finned balancer

[John F.]

The engine shop is balancing the rebuild of my original '67 L79 327 and hopefully it is done next week. My car had a replacement engine as the previous owner of the car lost an arguement with a connecting rod back in '92. The replacement engine has a non-finned 8" balancer. It is my understanding that the '67 L79 used the finned balancer. A respected major restorer told my engine shop today that finned balancers were used only on FI cars.

My L79 car was built 7/12/67, give-or-take. Should it not have a finned balancer? Is it possible to find one for less than my left arm?

Thanks.

[Joe L.]

Re: finned balancer

John-----

Yes, I believe that your 1967 L-79 was originally equipped with a "finned" balancer, as were all 62-68 Corvette "special high performance" 327s. This includes 340, 350, 360, 365, and 375 hp engines produced during that period. This balancer is and always was GM #3817173 and is still available from GM, but all GM #3817173 balancers are not created equal.

Sometime after the last "finned" balancer was used on a PRODUCTION Corvette in 1968, the design of the part changed for SERVICE. The balancer hub rear "fins' were eliminated and the hub was otherwise subtley redesigned to accomodate. So, the GM #3817173 balancer that you get today is not exactly the same as the part of yore.Functionally, however, it is the same.

Actually, as I have stated before, I do not believe that these "fins" were at all fins in the sense of "cooling fins" as many folks think. First off, there is absolutely no reason that a balancer would need cooling fins; no significant heat is generated at this point. Second, the "fins" are not configured in such a way that they would even provide any cooling inasmuch as they are non-directional. I believe that what is often mistaken for "cooling fins" are actually reinforcing ribs used in the original design to strengthen the balancer crankshaft mounting hub. Later, some alternate means of providing equivalent strength was used. This may have been specified on the original blueprints for the part with the option given to the manufacturer or the blueprints may have been later modified to provide for this change.

I don't know of any way to obtain a "finned balancer", either a restored original or a reproduction, without paying a hefty price.

[Richard T.]

Re: finned balancer

Your car should have the finned balancer. What you probably have is the G.M. service replacement part that is the same except for the fins. The 8" finned unit was for all H.P. small blocks 62 thru 68 not just F.I. cars. They were originally used on the 340 and 360 H.P. solid lifter motors in 62 and 63 and then on the 350 , 365 and 375 H.P. motors till 68. They can be found at swap meets from $175.00 to $250.00. If you buy a used one try to make sure that the rubber between the inner hub and outer ring is in good shape and not rotted too bad. When they get real bad the outer ring can spin. The timing mark should line up with the key way slot in the center. If it doesn't the outer ring has spun. I found an NOS one at a swap meet 2 years ago so there's still a couple out there. Rich #2276

[John F.]

Re: finned balancer

Joe & Rich

Thanks for the detailed responses. I'll be looking for the finned balancer if I can find one. If not, service parts next week! Thanks alot!!

John

[Joe L.]

Re: finned balancer

John----

The current GM LIST price of the balancer is $85.83 and less from competitive dealers. For that, you get a brand new, perfect GM balancer. So, if you can live without the "fins", you might be a lot better off functionally and financially.

[Mike Goen]

Re: finned balancer

John, I had a problem finding the high horsepower balancer for the 283/270 engine I'm building. I discovered a place where they claim that they build a visual duplicate but with current technology. They say they have put a lot of research into the subject and I understand that they provide to all the catalog houses. They came highly recommended. The one I ordered is in the mail - $230 + S&H, how much did you say your left arm is worth? The guy's info is:

Goat Hill Classics Paul D. Baker (the pulley king) 2037 W. 16th St. Long Beach, Ca 90813 (562)437-7664 fax (562)437-1113 E-mail: goathil@aol.com

He seems fairly responsive to email, you might check him out before you give up. // Mike

[Gavin Norman]

Re: finned balancer

John, you may also want to check your timing cover to make sure it is the right match for the balancer. I think most covers will work but the timing tab on the SHP engines, at least for the 63-65 327s, is unique with the letters 'A' and 'O' at each end of the scale; 'A' representing 10 degrees BTDC. I'm sure the guys who have responded to your question can set it straight if my facts aren't quite right.

[Loren L.]

Re: finned balancer

I'm afraid that you are going to find that this balancer is 1/2" too large in diameter, has holes punched in the outside ring and is not correct. It will "fit the hole", "carry the pulley" and it is the one that most of the suppliers sell, but it is not correct.

[Mike Goen]

Re: finned balancer

You may be right (?) I haven't seen it yet. Paul swears to be working from original blue prints. I'll let the board know when it gets here next week what I got, then you all can help me figure out if it's correct. I've never actually seen a 60 high horsepower balancer. // Mike

[Loren L.]

Re: finned balancer

Alan Koosed (Red Rooster) has (had?) one that is NOS in the box.

[Mike Goen]

Re: finned balancer

Loren: Well it arrived today. It is 6.5 inches and, as you suspected it has holes around the outside edge. My JG has no discription other than a number and to say it is not "stepped" like the 230hp version. While I was searching I did find a guy with an NOS HB, he wanted over $500 bucks ($550 I think it was) . . . insane by my standards. // Mike

[Loren L.]

Re: finned balancer

Yep that's the same one that he sent the refund check to me on. I'm not sure where you are - Alan Koosed is at the Chicago show (I think) this weekend - email at rqqster@earthlink.net - when he had the NOS HB, he wanted $400; also had another that he sold for $250-275. You might also contact your buddies that play with 348's; this balancer was also used on H/P 348's (read tri-power) in 59-61 and PERHAPS (off the top of my head) some early 409's. I'll add your name to my list as #4 that I know of that is looking for one. If I find one at Pomona this weekend, it sounds like an e-bay auction item ...

[Terry M.]

Re: finned balancer

I can confirm the Rooster is in Chicago this weekend - he and the pulley king are in adjacent spaces. I'll alert him to check his e-mail

Terry