Thread: harmonic balancer installation

Tweet

I don’t know about other than SBC, but I do know that the correct way to install a harmonic damper on a SBC is to coat the crank snout and the inside of the harmonic balancer with anti-seize compound and press the damper into place with a proper installation tool.

Some people think that the woodruff key is supposed to keep the harmonic damper in place on the crankshaft snout. This is not the case as it is much to small to take the stress imposed by a crank turning at thousands of RPMS that is being hammered by multiple explosions. The key’s only purpose is to position the damper correctly during installation - it is the press fit between the damper inside diameter (ID) and crankshaft outside diameter (OD) and a grade 8 bolt properly torqued, that prevents the damper from spinning on the crank. The ID of a damper should not be honed nor the crank snout relieved to provide a slide on fit. [I concur with IC2 on light dressing of nicks and burrs] If a tight fit is not achieved, a damper's effectiveness is minimized because it does not maintain firm contact with the crankshaft and even a slight wobble can be disastrous.

I have one similar to this, at NAPA for about $45-50. It's worth it if you're going to build more than a few motors. Most NAPA store will rent one for less than ten bucks.