am
As allways a wonderfull work. ;D

I think the MSD is described in Vizard book (powertune BMC A )
Having seen your pictures, I'm also thinking that the inlet manifold for single weber like on a Murena might have been easier to match and potentialy giving a better flow.
I've several of these and lately I cut out the water supply from one of them.
The idea was to see how I could adapt it to a 1200S engine (different angles) but also to not heat the mixture.
Not feasable !
Actually, thinking about it, you might take an advantage of this by having a replacement of an intercooler : connect these pipes to a small different radiator (in front) with an electric pump and voilà ! you'll cool the mixture. This would however be more appropriate to a turbo engine.

The very good news is that normaly in about 12 days we might see your completed engine  :D

Keep going !


Title: Re: Supercharging a Bagheera
Post by: suffolkpete on November 25, 2009, 08:50:59 am
The vacuum advance is to give more advance when running at higher engine speeds on a light throttle when vacuum is at its highest.  Centrifugal advance progressively advances as engine speed increases and this is the one you would have to alter.  You would probably not notice a huge amount of difference if you disconnect the vacuum except perhaps in fuel consumption.  I guess you'd have to fit stronger springs in the ditsributor but I have no idea how to determine the type to use other than trial and error.


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 25, 2009, 09:34:23 am
Spyros wrote..I'm also thinking that the inlet manifold for single weber like on a Murena might have been easier to match and potentialy giving a better flow.

Yes it does look a bit clunky doesn't it? Hardly "gas flowed"!

I had always imagined a row of nicely curved stainless steel inlet pipes like the "bunch of bananas" in the Alfa V6 and many other modern cars. I would still like to do that but getting the concept working and  proved seemd to be more important than going for aesthetic perfection at the start. Plenty of time for development!

Thanks for the kind words.

Andy


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 25, 2009, 09:38:22 am
Suffolkpete wrote...
Centrifugal advance progressively advances as engine speed increases and this is the one you would have to alter.

I read something in the Allard-Shorrock instructions about fitting a ring in the dizzy. I wonder if this limits the travel of the centrifugal advance?

I was only thinking of the vacuum advance mechanism. You have opened a new line of thought. Thanks very much.

This is a good time to be looking at the dizzy as it is much easier to get at without the head in place. Good timing too (no pun intended!).

Thanks

Andy


Title: Re: Supercharging a Bagheera
Post by: Spyros on November 25, 2009, 07:23:23 pm
Spyros wrote..I'm also thinking that the inlet manifold for single weber like on a Murena might have been easier to match and potentialy giving a better flow.

Yes it does look a bit clunky doesn't it? Hardly "gas flowed"!
Yes yes ...
But a thick piece of aluminum would have been enought to join that manifold to your right angle part.
You wouldn't have had to TIG weld this box
(http://www.matra-bagheera.com/Plan/Resto/Mechanic/Engine_Rebuilt/manifolds/1or2carbs.jpg)

Today I read some documents about the adaptation of Constantin blower on old peugeot.
They changed the advance to zero.


Title: Re: Supercharging a Bagheera
Post by: Spyros on November 28, 2009, 04:25:18 pm
Some others are trying ...

http://translate.google.be/translate?u=http%3A%2F%2Fwww.simca-competition.com%2Fles-autos-des-membres-f19%2Fma-r2-turbo-t1739.htm&sl=fr&tl=en&hl=fr&ie=UTF-8 (http://translate.google.be/translate?u=http%3A%2F%2Fwww.simca-competition.com%2Fles-autos-des-membres-f19%2Fma-r2-turbo-t1739.htm&sl=fr&tl=en&hl=fr&ie=UTF-8)


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 28, 2009, 10:56:44 pm
I regret that I was not able to make the link work! I think the translation got in the way, plus the need to register to access the site.

Can you summarise this item for me please?

I had not seen this Simca Competition site before. Interesting!

Andy


Title: Re: Supercharging a Bagheera
Post by: Spyros on November 29, 2009, 12:35:57 am
Can you summarise this item for me please?

The site is purely Simca Rallye oriented. With a little bit of other things.

So here it is :
Simca Rallye 2 Turbo
First with a Constantin compressor with belts and a ratio of 1.9 (can go up to 2)
(http://i98.servimg.com/u/f98/14/58/39/44/s6001610.jpg) <= this image is coming from this site. Please visit it for more details
And injection.

But we wanted another gearbox, so we head for a 5 speed.
First we tried an Alfa but the oil didn't run in the right direction.
So we tried a 5 speed from a R5 Alpine Turbo but we had a problem (doesn't say what)
So we went to a 4 speed VW, knowing that then we could replace it by a 5 speed Porsche

But then we realized that this compressor has to turn in ... the other direction

So we throw the compressor away and went for a turbo.

To be continued (I suppose)


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 29, 2009, 05:46:17 pm
Thanks Spyros for the Picture!



Andy


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 29, 2009, 05:58:06 pm
Mick Ward of the Simca Club UK made these comments about the yellow Supercharged engine in the "My Project" thread. They seem to apply also to the layout of the Spyros engine picture...

  I was looking on the  MatraSport forum for anything on supercharging and spotted the pictures of the yellow engine with a DCOE weber attached to the blower.  This engine is in a 'period' group 4 SIMCA 1200S coupe which has appeared at a number of shows in France..  You note the position of the distributor.  The top of the timing cover is the original position for it on the upright, anticlockwise versions of the engine used in the 1000s and 1200S coupes.  The 1000 cam has an extra bit cast on the end with a extra gear to drive the distributor.   The gear driving the cross shaft inside the block then just drives the oil pump.  The hole for the distributor on the transverse engines is covered by the base of the water pump on the 1000 block..
                                    All the best                      Mick

Andy Owler


Title: Re: Supercharging a Bagheera
Post by: Spyros on November 29, 2009, 06:15:34 pm
I might have other pictures of this supercharged Simca 1200S. Let me try to find them

Also, I've sent an email to the guy of the previous picture.


Title: Re: Supercharging a Bagheera
Post by: Spyros on November 29, 2009, 08:32:26 pm
Not my picture (cannot find them  ???)

(http://images.forum-auto.com/mesimages/203005/49.jpg)


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 30, 2009, 08:49:47 am
Interesting to see the whole engine space!

I like the pressure relief valve on top of the inlet manifold. Simple and self resetting. The one I received with the Shorrock Blower is a 6mm 1/4R Norgren pneumatic relief valve which although better than nothing, is grossly inadequate to relieve the explosion pressure caused by a backfire through the inlet valve into the inlet system. I am planning merely to omit the last hose clip on the 50mm pipe where it enters the inlet box. The explosion pressure will cause the pipe to blow off and make the system safe but it will probably not reseal. On the motorway this would be a problem but on a sprint or hillclimb track it is just an inconvenience and better than blowing out a gasket or suchlike. This picture gives me an idea of how I can make a similar safety valve.

How do they get at the spark plugs? Unlcear! On my system they are more accesible than usual thanks to the absence of the carb(s).

The plastic "oil catch tank" on the right side is also interesting. I am hoping to direct the vent from the rocker cover into the inlet tract as usual. Not yet designed though!

More news follows... We are almost there!

Andy Owler


Title: Re: Supercharging a Bagheera
Post by: Spyros on November 30, 2009, 10:19:13 pm
Changing the spark plugs ?
It makes me think of the Mi16 conversion of the Bagheera of a German friend.
I had the impression that to change the oil filter you had to remove the engine.

