[V8] V8 engine swap to C4 Avant

[Dave Saad]

I read somewhere that bell housing to engine bolt patterns are pretty constant over Audi engines of all flavors. I have no idea if that is true though - just read it in the inter-tubes. On the S6, I say buy one that has a good body but needs work. Get it cheap. Have your trusted guy do the work to your specs. You then know exactly the status of everything. To me stacks of receipts mean the car has been worked on a lot and that is a bigger negative than a car that has just been driven for x miles without visiting the dealer on a regular basis. 

Sent from my iPhone

> On Jan 25, 2017, at 6:01 PM, Acadian Lion <Acadianlion at hotmail.com> wrote:
> 
> At the great risk of inciting a few more death threats because I am 
> exploring the possibility of replacing the 2.8 V6 and 4HPFLA 
> transmission in my '94 100CS with a 3.6 V8 and its 4HP24A automatic 
> transmission, I have some new information about possible issues with the 
> swap.  So far to my knowledge no one has made a swap like this one, or 
> more precisely, I have not FOUND an example of this swap. There are 
> many, many installations of V8 engines into the C4 Chassis cars, but all 
> seem to have one thing in common:  they ALL involve the changing of the 
> transmission type to either a five or six speed manual. ALL of the work 
> has been very time consuming and very expensive, because the differences 
> in the transmissions presents enormous challenges that are either 
> daunting to even the best of amateur mechanics and VERY expensive to the 
> person who hires a pro to do it.
> 
> I get all of that. But the swap of a V8 into the engine bay of a C4 car 
> isn't the nightmare space wise that installing one into a Type 44 car, 
> like a 200, say.  The V8 WILL fit with one detail that could really be 
> problematic. The unknown answer to the big question I have right now, is 
> will the 4HP24A transmission be a direct fit.  IS the front wheel drive 
> shaft placement direct to the placement of the front wheel?  The best 
> answer to the question is probably to find out the dimensions of the 
> transmission case.
> 
> I suppose another question is will a 4HPFLA transmission bolt to either 
> the 3.6 or 4.2 V8 engines?  That might solve the problem. I know that 
> there are engine mounts readily available for the installation ($200 to 
> me right now, if I want them). But the question is how well or how 
> difficult will be the mating of the front wheel drive components of the 
> Quattro system.
> 
> Another issue that has been pointed out to me is the presence of the 
> drivers side distributor and the brake booster.  There is insufficient 
> room to DO anything with the distributor once it is there, UNLESS the 
> brake booster can be moved in some fashion.
> 
> Now, there is yet another workaround for that, and that is to use a V8 
> from a later car, one with coil packs instead of distributors.  But 
> again comes the question, "which transmission"?  I have a significant 
> resistance to the Tiptronic transmission because of their reputation for 
> grenading at around 100,000 miles or before, and their reputation for 
> oil leaks is pretty strong, also.  I do not believe the 4HPFLA 
> transmssion will mount at all, nor do I fantasize about that 
> transmission taking the torque of the larger (or maybe any) V8 engine.  
> I also have a sort of aversion to the idea of using coil packs also, 
> chiefly because of stories I have read of coil pack failures in later 
> model Audi engines in general.
> 
> I am waiting to hear back from ZF about the transmission dimensions and 
> data that will give me a bit more information.  On the surface, I 
> "think" the engine cases are the same generally because the 4HP24A 
> transmission was used at the factory for the Euro C4 V8 which was never 
> imported.
> 
> In the end I doubt this will get done at all, but at least when I decide 
> to send the old wagon to the crusher I'll know I have given all the 
> alternatives a chance.  And for anyone who might suggest it, yes, I'd 
> love to have an S6, IF I could find a one owner example with 80,000 
> miles that had EVERY service record from new, AND preferably, had just 
> had the Tiptronic ovrhauled and the timing belt service done.  As of 
> right now, IF such a car exists, it would cost more than the swap of the 
> V8 into my old wagon and it would probably still have the typical 80,000 
> mile engine leaks.
> 
> Roger
> 
> _______________________________________________
> Audifans V8 mailing list
> Send posts to: mailto:V8 at audifans.com
> Manage your list connection: http://www.audifans.com/mailman/listinfo/v8
> 
> You can help keep the audifans site running by shopping at http://audifans.com/shop/
>