GTII

I was wondering if it is a big problem to balance a stock LS7 crank, if one were to use a 4340 billet rod instead of the factory Titanium rod. I tried the best I could to get a bobweight for the factory recipricating assembly. I came up with a bobweight @ 1554 grams.
Piston 482
pin 132
rings (est.) 42
locks (est) 4
Small end, rod 136
Rod bearings (est) 45
Large end, rod 328
oil 6

The assembly I would like to use came out to a bobweight @ 1856 grams

My question is weather or not this crankshaft would have been designed for a lighter mass or is it like any other crankshaft that just has weight added or removed in order to be balanced? Some have suggested starting out with an aftermarket crankshaft which may have heavier counterweights to start with..... any thoughts?

Shawn @ VA Speed

iTrader: (3)

i've done a couple of them-takes alot of mallory to balance out correctly.I would just buy an aftermarket crank and be done with it,makes a nicer job

GTII

Thanks for the info shawn. I spoke with callies today to look into a dragonslayer crankshaft for a LS7. They told me that when they balance their cranks with the kind of bobweight I mentioned, they typically use between 5 to 6 slugs. The reason being that the forging they use is based on a GM LS7 crankshaft to begin with. I will look into some other aftermarket companies and see what I come up with.