Allthough... his car is running since a long time. And a remote oil filter would address the issue.
Here... not so easy ... but interesting work anyway


Title: Re: Supercharging a Bagheera
Post by: andyowl on December 07, 2009, 09:54:20 am
We have a Supercharged Bagheera!

We made it to the MECUK meeting yesterday by 1350 (it started at 1200) admittedly on a trailer because I solved the bad running problems only that morning. Some members were given rides but time did not allow for everyone, so apologies to those who did not get to ride yesterday.

I got the engine started on Wednesday afternoon but there was severe vibration of the blower drive shaft. It was clear that the shaft needed support near the blower and a simple "pillow block" bearing was ordered from RS which arrived next morning together with a harder "spider" for the Lovejoy coupling. These were fitted on Thursday and the engine run again. There was a great improvement in vibration although the engine could not be made to run at less than 2500 rpm. At this speed the vacuum was about 50% but the brake servo was not very effective.

I spent some time on the internet on Friday looking at SU carburettor web sites and learned that vacuum leaks can be a big problem. (This is news to a Bagheera owner?!) Overnight I realised that while vacuum leaks are hard to find, pressure leaks are much easier! If I put some compressed air in the inlet system the application of soapy water to the outside of all the joints will show bubbles if there are leaks! And so it did but it was not until Sunday morning that I had time to try the theory.

I blanked off the carb outlet with Duck Tape and put the air into the vacuum connection. It was obvious very quickly that the inlet box was leaking from every joint! I had purchased new screws to hold it down and had assembled it quickly without checking the thread length nor applying Hylomar gasket sealant. The screws were just too long by about 3mm and they were not compressing even the red fibre washers under their heads.
 I cut about 5mm off the screws and applied Hylomar to the joints and the top elbow. An air re-test showed that all the leals had gone!

The engine this time could be adjusted down to 1200 rpm, which is still too fast, but there was at least enough vacuum to work the brakes! I drove down the road to the first turning point and back again. We had a running car! It was now 1200 and the decision was made to go the the meeting which was about 50 minutes drive from home. But that was only after getting out the trailer and coupling it to our tow vehicle. That and loading the Bagheera took another hour so we arrived at 1350!

Drving across the crowded car park was the longest journey with the blower, but we had kept the promise to have a Blown Baggy Joe at the December meeting. (Why do I make these rash promises??)

There is more work to be done including making or finding a pressure relief valve for the inlet box. Twice it backfired while trying to start the engine and each time the inlet pipe was blown off the elbow (you will see from the photos below that there is no hose clip on the last pipe intentionally to allow explosion pressures to escape). I found out during the air pressure test that it will come off at 0.2bar (3 psi) which is "safe" but very limiting as I hope to get up to 1.0bar supercharging pressure.

My apologies to the many people at the meeting with whom I did not spend enough time particularly "Suffolk Pete" who has contributed many times to this and my other threads. Great to put a face to the words!

Thanks to you all for your support and advice. Very much appreciated.

Andy Owler


Title: Re: Supercharging a Bagheera
Post by: Spyros on December 07, 2009, 07:00:10 pm
Wonderfull.
Do you feel some effect already ?
What is this gold coloured bolt above the clutch housing, on the second picture ?


Title: Re: Supercharging a Bagheera
Post by: Anders Dinsen on December 07, 2009, 07:59:50 pm
Wow, well done! Congratulations, Andy!  8)

/Anders


Title: Re: Supercharging a Bagheera
Post by: andyowl on December 07, 2009, 08:44:58 pm
The gold coloured "bolt" above the clutch housing is a brass "female" pipe fitting into which I have screwed the "Low Oil Pressure Alarm" switch which has a 1/4R male pipe thread. The blue circle is the collet through which the nylon pipe passes when it is in place. I have not yet connected this to the oil supply nor to the large alarm lamp in the car. The Shorrock Supercharger consumes engine oil at a slow rate for its own lubrication and I worry that I will run out of oil and not notice in time. One of the corners at the Mallory Park circuit ("Gerrards" is a 180 degree, large radius, very fast turn) is famous for causing "oil surge" and cars which are low in oil level often lose all oil pressure. I am even thinking of fitting an alarm Klaxon just in case I do not notice the alarm light!

On top of the banjo fitting which connects the oil pressure gauge transmitter to the oil supply was what looked like an oil pressure switch but I have never seen a Bagheera with an oil pressure warning light. Is it just that the righthand drive Bagheeras do not have such a light or do your lefthand drive Bagheeras also not have them?

Glad you are pleased with the result! All the support I have received has played a big part in getting the job finished! Well nearly finished anyway!

Yes, I can certainly notice a difference even with only +0.2bar boost pressure.

I need now to check for anything starting to go wrong after the short runs we have had so far and then start to "finish" this part of the project. A dry road would be nice, a pressure relief valve essential and a hose clip to allow the boost pressure to go over +0.2bar. A trip to the rolling road and fine tuning of the SU carb is pretty important too.

An article on SU tuning suggested that an on-board Oxygen ("Lambda") sensor and display would allow continuous monitoring of whether the mixture is "Lean", "Rich" or just right. Does anyone have experience of these devices? Demon Tweeks sell the Lumenition "Air-Fuel Ratio" system where coloured LEDs tell you whether the mixture is OK or not. Changing the needle in the SU carb will allow the mixture to be altered easily and progressively.

I also dribble over the Lumenition "Knock Sensor" which should warn of potential damage due to pre-ignition, always a worry with a supercharged engine. After that a water injection system should allow higher boost pressures and even more power!

So you see why I talk of "phase one" of this project!

Andy Owler


Title: Re: Supercharging a Bagheera
Post by: suffolkpete on December 07, 2009, 08:57:39 pm
Quote
Great to put a face to the words!
  It can't be a very memorable face because you saw it last year when you gave me a ride in the Djet :)
Seriously, keep up the good work, I'm amazed by what you've achieved in such a short time and I'm finding your progress very interesting and educational.  Maybe I'll get a ride when it's fully sorted.


Title: Re: Supercharging a Bagheera
Post by: andyowl on December 07, 2009, 09:11:52 pm
Oh dear! Sincere apologies! I have (had once upon a time) a reasonable memory for faces in the past but connecting the face with a name is always a nightmare for me! Advancing years has not improved matters and I have become a strong advocate for having name badges at meetings and exhibitions.

I was a sales engineer for many years and gave lectures on my pet speciality (preventing explosions in flammable gas atmospheres such as oil rigs and refineries). People often came up to me and greated me like an old mate. I hadn't a clue what their names were. Very embarrassing!

I hereby apologise in advance to all whose name (and face) I cannot now remember.

Andy


Title: Re: Supercharging a Bagheera
Post by: andyowl on December 15, 2009, 09:56:51 am
Having had a chance to use Baggy Joe several times on the road since the Matra meeting on December 6th the initial impressions are very good!

Damp or wet roads have limited the opportunities to apply full boost but the main limiting factor has been the absence of an explosion pressure relief valve. If a backfire occurs in the inlet manifold the resulting explosion pressure can get up to 7.5 to 8 bar (118psi). Although the pipework and the manifold itself can probably take that pressure, for a few milliseconds at least, the effect on the blades in the supercharger could be very damaging. 

To minimise the risk of explosion damage I have not fitted the last hose clip on the inlet system with the expectation that the pipe will blow off if the pressure gets too high. This happens at around 0.2bar (3psi) And it does, frequently! On Sunday in a drive of only 2-3 km the pipe came off three times! My passenger got tired of jumping out and pushing it back on again. We took a risk and fitted the last hose clip and then allowed the boost to get up to 0.5bar (7.5psi) and the car flew down the road!

