MatraSport Forum

Each model => Bagheera => Topic started by: andyowl on September 04, 2010, 09:41:02 am



Title: Bagheera exhaust improvements
Post by: andyowl on September 04, 2010, 09:41:02 am
I want to improve the exhaust system on our competition Bagheera. The recommendation, when tuning an engine or fitting a supercharger, is to fit a "free-flow" exhaust system.

Are any such systems made for the Bagheera? I have heard of the "Devil" exhaust manifold but is it any good? Does it come with a silencer? Cost?

Can the exhaust ports in the cylinder head be opened out? They seem very small?

How about taking apart the old silencer, using the two original pipes from the exhaust manifold and fitting two "Straight through" silencers one for each of the pipes? "Cherry Bomb" is one make of straight-through silencers. GBP35 each on eBay. Two separate outlet pipes would be fitted.

A competition car noise level is monitored and must not exceed 110dB. Baggy Joe presently is around 97dB even with the supercharger fitted.

Any thoughts?

Andy


Title: Re: Bagheera exhaust improvements
Post by: Spyros on September 04, 2010, 03:46:45 pm
About 10 years ago, I wrote this page on the subject ...
http://www.matra-bagheera.com/Plan/Resto/Mechanic/Engine_Rebuilt/Exhaust/exhaust.html (http://www.matra-bagheera.com/Plan/Resto/Mechanic/Engine_Rebuilt/Exhaust/exhaust.html)

Interestingly, the supersprint has been remade by the company who took over : Tubistyle
I had then contact with a member of one of the Italian club who was implied in this story.
Not sure of which one.

The exhaust ports in the cylinder head can be opened but (at least on an unblown engine) you should not match them with the exhaust.
I saw this several times and it's a big mistake to match the opening with the exhaust manifold.
The step has a purpose : acting as an anti reverse for the exhaust gases.
If you have a wide band camshaft this is even more important since the unburn gases will be contaminated by the reversing burn gases.
Sometimes, this  step is more sofisticated. (same principle as the rimflow valves)

I've seen a very open exhaust for Simca rallyes. The IRESA C76.
But the problem is that it will interfeer with the rear engine support


Title: Re: Bagheera exhaust improvements
Post by: andyowl on September 04, 2010, 09:10:10 pm
Coincidentally Gerard Magro has just sent to me the photo below of a prototype Matra-Simca engine. The text is just readable but it seems to be a 16 valve head, two overhead camshafts and a very fancy exhaust system! Fuel by injection or carbs!

It was intended for the Bagheera and is based, it says, on Matra's V12 head technology. Makes me dribble! There is no date given but it must be mid-1970's?

The engine block looks very familiar, flywheel, oil pump and filter etc. I wonder where the engine is now? The Matra Museum perhaps? Drawings? Serious money I ma sure.

I am kicking myself for not asking Gerard for more information on his CG-Simca engines when I had the chance last weekend.

What a picture!

Andy


Title: Re: Bagheera exhaust improvements
Post by: andyowl on September 04, 2010, 09:29:34 pm
This is a smaller version of the 16V engine - I found the other great for detail but hard to get an overview.

I asked at my local exhaust supplier today about straight-through silencers. They have to supply only EU approved systems but he suggested that I should try "Mr Exhaust" in Reigate Surrey who will make special exhausts. It might be interesting to get a quotation.

Andy


Title: Re: Bagheera exhaust improvements
Post by: andyowl on September 04, 2010, 09:42:06 pm
Link to Mr Exhaust...

http://www.mrexhaust.co.uk/index.php?p=factsheet_custom-build

Certainly worth a try!

Spyros... Did you say once that you have an engineering drawing of the Bagheera exhaust ports on the cylinder head?

Andy


Title: Re: Bagheera exhaust improvements
Post by: Spyros on September 04, 2010, 11:50:17 pm
Yes I have.
I can provide an autocad file


By the way, I pictured this fuel injection Simca Rallye engine. It's not intended for a Bagheera.
If you are interrested in 16v, there is another way.
One of mine will just go back in a Bagheera chassis tomorrow to see if it will fit... if only I could find back the gearbox silent block  ???


