8" Harmonic Balancer

[Brian Monticello]

I'm converting my NOM 327/300 to the SHP configuration. I know the SHP balancer is 8" in Diameter but what was the thickness? What was the offet angle between the mark and the keyway?

Thanks,
Brian

[Joe L.]

Re: 8" Harmonic Balancer

Brian------

The balancer of which you speak is about 1-3/4" thick +/- 1/16". I've forgotten the angular relationship between the keyway and the timing mark, but for these pre-69 balancers I think that the keyway and timing mark might be aligned. For 69+ balancers there is, as I recall, a 9 degree offset.

In any event, there is only 1 8 inch balancer that will work for your 327 application. That balancer is GM #3817173 and it's still available from GM although it no longer has the "fins" that original PRODUCTION balancers had on the inner surface of the balancer hub.

[Brian Monticello]

Re: 8" Harmonic Balancer

Joe, Thanks for the quick response.

Here's another question and I'm sure some of you will shake your heads while reading this. If I purchase a post-69 balancer, fill the timing mark, and create a new mark (say with a thin dremel cut-off wheel) do I risk upsetting the balance of the harmonic balancer.

Yes, I do realize this is bubba-like. I just want to know if it will work.
brian

[Joe L.]

Re: 8" Harmonic Balancer

Brain-----

If you're talking about purchasing a NEW 69+ balancer, you're not going to save any money; the balancers cost about the same.

However, you could do as you describe. I don't know how you're going to "fill" the existing groove, but, in any event, whether you do or not, I don't think that you'll affect the balance of it in any significant way. You don't really need to make a groove as deep or as wide as the original.

[Mark #28455]

Re: 8" Harmonic Balancer

You could "fill it " by MIG welding but remember, if the balancer comes apart it can cause a lot of damage that's why most racing organizations don't allow stock dampers. If you're going to "fudge it" anyway, consider an aftermarket balancer - available new in mags like circle track for about $50 to $75. The majority of the damper is covered by the pulley anyway.

[Dennis C.]

Re: 8" Harmonic Balancer

Reproduction finned balancers are available - just thought I'd mention that. Best, Dennis