The risk of a backfire is very real! While unloading the car from the trailer on Sunday evening after the meeting, in the dark and wet, I had two backfires while trying to start the engine. The first was unexpected and the subsequent noise while cranking was quite different. With a torch I could see that the inlet pipe had blown off as intended. I pushed the pipe back on, got back in and tried again to start it. This time I watched the engine through the mirror and saw a large blue/yellow flash as the backfire escaped through the open pipe, once again blown off!

So the focus is now on finding or making a relief valve. The conventional pneumatic pressure relief valve as fitted to superchargers is only 6mm bore (Norgren 1/4" type). All my instincts say this is too small to relieve the explosion pressure fast enough. The water industry has valves much larger than this and the RS catalogue (www.rswww.com) lists several 3/4" valves at less than 25% of the price of the 1/4" Norgen pneumatic version. Worth a try perhaps?

But my real wish is to make a 30 or 40mm relief valve like the one we patented in 1976 for our company's use. It was designed to act as an automatic outlet valve for a control cabinet that had to be purged with clean air before the electricity was turned on. The walls of the cabinet might be 2m high x 900mm wide and deep so there was a very large surface area for the pressure to act upon. Our valve was 50mm bore, fitted on the outside and the valve disc was suspended on a stainless steel leaf spring. It was held closed by a permanent magnet inside the cabinet with the air gap adjusted to give the right opening pressure typically about 10mbar (0.15psi). When the purging started the cabinet pressure rose to 10mbar and the valve popped open! We detected the opening action with a reed switch and that was calibrated to give us a purge air flow rate. The patent ran out some years ago so we could use the same principle again on the blower! More thought needed.

Maybe there is a new market here!

My other concern it that the blower installation is noisy! Very noisy by most commentators' opinion and I wonder if it will pass the noise tests imposed by the FIA and MSA at race meetings. I am arranging for one of the official scrutineers to check the noise level as 110 dBA is the maximum permitted for our class in Sprints and Hill Climbs. This should happen during the next 2 weeks hopefully. At the last meeting, pre-blower, the exhaust noise was measured at 91 dBA, well below the level allowed.

Happy Christmas to all members and sincere thanks for your continuing support in this project.

Andy Owler



Title: Re: Supercharging a Bagheera
Post by: Stig on December 15, 2009, 05:14:02 pm
Hi Andy,

I have been watching this thread with great interest. Faboulus job!!
Great idea with the permanent magnet controlling the opening pressure and giving the "pop" effect.
Only drawback as I see it in this application could be vibrations but maybe the force required to pop the valve is much greater than can be created by vibrations.
An alternative to the permanent magnet could be a solenoid.
Assume that you have a valve body looking very much like an intake or exhaust valve.
Connect the stem to the plunger of a solenoid in such a way that the solenoid keeps the valve closed.
You have to make sure that the plunger is not fully seated in the solenoid since it will be extremely strong at the fully seated position.
By simply regulating the current through the solenoid you should be able to adjust the release pressure.
The solenoids built in nonlinearirity should give you the pop effect.
You may even have a microswitch which cuts the current when the valve pops.
There has to be a weak spring which returns it to closed position and thereby closing the switch and give the solenoid its current back.
In my opinion this could be done very simple. I am visualizing a valve looking something like a thermostat where the wax bulb is replaced with a solenoid.
Just an idea.

Best regards,

Stig


Title: Re: Supercharging a Bagheera
Post by: andyowl on December 15, 2009, 11:07:19 pm
I like the idea of a modified thermostat housing. It is about the right diameter and the solenoid or magnet could replace the wax bulb. As an assembly it could be calibrated for opening pressure before fitting to the car.

I would like to try an opening pressure of 1.5bar, i.e. 50% higher than the maximum operating pressure of the blower.

How well do thermostat valves seal tight? Not something I have thought about before! It needs to be tight under vacuum or we will have an inward air leak.

With the rectangular inlet box we have space for relief valves on each side of the central inlet elbow. Maybe the "clunky" design of the bax has some merit after all. The books recommend that the relief valve(s) are located in direct line of the explosion pressure wave. Having two can only help that.

More thought needed.

Andy


Title: Re: Supercharging a Bagheera
Post by: Stig on December 16, 2009, 04:22:03 pm
A standard themostat may not seal good enough. I used it mainly as an example of what I was thinking about.
From what you have said sofar it seems as if the valve has to be designed for frequent useage.

Do you have any idea of the maximum working temperature the valve and its seal has to withstand?

What about the escaping gas. Do you have to have some sort of catch tank to prevent any risk of fire?

Regards,

Stig


Title: Re: Supercharging a Bagheera
Post by: Stig on December 16, 2009, 11:28:05 pm
Another valve idea just popped up.
The drain valve in a standard wash basin. It is aproximately the right size, seals well and the fixed part has exterior threads.
Only drawback is that the valve stem points in the wrong direction but that should be easy to fix.

Stig


Title: Re: Supercharging a Bagheera
Post by: Spyros on December 18, 2009, 09:27:20 am
Just a question.
On the period compressor adaptation I've seen on the web, I didn't see any relief valve.
- Did I miss it ?
- Do they do it differently ?


Title: Re: Supercharging a Bagheera
Post by: andyowl on December 18, 2009, 11:07:07 am
Did they have a relief valve? Good question!

I think Shorrock and other "rotary vane" superchargers are particularly vulnerable to sudden and severe pressure waves coming from the wrong direction. The vanes themselves are quite thin (I don't remember how thin, but just a few mm) and I could visualise them being bent by the explosion pressure. If they bend, even momentarily, they will jam in their guide slots and destroy the rotor. No second chance.

Other designs such as the Roots/Wade multi-lobe, Sprintex rotary screw and centrifugal blowers do not have this risk and probably don't need relief valves.

Maybe I am being paranoid and worrying too much but I note that the original Shorrock literature I have shows that a pressure relief valve was always provided as part of the installation kit. Manufacturers do not supply something in a kit that is not necessary, it increases their costs and raises the price on a product that was already considered as expensive.

Interestingly, in looking through my old blower literature, I found the receipt for the blower I have just fitted. I paid £475 for the Shorrock type C142 blower in July 1993 after seeing a "for sale" advertisment in "Car and Car Conversions".  In the same year I paid £200 for the car that was to become Baggy Joe, complete with an MoT test certificate, and drove him home. It only took me 16 years to put the two items together! That's a lot of planning time!

Weather permitting I am meeting the MSA scrutineer with the noise tester on Sunday to find out just how noisy we are. I will need some sort of relief valve for that drive and I received yesterday a magnet with which to make a Mk1 magnetically closed valve. Watch this space!

Andy


Title: Re: Supercharging a Bagheera
Post by: Spyros on December 20, 2009, 10:20:07 am
Understood,

I must have been confused by the type of superchargers
Like the one described on this page ?
http://www.spridgetmania.com/web/DisplayID/1710/SCatagory/ENGINE/DisplayType/Technical%20Information/ArticleV.cfm (http://www.spridgetmania.com/web/DisplayID/1710/SCatagory/ENGINE/DisplayType/Technical%20Information/ArticleV.cfm)

and also by the size of the usual valve
On this picture
(http://www2.mgcars.org.uk/images/bbs/posts/97_2009110408445332527_61543776604047_1258203982.jpg)
Is this the valve that is hidding itself under the rubber pipe, close to the SU ?

http://www.mg-tabc.org/supercharger/Shorrock_ABC.pdf (http://www.mg-tabc.org/supercharger/Shorrock_ABC.pdf)

Could it be that further tuning of the ignition and cooler spark plugs might reduce the backfire tendency of your engine ?
On standard engines, bad ignition timing can induce this.


