Ok all while I was playing around with my new REPU(never owned one before)I decided to take the intake manifold off to see exactly what kind of porting was done to the motor.After removal of the mani i noticed that the 2 rotor housings were not the same.One has a passage for coolant to the intake and a recess for the o-ring but the other(front)doesn't hava a passage just a hole but not all the way into the coolant runner.Also the front has a hole that has been sealed up where an injector would go.Is the lack of coolant going through the intake manifold going to hurt anything,or is the coolant still getting through the rest of the engine?I'm not sure how much this engine has been ported because i don't know of a way to measure the port area with the engine assembled but I can say the ports feel a lot bigger than the ones on my 12A i had sitting next to me at the time.Now I know the 12A and 13B are like apples and oranges but these ports felt huge,but there was no extra bridge that i felt that would say it was a bridgeported motor.Hope you guys can help me.Oh yeah are all 13B 4 port intake manifold gaskets the same,or will i need a special one for the different rotor housings?I hope i am explaining this right.
74 green REPU w/factory air
Early production 79 Spark yellow RX-7 GS
...your motor was built with mis-matched rotor housings...? May or may not pose issues... As to the blocked off water passage in the intake, remember the racing beat manifolds--among others--delete that as well... however, one would think uniformity between the two rotor housings would be important... sounds also like it might have a (big?) street port...? Can you track down the builder, and/or folks to talk to who know, or know of the builder?