Does any one know approx. how many grams are needed to internal balance a cast 440 crankshaft? Thanks

Think you'd need to be more specific about rod & piston combo for anyone to take a shot at that one.

Every situation is different, but back in the day when 451s were the engine of choice, I remember a board member who put together a cast crank 451 that was internally balanced by using lightweight rods and pistons. I would guess that if one took 200 grams off each piston/rod, it'd probably internally balance without Mallory metal (sintered tungsten).

R.

Most 451's are probably forged cranks.

DIDN'T I say CAST CRANK?

I am talking about a very specific build, not generalizing. The build used the 440 cast crank with the mains turned down, and left the counterweights as they were originally. He had to do some grinding in the block to clear the counterweights, but it wasn't a lot. He was able to get the bobweight down to the point where it internally balanced.

Using a forged crank for a 451 the counterweights are usually turned down to fit in the block without grinding, and everything balances without Mallory.
This can all be done because the MOPAR pistons are so incredibly heavy. Also the rods are on the chubby side. Replace with lighter aftermarket parts and it works out.

R.

Missed the "cast crank" part bud. Sorry to ruffle your feathers...

Sorry, I am feeling a little tense today.

R.

I built a cast crank 451 in 2006 and it had 440 source H beams and Ross pistons and I didnt turn down the counterweights on the crank, I ground the block for clearance. It internal balanced very easily with no mallory metal. The engine is still running fine today in my Challenger.

The info i have (gleaned from moparts mostly) is that a 440 cast crank and a forged crank weigh the same (69 lbs), I would like some more accurate info on that, also according to info posts around the traps a 400 cast crank is 2 lb lighter than a forged 383, 64 vs 66.

If you used 440 source rods on some under 600g pistons the target bobweight would be around 400g (and more) less than a stock 440, which i would like to hope would balance without extra metal

With stock weight components? I don't need exact numbers just a ball park from anyone that has balanced one or had it done.

or to ask this question in reverse form, what is amount of the offset weight on the damper and flexplate?

That's the answer to the question. How much weight and how far from center is it placed? I think it's worth having heavy metal added.
This doesn't help, but the balancer for six pack engines has a 6.5 oz imbalance.

It's actually oz-inch. The old Chassis book had all those numbers and they're probably in the Tech Archives.

R.

I am trying to use cast cranks for street engine with out using weighted balancers or flex plates.

You should be able to get a cast crank 440 to balance internally as long as you use lighter weight forged pistons. Aftermarket rods would also help the situation. I think the cast crank will balance at about 2500 gram bobweight but it has been a few years since I did this exercise.