Wade Supercharger on a Bagheera

[andyowl]

After agonising about "what do we do now?" we decided to use the "new" 1442cc engine I bought from Peugeot around 1992. Peugeot were trying to empty their stores of old Simca parts and they offered these Bagheera engines to Matra and Simca Club members for £200 each still in their original wooden boxes. With 4 Bagheeras in the family it seemed a good idea and like many others members I bought one. I kept it in the "pit" under the garage floor and tripped over it constantly. The worry was that it might have corroded beyond use! It got wet when we had a fire in the pit while welding Baggy Rouge. The smoke was so thick we couldn't see the flames 1.5m below us! A water hose put the fire out but the bottom of the pit was 150mm deep in water! I feared for my "new" engine.

The new pics below show that it has survived very well. It was well oiled internally and externally and it is like new. In only one external area is there any sign  of slight rusting.

We stripped it down during this week and the parts go off for balancing on Monday. The head now needs stripping too ready for gas flowing. It is nice to be back working on Baggy Joe"  Andy

[GP]

The  "Spitfire Hunters" in Burma are not having too much luck. Could they have a look in your garage pit please? 

[andyowl]

I'm not sure we would get a Rolls Royce V12 Merlin in the back of a Baggy! Fun to try though!

Andy

[andyowl]

Gasket  -  observations...

In stripping down both the new 1442cc head and the tired 1592cc head some interesting things were noted. New to me but probably not to most of this illustrious group, but here goes...

The 1592cc engine has the cylinders at a larger bore than the 1442cc but they are also moved further apart. This can be seen in the first picture below. It is amazing that Baggy Joe ran at all when we first started this process since he had been fitted with a 1442 head gasket onto a 1592 cc engine. There can have been very little gasket doing any sealing!

The exhaust manifold gasket for both engines has holes much larger than the exhaust ports as can be seen in the second picture. Why would they do that? We want to get much larger exhaust valves fitted. Maybe some vehicle has ports that large? Any suggestions? I should check the gasket against the exhaust manifold too!

I plan to get a special exhaust system made with 4 separate pipes and much larger bore to help get the supercharged exhaust gases away faster. Any experiences of doing this for a Bagheera? Andy

[Spyros]

Hi Andy,

I finally got access again. I was stupidly checking the send me the question checkbox

The gasket has to match the exhaust manifold and not the head exhaust ports.
It is normal to have a step there.
It's meant to get a venturi effect that will accellerate the gazes out of the head.
And also to counterbalance the pumping effect of the engine.
People who equalize the ports don't understand how the engine works.

Having said this, the sizes of the ports might not be ideal

[andyowl]

Spyros wrote...
"...It's meant to get a venturi effect that will accellerate the gazes out of the head.."

I've heard that said before but a "venturi" has a smooth inlet, a rectricted middle and smooth and gradual outlet. It also causes a pressure loss (or Back-Pressure") which, in our case, will restrict the flow of gas away from the exhaust valve.

"Steps" are not generally considered good practice in fluid flow dynamics. I don't understand why they would be good here?

I always thought that the conventional wisdom was to make the ports (inlet and exhaust) match their manifolds.

Do you have any source references that I read to educate me on the subject before we (he, not I) start to remove metal from the exhaust ports? That should happen this week.

Andy

[bert1]

Do you have any source references that I read to educate me on the subject before we (he, not I) start to remove metal from the exhaust ports? That should happen this week.

Andy

Andy this is the "bible" on the subject. It can be a tough read though. In places gets very technical.

http://books.google.com.au/books/about/The_scientific_design_of_exhaust_and_int.html?id=oIZTAAAAMAAJ&redir_esc=y

[andyowl]

I looked at "The Exhaust Bible" on Amazon (GBP 39) and decided that I would ask my "experts" about exhausts!

Dermot, the tuner, agreed that a "step" (= smaller size for the exhaust ports in the head and larger size for the exhaust pipe internal diameter) is used on "normally aspirated" engines to encourage a "pulse" of exhaust pressure which, at a particular engine speed will cause the gases in the pipe to resonate and increase the gas flow. This is used for example on F1 engines producing a useful power boost but over a very narrow rev band.

We are trying merely to enlarge the passage size and allow the exhaust gases to get out faster. A supercharged engine objective is generally not to be high reving but to produce greater torque all through the rev range.

Dermot has finished balancing the new engine and starts today on fitting larger exhaust valves. Progress! Andy

[GP]

Hi Andy,

Further to the disscussion on head and manifold interfaces I scanned a couple of pages from a tuning book I have which explains things simply.
 
"How to modify Ford S.O.H.C. engines" by David Vizard. ISBN 0 86343 0856.

Cheers,

Graham

P.S. How is the rebuild coming along?

[andyowl]

The exhaust has been built and is ready to collect. I think it looks good, but time and the Rolling Road will tell us!

I have asked him to supply also a 90 degree elbow that can be fitted to the outlet pipe to further reduce the noise level.

It would also allow the addition of another external silencer if the noise is just too loud!

I have arranged for our local MSA Scrutineer to check over BJ when we have finished the current modifications to produce a "Competition Log Book" to satisfy the French Scrutes at Etretat who are reluctant to accept a simple M.o.T. as proof of road-worthyness!

Making progress!

Pics in the next posting!  Andy

[andyowl]

New exhaust!

Pictures.

Andy

[GP]

Hi Andy,

The exhaust looks absolutely fantastic. Who manufactured it for refererence please?

My Murena is still under a dust sheet sulking along with me. Seeing this has inspired me to pull my finger out! 

Cheers,

Graham

[andyowl]

Baggy Joe's new engine is going together well. We are now doing all the little external bits (Distributor mounting, oil dip stick etc. )
I am planning to do a bench assembly of the whole thing including the blower and exhaust system for photography purposes. I want to demonstrate that I have a very similar design to the one in the ETAI Bagheera book. This may make it easier to get my "Competition Car" Log book. The fact that mine was completed before I even purchased the book is gratifying!
Electronic ignition... I am inclined to use the OMEX 200 ECU as it seems to have all the features I think I need. (www.omextechology.com). These include the ability to "Map" the ignition advance and retard according to the state of the engine e.g. water temp, air temp, and manifold pressure or vacuum. Northampton Motorsport were demonstarting the system at the Race Retro show recently and offered to set up the system on their rolling road. Very tempting for a non-electronics person like me!
Andy

[andyowl]

Pictures of the trial assembly engine. Apart from a lot of the bolts and the carb it is complete.

Although I wondered if this would prove to be a waste of time, somehow one can see things in the pictures that were not obvious "in the flesh".

Example: The right hand exhaust is very close to the oil filter. Maybe we need some sort of heat shield fitted. When the oil is flowing the heat will simply make the oil warm up faster, not a bad thing in limited quantities as getting the engine thoroughly warm before a Sprint or Hill Climb takes a lot of idling. I'm more worried by what happens after the run and the oil has stopped flowing. The heat could build up quickly and maybe damage the filter element itself.

Comment?

The real assembly starts tomorrow.

Andy

[GP]

Hi Andy,

How did the engine assembly and the Lydden Hill Sprint on the 6th. July go?

Cheers,

Graham