gMAG

iTrader: (1)

I purchased a used crank from ebay. Upon receipt, I found that the end of the crank has a approx 1" long x 1/8" deep drill bit hole, where the balancer was. The drilling begins at the end/outside of the crank, and proceeds inward toward #1.
It looks like this was done to relieve a balancer, to remove it.
My question is...should I fill this 'groove' with some lead? Or, does it matter, being that the missing material is located close to the center of the rotating assy?
Opinions, please.

Atomic

iTrader: (37)

Is it on the outside edge of the crank snout? It may have been there for someone to pin the crank.

mark21742

Sounds like a pin slot for the balancer/ pulley.... Maybe someone was running a supercharger with it?

gMAG

iTrader: (1)

The drill mark is neither straight, even, or equal depth.

mark21742

I think is leave it, maybe even clean it up and use it for a pin groove

The Alchemist

iTrader: (19)

That looks like someone pinned it and the fixture moved on them. I've seen that firsthand before.

gMAG

iTrader: (1)

Maybe I should drill three more...at 90deg intervals. Kind of a rebalancing.

The Alchemist

iTrader: (19)

I don't know if you would be able to see that weight difference balancing it. It's so close to the center line, and now much weight could it have been, a few grams maybe? What it looks like is they drilled it the first time, and the pin was too small, so they stepped up to a larger pin to match up with a keyway in the pulley. That's my guess.

gMAG

iTrader: (1)

^^Perhaps you & Mark are correct. The missing metal pretty much hugs the centerline. Maybe my concern is overstated.
It would be easy enough to spread some softened lead into that groove, though.

RonSSNova

iTrader: (3)

It is typically done for centri supercharged cars.
Popular in the Vette world.

Personally I think it's a dumb *** way to do it. But it is done w/o removing the balancer.
Take it apart once, you won't get it lined back up perfectly.

In your application, I think you can leave it be. I don't think lead would do any good except to make it look better.

It could have been welded and remachined while the crank was out.

618HAWK

iTrader: (361)

Another option provided the current width of the area in question, is not too wide. I would to take it to a machine shop and see if they can cut it to the end for a square key way, cleaning that area up.
Most all aftermarket balancers are keyed were the stock units are not.
Then if you ever decide to go FI you will be ahead of the game. Nor would you have to worry about a balancer spinning on the crank. Not that it is a common problem.

mark21742

A few times I have seen hard high rpm shifts start sinning the pulley and back the bolt out....rare but it does happen from time to time