Non sealed/spec motor for the fm chassis?

[Dmitri]

I'm planning to run one more year in Midwestern council with my fm, and I'd like to put together a cheaper power plant for the car to swap in and not put another seasons worth of hours on my sealed motor. What are the differences between the fm motor and the 13b from the rx7? Which years, port styles side plates work with the fm intake manifold? I'm not looking for much additional performance, maybe a small power bump from a bridgeport/race port.. what are the realistic hp/tq limits of the transaxle?

[Purple Frog]

Trany lives well up to about 175 lb. of torque.

[mstephenson51]

the legal one is the 6-port 13B. You could very easily swap the sealed section out with a non-sealed exactly the same and nothing else on the car has to change.... Same intake, exhaust, carb, trans, everything.

That would to me be the easiest thing to do.

If I recall, the 13B was in a few cars from 74-78, and the RX-7 from 84-94? I cant remember what years and cars to be honest.

A safe bet would be to call Drummond and he might even have a used non-sealed motor for ya.