I've talked with a couple of machine shops concerning balancing my assembly. What confuses me is that some of them want to balance the assembly with the flywheel an balancer that's going to be used, others don't require the flywheel/flexplate or balancer. Intuitively it seems to me that balancing the whole assembly with the flywheel and balance attached would be best, as long as the adjustments were made by adding, removing material from the crankshaft. Two different machinists have told me to be leary of machine shops that would balance LT1 rotating assemblies without asking for the flywheel/flexplate and balancer.

I'm a little confused.

 

Those shops wouldn't need a flywheel or balancer because they would neutrally balance the assembly. This is how it would come if you ordered Eagles rotating assembly pre balanced- neutral. Then just add a stock or aftermarket balancer in the front (which comes neutrally balanced) and a neutrally balanced flywheel.

Apparently, some crankshafts are much easier to balance also due to the design. I think Callies is one of them. If I remember correctly, the Eagles are harder to balance than most. Scat also makes some pretty good cranks, and some of them come neutrally balanced if the matching rods and pistons are used.

Anyway, take your time on this and get it right. The guy who did my engine didn't know what the **** he was doing. He drilled holes in the front balancer, crankshaft, and flywheel. I think he should have added weight to the crank, not take out any. I've had a vibe in the 3800-4200 rpm range ever since I sparked the motor up 4 years ago and it hasn't gone away. After 4200, the vibe disappears and rev's okay.

 

Balancing is obviously very important in many ways...bearings, crank, performance in general...but for the piston question. I had some SRP pistons, they are PN 138103. 16cc dish, will run 10.4:1 on 58cc head. It'll run.