Old Topic: Counter Weights
 

I know these questions have bounced round before but I can't find the answers I need in the archives. So if you do not mind.....

I am reassembling the engine for my SA22. I have heard that exchanging the 30 pound flywheel for a lighter FW from a later 12a can gput a little more spring in its step.

I sourced a 26 pound FW from an 84-85 12a (verified based on Mazdatrix FAQ page) but the guy is only 90% positive that the front counter weight is correct. I'd prefer to be 100% before putting the engine back in the car.

The counter weight is much smaller and shaped differently than the stock CW for my car. But, I cannot find any distinguishing marks or stamps on the thing and Mazdatrix FAQs do not describe the the CWs.

Can someone tell me how to tell if I have the correct CW?

Thanks,

Herb

you might want to post a photo of it. Jeff20B is pretty good at ID-ing counterweight on sight and he just may find this thread.


on an FYI note: why did you post this in the Build section?

The flywheel you got is wrong. Sorry to crap in your cocoa puffs. :)

Post some pictures. If you have the right front counterweight I should be able to tell you. And look for a 23 pound 81-82 flywheel. Look here again to see what it looks like. Flywheels

What is "wrong" with the 84-85 flywheel?

Will post pics when I get home.

Apparently the 84/85 flywheel and counterweight don't balance with the slightly heavier SA22 rotors, so you can't combine SA rotors with the later 26 lb FB flywheels.

However the even lighter early 81/82 FB flywheel (23 lbs) and counterweight do balance with the heavier SA rotors, which I guess were still being used until 1982.

For reference, here's what the 23 lb 81/82 flywheel and counter weight look like

Attachment 685895

And here's the heavier 30 lb SA flywheel and weight

Attachment 685896

And here's the 26 lb 84/84 flywheel and weight (also used in 83)

Attachment 685897