Anyone have a problem getting a old KB Top Fuel crankshaft 4.500 long stroke with full counterweights and stock Mopar rod journal sizes to neutral balance with a set of 7.100 long H beam steel rods with a set of domed 440 pistons?
I am, dang it

Prolly got to add Mallory. They run a small bore and alum rods. Fit the flange at the same time.

I just run a 440source 😁

Both my Molnar 4.500" balanced with steel Molnar rod. No mallory.
Doug

What type of balancer are you using.

I ordered a ATI 440 external balancer per their request several months back, they said that they needed that balancer to be able to finish the balancing on the crankshaft, NOT SO
I ordered a 440 Source forge steel non center counterweight crank 4.500 stroke with BB Chevy 2.200 rod journals today to be drop ship to the machine shop here in Oregon. I 'm hoping that will work okay

Going from heavy parts, ie hemi junk, to light weight parts is almost always a remove. No heavy metal, probably want to lathe turn it to get a lot of mass off. S/F...Ken M

They said yesterday that they needed to add 12 ounces to it, 6 ounces on each end. It has a bunch of Mallory metal in it already..
I'll weigh the steel H beam rods when they return all the parts and then weigh some Carrillo aluminum rods I have on the shelf and see how weight difference there is between the two and go from there.
I'll, hopefully, use that cranks and rods on another build later once I figure out how to use it without having to spend a bunch more money on it to use that crank and rods

That doesn't make any sense to me. What is the bob weight of the current parts going into it? 12 oz, ie 12x28gm add? That's preposterous. With heavy metal already in the crank? Not adding up? S/F....Ken M

Hemi bore on a fuel car is 4.187 or so. Cab is prolly building a 4.5 bore for what he's wanting to do. .

Yes, but those stupid hemi pistons weigh 800+ gms, even if they're flattops for 8:1 compression and they generally used pin buttons, which are heavy as hell. The aluminum rods should weight less than steel, except they're generally giant barbel shaped rods from BME, so no significant difference than conventional steel rods. I haven't done any 426 type fuel engines, but I've done some 417 front engine stuff, and it's not light at all. A 426 fuel engine, I'd bet the bobweight is over 2800gms, no where near what a wedge is going to be. S/F....Ken M

^^^^This^^^^ I have done a few old fuel cranks, the last one was a center counterweight and I had to remove 512 grams, it made me sick to drill into the heavy metal. I can't imagine adding weight to a heavy crank.

Do you have the bob weight numbers?


Joe

Sure dont sound right to me, maybe have someone else check it.

x3

I would get a second opinion. Good idea to go with plan B and order a 440 Source crank.

Your correct: up: I'm using aa Icon shelf piston on this KB block B1 headed 572 C.I. motor that I'm building for NOS. These Icon pistons have a raised dome along with heavier wall .990 wrist pins for the NOS so maybe those pistons are heavier than the smaller bore Hemi pistons weighed
I'll try and use that crank and possibly rods on another wedge build later this year

What is the bobweight stamped on the crank? I'd imagine you'll wind-up around 23-2400 grams with the current recip assembly.

Both cranks are at the machine shop, I'm hoping to get both back this month and start mocking up the 572 parts
I'm debating on having a cam reground or use the solid roller cam I bought from Koffels years ago for a N/A B1 motor
I'm planning on spraying it with NOS from 150 hp up to 450 HP