Back in May, EngineLabs Magazine asked readers to send in questions for SCAT Crankshafts’ very own, Tom Lieb. Now, he’s answered 10 questions related to all things crankshafts, connecting rods and pistons.
Check out one of the questions and answers:
I installed a Scat 383 internally balanced forged stroker kit in a first-gen SBC 350 four-bolt main block a while back. Sometime later, I was told by a keyboard cowboy on one of the car forums that the Scat crank required the use of a specific harmonic balancer which I was not using. My engine builder never said anything and I’m curious if there is in fact any problem running a Fluidamper harmonic balancer with a Scat 383 forged crank. If so, what is the preferred balancer?
– Steve Hayes
Tom Lieb: Steve, SCAT cranks do not require a specific harmonic balancer. Like all cranks they require a balancer that is properly designed for a performance engine. 90-percent of crank breakage in the front half of the engine is due to a balancer that is too large in diameter, too heavy, has moving parts, and cannot be balanced with the crankshaft. Moving parts include both fluid and mechanical pieces. These dampers cannot react fast enough to rapid acceleration and deceleration. Therefore, they create harmonics that will eventually fatigue a crank and break it. These dampers were designed for industrial applications that run constant speed in narrow RPM ranges. So, that being said, the smallest diameter, lightest weight, and an elastomer design is best.
Read the questions and his answers, here.