Well after looking and reading some articles on the LS1, I am wondering how the flywheels are balanced. The concenus is that when you switch to a Hayes, SLP, Fidanza or another brand of flywheel you need to transfer the counterweights on the edges of the factory flywheel to the new flywheel. Is the flywheel 0 balanced from the factory and the counterweights balanced it in respect to the crank? Flywheels are kinda like wheels/tire combos you can't just reference the wheel and tire and add the same weight to balance the combo to another identical set. Can anyone shed some light?
Phillip :confused:

 

I think the clutch and flywheel are balanced together. So you cannot break them up.

 

I think everything comes separately nuetrally balanced.
But whatever the flywheel hooks to on the engine.. whatever that piece is called may have some weights or not.

Actually, balancing the engine to the flywheel from the factory... I think you need to watch your flywheel for weights. If replacing the flywheel, you are supposed to transfer them to the same location on the new one.

 

By that statement the flywheel would be 0 balanced and the weights would balance the rotating assembly(crank and flywheel) correctly.
Phillip

 

i am dealing with a similar issue with the the new motor going into my car. what i have learned (someone correct me if i'm wrong), the stock flywheel is a 0 balance, then ballasted upon install onto the stock motor since the stock motor is not itself internally balanced. This is why when you go to a new flywheel on a stock motor, you must place the ballasts/weights in the same spots as the old in order to maintain an 'externally balanced' reciprocating assy. This would assume the new flywheel you purchased aftermarket is 0 balanced (should be). My issue is that i will have an 'internally balanced' motor, therefore, will send my flywheel out to have 0 balanced (essentially, ballasts removed). hope this helps!!

 

1. Mark the bolt locations of the assembly in the car - i.e., mark the relationship of the pressure plate to the flywheel and the relationship of flywheel to the crankshaft.

2. Take the old assembly (flywheel and pressure plate) to a balance shop and have the new assemblies balanced to match the old.

3. Re-assemble the new flywheel / pressure plate exactly in the same relationship to the crank as the old.


[Modified by Paradigm, 9:34 PM 9/1/2002]

 

That is exactly what I was thinking. When you think about it that is the only possible answer. I guess we just need some hard answers that the LS1 motor is externally balanced on the flywheel.
Phillip

 

I've got a related question: how do you balance the flywheel / clutch / engine on a stock factory setup? I've got a 2002 Z06, and there is harmonic vibration at 1600, 3200, etc. What is the procedure to find out which element is out of balance?

SportsCars

 

If you don't get this right, you will have an expensive nightmare on your hands. I had a new clutch installed in my 2000 Coupe and from then until I traded it in, I had a car that was unpleasant to drive to put it mildly.

The LS1/LS6 engine is "externally balanced". There may or may not be weights in both the flywheel and the harmonic balancer to achieve this balance.

When you purchase a new clutch from GM, you get a flywheel, pressure plate, and disc as an assembly. This assembly is supposed to be "neutral balanced". There is a extra hole in the flywheel near the holes for the crankshaft bolts. There is also a hole in the crankshaft. In the past, these holes were always lined up assuring proper balance, etc. However, on the LS1/LS6 this is NOT the case. These holes may be aligned, but more likely, they are not. The crank and flywheel must be marked before the flywheel is removed so that the new flywheel can be installed in the exact same position relative to the extra hole in the crank and the extra hole in the flywheel. If you lose this position, you are screwed.

Next, you must locate the weights installed in the extra holes on the outside edge of the flywheel. There may or may not be a weight or there may be multible weights. Further, there are three sizes of weights. They are a press fit. Remove the weights you find and install them in the new flywheel in the exact same position relative to the extra hole at the crank.

As a precaution, you may want to take your old flywheel assembly and your new flywheel assembly to a machine shop and have them both checked fro neutral balance. If there are differences, have the new one matched to the old one. This assumes, of course, that you had no vibration with the old clutch assembly.

All this is stated in the repair manuels. But who reads them? Damn few dealer mechanics and just as few repair shops or tuners. Since 1955 (265 CID motor), the two holes have been lined up. In some motors there has even been a pin in the hole so that the flywheel could only be put on one way. Now it's different and the mechanics don't even give it a thought. They just put it on the old way.

A local mechanic ignored a detailed discussion about this with the Corvette owner, and installed the clutch the "old" way. There was a bad vibration afterward. When questioned, he said he had installed at least 20 clutches the "old" way and never had a problem. At least no one complained. After mcu complaining and threatening by the owner, GM sent a couple of service techs to install a new clutch. Somehow they got it right. I would assume that they played with weights until it stopped vibrating. Took a couple of days.

Avoid this problem like the plague!

Good luck.