The shop that does my balancing called today and said my new cast steel (namebrand) crank for my 496 is too far off to balance(off 300grams on both ends). I have all the correct suggested parts for the rotating assembly and the bob weights add up within what the manufacturer says the crank should balance with.

Has anyone on here run into a "bad" new crank before that could not be balanced?

Let me guess, Scat or Eagle?

kamero,
Have seen it plenty of times with the "inexpensive" crankshafts. Call the crank manufacturer and make them replace it. I have seen them boxed wrong, and marked wrong. If it is supposed to be internal balance, it may actually be an external balance crank in the box. Etc Etc Etc. You get what you pay for :rolleyes:

my buddie just went through it with a good deal he thought he got off ebay it did ballance out though after 300 dallars of mallory metal.i would send it back

We took the crank over to another balance machine this week and had the same results, a little over 300 grams needed on both ends counter weights. We called the manufacturer and they said the target bob weights are 2400. Mine bobs in at 2422, so it is within reason. The catch is, I bought this crank almost two years ago and I have one of the first ones they built like it. They are taking it back and sending a replacement. But they never admitted to having any problems with any other cranks like mine. I guess we will see.

I've got a factory reground 10/10 Eagle 4340 crank awaiting my 468 build, should I be worried?

badbob i dont know if i would be woried or not but it might be a good idea to have it checked just for insurence if the crank has not been balanced already

OK, the new crank came in last week. It has the exact same part number(stamped on the front counterweight) as the old one, but it is a different looking casting. The counter weights are much larger and the rear flange is counterweighted also.

On the balance machine the new crank was within a couple of grams on one end and needed a little heavy metal on the other, but it balanced with no problems.

I just got the rotating assembly finished and should have the engine in the car by tomorrow for a test fit of the headers before coating them.

Sure am looking forward to seeing how this 496 pulls compaired to the 406 its replacing

Don't 267, 305 and 350 SB cranks and 396 and 427 BB cranks differ by counterweight thickness on the big counterweights due to the pistons being different sized and weighted??

Therefore if you try to use a smaller bored motor's crank in a bigger bored motor, even though it will fit fine, it still won't balance the same OR as easily...

pdq67

what brand and part was the crank so i can stay clear