1968 L79 Harmonic Damper

[Jeff P.]

I've looked through many threads on this subject. They are mainly C2 cars and later big blocks. I just pulled mine off . Cleaned it enough to read front and back. This is 8" and width is 1 11/16. No fins. Markings on the front read " MC", "S-2 " with B8. The rear is unclear. Looks like F162. Thank you in advance. Also after reading many posts for no paint on the inside and front middle , this damper was painted on both sides.

[Joe L.]

Re: 1968 L79 Harmonic Damper

I've looked through many threads on this subject. They are mainly C2 cars and later big blocks. I just pulled mine off . Cleaned it enough to read front and back. This is 8" and width is 1 11/16. No fins. Markings on the front read " MC", "S-2 " with B8. The rear is unclear. Looks like F162. Thank you in advance. Also after reading many posts for no paint on the inside and front middle , this damper was painted on both sides.

Jeff-----

If you're asking if the balancer is the correct configuration, I believe it is. I believe the "finned" balancer was dropped during the 1967 model year, if not before. So, I would expect yours is the correct configuration.

As far as whether it's original to the car, I don't know. If it is original, then I'd say it's been off the engine at some point and painted off the engine. Originally, the balancers were painted with the engine assembly. So, there should be little paint on the rear side and certainly not completely painted.

[Mike T.]

Re: 1968 L79 Harmonic Damper

Jeff, I have a similar damper from a '68 L79 that came in a Chevelle. No marks to be seen on the front face but on the inside of the 'spokes' I can just make out "F-17" and on the same spoke "6-2" and on the next spoke over it has a stamped "2" and a pair of 'diamonds'.

[Jeff P.]

Re: 1968 L79 Harmonic Damper

Thank you joe and mike. Joe, have you ever heard or seen these markings I the front? Hopefully some other 68 L79 owners will chime in. Looks like mike for whatever reason this damper might be for other Chevrolet applications.
One last thing joe, were different dampers in 68 SB's used for AC, Power Steer options. Thank you again guys.

[Mike T.]

Re: 1968 L79 Harmonic Damper

Jeff - From what I read a long time ago, the L79's destined for vehicles other than Corvettes got the same basic equipment but with restrictions due to the air cleaners and exhaust systems, they rated the non-Corvette L79's at 325 horsepower, at least for the Chevelle in '67 and '68. No doubt Chevrolet also wanted the Corvette to come out on top in the horsepower listings.

[Joe L.]

Re: 1968 L79 Harmonic Damper

Thank you joe and mike. Joe, have you ever heard or seen these markings I the front? Hopefully some other 68 L79 owners will chime in. Looks like mike for whatever reason this damper might be for other Chevrolet applications.
One last thing joe, were different dampers in 68 SB's used for AC, Power Steer options. Thank you again guys.

Jeff-------


The GM #3817173 balancer was used for all 1965-68 L-79, Corvette or otherwise. It was also used for 62-65 Corvettes with mechanical lifter small blocks. Design features of it changed somewhat over the years, including the shedding of the "fins", but all are functionally interchangeable.

Different balancers were not used for cars with A/C or power steering options for ANY year. However, different pulley sets were used. For 1968 there were 2 different size balancers used for small block Corvettes----a 6-1/8" for 300 HP and the 8" for the L-79.

[Jeff P.]

Re: 1968 L79 Harmonic Damper

Joe, revisiting this thread with a front and rear view of the damper. B8 is stamped on both sides,a date code possible ? Notice that the weights aren't painted. image.jpgimage.jpg

[Joe L.]

Re: 1968 L79 Harmonic Damper

Joe, revisiting this thread with a front and rear view of the damper. B8 is stamped on both sides,a date code possible ? Notice that the weights aren't painted. [ATTACH=CONFIG]67592[/ATTACH][ATTACH=CONFIG]67593[/ATTACH]

Jeff------


This is a SERVICE-only high performance balancer. Note the "M-C" embossment Some of these balancers, as well as some standard balancers, were once-upon-a-time painted out of the box.

[Jeff P.]

Re: 1968 L79 Harmonic Damper

Thank you Joe.

[Jeff P.]

Re: 1968 L79 Harmonic Damper

Joe, are there topical date codes on a 68 L79 327 or markings?

[Loren L.]

Re: 1968 L79 Harmonic Damper

Jeff-------


The GM #3817173 balancer was used for all 1965-68 L-79, Corvette or otherwise. It was also used for 62-65 Corvettes with mechanical lifter small blocks. Design features of it changed somewhat over the years, including the shedding of the "fins", but all are functionally interchangeable.

Different balancers were not used for cars with A/C or power steering options for ANY year. However, different pulley sets were used. For 1968 there were 2 different size balancers used for small block Corvettes----a 6-1/8" for 300 HP and the 8" for the L-79.

The fins had NOT been shed in 1968.

[Joe L.]

Re: 1968 L79 Harmonic Damper

The fins had NOT been shed in 1968.

Loren-----

Well, technically speaking, you're right. The fins were not shed for 1968. They were shed earlier, perhaps late 1966 but certainly by 1967.

[Joe L.]

Re: 1968 L79 Harmonic Damper

Joe, are there topical date codes on a 68 L79 327 or markings?

Jeff------

I'm really not sure about this. I've seen what APPEARED to be a STAMPED date code on the outer ring of some of these balancers. The "B8" on yours might be a date code but, if so, the format and style is different than what I've seen.

By the way, the "M-C" embossment on the rear of your outer ring signifies that the outer ring is cast of malleable cast iron. This is a much stronger material than the gray iron used on most balancers.

[Loren L.]

Re: 1968 L79 Harmonic Damper

I guess you'll have to explain to me how I'm "technically speaking" right if you're telling me that there were no finned balancers in 1967 but I have seen 3 ORIGINAL OWNER 350 HP 327s here in Phx with finned balancers.

[Joe L.]

Re: 1968 L79 Harmonic Damper

I guess you'll have to explain to me how I'm "technically speaking" right if you're telling me that there were no finned balancers in 1967 but I have seen 3 ORIGINAL OWNER 350 HP 327s here in Phx with finned balancers.

Loren------

Just like I said. You said that the fins were NOT shed for the 1968 model year. That's correct; they were NOT shed for the 1968 model year. They were shed EARLIER than the 1968 model year.

How can 3 original owner 1967 L-79's in your area have finned balancers? I have no idea. The GM specification for the GM #3717173 balancer was changed in late 1965 or early 1966 and eliminated the fins. Why? I don't know, for sure but here's my guess: (1) the fins didn't accomplish much, anyway, and (2) the fins had to be eliminated so that the balance weight holes could be added for final engine assembly balance.

Just a note regarding the balance weight holes: the balancers are balanced at the time of manufacture by the drilling of holes, as necessary, in the outer ring. Final balance when installed on the engine is accomplished by adding weights, if necessary, in the balance weight holes. This is done at engine start-up at the engine plants. I don't think this was done prior to 1966.

I feel bad for guys that have a 1967-68 Corvette with L-79, found their engines had a non-finned balancer, and changed it to a finned balancer. In doing so, they made their cars non-original in order to make them "original".