Title: Re: Supercharging a Bagheera
Post by: andyowl on December 20, 2009, 10:06:43 pm
Yes, the you can just see the Shorrock relief valve below the rocker box oil vent  pipe near the SU Carb. There seems to be a black stain around one of the valve outlet holes perhaps suggesting that there is frequent use of the valve! How nice the installation looks with its bright red paint and everything neat and tidy. Not a drop of rust in sight! Sets us a good example!

The Mini Cooper web site is interesting too. Shame that the supercharger kit is no longer available. I wonder what it cost? The installation is very neat (and small!).

The other Shorrock site is very interesting too. I have visited it before and tried to contact the owner. I learned that he died last year and that a friend is keeping it going in his memory. What a waste death is! I said I would be interested in contributing to it if his widow chose to continue with it for the benefit of other Shorrock enthusiasts. No answer yet though.

We met the MSA Scrutineer today for noise testing despite the snow and bitter cold. I confess that I took the car on the trailer rather than drove it there.  I had not had time to make any sort of relief valve and we reverted to having a loose inlet pipe as our safety device. Just as well we did too as the engine backfired again during starting while hot. I saw the flash from 20m away!

The allowable noise level, he said, for "Sprints" is 105dBA. Baggy Joe without the Shorrock was measured at 91dBA at "Sprint Royale" in October. Today we measured 96dBA on the right side and 97dBA on the left side (where the blower is located). Well below what is allowed. Good news! Even so I want to do something about reducing the external noise level as it does make the car a little conspicuous going down the High Street. Not that a bright yellow, wide wheeled and lowered, competition car is inconspicuous in the first place! At high revs the noise inside makes my ears hurt so putting back a bit of sound deadening might be a good idea there anyway.

A number of FDMC Club members joined in the discussion as to how and why we have installed the blower the way we did. Lots of suggestions were offered (some better than others of course) but lots of interest was shown! I think we are raising the profile of the Matra Bagheera quite nicely. One chap thought we had a V8 in there! There's a thought!

One strange phenomenon is that, at nominal "tickover" 1,800RPM, the engine speed cycles automatically from 900 to 2500RPM, like "hunting" on a big diesel engine. The elbow on the inlet pipe is partially collapsing under the vacuum and this seems to restrict the air getting into the engine. The engine slows down, the vacuum decreases and the pipe expands again and the engine speeds up! Bizarre! I think I can fix that by putting some internal support tubes into the elbow. We might be able to lower the "tickover" speed then.

So we can now proceed with the next stages such as finding an expert in tuning SU carbs on a rolling road. And so many other things too.

Andy


Title: Re: Supercharging a Bagheera
Post by: andyowl on March 06, 2010, 09:40:45 am
In December 2009 Stig wrote.. Another valve idea just popped up.
The drain valve in a standard wash basin.....

I have abandoned my plan to use a magnetically closed explosion relief valve on Baggy Joe and used instead the principle of Stig's idea of a "wash basin drain valve". Thanks Stig!

The magnet to keep the valve closed at 1.5 bar was so big there was no room for the exploding gases to flow around it. Our magnetically closed pressure relief valve was originally designed to open at 50 millibars and it worked very well. 1.5bar is much harder to hold closed!

Our aluminium manifold box, with its flat sides, becomes the body of the "valve" with the valve disc on the outside and the stem pointing inwards. Over the stem is a spring pressing on the inside of the box and the end of the stem has an M8 nut and a large washer holding the other end of the spring. Tighten the nut to compress the spring and we have an adjustable explosion relief valve which opens outwards to relieve the pressure! Just like Stig suggested!

I did a trial assembly yesterday and it seems to work. Today the Neoprene seal gets added and time to take some pictures.

Tomorrow we rebuild the Blower Drive shaft with the new universal joints and go racing again on March 21st at Aldershot at the FDMC "March Solo". Seven entrants in the Historic Class so far including: MGB, MGBV8, Mini Cooper S, Austin Healey Sprite (2009 Class Winner), a "Kougar Jaguar" whatever that is, and a 1592cc Supercharged Matra Simca Bagheera S! Should be fun!

Andy


Title: Re: Supercharging a Bagheera
Post by: andyowl on March 08, 2010, 09:50:28 am
The backfire explosion pressure relief valve is finished but yet to be "tried in fire"! That will follow in a few days I'm sure. But here are the pics for those wanting to do their own...

The inlet manifold is a simple rectangular box (beautifully made by a welder friend) and the relief valve is located at the centre under the inlet elbow facing forwards (so the driver can see in the mirror the flames and slow down?). It could also be used to limit the maximum supercharge pressure but that would mean unburnt flammable mixture being discharged into the engine compartment looking for something else to ignite it. Not a good idea!

The pics show the spring centred on the compression plate with its M8 tapped hole in the centre. The 4 off M3 screws at the back keep compression on the spring so that the M8 central bolt can be removed without the internals falling out of alignment e.g. to allow replacement of the neoprene valve seal. The compression plate is assymetrical to stop it rotating more than 90 degrees when the central bolt is turned to adjust the level of compression and hence the opening pressure.

The outlet has five 14mm holes for the escaping gases - they should have been 15mm diameter but my 15mm drill went missing! They can always be drilled out later. The five small countersunk screws protrude into the manifold and keep the other end of the spring centred. They also form a "stop" so that the spring cannot be over compressed and prevent the gases getting out.

The view through the inlet hole shows the spring at about half travel which should give an opening pressure of 0,5 bar / 7.2psig. This is lower than I want but better to start with a lower opening pressure and build up the power slowly! A stronger spring is on order but is on a 4 week delivery.

More pics of the new drive shaft arrangement to follow shortly.

Andy


Title: Re: Supercharging a Bagheera
Post by: andyowl on March 11, 2010, 08:14:10 am
The backfire pressure relief valve works! Trying to start the engine yesterday there were two backfires! I eventually got the engine running and although the mechanical noise is much reduced with the new universal joints the engine itself was very "rough". I looked at the "Supercharger" pressure gauge on the instrument panel and saw that it was showing zero even when I slowed and speeded up the engine. I realised that I had failed to reconnect the gauge to the manifold! Not only that but I had not even replaced the 1/8R (BSP) gauge connection and now had a 10mm hole in the inlet manifold! Not surprising therefore that it was difficult to start!

With the gauge reconnected the engine started happily with about -0.6bar in the manifold at 3 000 r/m.

I cannot get the engine to run at less than 2 500 r/m without slowly stopping. I think it is a carburettor  problem but my last experience of a SU carb was 40+ years ago on my supercharged Vauxhall Viva HB. Too long ago to remember! Through a local British car restorer friend I have found a man who knows about SU carbs and we have arranged to see him on Monday. His name is Alan Hill who is a specialist in restoring Morris Minors of all vintages. His business is called "Over the Hill Motors"! Neat huh?

Before fitting the manifold back on the car I made some "debris guards" as you can see in the pictures. I am worried that some part of the relief valve may fall off (despite using Locktite Threadlock on all the threads) and to prevent debris falling into the engine I thought some wire mesh might be a good idea.

