When building up a block with new rods and pistons, does the motor need to be balanced by a shop? I've noticed some people who installed the parts themselves, don't mention ever getting it balanced. Anyone know?

 

balancing becomes more critical with applications that have higher cylinder pressures from what I understand. I am sure the majority of people wouldnt do this due to the time and money it would take to accomplish.

 

Thanks. The main reason I was asking is because a friend of mine is building his B18B up w/ 12.5:1 pistons and i think crower rods. He just spent a sh!tload of money having a shop build and balance his motor, when I know we could have installed the parts ourselves. I guess the money is well spent if you can afford it, but don't know how much better noticeable performance there would be.

 

balancing an engine is worthwhile, mostly if you rev high. I read an article that stated that a balanced engine can last 50% more than a normal engine cuz there is no vibrations that can eat the bearings as well as the seals. I would do it without thinking if i have the money.
you would feel it at high RPMS which i'm quite sure he will see.