Engine Orientation in a '40

[Chris Duncan]

Re: Engine Orientation in a \'40

This would solve the design problem of rigidity at the rear shock/suspension pick up points. You do have to make the concession of a rigid mounted engine, which is considered full race because of the increased vibration.

With a G50 you would have to change the inverted lower A-arm a bit because the axle centerline is rearward of the trans engine bolting face.

I think the original ZF allowed more room around the bell housing which consequently allowed more room for the chassis in this area, especially underneath. I think the reason a lot of the kits are weak in this area is that the more economical transaxles don't allow as much room.

the original "horse collar" as it was called is very substantial all the way around.

You could have an adapter plate that doubled(tripled?) as a engine mount and a chassis stiffener but I think you would want at least 1/2" thickness. I made my adapter with intergral engine mounts but I used urethane bushing isolators which negated any transfer of stiffness to the chassis.

If you did put mounts on it I would put 4, one in each corner, this would probably make it even stiffer than the horsecollar.

 

[Chris Duncan]

Re: Engine Orientation in a \'40

The distance from engine/trans face to axle centerline is fixed to the given transaxle.

The axle centerline to wheel centerline is more or less fixed obviously. You want as little drive shaft angle as possible, it robs power, you usually already have some angle in the vertical direction because of wheel movement. (you need some angle to keep the CV balls from running in one spot.)

So this means the engine trans face is more or less in a fixed position. All you can do to get the shock/suspension pickup horsecollar area of the chassis to line up with the engine trans face is to move the chassis. This may be problematic because it needs to move forward and the coilovers are already about as far forward as they can be without making a heavier and possibly weaker lower A-arm.

On my scratch chassis it's about 4" from trans engine face to shock suspension pickup centerline. You might be able to just tie the mount/ adapter/ stiffener plate into the chassis a little in front of the shock/ suspension centerline and still gain some rigidity. The typical adapter plate is already almost as large as the horsecollar area, 4 mount extensions off each corner wouldn't add all that much weight but it would add a lot of rigidity. On my chassis about 25 percent of the total flex was is the horsecollar area, definitely a weak point of any tube frame. It's hard to put a diagonal through the transaxle.

The original horsecollar was an 8 sided shape, almost approaching a circle which is more rigid than the typical tube frame which is just a 4 sided trapezoid shape.

 

[StuartB]

Re: Engine Orientation in a \'40

I love the thinking behind the modular approach and from first glance have a couple of questions.
With the known issues regarding strokers potentionaly splitting blocks, would the torsional loads accross the engine be playing with fire with a stroker fitted?
And talking of playing with fire, did this car run a conventional exhaust system directly over those shocks or was an alternative solution found?
Any thoughts?

 

[Paul Thompson 'Hooligan']

Re: Engine Orientation in a \'40

Hi Stuart -

As I recall - Ray's innovative Spyder had a non-crossover system, that had a single long box running from each set of (unequal length) headers to the rear. Which is why the exhausts exit either side of the central rear cutout.

I also vaguely think this motor might have had a 351 installed in it /ubbthreads/images/graemlins/confused.gif but I'm not too sure, I'll look at some more pics I have..

 

[Chris Kouba]

Re: Engine Orientation in a \'40

So were there any long term effects of having the motor serve as a stressed member? I look at the engine block as 50's or 60's technology and I can't quite imagine that it was designed to absorb and distribute the types of stresses and loads those tires/suspension are capable of generating. Did someone do any FEA on it prior to trying or has it already been proven on some other car and I just haven't realized it?

Actually, looking a second time, is the engine even a stressed member? Is there some provision for the adapter plate (block to tranny) to bolt to the mono somehow?

Regardless, it appears to have worked and I am curious as to the details surrounding it. If there are any other pics out there, I'd be really interested in seeing them.

Also, what sort of transmission/suspension is that? It looks stolen off of a CART or IRL car. Does anyone know?

Thanks in advance,
Chris

 

[Paul Thompson 'Hooligan']

Re: Engine Orientation in a \'40

Hi Chris -

Motor was was mounted rigidly via 0.5" plates front and rear so must have been providing some structural strength.

Re the trans - it's still a standard Renault UN1 under those suspension bits and was very much structural but never failed so I guess it was ok....

Ray had lightweight, push-rod suspension on his race R42 too, so I suspect it was nothing new to him. It did have inboard push rod suspension on the front too.

Another few pics.. /ubbthreads/images/graemlins/smile.gif

 

[Chris Kouba]

Re: Engine Orientation in a \'40

Wow, a standard production gearbox. I wouldn't have guessed it would be able to support that setup. Very impressive!

Is the rear suspension swiped from a different car or did he cook that up as a custom job as well? The people on this site do some very impressive undertakings!

If you have more pics of it fit together showing the mounting of the suspension bits and how/where the plates attached to the mono, I'd be interested in seeing them as well.

Thanks!
Chris

 

[John W]

Re: Engine Orientation in a \'40

Paul,
a slighly different question. Whos make of chassis did the latter car with inboard suspension start out as (GTD base ?), or was the entire thing built from the ground up ?
Just wondering as I would think one hell of a lot of mods would be required to make that setup fit in a chassis designed for conventional suspension.

It looks very nice indeed.

Cheers,
John.

 

[Paul Thompson 'Hooligan']

Re: Engine Orientation in a \'40

Hi Chris / John

Rays R42 came first - inboard suspension at front - very quick, but totalled at Shelsley Walsh a few years back.

Rays spyder, as detailed above came later, (99?) and had inboard shocks front and rear - and as above. It was ALL Rays design - very innovative - seemed to work well. When I drove the Spyder at Goodwood it cornered well, giving very good feedback and was easy to drive quickly with little time 'in the seat'.

All suspension links, arms etc etc were designed and made by Ray using tear section tubing. Clever sod!!

The first part of a series of articles was published in the current club mag - detailing Ray's history, or some of the early part of it and he seems to have personally built 'dozens' (yes 30-40+) vehicles....

 

[Keith]

Re: Engine Orientation in a \'40

Well that previous picture certainly answers the "burning" question as to how the exhaust is routed to avoid overheating the shocks! /ubbthreads/images/graemlins/laugh.gif

 

[Paul W]

Re: Engine Orientation in a \'40

Looks like a renault UN1 to me, with an extra plate between the rear 5th gear cover.

 

[Chris Kouba]

Re: Engine Orientation in a \'40

Paul,

Thanks for posting the pics in such a responsive fashion. I am continually amazed at what members of this forum are doing.

Chris

 

[Paul Thompson 'Hooligan']

Re: Engine Orientation in a \'40

My pleasure - one last look.

The motor mounted at the front - mainly via 3 bolts to each head through spacers (arrowed and one having fallen down lower in pic)

And to the rear, it fixed to the 0.5" alloy plate running across the chassis rear. I vaguely remember Ray telling me that after fitting it all together, the rear plate was cut, either side of engine to make easier removal and then plates bolt to either side of the joint when re-installing.

Like I say - Ray is a very clever so and so! /ubbthreads/images/graemlins/grin.gif

 

[Paul Thompson 'Hooligan']

Re: Engine Orientation in a \'40

Found these last two pics of setup - from Bovington Sprint 2000.

 

[Keith]

Re: Engine Orientation in a \'40

Some good engineering here. /ubbthreads/images/graemlins/smile.gif