Wanted: Free Chevy harmonic balancers

[TheSilverBuick]

For some testing work on the OHC Pontiac engine I want to see if any aftermarket SBC balancer might work for it, but first should see if a stock balancer would work.

Anyone have a stock Small Block Chevy harmonic balancer collecting dust and willing to give away? I'll cover shipping in a flat rate USPS box. Pulleys with it would be a bonus.

I'd be interested in ones with a serpentine belt setup as well as V belt. I'd be interested in a 4.3L V6 one as well if they have the same crank snout diameter as the SBC.

[82z]

I should have something laying around.does it matter if it's for a 400?

[TheSilverBuick]

I don't think it does. I'm not a chevy expert by any means, but from looking at aftermarket balancers they seem to cover 305-400's fairly commonly, so would assume the crank snout diameter (the important part for my purposes) would be the same.

[68scott385]

What about a diameter preference?


400bsc balancer is offset weighted for external balance

[TheSilverBuick]

And it can be pretty beat/worn. I don't think diameter is as important, but I should probably measure mine to not be any bigger than "x". My end game is to see if I can find one that I can make the alternator/water pump belt system work, then get an aftermarket equivalent.

[Beagle]

They're kind of all over the map for sizes (Width and diameter) Randal, and a 400 wasn't internally balanced IIRC. I may have a 350 low performance unit in the garage, is there a measurement you are looking for though?

[TheSilverBuick]

I'll have to follow up with some measurements when I get home. Since I am only running a single belt, I just have to get the waterpump and alternator shimmed right to line up the belts.

Any of these balancers I recieve will never actually be on a running engine, just mock up purposes.

[Beagle]

lemme go check....

[Beagle]

Only orange part I can find at the moment is a long water pump. I'll keep an eye out for it.

[Aircooled]

I would be hesitant to use an torsional dampener designed for 4 pulses/revolution on an engine that generates 3 pulses/rev.

[TheSilverBuick]

I'm hoping to find an appropriate fluid dampener, but will work from there.

[Beagle]

I'm unclear on how a zero balance damper would know if it was on a 6 cyl or an 8cyl?

TSB, are you looking for the pulley stack information? I think there were a couple of widths on the SBC stuff too? Sorry, I'm not getting the picture. I old and stoopid today. I'll keep looking regardless. I need to get all the orange parts into an orange pile at location X anyway.

[TheSilverBuick]

Yup, primarily looking for how the various pulleys line up. Hence a v-belt or serpentine. As long as I can work out it not hitting the water pump pulley I am good there. From what I've seen a BBC waterpump pulley will bolt onto the OHC water pump for a serpentine belt conversion. Right now though I have zero chevy balancers to even start with a reference point of I need the belts to be X distance from the back of the balancer, etc.

Balancers for SBC are far commoner than the OHC, which are getting rarer and lack mass for higher harmonic dampening. A V8 one I'd expect to have more mass from more pulses, and aftermarket ones for more RPM. I would be going for a zero balance dampener eventually. The OHC guys are too hung up on originality to do any other real R&D on this. I've stuck the OHC balancer on a 292 crank with no problem and from what I gather the 292 has the same crank snout size as the SBC. So A=B, and B=C, so in theory A=C here. Ideally I want to use a fluid dampener that isn't tuned to any particular harmonic, just absorbs them, but again I don't have a baseline from a stock dampener to say if it would work or not pulley wise.

[Bamfster]

I'll look up in the attic for you tomorrow, and if I have one you can take it with you this weekend.

[TheSilverBuick]

Sweet!