Crankshaft Balance Q's

mn12sc35th

Registered User
How well balanced is the stock crank? I'm looking at using a zero balance flywheel, balancer, and crank pulley as well as a new set of 94 Pistons/rods that are balanced to with in +/- 1 gram. Should I take the crank to a machinist for closer balancing or should it be fine stock?
 
It is close stock but not as well as custom balanced by hand. If you're concerned enough where close isn't good enough go ahead and have a good machinest balance the assembly, cranks get balanced to the rest of the parts not by themselves. You should take all of the rotating and reciprocal parts along to have the assembly balanced.

Vernon
 
Is it close enough stock to need rebalancing? How much would it cost to have it balanced? I just don't want to worry about the bottom end. I want to make sure it's done right so I don't have to be back in it. If it's balanced enough stock to run the setup I'm looking at, I probably won't balance it. The only reason for the pistons is that I got a great deal (brand new balanced to +/-1 gram 94 Pistons/Rod/Total Seal rings/rod bearings for 400$) I need a new balancer and want an aluminum fly while while its out. Thanks for the info.
 
Well, whether or not it's close enough is a matter of opinion. Most vehicles aren't that close and nobody cares. But without the extra step who knows. By the way you are going about it and the concerns you express I say do it and put yourself at ease. You should be able to have it done for around $150. Do it once, do it right.

Vernon
 
I just don't totally understand what I'm getting myself into sometimes. I don't want to over look something minor and have to tear it down again later. Thanks for the info. I think that's probably what I'll end up doing. Plus I figure it can only make it run better. Thanks again.
 
balance it, the balance is crappy, costs about 200US/300cnd, make sure you have a good(rubber ring not cracked etc etc) damper to begin with, and toss that heavy stock damper pulley and buy an ASP unit, trust me;) . Your balancer exploding worries due to the added weight and bad balancing will be long gone like so many people have to deal with:D

Lots of weight on the damper(due to steel crank pulley) and bad internal engine balance(obviously cause damper stress) cause the stock damper to destruct:D
 
I was looking at an ASP pulley set, and a new balancer anyway. I kind of figured I should go ahead and balance it seeing as how everything else is already balanced.
 
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