The pictures show the new universal joints and their black rubber gaiters. I have thought about what might go wrong with this drive shaft and the most likely failure point seems to be the 16mm aluminium shaft on the blower adaptor. All the rest of the drive system is stainless or mild steel and well strong enough. If that ally shaft breaks I will have the drive shaft still rotating loose until the engine stops but potentially doing much damage. So I have left in place the intermediate bearing carrier that was fitted to try to reduce the bad vibration we found originally. I have simply taken out the bearing itself and left the surrounding ring to restrain the drive shaft if the ally blower shaft breaks. I hope I never find out whether it works but it is reassuring that it might not destroy the valve cover or the bulkhead!

More later!

Andy


Title: Re: Supercharging a Bagheera
Post by: Anders Dinsen on March 11, 2010, 09:17:30 am
Hi Andy

I really enjoy reading your progress reports. Thanks also for sharing the funnier experiences! We've all tried that, so I don't feel bad laughing over the missed connection of the pressure gauge :)

About the mesh, on N/A engines, mesh is usually not recommended as it disturbs the airflow quite a bit. The mesh itself of course reduces the area through which the air flows, but more important it also creates quite a bit of turbulence, reducing airspeed. Mesh used to be popular on competition cars in front of carburettors instead of filters, but it's not a good idea - a proper filter is always better if you don't dare running without. I understand why you want it, but you're after power... I'd remove it and accept the risk. Besides, nuts don't just fall off if tightened correctly - and especially not when done with loctite :)

Keep up the good work and good luck with mr. Hill :)

/Anders

Just noticed one other thing: You don't need the heat insulating carb bases with your new setup. A simple paper gasket will do.


Title: Re: Supercharging a Bagheera
Post by: andyowl on March 11, 2010, 02:31:57 pm
You make good points about the undesirable side effects of the mesh. It will be very easy to remove when I have built up some confidence of the valve's reliability. I try to work on the principle of "Safe with one fault" rather like the concept of modern twin circuit braking systems.

The point about not needing the heat insulating spacers fitted below the inlet manifold is also well made. However heat build-up is still a potential problem with a blower as the compressing action of the blower itself will increase the temperature of the inlet mixture and, as another forum member mentioned, a water injection system to cool the inlet mixture is something quite close to the top of my development programme. If we start to inject water when the manifold pressure rises above atmospheric the engine is already working hard and should not complain about water in the fuel! I have already obtained a pressure switch to control the water injection and a vacuum switch for the blower lube oil system

wbw

Andy


Title: Re: Supercharging a Bagheera
Post by: Spyros on March 14, 2010, 09:35:16 pm
Andy,

This afternoon, I was looking at the pictures I took a week ago.
What types of brake pads do you use ?
Since already some times, I converted mine to EBC Green stuff

Regards


Title: Re: Supercharging a Bagheera
Post by: andyowl on March 15, 2010, 09:32:34 am
Spyros wrote...
What types of brake pads do you use ?

It is some time ago and I will need to look back at the papers.

I don't remember at this moment, although Green Stuff has been recommended within the MECUK.

Andy


Title: Re: Supercharging a Bagheera
Post by: andyowl on March 20, 2010, 09:16:38 am
I road tested Baggy Joe with the supercharger several times in the last week. The power increase feels HUGE! It was at least an hour before my knees stopped vibrating after the last run with the relief Valve opening pressure increased to about 0.8 bar. The car just flies and the "Blower Howl" makes my spine tingle. There are too many things happening at the same time to register them all. Wow!

There have been some problems however. During one of the first runs I could hear the Relief Valve ("RLV") opening with about 0.2 bar on the boost pressure gauge. I screwed down the spring a bit and the maximum boost pressure rose to 0.5bar. Feeling brave I gave it a last adjustment to the limit of the thread on the screw. 0.7bar was seen briefly but it started to drop back again. I looked at the neoprene valve seal and saw that it was dissolving! Despite the "material compatibility charts", which suggest that Neoprene is OK with unleaded gasoline, my neoprene foam gasket doesn't agree! As a short term fix I have made a very thin (0.05mm) brass disc to go between the foam and the manifold body. I hope this will reduce the contact between the gasoline and the rubber. I have not driven this solution yet.

At long last I have wired up the "Low Oil Pressure Warning Light". I had forgotten that I had done most of the work already and the hook up was very quick. The light itself is a 25mm lens where the cigar lighter normally sits. I can see it through the lower half of the steering wheel. It should be very visible if it lights up during an event. The oil pressure gauge also works but that requires "looking at" whereas the bright alarm light should attract attention. I hope it never needs to operate. The big worry is that the Shorrock blower consumes engine oil and it may not take long before the oil needs filling up again. In the heat of competition I may forget. The warning light is the last chance! What I really need is an oil LEVEL warning system.

Oil leaks in the nylon pipes feeding the oil pressure warning light switch and the blower lube oil line have also been a problem. I have used "Legris" pneumatic push-in fittings for over 30 years and found them very good if installed correctly. If air leaks out nobody really cares or noticed. Oil dripping out is a very different matter and easy to see especially if it results in smoke (Oh my God, its on fire!) or "What is that puddle on the floor" or worse "If your car leaks oil on the race track you will be banned and hated by everyone else". Not a good scenario! So I think I will have to re-pipe the system using compression fittings and/or use copper pipe. I checked in the RS catalogue last night and only Enots/Norgren compression fittings are listed. I loathed these fittings when I was a site engineer in the '60's and I don't feel much happier about them now. Apart from expensive USA Oil Industry compression fittings, anyone got any ideas on better systems? Wade and Simplifix were two competing brands 20 years ago but I haven't checked recently. Using copper would seem to be a good idea but I worry about fatigue cracking. Maybe I should be using oil-resistant rubber pipes?

Finally, I have now cut two large holes in the engine cover (yesterday) for the top of the SU carb vacuum dome and for the carb air inlet filter. Not the prettiest jigsaw job I ever did but the first AutoSolo event is tomorrow and the scrutineers will want an engine cover in place, even with two holes in it! Today is time to stick the fabric back on the engine cover, re-fit the interior trim (door cards and original twin passenger seat) as they are also required. Adding weight is not what I want to do!

Wish us luck.

The event (Sunday March 21st) is held at the Montgomery Lines parade ground, off Alison Road in Aldershot, Hampshire. Entry is free to spectators. All welcome. Come to the motorhome and stay for coffee! We should be there around 0830. Action starts after the driver's briefing at 10am. You may get press-ganged into helping to marshal!

Andy


Title: Re: Supercharging a Bagheera
Post by: Spyros on March 21, 2010, 10:00:54 am
Hi Andy,
You are progressing so quickly !
I'm not sure to understand how you made the low pressure light work ?
Don't we have, by default, the sensor, however unwired ?

If I understand well, you needed an oil supply for the blower.
Did you took it from the oil pressure sensor or elsewere ?
Like I'm doing here ?
(http://img517.imageshack.us/img517/5368/adscn6410ul0.jpg)

Regards


Title: Re: Supercharging a Bagheera
Post by: andyowl on March 22, 2010, 03:54:46 pm
If I understand your picture correctly you have drilled and tapped the hexagonal head of the bolt that holds the oil pressure transmitter in place. My bolt head now has an M5 thread and a M5/6mm Legris stud coupling in place. What thread is yours?

When I think about it my "bolt" is in fact the remains of the low oil pressure switch which did not work. They are not intended to be taken apart but I did it anyway! Because the "bolt" head was concave the biggest thread I could make was M5 but yours may be 1/8"? That seems much better than M5 which looks very fragile especially with steel braided hoses.

Your hoses are  "Aeroquip"?  They look very good. Very professional! "Proper Job". I must find a local source of those hoses and get some prices. Do you buy locally or via the internet? Expensive?