Title: Re: Bagheera exhaust improvements
Post by: andyowl on September 05, 2010, 08:04:53 am
Spyros wrote... One of mine will just go back in a Bagheera chassis tomorrow

You have more than one 16V Bagheera engine??

Tell us more!

Andy

PS I didn't see the 16V Simca engine pic.


Title: Re: Bagheera exhaust improvements
Post by: Spyros on September 05, 2010, 12:08:18 pm
Well, about the Rallye 16V Engine, I didn't print them since they were not related to the subject.
I'll find them back because some of the details I pictured are quite interresting.

Looking for some pictures of these 2 engines, I've discovered that I was even more productive that I remembered :

http://www.flickr.com/photos/14298769@N05/2089589366/ (http://www.flickr.com/photos/14298769@N05/2089589366/)
This is the inside of my 4 exit Ansa exhaust

And ...
(http://farm3.static.flickr.com/2212/2089589238_937f5f04dc_b.jpg)
here the inside of a standard Bagheera exhaust (well standard, not sure. Could have been a Bosal )

Still on the exhaust side, the Autocad file I must have somewhere can be given directly to a laser cutting shop. The diameter of the ports is higger than standard but I have to find it back first to tell you

My 16V engines ... are nearing completion

(http://farm4.static.flickr.com/3212/2600163499_42af7da456_z.jpg?zz=1)
Let's call this one Mr Blue.
It changed a lot since this picture and one of the last remaining bit will be to machine the block in order to raise the compression ratio

(http://farm4.static.flickr.com/3294/2600992710_750cc8d46a_z.jpg?zz=1)
And let's call that one Mr Red.
Mr Red is actualy an older built than Mr Blue.
I was not satisfied with some aspects
- The complicated path of the belt and the potentiallity of interference with the engine support and the water inlet
- K-jetronic injection
- Some things in the oil circuit.
In the other end, the injection, with the inherent low compression would make this one rather fit for a blower, let alone the available space in the Bagheera engine bay


Title: Re: Bagheera exhaust improvements
Post by: lewisman on September 05, 2010, 12:22:05 pm
If you were interested, I have a custom made stainless steel exhaust from a Bagheera. It has twin outlets and straight through pipes inside. It connects to the standard cast manifold but I am sure that would be easy to change.

Let me know and I can take some photos.

David


Title: Re: Bagheera exhaust improvements
Post by: Spyros on September 05, 2010, 04:15:33 pm
One of mine will just go back in a Bagheera chassis tomorrow to see if it will fit... if only I could find back the gearbox silent block  ???

Despite a day of digging in my parts, I couldn't got hold of this part : not the silent block but the S shaped part going from the silent block to the gearbox.
Does any of you have such a part, in order to give me the height ?  ???
It was coming from a Talbot Solara 1600 with a BE1 gearbox. So not the Murena one 


Title: Re: Bagheera exhaust improvements
Post by: andyowl on September 06, 2010, 01:02:16 am
Spyros wrote...not the silent block but the S shaped part going from the silent block to the gearbox.

Is there a part number in the Bagheera parts catalogue or is it a unique Solara part?

I presume that the 1600 Murena Gearbox mount is the same as the Bagheera?

Andy


Title: Re: Bagheera exhaust improvements
Post by: andyowl on September 06, 2010, 01:07:00 am
Lewisman wrote...I have a custom made stainless steel exhaust from a Bagheera

I am interested!

Did you try it on a car? How noisy is it? Is it a "nice noise"?

Geographically, where is it located?

How much are you asking for it?

So many questions!

PM reply if you prefer! Include your phone number please.

Andy


Title: Re: Bagheera exhaust improvements
Post by: andyowl on September 06, 2010, 01:17:52 am
Spyros, ref silencer internals and fancy engines!

The standard exhaust silencer looks very restrictive! 4 off 90 degree bends at least. Was there some sound absorbing material around the pipes that has been removed for the picture?

I have trouble with Flickr - it may be an AOL problem - so I haven't seen your 4 outlet ANSA version yet.

The engines are very impressive. Are you still working on the final details? You have done a lot of work already!

Inspirational!

