i knw mazda made some changes and i have an 83 does that mean i have to get a 83 12a for it to be a direct swap. pluss i've heard in 83 they got lighter rotars and these motors respond to modifications better then the earilier models. any wayz if i buy a used enging is there any way i can tell what year it came from b looking at the outside of it???

 

<82 had heavier rotors and a lighter flywheel
>82 had lighter rotors and a heavier flywheel

I've never heard that one is easier to mod than another but the 83-85s had a poor oil cooler.

 

Get the 83-85 12A engine, put the aftermarket flywheel on it and swap for an earlier or 2nd gen oil cooler.

The best of both worlds... Easier to do that than find lighter rotors and counterweight for the earlier engine.

 

again is there a way to tell from the outside what engine is the eariler one or the later one????

 

GSL-SE has a 13B all the others have 12A
And GSL-SE started in 84
correct me if i am wrong anybody, im not 100%

 

the external differences between 12a's there were two different 12a's in rx7's 83 and on had lighter rotars and i'm trying to figure out if i can tell the difference fron the outside?!?!?!

 

Is the place where you put the oil filter attached to the engine?

If it has fins on it, it's 83-85... if not, it's earlier...

EXCEPTION: The filter mounts are changable, and it is a popular mod.

Look for tubes that are cut off for the coolant to the late style oil cooler.

 

when i changed my s1 engine over for a s3 engine the only difference i could find was the engine number was in a different spot and the water outlet at the back of the engine near the spark plugs was a 'T' so it could send water to the crapy oil cooler.