i have a sa79 12a engine


83fb s 12a engine

83fb le 12a engine

 

The 79 engine has different weight rotors,thus a different flywheel.

The 2 '83 engines should be identical,assuming they are both actually original 83 engines.Use the Mazdatrix FAQ guide to determine the origin of each flyhwheel....
http://www.mazdatrix.com/faq/flywheel.htm

There are a total of 3 different 1st gen RX-7 12A flywheels......

1)79-80 for 215MM clutch,30lbs
2)81-82 for 215MM clutch,23lbs
3)83-85 for 225MM clutch,26lbs......rotors are lighter.

 

ok so i checked mazdatrix out thanks steve


the 79 engine had a 8and 2 stamped on the flywheel mazdatrix had no id for the fly wheel
the 83 le had 31 which is the 83-85 engine
the 83 s had a 2 and 56(this is the thinner flywheel) mazdatrix had no id for this on either

any clues

 

Pull em' ,strip em' down and weigh em' on an accurate scale.That will tell you for sure which rotor set, they are designed to balance.
The 79-82 flywheels are made to balance the same rotor sets,the 81-82 is just a lighter flywheel for better response,but the offset balance weight is the same.
The 83-85 flywheel is a little heavier,but there is less offset balance weight to match the lighter rotors.The obvious difference is the larger clutch running surface.

It doesnt really matter which motor you install them on,so long as you dicearn between the 79-82 engine/flywheel and the 83-85 engine/flywheel.The rotor weights and clutch size are the primary concerns.There are no other critical differences within the two families of 12A flywheels....