Flipping FlyWheels!?
 

Hey guys-

I just picked up another engine for one of my cars...however the engine that I got has a different flywheel than the other ones that have been in the car... The ones that are in the car seem to be thicker....

Can I just unbolt and switch them?


Thanks!

Different years have different flywheels. The 79-80 had a heavier flywheel than the 81-82 models, but they can be interchanged. The 83-85 had a different size clutch, and is balanced different, as the rotors are about 1/2lb lighter than earlier models. Using an 83-85 flywheel on a 79-82 engine causes an unbalance in the engine.

You forgot to mention the front counterweight differences between '79-'80 and '81-'82. The '79-'80 is a half circle like 13Bs and the '81-'82 is less than half a circle and weighs less. Probably a good idea to swap them both is you want to swap flywheels between them.

True, the 81-82 counterweight is smaller/more compact than the 79-80, and should be used in conjuction with the matching flywheel, but the rotor weight is the same for 79-82.

That is correct.

I need to take some pictures... To see if I can just change the flywheel without changing counterweights...

I am not sure which year I have...

Thanks for the link. This made it very easy to identify my flywheels. I purchased a rebuilt 12A engine on eBay last year for my 1985 GSL project. To my surprise the flywheel is from a 81-82 (215mm). The picture looked the same and has the "21" stamped on the engine side of the flywheel. The brand new clutch I purchased will not work because it's from a 84-85 12A (225mm). Since I can't change the flywheel without changing the counterweight, it is much easier to just buy a new clutch. Plus, I like the idea of having a lighter flywheel.

Will the 84-85 12A (225mm) clutch work on a 1985 GSL-SE 13B? I need to transplant a 1984 13B in my 1977 REPU this summer and I hate to see the new clutch go to waist.

Also, will the 84-85 starter work with the 81-82 flywheel?

Good thread.

Yep. 83-88(N/A) all use the same clutch.

You wouldn't want to swap the 85 flywheel on the 81-82 engine anyways. Rotor weight is different, and it would unbalance the engine.