Bizarre drivetrain help needed for a mid-engine hatch.

I was recently gifted a Golf Mk1 roller project. I've always liked their looks and utility, but an not so into fwd, so I was brainstorming alternatives.

Aside from most of the mid-engine projects dying on the vine, the big problem I have with them is they they destroy the utility by occupying most of the hatch, along with much of the former engine compartment, too. I decided that the Toyoya 2TZ-FE/FZE from the Previa had to be part of the answer. (for those who don't know, it's a horizontal inline 4). I could end up with an open hatch and flat floor, slightly raised.

Image: toyovantechforums

Problem is that I want to mate it to a transverse fwd transmission, but the Previa engine has the output on the wrong side. I'd be really fast in reverse. I thought that a trans for a reverse-rotation Honda would work, but it doesn't, because the bellhousing side is reversed also.

I don't like Boxer engines, and the Subie trans looks like it's going to add too much length.

I know it's goofy, but...does anybody have creative ideas for how to achieve a lay-down I-4 in a compact mid-engine configuration?

Thanks!

Cut the floor and start welding. You might want the prévia rear suspension too. I applaud your efforts. That engine isn’t awful, it just needs a lot of help making power and there is zero aftermarket, so be prepared to DIY everything for increasing power. A yota motor in VAG product sits just fine with me!

For placement, you could mount it beside you in the passenger floorboard and run to the previa axle mounted in the back. 

Remember- there are easier ways to accomplish what you want if you abandon that engine/trans combo. 

Perhaps you're overcomplicating things by insisting that the usable-hatch RWD conversion must also be a middy...

Reversing gearbox between the engine and flywheel (added $$$$ + width), or longitudinal drivetrain configuration with a Subie/Porsche/Audi gearbox, those are the only ways...you might be able to hide the tail of a longitudinal gearbox just behind the rear bumper skin depending on the rear overhang length. I know it sticks out the back of a Gen1 Insight...

I'd use the stock Previa drivetrain with a V-drive.

If you must mate it to another transaxle, I'd go look at the back of a 924/944. 

They are a hatch with a transaxle mounted under the hatch floor (which is fairly high) and there are adapter plate drawings available for V8's, etc. so you could use those as a basis for a Toyota engine adapter.

I don’t know if I would do this much work to any car for such little pay off with that engine

Great input. Thank you!

Trackmouse, there is a supercharged version (;  I have no idea if mods are available for their other engines that share the architecture. I want it to be nimble and playful on skinny rubber, probably not something used to go for a time attack title.

Could I invert an fwd transmission?

The other idea I had was to use a conventional upright I-4, but look into laying it over myself. I could collect oil directly from a modified valve cover, leave  some tilt to the block, create a custom pan/sump, and possibly add some guides and ports inside the block to  extricate oil and get it to the pump. That Previa engine is designed with larger ports in the 'side' of it's block. I wouldn't do that, exactly, but might be able to funnel and collect oil to speed it's return to  the pump.

Do you have issues with a normal front engine rear drive set up? Seems it would be easier in the long run and you have many more options for engines and the same amount of interior space.

The mid engine is still a cool idea though, and if that is where the desire is only suggestion I could give is maybe an early Porsche boxter or 911 (the ones with IMS issues) dunno if it would be cheap enough but could be worth a look.

If the whole issue is that you dont like fwd, i would probably look at front engine awd. Either a subaru or honda crv driveline.

You could use the Previa transmission and keep it FWD?

Could you maybe mount it midships in front of a conventional transmission with a super short driveshaft to a diff mounted to the body, then an IRS setup?  If I recall, that engine was in the T series.  A transmission from another T series, like a T40 from an early Rolla _might_ work directly.

To be honest, I'm not a huge fan of AWD. I had a WRX, but didn't enjoy it that much. I actually like having fairly low limits for cornering and acceleration, so that I can have more fun at lower speeds.

I figured that if I was going to do a lot of cutting, I'd like to have something I've never experienced: mid. For front engine/rear drive, I have Datsuns.

