Dauphine / 4CV dohc conversions

J

Jack Williamson

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Fellow Frogger
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Does anyone have any info re DOHC conversions for the 4CV / Dauphine engine?

There was at least one period twin-cam conversion called Boudot--not easy to find.

Perhaps some modern sub-litre head could be adapted from, for example, a Nissan Micra / March. Of course it wouldn't bolt on; it would be a major engineering project. That's why the Creator made Bridgeports.

Anyone ever see such a conversion? Can you supply any details of what you saw?

Thanks very much in advance.

Maybe a head from a Fiat-Abarth 850 would work ...
 
Best chance would have to be with something Korean or Japanese... you need to take a head gasket to a friendly head repair shop and cast around.

With the tight bore spacings of today, you probably stand a chance.

Then, you could also check the motorcycle scene...
 
For those wanting to know more

<a href="http://www.chez.com/delaunoy/technique/boudot/boudot.html" target="_blank">http://www.chez.com/delaunoy/technique/boudot/boudot.html</a>

Seems like an interesting project, but what is the intention for the use of the car at the end of the day? If a replica "non Boudot" head is sourced from a Brand X car it may exclude it from any class as it wouldn't be a period fitting. How about a replica 1063 conversion, or one using a head from a very early Dauphine G with angled valves (alloy rocker cover version) which may have more tuning potential than the later Dauphine G head. Sourcing one of those heads would also be another problem in itself!

Good luck for an interesting conversion!
 
Simon:
.....but what is the intention for the use of the car at the end of the day? If a replica "non Boudot" head is sourced from a Brand X car it may exclude it from any class as it wouldn't be a period fitting.....
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Presumably it doesn't have to be...

But just as would be the case if you cut the centre out of a Jag head and welded it back together and bolted it up to a 403 block, of if a motorcycle head fitted the Renault, it would be a personal toy.

Interesting would be an understatement!
 
Another interesting re-creation would be one of the John Cooper Dauphines, with a Coventry Climax motor stuffed in the back.
 
Hmmmm interesting, can anyone read French to translate for us.

I have an article somewhere dating back to the mid to early fifties and that features a twin cam 750 very similar looking to this one. It apparently was canned in favor of the 1063. The 1063 was just as powerful at half the cost.
Now, if you want to build an interesting 750, do a replica 1063.

David.
 
Another interesting re-creation would be one of the John Cooper Dauphines, with a Coventry Climax motor stuffed in the back.

These Coventry Climax motors were in early Morgans and, in my opinion, were fairly ordinary. But there were/are quite a few about as they were also used as 'stationary engines' to run generators and pumps - good luck finding one
 
Was the Morgan fitted with the FWA?

I thought Morgans gave up on C-C engines before the war, and I would have thought that the FWA was a war baby... for use fighting fires in the Blitz of London.

Somewhere I have a picture of Boughton's pre-war Morgan that was converted to a single seater... it would have been C-C powered, I'd say.

And on the other side of the street... I saw a Morgan 3-wheeler replica the other day... or lookalike, anyway. Very much unlike Moggies... it had wishbone front suspension and a lovely V4 Honda engine sitting proudly up front ready to chirp the rear tyre in any gear!
 
604 tragic:
[These Coventry Climax motors were in early Morgans and, in my opinion, were fairly ordinary
Click to expand...
Coventry Climax engines made after WW2 are a really neat all alloy OHC design. By the standards of small car engines of the time they most definitely are NOT ordinary. These engines were a favorite of Lotus for their competition cars in the late 1950s.

