Originally Posted by 65malibuSS
i have a chevy 350cid, im rebuilding the top end and the balancer i took off is an 8inch, it weighs 12lbs (internal balance i think, i dont see any weights in the balancer). my question is the new one is 6.75 and only weighs 8lbs., ati suggested the balancer to me, but the weight and size thing seems odd to me(it being so different). does the new one sound right? any help would be great, Thanks
It depends on how the engine is used, and what parts make up the reciprocating assembly. If it's going to be run hard and/or raced- unless it's an all-out, drag-only engine- I would use the 8" damper.
Actually, I use the big dampers whenever possible. The 302 Z/28 and the LT-1 SBC used 8" dampers. The externally balanced 400 damper is 8". A small damper might be a good choice for just drag racing or for smaller displacement engines, relatively lower output engines and engines used sedately.
Originally Posted by lg1969
All sbc motors are internally balanced with exception 400sbc.
Well, sort of. The 1-piece RMS engines use an externally balanced flexplate or flywheel, but w/a neutral balance damper. Kind of "half and half".