You have inspired me again!

The picture below is of the finished engine cover complete with the "Supercharged" badge. I didn't want to fix the badge until I was satisfied that the car was good enough to enter the first event of 2010! Superstious perhaps?

I will put a report on yesterday's AutoSolo event under the "Roll Cage Wanted" Thread.

Andy


Title: Re: Supercharging a Bagheera
Post by: andyowl on April 02, 2010, 12:35:06 pm
"Rolling Road" testing....

Yesterday we visited TCS Performance Ltd., near Bishop's Stortford, who provided the rolling road on which Baggy Joe was tested last August at the Practical Performance Car "RetroRide" event at Haynes Motor Museum.

[Just in case someone is not aware of what a "Rolling Road" does here goes. The driving wheels of the car rest on two large rollers which are connected to generators. The driver runs the engine and accelerates the rollers through 1st, 2nd, 3rd and 4th gears. He then lets the engine slow down to around 1,500rpm and opens the throttle fully. The generators provide the load on the engine and the computer records the electricity being produced and converts that to "Horse Power". A graph is plotted showing the Horse Power at the wheels, calculates the HP at the flywheel i.e. excluding the losses of the transmission and tyres, and several other things. Air/Fuel ratio is important to a blower system as having a mixture with too much air can cause the pistons to overheat and melt! He also records the inlet manifold pressure (the Blower Pressure) and several other things if you wish.]

In August last year the maximum Horse Power recorded was 88.6HP. (I need to convert this Imperial figure to metric! Do you prefer kW or something else?). We now know that a 1592cc Solara engine had been fitted by a previous owner and that it is in reasonably good condition.

Having now fitted the supercharger and got it running reasonably well, I felt that we should have some proper testing done to try to maximise the power and check those things that are difficult to do while the car is stationary such as how the mixture varies throughout the rev range and check the ignition system working with the engine under high speed/high load  conditions. All these can be done on the rolling road with the car stationary.

The car was reversed onto the rollers and strapped down very tight to prevent it coming off and running down the road! Sensors were added including a "Lambda" sensor to measure the Air/Fuel ratio and a thermocouple to measure the inlet air temperature. My blower pressure gauge was disconnected and the manifold pressure sensor connected in its place. There must also have been a connection to the ignition system (to monitor the engine speed) but I don't remember seeing it.

The photoghraph of the computer screen below showed some of the many graphs the computer produced. I will scan the paper graphs he provided shortly but the main interesting figures are shown. At the top right hand corner are the maximum Horse Powers recorded with 98.2HP being the HP as first tested and 112.7Hp the best we achieved after changing settings. So we gained 14.5HP just for changing the mixture, changing the ignition timing and closing the spark plug gaps down to 0.65mm! He charged £60 (about Euro65). So compared with August 2009 we have increased the power from 88.6 to 112.7 a gain of 24.1 HP or 27.3%.

I confess this is not quite as much as I had hoped for as the conventional wisdom suggests that 40% increase should be achievable. Still it feels a lot better and I would be very pleased to improve the driver's performance by 27% in four months!

More pictures and analysis to follow later.

Have a nice Easter!

Best wishes, Andy Owler


Title: Re: Supercharging a Bagheera
Post by: andyowl on May 28, 2010, 01:26:20 am
Pre-Prescott update...

The Blower is working well although I continue to have problems keeping the universal joints from slipping on the drive shaft. The shaft is stainless steel (type 304) and is drilled to accept the cylindrical ends of the M6 grub screws. The grub screws are High Tensile steel and harder than the stainless. In consequence they distort the stainless and need constant tightening. Lockite helps but that makes them hard to remove or re-tighten. Maybe a second or third screw on each joint is worth trying. Proper "Woodruffe" keyways are the right answer but they are expensive to produce.

I have recently realised that the stainless drive shaft is not a genuine 16mm diameter but 5/8inch diameter. This is actually 15.875mm diameter. This gives some very undesirable clearence and may encourage the locking screws to vibrate loose.

As I think I have already reported, I have replaced the original simple universal joints with better quality "zero - backlash" joints. The problem was that they quoted 6 weeks delivery time for the 16mm version (before I knew about the 5/8inch shaft) and I settled for 20mm bore with 20/16mm reducing bushes. This has introduced even more potential "slop" but now does allow me to upgrade the drive shaft to a genuine 20.00mm diameter. Next step perhaps?

The special 16mm aluminium adapter bush that connects the second U/J to the blower drive flange was replaced yesterday with a 20mm steel version. Maybe it is my imagination but already there seems to be less mechanical growling when the blower is working hard.

And it does "work hard" when asked! In 1st gear there is barely enough time to read the tacho and change gear into 2nd before I exceed 5,500 rpm. I have set this "on the road" limit as the blower is not intended to go faster than 6,000 rpm. The U/Js are already limited to 4,000 rpm but they were the best I could find. On the public road I struggle to keep this lefthand drive car out of the hedge and on my side of the centre of the road at the same time as watching the tacho and noting the blower pressure.  Perhaps I need a data logger! Nearly 50 years of changing gear with my left hand takes some un-learning. More practice needed.

I took Baggy Joe to the Builder's Merchant ("Bricolage") today. They know me quite well but in Grey Baggy and our other cars but not in something low, growlly and very yellow! Caused quite a stir - they all came out to look! My "street credibility" went up several notches especially with the young lads! Pity I am too old to go "pulling the birds"!.

With Best wishes,

Andy


Title: Re: Supercharging a Bagheera
Post by: Spyros on June 10, 2010, 10:00:27 pm
I just watched again the video I recorded from inside your yellow beast : Wonderfull  ;D
The sound is not as frightening on the video than in reality

Thanks a lot for the drive !

I'm just wondering : Will BaggyGrey suffer from the BaggyJoe daily usage ?


Title: Re: Supercharging a Bagheera
Post by: andyowl on June 11, 2010, 01:31:09 pm
Spyros wrote...Will BaggyGrey suffer from the BaggyJoe daily usage ?...

Baggy Joe is not really in "daily use". Although I do sometimes use him during the week he is not really suitable for going shopping everyday!

The Four point FIA seat belts are awkward to put on and the total lack of security in the boot makes it a worry to leave tools (or shopping) in there. I don't like going too far without the tool bag as we are still finding "teething problems". The heat build-up above the exhaust manifold when the engine is switched off makes me open the engine cover each time we stop for more than a few minutes. This is not a problem in competition but is a pain in "daily use". If I do not open the cover the heat cooks or melts any shopping . Not very practical!

During the Spyros drive yesterday the engine, under pressure, started to be erratic with the pressure rising and falling for no obvious reason. We checked the engine when we arrived at the lunch Pub and the inlet box had a lot of oil on the top. This usually means that the explosion relief valve is opening when it should not.

The last time this happened I found that the spring holding the valve closed had weakened and distorted, I assume due to the residual heat build-up after the engine is switched off. I replaced it with another, stronger, spring and it worked well at Prescott. But today I think it may be damaged again.

I need to re-build the relief valve with the spring outside the inlet box rather than inside. A question of time (as usual!). Our next event is on July 11th so I have a little time for some more development!

Spyros... Can the video be put on the 'net? I would like to see it too!

Andy


Title: Re: Supercharging a Bagheera
Post by: Spyros on June 12, 2010, 12:10:59 pm
Spyros... Can the video be put on the 'net? I would like to see it too!

