'61 Harmonic Balancer Question

[Larry B.]

Were all balancers in '61 6" in diameter? What was the difference between the standard and SHP balancer. I am trying to figure which one I have. Thanks Larry

[Joe L.]

Re: '61 Harmonic Balancer Question

Were all balancers in '61 6" in diameter? What was the difference between the standard and SHP balancer. I am trying to figure which one I have. Thanks Larry

Larry------


They were all ABOUT 6" OD but I don't know that they were all EXACTLY 6" OD.

Both balancers are "stepped" and, basically, the easily identified difference is this: the lower HP balancer has a reduced OD section on the front and the larger OD section at the rear. The SHP balancer has the larger OD section at the front and the reduced diameter section at the rear.

[Larry B.]

Re: '61 Harmonic Balancer Question

Thanks Joe. I thought they were all the same diameter.

[David L.]

Re: '61 Harmonic Balancer Question

Larry,

Pictured is some of the research that I did on harmonic balances about 20 years ago. At that time I also collected about 20 or more balancers from 1960's Chevrolet 283 junk yard cars. The photo on the left is research on 62-65 250 & 300 HP balancers (I call this a type "B" in my research) but the 1959-1961 balancers that I found are the same shape but the part numbers are different. The photo on the right shows the 1966-1967 low HP balancers. The type "E" is from my research only.

low HP Corvette balancers

1958, GM # 3743849 (type "A", no holes around rim)
1959-1961, GM # 3760584
1962-1965, GM # 3817684 & GM # 3861968 (type "B", 12 holes around rim)

If you need a stepped balancer send me a PM. According to my notes I have one from a 1960 Chev. 283 w/P.G. "T0609D", a 1961 Chev. 283 w/P.G. & 4BC "T0403DB", and many more.

Dave

[Larry B.]

Re: '61 Harmonic Balancer Question

Good Research Dave!

[Robert B.]

Re: '61 Harmonic Balancer Question

Here is a picture of the vibration dampner for my 1960 270 horsepower 283.

[Las K.]

Re: '61 Harmonic Balancer Question

David, Just for information sake, I'd like to jump in on this discussion. I have a low HP '61, which would fit your #684 left side attachment, but mine does not have the holes on the thin part of the balancer. It is solid. Do yo have photos of the different variations?

[Ray C.]

Re: '61 Harmonic Balancer Question

I have up-loaded pictures of two balancers, front and back views. The balancer on the left are for the low horse motors and the balancer on the right is for the high horse motors.

Ray

[Las K.]

Re: '61 Harmonic Balancer Question

Ray,

Thanks for the confirmation. I have the low HP as pictured.

[David L.]

Re: '61 Harmonic Balancer Question

David, Just for information sake, I'd like to jump in on this discussion. I have a low HP '61, which would fit your #684 left side attachment, but mine does not have the holes on the thin part of the balancer. It is solid. Do yo have photos of the different variations?

I know that I have a type "A" (my designation) balancer from a 58 Chev. 283 that does not have the 12 holes around the rim (from my research notes and sketches). Off hand I can not remember if my 1959-1961 balancers have the 12 holes or not. It's been a very long time since I have studied or even looked at these balancers. In the next few days I will dig out my collection of balancers. I know where they are in my garage but I will have to do some "digging".

NOTE: My type "A" stepped balancer weighs about 6.7 lbs. My type "B" stepped balancers each weight about 6.4 lbs. I guess by drilling 12 holes the weight is reduced by about 0.3 lbs.

Dave

[David L.]

Re: '61 Harmonic Balancer Question

I have up-loaded pictures of two balancers, front and back views. The balancer on the left are for the low horse motors and the balancer on the right is for the high horse motors.

Ray

Ray,

Do you know the model year of your low HP balanced (without the 12 holes)?

Dave

[Ray C.]

Re: '61 Harmonic Balancer Question

The pictures of the low horse balancers were provided to me by a friend for a chassis presentation that our chapter is having this spring. I cannot tell you exactly what year they were removed from, but were listed for a 1958-1961 low horse engine. The research I have done would lead me to believe that they are for 1958 to 1961 model. I believe that the earlier balancers had the pulley attached (riveted) to the balancer. I do not have a date when this practice ended and the style in the above pictures started. Maybe someone with knowledge on the 1956-1957 models will comment.

I am attaching a picture of a 1956 balancer.

Ray

[Las K.]

Re: '61 Harmonic Balancer Question

David,

Thanks. My early '61, low HP, came with the type A as pictured.

[Loren L.]

Re: '61 Harmonic Balancer Question

The Hi-Po 59-61 balancer, 3764318, carries the blueprint notation for NO HOLES IN THE OUTER RING.

[David L.]

Re: '61 Harmonic Balancer Question

I looked through all my 58-61 low HP balancers and only a few were tagged.

The 2 photos on the left are of a balancer from a 60 Chev. (eng. stamped "T0328E" , intake casting date "C 21 60"). Note that the large diameter part is made from thick sheet steel and has 12 holes. I call this a type "C" balancer and weighs about 3.1 lbs. I have no idea what the GM part number might be.

The 2 photos on the right are of a balancer from a 59 Chev. (engine stamped "T0520D", glass code was "JY" or May 1959). This balancer has the 12 holes.

I have to assume that both of these balancers were original equipment. Both came from car in a junk yard in Northbridge, MA.

I have noticed that the rivet heads on my many 58-61 balancers have different markings. I assume that there was more then one vendor that made the balancers. Did one vendor make the balancers with 12 holes and use plugs for balancing and the other vendor just drill shallow holes for balancing?