Harmonic balancer with fins

[Tom P.]

I'm sure it's been asked and discussed many times, but I'm going to ask again.
What years and engines received finned harmonic balancers. I've always understood it to be just the solid lifter 327 engines (62-65) and not hyd lifter engines (ie L79)? Additionally, did the 302 Z28 engines get finned balancers?

[Joe L.]

Re: Harmonic balancer with fins

I'm sure it's been asked and discussed many times, but I'm going to ask again.
What years and engines received finned harmonic balancers. I've always understood it to be just the solid lifter 327 engines (62-65) and not hyd lifter engines (ie L79)? Additionally, did the 302 Z28 engines get finned balancers?

Tom-----


There was only one balancer I know of that ever had "fins". This was the GM #3817173. This balancer was used for all 1962-68 327 applications using an 8" balancer (i.e. L-76, L-84, L-79). It was also used for 1967-68 Z-28 (but not 1969 Z-28 which had a revised timing mark).

However, not all examples of this balancer actually had the "fins". Some folks think that at least all of those used in PRODUCTION and available in SERVICE during the same period had the fins. I don't think so, though. I think the fins may have been eliminated about 1967.

[Tom P.]

Re: Harmonic balancer with fins

Joe,
Thank you very much. That's kind of what I thought, but I've never been sure.
Some say that the 302 Z28 engines got finned balancers, and some say they did not. It has always been my understanding that when the timing mark changed on 69 models, the fins were gone (also, I've always thought that only solid lifter engines got finned balancers, and not L79 engines).

[Joe L.]

Re: Harmonic balancer with fins

Joe,
Thank you very much. That's kind of what I thought, but I've never been sure.
Some say that the 302 Z28 engines got finned balancers, and some say they did not. It has always been my understanding that when the timing mark changed on 69 models, the fins were gone (also, I've always thought that only solid lifter engines got finned balancers, and not L79 engines).

Tom-----

The 1969 Z-28 balancers definitely did not have the "fins". The balancer was very similar to the 69-70 L-46 balancer except tuned slightly differently.

Some 1967 Z-28 3817173 balancers may have had the "fins" but I doubt that any original 1968 3817173 Z-28 balancers had them.

[Mike E.]

Re: Harmonic balancer with fins

Joe,
Was crankshaft for that balancer tapped for a bolt?

Mike

[Joe L.]

Re: Harmonic balancer with fins

Joe,
Was crankshaft for that balancer tapped for a bolt?

Mike

Mike-----

All 327, 302 engines originally using the GM #3817173 balancer were equipped with crankshafts with a balancer retaining bolt tapping.

All 1969 and later 350 cid engines were equipped with crankshafts with a balancer retaining bolt regardless of what balancer was used.

[Mike E.]

Re: Harmonic balancer with fins

Mike-----

All 327, 302 engines originally using the GM #3817173 balancer were equipped with crankshafts with a balancer retaining bolt tapping.

All 1969 and later 350 cid engines were equipped with crankshafts with a balancer retaining bolt regardless of what balancer was used.

Thanks Joe,
From everything that I've read that's what I thought.

Mike

[Barry H.]

Re: Harmonic balancer with fins

Tom, My 65 L79, 327/350HP (s/n 15,4xx) with Hyd lifters has a Finned Damper, as does my 62 327/360 HP FI with solid lifters. Both also have the crankshaft bolt with the large washer to keep the Damper from coming off. If I remember correctly the 67 L79 that I owned 20 years ago also had the "Finned Damper" with bolt. Barry Holmes

[John D.]

Re: Harmonic balancer with fins

As Joe mentioned not all the '173 balancers sold by Chevy had fins. The over counter replacements sold in late 60's, etc didn't have fins.
I remember ordering one in 1978 and was disappointed. John
On my 63 it wasn't easy finding an original TR bolt with holes in safety wire holes in it. Although no safety wire was used. But you didn't ask that.

[David L.]

Re: Harmonic balancer with fins

The 1965 and older SB balancers did not have stamped date codes so I assume that the 1963-1965 finned 3817173 balancers also do not have stamped date codes. I believe that the stamped date codes appeared in 1966 model year. I once owned a 327 balancer stamped "E6F" (May 1966, the "F" must be the vendor) that was removed from a complete 1966 Chev. 327 stamped "T0521HAR" (May 21, 1966) that had all the other engine components (starter, intake, distributor, alternator, etc.) with April and May 1966 date codes. I have many other Chev. balancers from 1967-1970 engines with date codes.

I would think that the original 3817173 balancers on 1966 and newer engines would also have a stamped date code. Does anyone have a finned 3817173 with a stamped date code?

Dave

[Tom P.]

Re: Harmonic balancer with fins

I have two finned 173 balancers. Neither has a stamped date.
Most of my other balancers (350 and SB400) have stamped dates. I've never looked to see if my BB balancers have dates.

[Michael H.]

Re: Harmonic balancer with fins

I would think that the original 3817173 balancers on 1966 and newer engines would also have a stamped date code. Does anyone have a finned 3817173 with a stamped date code?

Dave

David,

I have a finned 3817173 damper stamp dated G64.

[Mike E.]

Re: Harmonic balancer with fins

Two points to this thread:
1). Early 62 340 and 360 hp cars had a finned balancer and did NOT have a crankshaft bolt. If I were home I'd dig out the GM info on that, but I'm on the road right now.
2). 62 finned balancers DID have date stampings.

[Gary C.]

Re: Harmonic balancer with fins

Tom,

My bought new '68 Z28 had a finned balancer.

Gary
....

[Michael H.]

Re: Harmonic balancer with fins

Tom,

My bought new '68 Z28 had a finned balancer.

Gary
....

I'm pretty sure that my new 68 Z28 also had a finned 8" balancer.