The 153 only had hub, a pulley, and maybe a rubber pad between them. The 181 had it's own dampener. I bought a new 181 unit when I got my 181 crank. It'll work for my milder build. The fours don't have the same harmonic issues as the longer six. They are going to be be rougher no matter.
Right!! I put a later model balancer from a six cylinder on Lockjaw when I first put the car together. Right now, the engine is mounted solid to a mid plate and bolted directly to the frame. No rubber mounts! I'm considering isolating it on rubber mounts when I go back together with it.
The natural vibration from the four cylinder was expected, but now that I have the parts and the opportunity, I figure I can cut down on the perceived vibration.
The balance work, the longer rods, a BETTER harmonic balancer, and rubber mounts SHOULD achieve this goal.