Andy

I wouldn't have done it without your permission  :)

You'll see that I took some freedom to try to fit all together

http://www.youtube.com/watch?v=0-eyKVzi66M (http://www.youtube.com/watch?v=0-eyKVzi66M)

I just hope that soon we will benefit from bbs tags to incorporate video directly in the posts



Title: Re: Supercharging a Bagheera
Post by: andyowl on June 12, 2010, 09:59:55 pm
Thanks for putting the video on the 'net! I thought it was a "First" for me and Baggy Joe but I see that Titus also has some video of Baggy Joe (including me visiting the gravel trap at Prescott!) Thanks to him too!

I cannot tell which run it was at Prescott as I visited the gravel on every trip up the hill. But I think it may be the first practice run as that was a "two wheel visit" as was the second competitive run! The others I think were only one wheel at a time!

Brilliant, thank you chaps!

Andy


Title: Re: Supercharging a Bagheera
Post by: suffolkpete on June 12, 2010, 10:58:39 pm
Loved the noise it makes :D


Title: Re: Supercharging a Bagheera
Post by: Spyros on June 13, 2010, 12:29:09 am
Loved the noise it makes :D
I even find it better in reality  ;)


Title: Re: Supercharging a Bagheera
Post by: Spyros on June 16, 2010, 12:56:58 pm
Andy,

Today, I posted the video of BaggyJoe on the Bagheera-café forum. I think you wouldn't mind.

I'm a bit surprised of the relative lack of interest since I only see the usual folks following your project.
To me, with relativelly low investments, you created a wonderful car.
- At low to middle revs, it is quite as civilized as a standard one.
- It doesn't appears more temperemental than a standard Bagheera.
- It's quick, nervous and has a terrible sound
- The roadholding is much better

I must say that I'm only wondering when I might decide to follow your path, or who will do it first  ;)


Title: Re: Supercharging a Bagheera
Post by: andyowl on June 16, 2010, 02:53:39 pm
Spyros wrote..  - The roadholding is much better..

That is an interesting comment. I do think the roadholding is better but I find it hard to compare objectively the righthand drive Bagheeras with the lefthand Baggy Joe.

Lowering the suspension has removed much of the rolling that is part of the traditional french feel but I find it hard to analyse the other features.

The "sticky" tyres must help too. I had the Yokohama A048 tyres on when you were in the car last week.

Andy


Title: Re: Supercharging a Bagheera
Post by: Spyros on June 16, 2010, 04:59:15 pm
I had the Yokohama A048 tyres on when you were in the car last week.

Andy
I noticed them.
When you take a runabout at an impressive speed, your smile is going from one ear to the other  :D

You might also have seen my legs being thrown on the side by the centrifugal force.
I advise to add a purposefull seat rest, like the one I show you

Spyros


Title: Re: Supercharging a Bagheera
Post by: andyowl on June 17, 2010, 10:11:43 am
Spyros wrote..  when I might decide to follow your path, or who will do it first ..

Well I do have another supercharger that you could use. It is a "Roots" type blower manufactured by Wade. I was told that it is big enough to supercharge a 3.5 Litre Rover/Buick  V8 but its output can be reduced by simply changing the diameter of the drive pulleys.

Like in Baggy Joe I planned to mount the blower on the rear bulkhead using a separate drive shaft with two universal joints to allow for the movement of the engine. The carb(s) would be in the luggage compartment away from the engine heat and this would allow the normal engine cover to be retained. It would also be much easier to work on than Baggy Joe.

If anyone would like to give it a try I can provide a list of the key parts.

Anyone up for a challenge?

Andy


Title: Re: Supercharging a Bagheera
Post by: Spyros on June 17, 2010, 12:33:38 pm
I like your idea of UJ for allowing the engine movement.
But for what I'd like to do, I don't have space for a blower fixed to the rear bulkhead.
You might remember that I spoke about engines with a VW 16 valves head.
It's reaching slowly completion and I have actually 2 version of the engine.
I've built 2 version of the engine head.
One based on a KR head and another one based on a PL head. There are subtle differences in the casting which made me decide to do so.
Then one is supposed to be using a Kjetronic (or other) injection and the other 2 big horizontal delortos (Delortos because they cost only 10 % of the price of the weber DCOE equivalent while having about 95 to 98% of the power capabilities and some of the design are much better )

Now the big issue with these heads is the compression ratio.
I'm close to 8 to 1 if I don't surface the top of the block and the head.
One of the engines (the carbuator one) is already surfaced but this also meant lowering the seat of the valves and of course changing the valves followers (done)

Thinking about it, a 8:1 ratio is what you need with a turbo or a compressor.
I'm actually thinking about a M45 Eaton, matched to the Kjetronic injection.
But not as you with a custom built overpressure valve.
More by using a big external wastegate. Something standard that can be bought without problem.
And also a king of air cooling devices. In France, I met a guy building a turbo in his Murena and he convinced me about the ideal device to cool the charge.
Ideas only because of the little available space

The 16V engine with injection or carb is fitting the Bagheera engine compartment. I'm not sure that adding the blower will still be possible


Title: Re: Supercharging a Bagheera
Post by: andyowl on June 17, 2010, 11:15:21 pm
Spyros wrote... I'm actually thinking about a M45 Eaton, matched to the Kjetronic injection....

Have you an idea about the power this may produce and which Bagheera engine size are you using?

Is there really space for an intercooler? Water injection maybe an alternative?

Andy


Title: Re: Supercharging a Bagheera
Post by: Spyros on June 18, 2010, 08:52:05 am
The engines I started with is actualy the 6J2 because you need evenly spaced bores.
I think these heads can also be adapted to the other uneven Simca engines but I didn't try. If yes I'd try with the shortest stroke.
I have to admit having 5 of these 1590 cc engines versus only 4 1440, one 1290, and one 1200 cc.

In order to rebore a worn 1590 engine, you need to be either very lucky  ;D and have a set of large overbore pistons, to use pistons comming from another make of engines or rob your bank and go for custom built forged pistons.
This will mean an engine of about 1700 cc.
Given that the original VW of 1800 cc was producing about 140 BHP (din), an easy calculation would leave something close to 130 BHP for an engine having the same type of injection.
Replace the injection by 2 horizontal carbs and ... I can only expect at least a similar number
Replace the cams by a schrick and it's said to produce 25 extra bhp, so about 155
Add a compressor ... I don't know
But I've seen such an engine, based on the 1290 cc, without blower, delivering 160 bhp, like nothing.

Actually, I would first be happy that it'd work ...

I'm not speaking about an intercooler but a charge cooler which may need less room in the engine bay but will mean other issues for the cold water supply ...


Title: Re: Supercharging a Bagheera
Post by: andyowl on October 20, 2010, 06:45:32 pm
Spyros wrote..I spoke about engines with a VW 16 valves head

Thinking about upgrades over the winter I wondered if you had made any progress with your 16V VW heads on a 1592 Bagheera engine?

I have concluded that I am not likely to get much more power from my "original" 1592cc engine even If raise the blower pressure further and gas flow the inlet path. The inlet valves are just too small.

Update please??

Andy


Title: Re: Supercharging a Bagheera
Post by: Spyros on October 20, 2010, 07:25:25 pm
Well, after months of waiting, last Friday I came back from my machine shop with a key piece.

It's a Simca-Talbot camshaft, that was totaly worn on which on end was cut. The end were you bolt the chain drive. On this side, a second piece of metal was put. This allow to prevent the camshaft to move back and forward, allow to put a basket to prevent the oil to go on the cam belt and to mount the cambelt drive.

