4-port rotary transmission swap
 

I have an early 4-port engine. The original tranny is shot, and I want to upgrade to a newer/stronger unit. Can I mate this engine to a later model transmission. For example, can I mate it to a late 80's TII tranny? If so, what's involved in making it work?

Thanks,
Mark

I should add that the engine/tranny isn't going into an RX7. All the driveshaft and motor/engine mount stuff I can figure out on my own. I'm really just looking for advice on how the two physically bolt together. I.e., flywheel issues, starters, clutches, etc. Also, is there a preferred year tranny for strength and durability?

Thanks again,
Mark

If you have a '74-78 transmission, you are in luck. The Turbo II transmission will bolt to your existing bellhousing, and you can use your existing flywheel and starter. You only need a special 215mm clutch disk that has the correct 1x23 splines, which Mazdatrix and Racing Beat sells. The driveshaft yoke will be different and the shifter will be in a *very* different place.

Great. That's exactly the type of answer I was looking for.

One dumb question, however: how do I know if my existing transmission is a '74-78? The vehicle origin of the tranny is unknown to me. In fact, I'm not even sure what the 4-port engine is out of... ;-)

Thanks again,
Mark

I am not sure (Jeff20B, help me out here eh?) but I think all '73-earlier engines used a top mount starter, so there'd be no starter mounting area on the bottom sparkplug side of the trans.

If you have a 4-port 13B, then it's got to be '74-78, and the bellhousing pattern changed starting in '74.