I have a harebrained idea. I would like the advice and knowledge of Ferrari afficionados before I undertake this.
I know of an otherwise complete 1978 308GTS for sale with no engine or transmission.
I also know of a complete drivetrain pullout--including subframe and rear suspension hub-to-hub--from a 348TS for sale.
I have worked on a 308 before. The World's First Reverse Fauxrarri
I did *NOT* do this incredibly horrible swap, but I did make the car driveable afterward. The owner bought the car already swapped, but undriveable with about 1" of compression travel in the rear suspension. I built the "top hat" structures at the tops of the rear struts, visible in the engine bay pics. They allowed the rear suspension to go from 1" of compression travel to 4" of compression travel. The owner said the car handled worlds better afterward. Obviously he sold it after I worked on it and it ended up back on eBay and Jalopnik.
I know that the 308 is a tube frame car. Based on my experience with the car I modified and on photos of the empty engine bay of the candidate chassis, I believe that I have the skills and expertise to mechanically adapt the 348 subframe to the 308 tube frame. I understand it will involve cutting and welding. However, because the 308 is a tube frame car, this is relatively straight forward as it will be purely structural. Botht the design and welding work will be top notch. The resulting car would have 348 rear suspension in addition to the engine and transmission.
I have done engine swaps before. The closest in terms of complexity is a Cadillac Northstar into a Pontiac Fiero. This involved structural modifications to the subframe as well as extensive wiring work, in addition to the usual engine swap items like coolant plumbing, shift linkage, etc.
My big questions/assumptions/reasoning:
Will it fit?
According to Wikipedia, the 308 has a 94 inch wheelbase and the 328 has a 92 inch wheel base. The 348 has a 96 inch wheel base. Are these numbers correct? Where do the additional 2" that the 348 has over the 308 show up?
I'm reasonably confident that it will fit, considering how large the 308's engine bay is and the unique layout of the 348 gearbox, keeping the axle right at the rear of the engine.
Can I get service information?
Can I get the factory service manual for the 308 and 348? Those two books will be extremely helpful.
Are there good parts suppliers who can get me Ferrari aftermarket replacement parts at reasonable prices?
BMW enthusiasts can go to www.realoem.com
and look through the BMW parts catalog. Is there a similar resource for Ferrari parts?
Dry sump oil system:
The 348 uses a dry sump lubrication system, but the pictures I have of the powertrain don't show a tank. However, there are a couple of large braided lines connecting (well, not currently) to things that would be in the body to the right of the engine. I assume that the oil cooler and dry sump tank are there in the 348 body, and I will have to find or make suitable substitutes for use in the 308 body.
I found this thread with some fairly detailed pics of the 348 engine bay... Oakes - Detailed: Ferrari 348 Spider - Rosso Red Overhaul - MBWorld.org Forums
I'm assuming that's the oil tank at the right rear corner of the engine bay.
I understand that the 348 moved the radiators and other coolers to the sides of the car, so it would make sense for the oil flow from the engine to go straight out the side to the cooler, then back to the tank, then to the engine from the rear. This corresponds to the positions of the connections I see on the pictures of the powertrain. I could easily be wrong about the direction of flow, however.
As mentioned above and shown in the 348 egine bay pics, the radiator is in the side of the car and the coolant overflow tank hovers just above the right header. Because the 308 has the radiator in front, I will have to find a location for the overflow tank. The overflow tank appears to be pressurized. I can find one to fulfill the same function, but in the interests of expedience and cost, it will probably be from a Cadillac or Corvette rather than a Ferrari.
Are the QV radiators larger than the 2V radiators to deal with the greater output of the QV engines?
The 308 uses a rod based shift linkage. I can't really tell from the pictures how the 348 gearbox is shifted. It should be straighforward, if multi-staged, to develop a shift linkage which will work.
I'm not yet sure if the recipient chassis has air conditioning. I'm assuming that both cars use an R12 system, due to their age and production years. Custom A/C lines from the body to the compressor are straightforward to make.
The fuel connection is visible on the engine pictures. The 308 fuel tanks are essentially in the engine bay. I don't foresee a problem, even if I have to use an external Bosch 044 pump and remote pressure regulator.
I will address wheel offset changes related to differences in track width when I have the parts in hand to measure.
Engine management (the big one):
I have several ideas for how to tackle this.
1. Obtain all the Ferrari parts and use the Ferrari engine computer. Per Wikipedia, this is a *dual* Motronic 2.5 system. The pictures of the powertrain and of the 348 engine bay appear to show throttle by wire and hot-wire MAF per bank. The candidate engine has some, but not all, of the wiring harness and does not include the ignition modules.
2. Use the 60-2 reluctor wheel and crankshaft sensor from the 348 engine to trigger a Motronic 3.3 from a BMW E34 540i with V8 (1993-1995). This box is tunable and can control a V8 with coil per cylinder ignition. However, in the BMW application it is designed for a single cable operated throttle and single MAF. I'm not sure how well the BMW software would handle the high RPM the Ferrari engine would turn, however.
I could *possibly* use the dual throttle by wire throttle bodies and control box from a BMW E32 750i. The drive by wire system is nearly independent of the engine computer in those cars. This would get a dual electronic throttle capability, but still only work with a single MAF. I would build ductwork to take the flow from a single MAF to the two throttles if I do this.
3. Use the 60-2 reluctor wheel and crankshaft sensor from the 348 engine to trigger a GM engine controller. The GM controller is fully hacked, but can only handle a single drive by wire throttle and single MAF. I would build ductwork to go from the single MAF and single throttle to the dual manifold inlets if I do this.
Am I crazy?
Thanks for your input!