Andy


Title: Re: Bagheera exhaust improvements
Post by: Spyros on September 06, 2010, 06:53:22 pm
Hi

I just noticed that Flickr requieres now a password on the URL
So, a direct view of the internal of the Ansa,

(http://farm3.static.flickr.com/2134/2089589366_6f06fd856a_b.jpg)

And now you will find the standard exhaust unrestricted in comparison
On the Ansa, there was rockwood around the pipes in the left & right chambers.
On the standard one also but only where the pipes are holed.

The part I'll find somewhere is not a Bagheera one. The Murena gearbox is a MA, not a BE1. I have 2 MA's and they are known to be weaker than the other one. So the part is not common. It's also a bit more difficult because 1.6 Solara with such a box is very unusual. I don't remember but I think they only produced them over a year.
The advantages of the BE gearbox is that it's is stronger but also you can find plenty of different gearbox ratios. I'm just wondering how much the internals are compatible with BE2 & 3 (5 or 6 gears)

For my engines, still lot's to do.



Title: Re: Bagheera exhaust improvements
Post by: andyowl on September 06, 2010, 07:30:38 pm
The ANSA silencer still does not look very "straight-through"! What did it sound like?

The four outlet pipes must have looked impressive!

I did not get a chance to call "Mr Exhaust" today. Perhaps I should call in to their works on my way to collect the Bagheera windscreen on Wednesday.

Andy



Title: Re: Bagheera exhaust improvements
Post by: Spyros on September 06, 2010, 09:09:16 pm
No idea of the sound, at least without the multiple extra rust holes.
When I opened this one, I couldn't believe it  ::)

I also have a drawing of another exhaust built by a former Bagheera owner.
It was quite interesting because the exhaust could be disconnected easely from the 4 into 1 manifold to allow works. Also the part holding the silencer (actually the standard plate) was located mid way of the silencer.
I'll try to find this back


Title: Re: Bagheera exhaust improvements
Post by: andyowl on September 11, 2010, 03:49:17 pm
Lewisman has sold me the "Custom Made Straight-Through Silencer" he refered to in his post of  5th September.

Thank you very much, and thanks also to Royal Mail Parcel Force for delivering it quickly from the Island of Lewis (Outer Hebrides to Surrey in less than 48 hours!) The Postman asked if I had bought a Llama!

Photos below. There are two places on the top surface where it has been opened and then re-welded and another on the bottom where there is an aluminium closure plate.

Lewisman - could you tell us what you know about its history? Everyone will be interested I am sure.

I plan to make our VAX vacuum cleaner able to act like a compressor and blow air though the pipes. I will measure the "back-pressure" and compare it with the standard stainless steel silencer (what is "standard" these days?)

R&D time I think!

My next event, other than the AutoSolo tomorrow where they do not check the noise levels, is a "National B Sprint" on October 3rd at Debden. I will try the "S-T" silencer on the road and take the old one with me to Debden just in case they complain about the sound volume.

Andy



Title: Re: Bagheera exhaust improvements
Post by: lewisman on September 11, 2010, 04:32:43 pm
The exhaust came fitted to my first Bagheera - an 'official' right hand drive 1978 S purchased in 1986.  It was bought from a chap called Roger Davies who ran Club Matra. 

I hit a sheep with the Bagheera in '87 and when the panels were removed I discovered a considerable amount of rust.  This was a car that was less than 9 years old!

Due to the delay in getting parts from France, I managed to settle with the insurance company for cash and used this to buy a high mileage '79 X "for spares" form Gordon Russel.  I ran this for about 18 months and rebuilt the S back to a decent standard, complete with re-trimmed interior, 1.6 Solara engine and a full respray.  I added the X wheels but kept the stainless exhaust as I had intended to fully restore the X and was considering a Lancia twin cam that was in my shed!

Unfortunately the re-build project clashed with moving house (and starting to build a new house) and it ended up scrapped.

The welding on the exhaust was to repair a loose baffle tube.  As always happens, the hole was cut in the wrong end first time round.  The aluminium plate was to seal a hole cut used to pack the exhaust with wadding.  It was my intention to replace it with a proper stainless plate at a later date.


Title: Re: Bagheera exhaust improvements
Post by: andyowl on September 11, 2010, 05:47:42 pm
Lewisman wrote:- The aluminium plate was to seal a hole cut used to pack the exhaust with wadding.

So if it was thought to be too loud I could take off your aluminium plate and put in some more wadding? Like a volume control?

Neat!

Thanks

Andy