Dave
 
David Cavanagh:
Hmmmm interesting, can anyone read French to translate for us..
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An Altavista computerised translation gives the following understandable passage (it is understandable so long as you are prepared to use your brain on some of the funny sentences):

"The great merit of Roger Boudot is to have straightforwardly innovated as regards transformation. Its engine which uses the basic elements of the 4CV Renault is a double camshaft at the head which does not develop less than 56 CH with 6500 t/m for a compression ratio of 9. The mode of maximum rotation ranges between 7000 and 7500 t/m. It is fed by two Weber carburettors doubles horizontal bodies cd. 03. It is the engine which equipped Vernet the 24 hours Peirard of Mans. But Boudot played of bad luck, and the cylinder head which it used this day there was porous. Nevertheless, with a maximum mode which did not reach 6000 t/m, the VP was chromométrée on the straight line with 175 km/h! We tested a 4cv Renault been driven by this engine. With a body rigorously of origin, we obtained the following results: maximum speed on the race track, 143,338 Km/h acceleration outdistances: 0 to 500: 23"4 0 à1000: 38"2 We are obviously very with the lower part of results which one can obtain with some other inflation, but the Boudot engine is a very particular case. It acts of a genuine engine of performance, only, undoubtedly that we had in France! We are sure that it did not finish making speak about him. Very soon, the transformation could be carried out by a certain number of mechanics approved, as well on a 4cv as on Dauphine. The price of the total transformation of the total transformation will be about 370 000 Frs (They are old francs, and a new 4cv was worth in 58 approximately 450 000 Frs)"

"This transformation is most important that one can carry out on engine 3 stage of the 4cv and the Dauphine one, and it acts of a real transformation of mechanic, moreover easy to carry out without error nor mécompte. The power is fantastic 63 to 56 CH on the 4cv and the mode can have passed up to 700 t/m! In this case, and it is currently the only one to our knowledge, the box 3 speeds can perfectly be preserved (what contradicts our preceding assertions) because of the power already very high at low mode and of the faculty of acceleration throughout the very wide beach of modes. Once again, it acts of an exceptional case, and a box with 4 or 5 reports/ratios would not be harmful, even if it is not essential. Let us see now how this transformation arises and which are the operations to be carried out: Envisaged in the beginning, as a transformation of car, in the form of standard exchange of engine, this modification of engine was then studied in the form of box of parts to even assemble oneself, formula interesting much more the mechanics and offering more facilities for the many requests abroad, in the USA in particular. Simplifications carrying on the useless details of normal use, such as for example the system of variation of chock of distribution in walk, and the adjustment of the play to the valves without disassembling of the case of camshaft. These two very useful characteristics on an experimental engine do not have a raison d'être on an engine with the well established characteristics. The box of adaptation includes/understands: 1 the cylinder head itself, with combustion chamber in the form of segment of sphere, special steel valves of large diameter and exhaust and individual and opposite inlet manifolds for each cylinder. 2 the camshaft case which, as its name indicates it contains the trees, but also push rods and pinions of drive carrying of the reference marks, which makes it possible to very quickly leave all the whole and without fear shift of the trees, either to reach the cylinder head, or to rectify the thickness of the hats of valves. 3 the case of the pignoneries of drive of the trees and the intermediate pinions. Here approximately, the order of the operations to be carried out: 1 does the group have to be bored and tapped in two places for the installation of the cylinder head bolts? This very easy transformation does not deteriorate of anything resistance group. 2 Preparation of the traditional cylinder head of manner; (grinding of the valves and assembly of the springs) traditional fixing of the cylinder head on the group. 3 Centering and fixing of the case containing the cascade of pinions of drive of the trees. 4 Appairage of the hats of valve and poses case of camshaft, timing setting. 5 Reassembly of the accessories, dynamo, starter, etc? without any modification. Two inlet manifolds are possible either for carburettors doubles corpsinversés, or for two horizontal Weber carburettors. The pipe exhaust which is connected to the pot of origin can, either be provided by the Boudot establishments, or manufactured by the assembler himself. A very detailed explanatory leaflet makes it possible to follow without possible error the process of assembly and the few besides reduced special tools with two chucks of centering, can either be provided or turned to the dimensions indicated by the note of assembly. The vehicle becomes true "Great Tourism" able to reach a speed of 160Km/h."

<small>[ 15 October 2003, 09:30 AM: Message edited by: davemcbean ]</small>
 
Coventry Climax engines made after WW2 are a really neat all alloy OHC design. By the standards of small car engines of the time they most definitely are NOT ordinary. These engines were a favorite of Lotus for their competition cars in the late 1950s.
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A version of the Coventry Climax engine was also used in the Hillman Imp. These many not be plentiful, but at least obtainable. Also, tuning bits would be obtainable, if not locally, from the UK and possibly NZ.

