Ive got a mint 90 RX7, with no compression on the rear rotor, but I have a running 86 RX7 thats never going to be road worthy again, too rotten. Do I just pull the running s4 motor and swap it into the s5? Or is it smarter to try and tear them both apart and make a freinkenstein out of the both of them? What seems like a better choice? If i do tear into the motors this will be my first Rotory Rebuild. I am a mechanic by day and have been a rotorhead as long as I can remember and have always wanted to tear one apart, just never had time or funds. Please help before I make the wrong choice, being on a budget and all.

 

On a budget? Swap the motor (just the "keg", keep all the S5 intake and everything). Have time, $1,000 for seals, and a different car to drive every day? Build a frankenmotor. S5 has some better components (lighter rotors I think, not sure what else).

 

I would swap the kegs like baldy said, then rebuild the s5 engine, you can do it on a budget i got a fel-pro gasket set, ra classic seals and oem corner seals and rebuilt mine a few years ago still on the road