Thinking Out Loud, Rear Engine AC VW Swaps & CCW Engines...

Say you took a CCW "Reverse Rotation" engine, say a '90s era Honda 4 cylinder, your favorite B or D series.

Adapt that engine to say a Subaru or Audi transmission.

Stick the engine in the back of the VW, bell housing forward, the transmission is now backwards from its original orientation.  Just like the AC VW originally had it, engine rear of the transmission.

So now that the transmission is backwards, with the RR Honda engine, it's still turning the correct direction to utilize all the forward and reverse gears as intended right?

Sure, except you'll be driving all of the gears backwards, reversing the thrust loads and and driving the weak side of the ring & pinion teeth. Probably better to use a standard rotation engine and install one of the subarugears reverse rotation ring & pinion sets.

I had this idea some years ago for my counter clockwise turning Fiat 850 motor. I went out and bought an Audi transaxle with the ratios I liked and then chickened out.  I had an opportunity to discuss the idea with a former Hewland Gearbox engineer a while back and he gave it a good long think and decided that the thrust direction would be a non issue as most transmissions have thrust bearings on both sides. As for the ring and pinion he said the shape of the teeth is for noise reduction and spinning it backwards would be slightly stronger but louder, not like straight cut gears loud, but it would generate a bit of noise. He started telling me about certain rear ends they flipped upside down and drove backwards in some racing situations.

I have actually restarted the project and the Audi trans is on my work bench right now.

I am more thinking a Honda in the back of a Fiat 850 would be a much better playtoy than an ACVW

You can flip the R&P on an ACVW transaxle, no need to play with other transaxles, and you don't have to adapt CV joints.

In reply to jarrettp :

Oh, there's a "need."

Yeah, you can't run the transmission backwards.  You need to find a CCW trans to go with it.

Easier to stay CW and find a ring/pinion setup to reverse the spins

The early swing axle VW transmissions are flippable. Just turn the transmission upside down. That's how a lot of early mid engine VWs were built.

Flipping the ring and pinion isn't terribly hard from what I've read/seen. My old boss had an IRS transmission that he did the flipped R&P mod to use a Corvair engine.

In reply to buzzboy :

Flippable, yes.  But they're still driven the same way despite the output being reversed.  You can't put a CCW engine on the bellhousing of a CW transmission and have it survive.

In reply to Curtis :

ACVW trans use spiral bevel gears instead of hypoidal, so driving it backwards doesn't blow up pinion bearings like say running a hypoidal ford 9" in reverse rotation. Swapping in reverse rotating turbo corvair motors was a hot thing back in the day

Hmmm... The things you learn.  Thanks.