Assassin

iTrader: (3)

this is about getting a stock crank balanced, now, if the cranks is balanced, and all the rods and pistons weigh the same(digital scale), would that be the definition of a balanced bottom end, there is nowhere around here that I can get the entire thing balanced but I might be able to send the crank out, and also, if all the main bearings are looking good, would it be worth the $$ to have it shiped out and balanced or could it be trusted? anybody have experience with this yet?, I want to use the stock crank and get forged pistons and rods, waiting on money to decide if I'm going high compression or low compression w/booooooooooost!


Thanks

Inspector12

iTrader: (29)

well if you haven't bought your pistons and rods yet you can buy pre balanced rotating assemblies. That is good enough for most people. I like to personaly have the crank rods and pistons balanced by a local shop that I trust and has a good reputation. Who's to say which is better. I just think (My Opinion) that you get a more accurate balance with all of it done buy the same shop ETC... No facts on that It is just what I do when building my motors. Hey good luck I am sure any way you go will be fine. I am sure some people who have done buildups will chime in with there thoughts.

Old SStroker

To have the crank balanced bob-weights are attached to the crankthrows. The weight is calculated from the weights of the pistons, rod, pins, locks, bolts and nuts, bearings, rings and a little oil. Most balance shops will want those parts along with the crank so they can calculate the correct bob-weight.

If you match the weights of the parts yourself, make sure all the big ends of the rods weigh the same and all the small ends weigh the same. There are simple, but very accurate fixtures for this. Comp Cams sells one.

If you are reusing the crank, are you considering having it ground .010 under? I would strongly suggest all new bearings, and probably the regrind. Shipping isn't all that expensive. You could send things to a shop that specializes in cranks. They often include balancing if you wish.

Insector12 made good points. I agree. How about the shop that will be boring and honing your block? Do they balance? Remember, they need the pistons to determine final bore size and the ring manufacturers recommendation for surface finish on the bores.

My $.02