im building my new engine. I have a low mileage stock-style balancer/dampner I can use...or I can fork out $180 for an SFI approved balancer/dampner. What the heck is the difference and does it warrant the extra cost?
I spoke to a guy at the SEMA convention one year who worked for Albert & Childs, the rod manufacturing guys, and he said they really aren't worth the money. He also indicated that they can cause problems by masking imbalances and creating weird harmonics.
All in all, I think the stockers work just fine, regardless.
I've heard that the fluid balancers can leak, but don't know personally.
I've seen 2 stock balancers come apart at high RPM at the track--not pretty.
Whichever balancer you use, be sure to give it to the machinist doing the balancing of the lower rotating assy, also the flywheel.
The SFI balancer is certified for a certain RPM not to come apart. Some NHRA classes require this written certification and require proof. It is not a two piece balancer like your stock OEM unit. It will not slip on the rubber isolator or come off during high RPM's. If you are going to run on the track a lot I would spend the extra $$$$.