That is what I have been saying all along:
The holes around the damper were intended to neutral balance the damper after it is bonded together.
Many new dampers that have never been on an engine have weights in those holes, so it is impossible for those weights to have been put there to balance the engine.
Those holes in the damper were never intended to balance the crankshaft -- that doesn't mean someone didn't do it.

So, if you have an engine with weights in the damper and the damper is 100% neutral balanced, and you decide to put a new damper on it, you will want the new damper to be 100% neutral balanced. And, the new damper may or may not have weights in it, but it will be neutral balanced from the factory. Therefore, you would NOT want to put any weights in it to undo the neutral balance -- in other words, the FSM is not correct when it tells you to put weights in the new damper in the same locations as the old.
Since it is easier to put weights in than take them out, I would always try it first.

I am not saying someone (GM or some else) didn't attempt to "trim" the engine by using those holes to balance the engine, but I am saying the presence of weights in those holes does not mean those weights are for engine balance -- you have no way to know.
So, the prudent thing is to assume the weights in the damper, if there are any, are for neutral balancing the damper unless you absolutely know otherwise.

I'd like to think that any engine I have that does not have a keyway in the damper/hub has a 100% neutral balanced damper on it.
That way, since all new dampers (never been on an engine at any time) from the factory are 100% neutral balanced, with or without weights in the holes, any new damper could be put on my engine without regard to pointer location or where #1 TDC is and the engine will be perfectly balanced every time.

Tom Piper

 

I put an LT1 from an automatic into my six speed car, brand new flywheel and have had no issues so far.

http://s68.photobucket.com/albums/i3...t=MOV01066.flv

 

I couldn't post these pics yesterday because photobucket was down.

I didn't check to see how many pins were in my factory dampener.

Something else that I don't think has been mentioned yet is that the factory hubs have been drilled like they where balanced as well. The aftermarket hub I have is solid.

 

Very good photos. Later! Frank

 

When I bought a new dampner from the dealer to send to Carroll Supercharging to be regroved for the blower belt, it did not come with any weights in the holes. The weight was in a bag inside the box to be installed later to match one preexisting on the engine already. When I bought a dampner from Auto Zone last year for my Trans Am, because the outer shell was spinning on the inner shell, it also did not come with the weights installed. It also had instructions inside to put the weight that came in the box with it, in the matching hole of the one coming off the car. The dampner will fit on the hub in only one spot and the hub, as per FSM, is supposed to only go on the crank in one position. These are the reasons I believed the way I did. Sorry for beating this dead horse over and over.

 

Thanks guys,

A trusted mechanic told me recently that it didn't matter where the hub went on as longs the cast on arrows on the hub & damper were re-aligned.
In my case, I aligned & marked the location of the hub arrow to the front cover (exactly 12 o'clock at TDC), so I'll put it back that way.

BTW, this all started with a leaky water pump. Since that came off, might as well do an MSD distributor, coil, plug wires, plugs, front cover seals...

A little problem right now trying to put 8.5 mm wires where the 8 mm ones used to be. Man, the routing's tight !

KLS

 

Hi,

I know this topic has been beat to death. Just wanted to add that on my 1992 while at the track (Pocono road race track) the stock damper/pulley started to seperate and wobble.

I replaced it with an ACP underdriven damper/pulley. ACP stated that when I receive the damper it will be balanced and can go right on.

It has been on for years and raced with no issues at all.

Steven

 

To finally end this discussion, someone should spend a few bucks and give Mr. Killebrew a call.

http://www.gordonkillebrew.com/pages/800741/index.htm

I did this several years ago and he explained all of this.