I'm trying to identify the (probably incorrect) harmonic balancer that came off of a 1967 L79 engine, to determine whether to have it restored or to begin looking for the correct balancer.
According to the 1967 TIM & JG (Fourth Edition, p. 86):
"The L79 350 hp engines use a heavy 1 3/4 inch thick balancer with an outside diameter of 8 inches. The interior surface has twelve integrally cast fins."
Also, in at least two NCRS Forum Threads, the 1967 L79 harmonic balancer should be (or is correct as) a "finned" balancer:
1967 L79 HT Harmonic Balancer
https://www.forums.ncrs.org/showthre...ancer&uid=2389
327/350HP engine
https://www.forums.ncrs.org/showthre...ering&uid=5910
However, according to "Corvette by the Numbers" (Alan L. Colvin, p. 511-514), the "finned" balancers were only used from 1962-1965 ("third design", date coded) and the 1966-1967 L79 harmonic balancer was NOT "finned" and did NOT have a date code. The 1967 balancer in Colvin's book is close to (but not exactly like) the one I have in the pictures below that came off the '67 L79 I'm in the process of restoring. The inside view of the Fifth design in the "Corvette by the Numbers" book matches the inside view of mine, but the outside view is different in the book than the one I have.
The markings on mine (8 inch diameter) are the following:
One the outside, there is "M - C" at the top (12 o'clock), and "S - 4" at the bottom (at 6 o'clock). On the inside, on the left-hand "spoke", is cast "F 1" on one side of the hole, and "6 - 2" on the other side of the hole. On the inside top spoke (pointing toward 12 o'clock) there is a diamond cast on the right hand side of the hole, and a capital "L" cast on the left-hand side of the hole. I have no idea what these casting numbers mean, and the book does not identify them.
So after all of this, I have three questions:
1. Is it for sure that the only correct harmonic balancer for a 1967 L79 327/350hp engine is a "finned" balancer with a date code, in which case the one that I have is definitely wrong?
2. The TIM & JG appears to be in conflict with the book referenced above. Is the book "Corvette by the Numbers" incorrect when it says the 1962-1965 "third design" was the only 8" finned harmonic SB balancer in a Corvette application, or am I misunderstanding something?
3. Can anyone identify what kind of balancer I actually have, and what application it must have originally come from?
Thanks to anyone who has read this far, comments and replies very much appreciated,
Scott
According to the 1967 TIM & JG (Fourth Edition, p. 86):
"The L79 350 hp engines use a heavy 1 3/4 inch thick balancer with an outside diameter of 8 inches. The interior surface has twelve integrally cast fins."
Also, in at least two NCRS Forum Threads, the 1967 L79 harmonic balancer should be (or is correct as) a "finned" balancer:
1967 L79 HT Harmonic Balancer
https://www.forums.ncrs.org/showthre...ancer&uid=2389
327/350HP engine
https://www.forums.ncrs.org/showthre...ering&uid=5910
However, according to "Corvette by the Numbers" (Alan L. Colvin, p. 511-514), the "finned" balancers were only used from 1962-1965 ("third design", date coded) and the 1966-1967 L79 harmonic balancer was NOT "finned" and did NOT have a date code. The 1967 balancer in Colvin's book is close to (but not exactly like) the one I have in the pictures below that came off the '67 L79 I'm in the process of restoring. The inside view of the Fifth design in the "Corvette by the Numbers" book matches the inside view of mine, but the outside view is different in the book than the one I have.
The markings on mine (8 inch diameter) are the following:
One the outside, there is "M - C" at the top (12 o'clock), and "S - 4" at the bottom (at 6 o'clock). On the inside, on the left-hand "spoke", is cast "F 1" on one side of the hole, and "6 - 2" on the other side of the hole. On the inside top spoke (pointing toward 12 o'clock) there is a diamond cast on the right hand side of the hole, and a capital "L" cast on the left-hand side of the hole. I have no idea what these casting numbers mean, and the book does not identify them.
So after all of this, I have three questions:
1. Is it for sure that the only correct harmonic balancer for a 1967 L79 327/350hp engine is a "finned" balancer with a date code, in which case the one that I have is definitely wrong?
2. The TIM & JG appears to be in conflict with the book referenced above. Is the book "Corvette by the Numbers" incorrect when it says the 1962-1965 "third design" was the only 8" finned harmonic SB balancer in a Corvette application, or am I misunderstanding something?
3. Can anyone identify what kind of balancer I actually have, and what application it must have originally come from?
Thanks to anyone who has read this far, comments and replies very much appreciated,
Scott
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