Can you just mount the engine and trans backwards? 

Do either really care what direction they're facing?

I think you are really limiting yourself by using the previa setup. I know you want storage in the hatch, but I would be more tempted to us a regular FWD setup and be happy with a small "trunk" area between the engine and the hatch proper. If you are dead set on a load floor, I would consider a subaru. The inline 4 is a LOT of length that the boxer would not have.

Having said that, look into a trans from a Mitsu eclipse. The engines on those were "backwards" from the later 4g63s used in the Evo 8 and beyond.

Crackers said:

Can you just mount the engine and trans backwards? 

Do either really care what direction they're facing?

This. Why would you not just spin the whole thing 180degrees (looking straight down from the top)?

Previa motor mounted to a standard fwd trans with the trans on the driver's side should work great. And the packaging actually seems really great too.

for that matter, could you just reverse the spin of the engine with different cams and timing?

It occurs to me that we may be having a translation issue. 

Does the Previa engine rotate opposite to the transverse transmission? In that case, turning the whole assembly around probably won't work depending on how the gears are cut. 

Thanks, Mad_Machine. That Mitsu trans could work. Interesting.

Robbie said:

Crackers said:

Can you just mount the engine and trans backwards? 

Do either really care what direction they're facing?

This. Why would you not just spin the whole thing 180degrees (looking straight down from the top)?

Only because it would then be rear-engine, not mid. That's why I asked if I could turn the trans upside down instead.

In reply to Crackers :

The Previa engine is normal rotation, but Toyota decided to lean it over on its right side. Most normal rotation fwd transverse trans mount to the driver's side of the engine. If I tried to mount the Previa engine to one, it would lean back and hit its own halfshafts.

I could mount it to an older Honda trans that's the mirror image of normal, but since that trans was designed for a reverse-rotation engine, and the Previa is conventional rotation, I'd get 5 backward speeds.

For some reason, the Mitsu transmission Mad_Machine mentioned has an extra idler shaft in it, so it sits on the passenger side of the engine, works with normal rotation, and could work.

I just think it'd be cool to have something unique. I guess I need to research that engine's internals to see if there are options aside from the factory supercharger.

Oh, ok, so it's a packaging issue. 

I'm all for stupid ideas. A rear mounted K20 in a CRX is high on my bucket list. 

Mitsu trans from a 90-94 Eclipse/Talon/Laser is your huckleberry.  They had a conventional rotation engine with the trans on the passenger's side.  

Nonturbo FWD transmissions are weaker than the turbo FWD transmissions but you should be able to keep one together under 250 HP plus they are smaller.  Bellhousings are all the same.  95-99 Nonturbo FWD are chrylser trans and not at all what you want.  

Turbo FWD and AWD transmissions are roughly the same in strength but AWD is bigger.  AWD can be converted to run FWD.  There is an equal length halfshaft available that fits in all of them, 90-94 AWD front drivers side was equal length.  

mad_machine said:

I think you are really limiting yourself by using the previa setup. I know you want storage in the hatch, but I would be more tempted to us a regular FWD setup and be happy with a small "trunk" area between the engine and the hatch proper. If you are dead set on a load floor, I would consider a subaru. The inline 4 is a LOT of length that the boxer would not have.

I agree a boxer motor sure seems to make the most sense in this case.

The obvious solution is find a wrecked Porsche Boxster and install that in the back of the Golf.

Dr. Hess said:

Could you maybe mount it midships in front of a conventional transmission with a super short driveshaft to a diff mounted to the body, then an IRS setup?  If I recall, that engine was in the T series.  A transmission from another T series, like a T40 from an early Rolla _might_ work directly.

This can work, the only problem is that the drivetrain ends up being super long, which is very bad for either interior space or vehicle length.

There are at least two cars on here with that kind of drivetrain, one of them is loosecannon's "MGB" where the engine sits where the passenger's footwell used to be, the other is a "sports racer" type race car that is extremely long.