Harmonic Balancer Weight

This isn't a studid question at all.
The short of it is that there are two Ford SB dampeners.
A Cleveland should use what is called a 28.2oz balancer.
The other balancer is a "50oz" and it is used on the 5.0 (or 302) engines of the 82 year and up.
Things to note: 1)The Boss 351, the real one has a factory balance weight of 27.3oz. If you bolt a real Boss 351 dampener onto your 4v or CJ, it is slightly out of balance. 2)engine balance technicians work where no one watches them and no one understands what they are doing. They take the easy way out and when they balance your reciprocating assembly remove the weight from the dampener and the flywheel rather then leave them alone and remove it from the crankshaft like they are supposed to do.
The reason is that it is a lot easier to do that way.
In my experience, good balance jobs don't even show up until you are somewhere over 7000 rpms. Many racers say 8000 rpms. The balance guys know this.
The problem they cause is that once they balance your assembly for you, you can't change the balancer (harmonic dampener) and flywheel without being out.
The dampener is not usually the cause of a major imbalance in the engine. The flywheel would cause more noticable harmonic variation. Particularly if one changed to an aluminum flywheel and went to a light weight clutch cover assembly (predominatently aluminum as well).
My suggestion would be to look at the dampener you have. They are actually two part.
If the rubber that seperates the outer half ring from the inner hub has no voids and it is not crumbling and falling out with voids in it, put it back in.
Cleveland dampeners with factory balance will usually have one or two 3/8" diameter drill holes in the face of the outer ring.
If you have a bunch more holes (like a dozen or so) it is likely that the engine has been rebalanced.
Also, the largest reason for the engine to be out of balance would be changing the pistons. The variation in the weight of replacement pistons these days is considerable.
If you "rebuild" an engine and change the pistons, specify that the reciprocating assembly be "sent out" for rebalance, and that the flywheel and the dampener be left alone. Sometimes the balance guy will threaten you with the cost of using Mallory metal, and that it is extra (and expensive). I would suggest the you authorize that. It will never come back that way but the crank likely will look swiss-cheezed on the balance weights.

quote:

Originally posted by Joules5:
Well I've got one of those "There's no such thing as a stupid question, just stupid people" type questions...

The only stupid question is the one never asked.

Doug, great answer.

Julian, old harmonic balancers have a way of coming apart. There is a company, damper dudes, that will rebiuld your balancer for about $70 plus shipping and handling:

Damper Dudes
6180 Parallel Road
Anderson, CA 96007
voice:530-365-2144
FAX:530-365-2251

Your friend on the DTBB

I gotta put these guys in my little black book.