A friend advised me to "match balance" the M6 flywheel with my old A4 flexplate I'm pulling off the motor. I called a local shop and they never heard of something like this. (and neither did I) So what is this, do I really need it and where do I get it done?
Thanks.

 

Its an internet term used only by people who have never actually replaced a flywheel/clutch before. Any shop who took money for this service is dishonest and was just charging extra labor. Usually the story is referring from flywheel to flywheel, but the same concept applies flywheel to flexplate.

The OEM flywheels were never balanced to the specific rotating assembly, so a new flywheel exactly balanced to match the old one may or may not balance the whole assembly better than one that is simply within the factory tolerance.

I saw the same exact advice the first time i did an fbody clutch and was looking for specific installation tips and also questioned the procedure.


-brent

 

If your using a stock LT1 FW I wouldn't worry about match balancing. If you're going with aftermarket FW you should match balance to an OEM FW. True- OEM FW's were never truely balanced, but I know first hand that some aftermarket FW's were not weighted properly. My Street Twin FW almost rattled my teeth out in its delivered form.

Steve

 

Ok, so how/where do you get this done? What type of machine do they use?

As you can guess, i'm skeptical, but willing to listen if you can explain some more. I don't pretend to be a machinist doing this for a living, but noone i've talked to has been able to explain this procedure.

FWIW, my mcleod was seemingly perfect out of the box.



-brent

 

My understanding is that it is done on a crank balancer. The oem FW needs to be bolted on a crank in a crank balancer. Then the add temporary weights to the crank to get it in balance. Then install the new FW. and check balance. Readjust counterweight on the new FW or drill holes in new FW to bring system back into balance. Now the new FW counterweight matches the OEM FW counterweight. I had Nutek do one for me about an eon ago. A good machine shop with a crank balancer should be able to do it and they'll probably have SBC crank laying around somewhere. Now, here's the big disclaimer: I have never personally balanced a crank or even witnessed a crank being balanced so, please if there is anyone else who has better details of this, feel free to correct me.


Brent, Can the Lions "run the table" this year?????

Steve - PSU 1979

 

I guess i'd kind of revert back to the orignal statement that since the factory pieces weren't matched to each other, why use a neutral crank and flywheels at 180 degrees versus just using an lt1 crank which is known to be well within spec.

This practice couldn't hurt, but wouldn't be worth the extra effort/complication since you wouldn't neccesarly end up any better off.

Much like madwolf's experience, i couldn't find anyone who actually knew of the process first hand. too bad someone froma machine shop who actually performs this operation doesn't step in.

Sad to say that I have no confidence in our lions untill i see some results. I was there in 99 for the last mediocre season we had. Some old timer asked me a couple of weeks ago what i thought of the team the day after Blue and White, i chuckled and told him "these days i mostly do my thing in the parking lot". I'm actually leaving in about an hour to go up for my brother's graduation, good times.......

-brent