Another harmonic balancer question

What is the purpose of these holes? I see some balancers with two & others with four.

 

Dynamic balance.

 

I see. So if I receive one that has two holes & in the pic online it has four, that is because this particular one needed less? Or should it be uniform across the board for each manufacturer?

 

Yes, the harmonic balancer with fewer holes required less material to be removed to keep it in balance.

Simple enough explanation if you are curious...

https://help.summitracing.com/knowl...d engine has,affect the other rotating parts.

 

Thank you!

 

We are lucky our crankshafts can be balanced as a single unit. I once had an engine where the pulley and balancer were separate parts. The balancing was done on the crankshaft at the factory. Those crankshaft pulleys did not use a rubber damper. However, if someone lost the balancer, it could be replaced, but the engine was never quite right again. The balancer and pulley required marking to keep the position if it needed to be removed and reinstalled to replace an oil seal.