cw383

iTrader: (6)

Hey all. I dropped my reciprocating assembly off at a machine shop with an excellent reputation in the area. I had them measure my block clearances and crank, bores ect so I can get good accurate numbers while blueprinting my new LDK, They called today and said everything is done, and when I asked about the crankshaft balancing they said it was dead on perfect and required no balancing. I have ZZP H-beam rods and Wiseco pistons, so that had to vary the bob weight. I'm very disappointed. To put it blunt, I dont believe them. Has anyone had balancing done? And if so how much was removed or added?

cw383

iTrader: (6)

Epiphany! Had a chance to just think. If the crank is zero balanced from the factory, and I hear they do a great job, plus with the rods and pistons being a matched set each respectively +/- 1 gram of each other, then I guess in theory, its possible it could be dead on out of the box.

cw383

iTrader: (6)

I was disappointed because I gave them a factory crank with aftermarket rods and pistons, and they said I was good to go with nothing needed. Initially, I was very skeptical of that claim. Was just about ready to go get a 2nd opinion. Traditional wisdom would say the rods and pistons being so different from OEM, of course it would require further balancing. But in thinking, with such tight weight tolerances in the aftermarket rods/pistons, that's really all they need to do is confirm the weight is equalized. The crank is zero balance, unlike a v8 where there's much more at play. I wasn't worried about the weight at all. I think I will be fine. It just shocked at first. Had to think on that one.

63 Nova SS

iTrader: (3)

Only thing I have had balanced were v8's. If they are just balancing rods and Pistons they should be close. Rotational weight is probably different but unless you are spinning to 8k it's probably ok.

TurboWood

It looks like you answered your own question, but I'll just add my support to your conclusion. There is no use for bob weights on a 4-cyl.

Daniel