Thread: Crank pulleys/ Harmonic balancers 351W

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Would someone kindly enlighten me on the crank pulley/should I keep the one that came with my 351w and harmonic balancers/do I need one.
I am rebuilding a 351W but the crank pulley is a bit scruffy, should I just get it chromed. Thanks

Yes........ you need it. Yes.......keep the one that came with the motor. I'd do powdercoat rather than chrome.

you can not powder coat the damper as for your pulley should you keep them ? if your not going to run the water pump alt power steer . air pump? what are you doing with the engine ? you can buy new pulleys and very nice hi dollar stuff from CV if you want race pulleys.the stuff is all out there

Sensing that you don't have a large inventory of shop tools (like a bench-mounted motor with a wire wheel on it), go down to AutoZone or Checker or whatever and purchase a wire wheel to mount up in your 1/4" or 3/8" drill motor. I think they have a 2" and a 3" diameter wheel. Wire brush all the crud off the pulley and give it a fresh coat of gloss black paint.

If they have an eccentric weight of some kind either cast into them or bolted on, then they are called a balancer/damper. If there is no eccentric weight on them, then they are correctly called a damper. Their function is to dampen harmonics that are set up in the crankshaft when the piston fires and sends a shock down through the rod to the crank. If these little vibrations, or harmonics, are not cancelled in some way, they will crack the crankshaft and the game is over.

There are 3 parts to them. The inner hub that press fits onto the snout of the crank, the elastomeric material in the middle and the outer inertia ring. In the presence of ozone from the atmosphere, oil, grease and other contaminants, the integrity of the elastomeric material can degrade to the point that the inertia ring can slip circumferentially in relation to the hub. This will render the damper incapable of showing a valid top dead center location on the inertia ring, so the motor can no longer be timed with a light. You must either rebuild or replace the damper at that point or bolt on one of those covers that the aftermarket makes that is degreed in relation to the hub. A bolt-on cover still does not fix the slippage problem, but it will allow you to time the motor with a light.

These guys do a fine job of rebuilding OEM dampers....
http://www.damperdoctor.com/

Thanks guys,forgot to tell you I am in the UK but have access to an engineering workshop, will just PC the original pulley.

Use it as a door stop.

Yes, you can get them rebuilt, but it isn't an obsolete item and places like Summit or Jegs will ship internationally.

There are a couple things that happen to them.

First and worst, the elastometric material will degrade allowing it to move in relationship to the keyway, making timing impossible to set. It can also fracture once it starts wobbling.

Secondly, the timing housing seal will wear a groove in the snout. There are inexpensive repair bushings that can be glued on, but again, why chance it with the other potential problem. I would suggest that you replace it with an SFI certified piece if you are going to turn high rpm's, if it's a grocery getter, then almost any vendor's piece will be fine