Balancing Callies Comet Crankshafts

Trying to balance a 43# Callies Compstar crank on a new build and we have determined it's just not possible. Where the bobs are there is no material left on the counterweights to add Mallory/Tungsten where it's needed. On the other side we can barely find room to drill. My machine shop is a lot sharper on balancing than I am but a friend using the same crank works for one of the top Sprint engine builders on the west coast and he said his boss said it was a nightmare to balance on my friend's car.

Have had standard weight Callies and, last year, a special made 36# crank and none had this problem. It seems like the counter weight machine work is the problem and wondering if any of you have run into this with them or if it's just bad luck us getting 2 problematic cranks.

I have had to make a counter weight to bolt behind the fly wheel before , dont like it but it worked...

After talks with a couple of very helpful Callies tech guys and being told that after about 1700 bobweight they could be problematic to balance and pretty time consuming and expensive to achieve I decided our 1799 weight wasn't practical so I'm going back to a standard weight crank.
The decision to stay away from the flyweight parts on this build wasn't hard as the super light stuff generally just doesn't seem to last as long in my experience.
The 43# crank will go on the shelf for another day along with the other parts accumulated over the years.

Can you add weight on the face of the c/w instead of the edge?

Suppose about anything is possible if the wallet is fat enough but like the old song says "you've got to know when to hold 'em, know when to fold 'em."

1800 grm bob weights , what rod and piston you using ?

Racetec 2618 4.130 flattops and Lunati Voodoo 6" H-beams. I've used the Racetecs a lot and never had a problem. Never used the Lunatis before but didn't think they were bricks. Guess I was wrong there.

yep , those lunatis are heavy , I pulled one of my customers spec sheet using 4.125 wisco,s and 6" dyers and the bob weights were right at 1600.....

Did a little looking and came up with a 675 g weight for the 6" Voodoo. Good grief, a long ways from my usual Scats, , Howard's and Compstars. The machinist I use regularly said he used the Lunati stuff quite a bit and liked them. So much for his recommendation. If I didn't have the standard weight crank on the way I'd probably put the piggy rods on the shelf.

Guess I'll try to use this build more on the momentum tracks we run...or put the HD brakes on . Thanks for your input FF.