The fact is that I didn't want to go to an external oil pump/dry sump. So I needed to keep the Matra camshaft for this purpose. (Like in the Lotus-Ford engines)

I already have 1 engine monted but only with 1 piston which is hold by an axe that was just machined down to allow not to be fixed forever to the rod.
Next weekend will be spent fitting the cambelt and turning the engine by hand with plasticin between the top of the piston and the valves.
Then I will be able to see if new valves recesses will have to be machined in the pistons.

Then calculation on the compression ratio to see how much I'll have to machine down the top of the piston.

Then exhaust collector ...

Then final assembly and start, first as a carburated version (2 Delortos DHLA 40) and checking the evolution to the KJetronic injected (potential to be blown)

I have pictures of a similar engine with dry sump : 160 - 180 BHP on Weber DCOE 45


Title: Re: Supercharging a Bagheera
Post by: andyowl on November 24, 2010, 12:11:43 am
Andy wrote..I have concluded that I am not likely to get much more power from my "original" 1592cc engine even If raise the blower pressure further and gas flow the inlet path. The inlet valves are just too small.

If I cannot easily increase the valve size (and unless Spyros goes into production with his VW heads that seems unlilkely!) increasing the blower output pressure seems the obvious way.

But the Shorrock Blower is already running at the maximum recommended RPM with a 1:1 drive pulley ratio. Gas flowing the inlet system would improve the quantity of fuel/air mixture getting into the engine but the improvement may not be great say 10-15% perhaps.

But I do have another "Wade" Blower. It is a twin rotor compressor recommended as suitable for 1300-3500 cc engines. I have not done any serious research into this machine but I assume the flow rate will be adjusted by changing the size of the driven pulley. Normally one thinks of supercharging pressures as around 0.5 to 1.0 barg at the inlet manifold with any higher pressure likely to lead to overheating and detonation. But with the small Bagheera inlet valves a higher pressure may simply get more fuel/air mixture entering the cylinder. It is the pressure in the cylinder that matters, not necessarily the pressure in the manifold.

The combustion pressure creates the pressure that pushes the piston downwards. In a slow reving engine (e.g. a ship's reciprocating steam engine or a stationary gas powered engines) one can measure the "BMEP" (Brake Mean Effective Pressure) and calculate the horse power produced. I suppose this may be possible with a petrol engine with a fast acting pressure transducer. Does anyone have experience of this technique?

Food for thought over the winter?

Andy

PS Charlie is now back home after four trips to hospital in 6 weeks! Maybe I can keep her out this time! Thanks for your good wishes.

AMO


Title: Re: Supercharging a Bagheera
Post by: andyowl on January 02, 2011, 09:04:28 pm
Happy New Year to you all! Charlie is still home, nearly four weeks. This is progress!

We are working on making an adaptor box to connect the Wade Twin Rotor Blower, Type R020, to the Bagheera inlet manifold. Photographs will follow shortly. It will be located directly on the manifold above the engine. Think of a Drag Racer layout and you will get the idea!

Planning ahead however I was thinking about the carburettor to use. A standard Bagheera DCNF would seem to be ideal. But how many to we need? Let me try this theory on you...

On a twin carb Bagheera, there is one "choke" for each cylinder. That choke only admits fuel/air mixture when that inlet valve is open, and that is only once for every two revolutions of the engine, i.e. it is only working for 25% of the time. I had not thought of the "stop/start" action of the air flow until now. If that one choke was flowing all the time e.g. fitted to the inlet of a blower running continuously, feeding fuel/air mixture to all four cylinders, it is working 4 x 25% of the time i.e. 100%. By adding the second choke on the same carburettor we should have the capacity to fuel at twice the rate needed by the standard engine and capable of producing, potentialy, twice the engine power!

Conclusion...We only need to use a single DCNF carb! That will simplify lots of things not least tuning it! Nothing to balance other than the air flow through both chokes (easy). Main jets are fixed and we can use one or both idle jets.

Is this too simple or am I missing somthing?

Your opinions are very welcome!

Andy


Title: Re: Supercharging a Bagheera
Post by: andyowl on January 03, 2011, 12:39:53 pm
Making templates for the Wade Blower..

The pictures show the general concept - you see the similarity with an American Drag Racer?

We have a choice of orientation in that the blower needs to rotate in the same direction as the engine and road wheels.

- The "Drive End" may be on the gearbox side of the engine (as shown in the picture) which would be simplest to do at present since we already have the Shorrock drive shaft at that side too. The downside is that we will also have the friction and power loss associated with the bearings and universal joints. Another problem is that the Wade Blower, unlike the Shorrock Blower, will move with the engine and we need to allow for that movement e.g. by having the Blower drive belt bearings fixed to the engine somewhere.

- Alternatively the "Drive End" could be on the right side of the engine above the crankshaft pulley which is the conventional USA way of doing things. The problem is that the engine mounting rubber block is exactly where the drive belt would go! An idea that we could make a different engine mounting system is being thought about! It might allow the drive belt directly off the crankshaft pulley minimising the friction and power losses. There would still need to be a tensioning device but it might be a better engineered design.

It would be fun to have the blower directly on the end of the crankshaft, "Bentley style", but that would require the right side rear wheel to be at least 500mm further out!

These blowers on Drag Racers always seem to have a toothed belt rather that "Vee" belts as used by Shorrock blowers. More research needed. Probably something to do with the power needed to drive the blower input shaft. This was stated for the Shorrock as 8hp but I have not found an equivalent figure for the Wade. I used 8hp at 6500rpm when sizing the drive shaft diameter.

Finally, I said earlier that the Wade Type R020 was intended for up to 1600 engines. This is not correct. I now know that it is intended for 2000-3000cc engines! It is said that one revolution of the blower will pump 2000cc of fuel air mixture. The 1600cc Bagheera engine only requires 800cc of mixture per revolution! That will be interesting!

More info at  http://www.bcsc.co.uk/info/allard.html

Keep those ideas and comments coming! This is the "R" part of "R&D" !

Andy


Title: Re: Supercharging a Bagheera
Post by: andyowl on October 21, 2011, 10:31:47 am
I have just purchased the new (?) Bagheera book by Andre Dewael published by E-T-A-I.

Towards the end of the book is a section about the other engine designs Matra considered including a 16 valve head on the 1294cc engine and a supercharged 1592cc engine. We all know of the U8 engine but I had never heard of the 16V nor the supercharged version!

My french is not good enough to pick up all the details (the book is all in french) but the linguists on the forum will do better!

The supercharged engine has the same configuration as my proposed Wade Blower with the blower above the inlet manifold. It looks smaller than my blower but produced 126 ch (HP?) at 6,200rpm. Performance figures are quoted so it was obviously a working car. This is compared with the Porsche 924 2 litre with similar performance. It appears to have been fitted in a "P29" prototype open 2 seater!  Where is it now I wonder?


Spyros... How is your 16Valve project going? Very quiet??

Andy Owler


Title: Re: Supercharging a Bagheera
Post by: Spyros on October 21, 2011, 10:17:08 pm
Hi Andy,

I didn't touch my Bagheera with a spanner for several months. Other priorities I'm affraid.

Dewael is wrong about the 16V. This is a Simca Rallye engine


Title: Re: Supercharging a Bagheera
Post by: andyowl on May 10, 2012, 09:15:17 pm
Last night I started taking off the Shorrock Supercharger and fitting the bigger Wade supercharger. Photos will follow soon.

Maybe we should start a new topic? Wade Supercharger on a Bagheera?

See you there!

Andy.