hey all....
heres a question for you...

can ANYONE list all the rotors they made for the engine 12a? in order from best to worst...reason being is that i have rotors stamped differently like c1 and others, what i want is to know whats best as far as compression and weight and all that good stuff....so if anyone can do that it would be great....!! im still learning so go easy on me...i want to start rebuilding a 12a so thats why im seeking this info. so thanks in advance for anyone who answers....

:AA:

 

There are only two different 12A rotors and they are the same compression ratio. The only difference is 83-85 rotors are slightly lighter than previous ones.

The letters are for balancing purposes. The idea is to use a pair that is no more than 1 letter appart.

 

ahh....i see, and the letters on the side of the rotor? in the tub i mean....one has "f n" and one has "r n" dose that mean front rotor and rear rotor? if there is somewere i can look to find this sh*t out instead of asking stupid annoying questions? please post or let me know where....thanks

:AA:

 

^^^ search button.

 

I think felix miatas site (which is in the FAQ thread) lists this. I thought there was 3 different ones. Early ( symetrical dishes) like 79-80 which were interchangeable front to rear. Then 81-83, then 83-85. But Im not sure.

 

well there 3 that i have seen and i have a page on 12a rotors and counterweights on a disk somewhere, a turbo- low comp rotor and 2 of the same comp but different weights, this is a fun topic, the letters relate to position in engine and counter weight i think, let me look for this disk...

 

Yes, I forgot about the Turbo rotors.