Engine to transmission mounting

[Spittybug]

Just a general question to those that have swapped in alternative engines. How do you go about figuring the mating of the new engine to the transmission? Am I correct in assuming that ANY engine other than one that was originally intended to mate with our Renault transmissions will need to have some form of adapter built? Is this simply some kind of bell-housing-perimeter-shaped plate with additional mounting surface for the engine rear face? If so, how does one extend the transmission shaft so that it still inserts into the engine with that extra "shim" between the two? Likewise for motor mounts. How does one know if it will align? Or does someone have to transplant both the tranny and the engine? If so, then mount, length and linkage..... the problems compound.

I've long thought about just slowly but surely building up an engine on the side to one day drop into the car. No immediate need, but every now and then you see something that someone has done and you get the urge! I'm not afraid of tackling such a project in terms of electrically, cooling and exhaust-wise integrating it into the car, but I have no knowledge or experience from a mechanical point of view.

Have we ever created a sticky list of just what engines have been successfully transplanted and a brief description of the mechanical mods necessary? That would make for a pretty cool thread I think.

[DMCVegas]

The best bet so far would probably be to head over to the Ford GT40 kit cars and start hitting them up for information. I've been wondering the same thing myself. So far I found a place in the UK that makes adaptor plates for SBC, LS-1, SBF, and Ford Modular to UN-Series transaxles like we have. And given the price of K-Jet parts now, I'm piecing together everything for a swap instead of a restoration if I can get an engine to fit.

Anyhow... Of all the discussions I've ever seen regarding the UN Series transaxles (though I wouldn't yet consider them exhaustive), be it performance or installation, the topic of Input Shaft Length has never come up. Best bet though might be to dig a bit deeper with the GT40 crowd to find out a bit more.

[Nicholas R]

The topic of input shaft length ALWAYS comes up. Yes, you have to accommodate for it. You have to figure out how to ensure it makes it all the way into the pilot bearing. I have a custom pilot bearing carrier in the crankshaft that offsets the pilot bearing outward. The same has to be done for the flywheel, clutch/pressure plate, and throw out bearing and fork, otherwise the clutch won't engage and disengage properly. If you do like I did and make your own flywheel, you can just build whatever offset you need into that part.

Also there is one input shaft available overseas that replaces the Renault input shaft outside of the coupler. It's longer and has a ford spline pattern on it, and is exclusively for mating a Renault un1/369 transmission to a small block ford.

[DMCVegas]

Are you talking about GTO Racing Ltd? They've got a good selection, including a conversion kit for a 6-Speed UN-1/369 with a custom input shaft length depending upon what you need. It eliminates the 5th gear overhang, but does require a spacer on the end to accommodate the extra gear. They've also got SBF & SBC bell housingins (though I did find another vendor who has LS1 & Ford Modular adaptors ready to go). The only thing there is they don't offer any prices on their site, and that tends to make me cringe... A few years ago there was a guy in Florida who said he sold these kits, but he wanted over $8K for the gears, and I don't even think that included a Quaife ATB.

[Nicholas R]

Are you talking about GTO Racing Ltd? They've got a good selection, including a conversion kit for a 6-Speed UN-1/369 with a custom input shaft length depending upon what you need. It eliminates the 5th gear overhang, but does require a spacer on the end to accommodate the extra gear. They've also got SBF & SBC bell housingins (though I did find another vendor who has LS1 & Ford Modular adaptors ready to go). The only thing there is they don't offer any prices on their site, and that tends to make me cringe... A few years ago there was a guy in Florida who said he sold these kits, but he wanted over $8K for the gears, and I don't even think that included a Quaife ATB.

Yea I've looked into that kit pretty extensively. When I inquired I was looking at ~$7,500. The kit looks pretty cool but you have to keep in mind that the 6-speed set doesn't use synchromesh gears (no synchros). It uses dog gears in the selectors, meaning shifting requires a lot more finesse. There is no synchro to match the shaft speeds when you shift so if you don't rev match, you're going to be in for a really clunky ride. Really, after practice, you'd want to work on clutch less shifting. The benefit is of course that the gears are way stronger. All the gears themselves are even straight cut instead of beveled; a lot stronger but a lot more noisy. It's like driving in reverse all the time. Definitely a cool option, but unless you're racing, I think it would get somewhat annoying to always be mindful of your shifting and the loud gearbox. Even the old M22 rock crusher transmission, which was definitely a loud one, had a 20 degree bevel to the gears instead of the standard 45 degree bevel. With no bevel you'll definitely hear it while driving.

[DMCVegas]

Straight cut? Hell no.

I did find another place here stateside that offers a single-piece input shaft with revised 1st & 2nd gears. First is straight cut, but that's it. Only thing is that they state it only fits UN's with a 52mm rear main bearing. $3,600.

[Nicholas R]

Straight cut? Hell no.

I did find another place here stateside that offers a single-piece input shaft with revised 1st & 2nd gears. First is straight cut, but that's it. Only thing is that they state it only fits UN's with a 52mm rear main bearing. $3,600.

Holloway Performance? I've tried to contact them but they've yet to get back to me.

There's also Tornado Sports Cars which is based out of the UK but they have a branch in the US.

[DMCVegas]

Holloway Performance? I've tried to contact them but they've yet to get back to me.

There's also Tornado Sports Cars which is based out of the UK but they have a branch in the US.

That would be them, yes. I couldn't think of the name at the time since I was at work.

Good to know about Tornado. Especially if they can sell entire bell housings rather than just adaptors so that I can get additional length out of the input shaft. Thank you!