I've recently aquired a '71 914 from a tenant that owed me rent money. I personally own a trailered 1991 Talon AWD drag car, so I'm no noob to mechanics. I have been researching the endless possiblities of engine combinations in these cars, and have several good ideas. I figured, what better place to critique them than here?
I've read that the 914 transmission is limited to 300/300, and the stock axles to around 250/250 with easy driving. The Porsche trans solutions are unbelievable in price for what I've worked with. My built auto trans for my drag car costed me $3600 including a billet converter! I'm not prepared to spend $5000 on just a transmission/transaxle setup, especially for just a fun project car!
Has anyone ever considered instead of adapting an engine to the stock-style transmission, why not have custom axles made to fit whatever motor/trans combo you went with, and the hubs? Just frankenstien the axles togather (with a little finesse, of course). My thoughts on the motor/trans would be something from a transversely mounted car, possibly a 3S engine, or 4g63 (since I'm already familar with them). The 3s engine and trans are from a mid-engine car. Obviously, custom engine, trans mounts would need to be fabbed. Cooling, fuel, exhaust, and what not are not the issue, as I've seen several radiator setups in these cars that would be easy to fabricate.
My main question is, is this feasible? It seems with the tons of experience and brains I'm reading over this board, surely someone has thought of this before, and not done it for whatever reason. I would love to put a larger displacement engine in it, but I don't know if I can find a transversely setup transmission to adapt to one. Thoughts?
Full Version: Adapting Motor & Trans to 914
Welcome turbo2liter! 
Check out my signature, there are many types of transplants but none so far with a Mitsubushi? engine. I'm crossing over to the tuner market with my Audi turbo...
Sounds like a cool combo, go for it! Finding a reasonably priced mid-engine transaxle to take more torque is the challenge. If you procede please post progress on your project.
Check out my signature, there are many types of transplants but none so far with a Mitsubushi? engine. I'm crossing over to the tuner market with my Audi turbo...
Sounds like a cool combo, go for it! Finding a reasonably priced mid-engine transaxle to take more torque is the challenge. If you procede please post progress on your project.
First off, a decent 914 gearbox doesn't always cost $5K. That's a worst case price. Certain parts in the gearbox are very expensive ($500 for just the first gear slider, $400-500 for some bearings), you just can't get around that. However, quite a few $200 used gearboxes only require about $500 in parts to freshen them up. It's mostly torque that kills these things, and the 300hp/300ftlb numbers are very rough.
There are also a few other transaxles that can do the longitudinal layout, such as some made by Audi, which have been used here and there. Boxster transaxles are very similar to the Audi units, and there is some effort to use those, as well.
I think at least one person has done a transverse engine layout in a 914, but it almost certainly requires cutting up the rear trunk and adding some bracing. There's plenty of room to do it otherwise.
It's not what you're used to, but turbo Subarus seem to be the best option for lots of power w/o doing a V8. They fit in the engine bay very nicely, there are adapters to bolt them to the transaxle already, and 300hp is pretty easy to reach. Since they have a very similar weight and layout to the stock engine, you're not even messing up weight distribution, so the car handles like stock.
There are also a few other transaxles that can do the longitudinal layout, such as some made by Audi, which have been used here and there. Boxster transaxles are very similar to the Audi units, and there is some effort to use those, as well.
I think at least one person has done a transverse engine layout in a 914, but it almost certainly requires cutting up the rear trunk and adding some bracing. There's plenty of room to do it otherwise.
It's not what you're used to, but turbo Subarus seem to be the best option for lots of power w/o doing a V8. They fit in the engine bay very nicely, there are adapters to bolt them to the transaxle already, and 300hp is pretty easy to reach. Since they have a very similar weight and layout to the stock engine, you're not even messing up weight distribution, so the car handles like stock.
Any B or H series Honda, 4g63/4 Mitsu, 3s Toyota, Nissan SR20DET with a FWD trans all use an East-West engine layout with the axles coming out transversely. Now for a N/S engine layout with the axles coming out E/W, that is more unique.
I know that Eric Plebani put a 4g63 into a 914, just wondered if anyone else had, or if anyone had any experience doing this kind of swap. The only downside I see to a 4g63 swap is that the trannies is those are also notoriously weak. Honda has strong trannies and engines, but would require a turbo to make any kind of serious power that I would like. Unless I went with an RA gearset, the Subaru is also notoriously weak trannies.
My thoughts have been to source an 3s longblock with trans. Seems to be the best/strongest combo, and they come from a midengine car already so the should surely fit well.
I know that Eric Plebani put a 4g63 into a 914, just wondered if anyone else had, or if anyone had any experience doing this kind of swap. The only downside I see to a 4g63 swap is that the trannies is those are also notoriously weak. Honda has strong trannies and engines, but would require a turbo to make any kind of serious power that I would like. Unless I went with an RA gearset, the Subaru is also notoriously weak trannies.
My thoughts have been to source an 3s longblock with trans. Seems to be the best/strongest combo, and they come from a midengine car already so the should surely fit well.
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