Ren
cheers!
 
REN TIN TIN:
A version of the Coventry Climax engine was also used in the Hillman Imp.
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Yeah that's kind of true, but it's really only loosely based on the Coventry Climax engine. Hillman needed a similarly light engine for their rear engined small car so they asked Conventry Climax for alot of advaice, hence the engines turned out very similar, however I'm not sure if there is much that is actually interchangeable between the two engines. An Imp engine and transaxle may be an easy an more obtainable combination to swap into a 4CV than a CC engine.

Dave
 
Has anyone ever done/considered a rotary conversion?

I used to race against a fellow who had a rotary powered Hillman Imp sports sedan, so that conversion at least has been done.

:p
 
davemcbean:
Originally posted by REN TIN TIN:
[qb]An Imp engine and transaxle may be an easy an more obtainable combination to swap into a 4CV than a CC engine.

Dave
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Sounds an awfully lot more complicated than "just" dropping in the mechanicals of an 8/10 gearbox/crossmember with 8/10/12/16 power.

The Renault equipment would be eminently more reliable than the Imp motor too :)
Click to expand...
 
Originally posted by davemcbean
<strong>Coventry Climax engines made after WW2 are a really neat all alloy OHC design. By the standards of small car engines of the time they most definitely are NOT ordinary. These engines were a favorite of Lotus for their competition cars in the late 1950s.
Click to expand...
They were 'ordinary' in some ways, three main bearings, for instance.

The FWB was the true racing version of the FWA, though a lot of people raced with the FWA. They were (the FWB) indeed fitted to a lot of Lotus cars, including the 9s and 11s and Elites, but they also came in Coopers and Elvas and Tojieros and Lolas and other cars... including a conversion Jack Brabham used to market for Triumph Heralds!

So they weren't that ordinary at all... but all the same, I'd agree that the later Renault engines would be more suitable for this job, particularly the 16TS.

As for the Imp, yes, it was a Coventry-Climax design (more than just advice there... collusion it might be called) and there were many similarities between it and the FWA/FWB line. But it was much smaller (875cc, would go out to about 1200 from memory, but the FWB went out to 1500 at a stretch), and it was more purpose-built.
 
Simon:
davemcbean:
Originally posted by REN TIN TIN:
[qb]An Imp engine and transaxle may be an easy an more obtainable combination to swap into a 4CV than a CC engine.

Dave
Click to expand...
Sounds an awfully lot more complicated than "just" dropping in the mechanicals of an 8/10 gearbox/crossmember with 8/10/12/16 power.:)
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Hey don't get me wrong. I agree with you!

I'd much prefer one of the Renault conversions. An 1100 bored to 1255cc with an 8 port head and a couple of webers would be sweet (short stroke, good breathing).

Dave

<small>[ 15 October 2003, 01:10 PM: Message edited by: davemcbean ]</small>
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Ray Bell:
Oh, yeah... there's stacks of FWAs about that have been used as firepump engines. Saw a bundle somewhere just a few weeks ago...
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Not only were they used as fire pump engines, but that was what they were designed for.
 
Correct, Stuey... that was their purpose in life. As I commented earlier:

Originally posted by Ray Bell
I thought Morgans gave up on C-C engines before the war, and I would have thought that the FWA was a war baby... for use fighting fires in the Blitz of London.
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The ones I've seen 'lying around' have been set up in frames for carrying to the location of fires, they're designed to be carried by two (running!) men, hence the need for lightness.

Later, when C-C made their twin cam V8 racing engine they labelled it the 'FPE' for 'Fire Pump Eight' and their four cylinder version that won two world championships was the Fire Pump Four. Nothing like sticking with your core business!
 
In answer to Renault 8 & 10s question about rotary conversion, yes it has been done in South Africa to a R8. I have only heard about it but Frans could give you more details. He told me it went very well.
Sounds like a good option, how heavy are rotary engines?
If they were about the same weight as a 1100/1300 motor it would make sense.

Ross renault_
 
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