Harmonic balancer 62 fi

[Anton S.]

Does anyone know if the balancer on my 62 Vette 360hp is correct. The numbers/letters on the front hub are "3883961", "137500", and "CS". It has a 8 inch diameter and is 1 3/4 inch thick, the hub has 12 each 1/4 inch holes, "M65" is stamped on the back outer ring and has 12 fins. I did an archive search and the best I could find is that #3817163 may be the correct balancer but am not sure that this is correct for a Jan. 62 build Vette???? Also, does the correct balancer have 12 fins and 1/4 inch holes???? Thanks for your help.

[David L.]

Re: Harmonic balancer 62 fi

The 3883961 8" balancer is listed in my 1966 Corvair-Chevy II- Chevelle Parts Catalog (Jan. 1966) for the following model:
66 CHEVELLE (327)

My 1966 Chev. Parts Catalog (Oct. 1965) lists balancer # 3817173 for 1962-1965 Corvette models w/F.I., S.H.P. (exc. 396) and balancer # 3883961* for 1966 Corvette models w/S.H.P. 327.

*There is a note: "Use with 3883206 key. Key # 3883206 is described as 3/4" across flat X 1/8" wide.

The 3817173 balancer is also listed for the following models: 65-66 CHEVY II, CHEVELLE w/ Sp. H/Per. (327)

According to Chevrolet Parts History GM # 3883961 was replaced with GM # 3817173 in March 1966.

The "M65" stamping on your balancer would be December 1965 which would match up for an early 1966 Chevelle w/327 or 1966 Corvette w/SHP 327.

According to Joe L. the 3883961 has a very shallow, 1/16" deep keyway in the hub and the 3817173 has a 5/32" deep keyway.

Dave

[Anton S.]

Re: Harmonic balancer 62 fi

As suspected it was switched along the way. Now I need to find correct one. Thanks David

[David L.]

Re: Harmonic balancer 62 fi

Your balancer still is valuable as it is correct for an early 66 Corvette w/SHP 327.

[Joe L.]

Re: Harmonic balancer 62 fi

As suspected it was switched along the way. Now I need to find correct one. Thanks David

Anton-----

Assuming the keyway difference has been properly dealt with (and I suspect it has), there is probably no functional reason that the balancer you have will not continue to function properly. As far as configuration goes, it should be the same as 3817173 except for part number stamping which cannot be seen. So, I don't think you're going to gain very much by obtaining and installing a 3817173 balancer.

[David L.]

Re: Harmonic balancer 62 fi

Anton-----

Assuming the keyway difference has been properly dealt with (and I suspect it has), there is probably no functional reason that the balancer you have will not continue to function properly. As far as configuration goes, it should be the same as 3817173 except for part number stamping which cannot be seen. So, I don't think you're going to gain very much by obtaining and installing a 3817173 balancer.

I agree.
Dave

[Anton S.]

Re: Harmonic balancer 62 FI

Hi Joe L and David L, Thank you for your input on my issue. Upon reading your replies I took some measurements of the crank woodruff key and balancer keyway. My measurements do not match any of the dimensions you all referenced. So looking further into details of my 62 Vette I discovered that I have a 1963 FI block and heads in my 62. I have decided to replace the engine with a rebuilt engine that has the correct block and heads. Therefore, since the keyway depth of my balancer hub is 0.120 in. and per Joe the correct balancer 3817173 has a 5/32 (i.e. 0.1562) depth, I will need to buy the correct balancer to fit my new engine AND probably correct timing chain cover?? Can you please reconfirm that the 3817173 is correct for a 62 FI 360 HP engine? Also, if you have the dimensions of the balancer key way (i.e. depth = 5/32 and width = ____) that would be great so that I can confirm that I am getting the correct part. I am also assuming that the 3817173 has 12 vanes on the back side of the balancer, is that a correct assumption?? Thanks for your time in helping me solve this mystery. Stay Safe, Anton

[Joe L.]

Re: Harmonic balancer 62 FI

Hi Joe L and David L, Thank you for your input on my issue. Upon reading your replies I took some measurements of the crank woodruff key and balancer keyway. My measurements do not match any of the dimensions you all referenced. So looking further into details of my 62 Vette I discovered that I have a 1963 FI block and heads in my 62. I have decided to replace the engine with a rebuilt engine that has the correct block and heads. Therefore, since the keyway depth of my balancer hub is 0.120 in. and per Joe the correct balancer 3817173 has a 5/32 (i.e. 0.1562) depth, I will need to buy the correct balancer to fit my new engine AND probably correct timing chain cover?? Can you please reconfirm that the 3817173 is correct for a 62 FI 360 HP engine? Also, if you have the dimensions of the balancer key way (i.e. depth = 5/32 and width = ____) that would be great so that I can confirm that I am getting the correct part. I am also assuming that the 3817173 has 12 vanes on the back side of the balancer, is that a correct assumption?? Thanks for your time in helping me solve this mystery. Stay Safe, Anton

Anton-----


The GM #3817173 balancer is the original and correct piece for all 1962-68 SHP 327. The version used through at least 1965 had a hub with 12 fins.

The timing cover for both 1962 and 1963 with SHP was the same.

Keyway was 3/16" wide.

[David L.]

Re: Harmonic balancer 62 FI

Anton,

My 1969 Chevrolet Parts Catalog (Oct. 1968) shows the following at the end of Gr. 0.659:

65-66 ALL w/key 3/4" long X 3/16" wide X 1/4" high...........KEY, crankshaft pulley hub.........3883206*

* NOTE: Used with pulleys and hubs having a shallow (1/16" deep) keyway only. All full depth (1/8") slots take standard key (106751 two short or 144542 one long) in group 8.960.

From Gr. 8.960 (Woodruff keys):

106751 3/16" X 3/4" No. 9 (5/16" high)

144542 3/16" X 1 3/8" No. 126 (13/32" high)

Dave

[Larry C.]

Re: Harmonic balancer 62 FI

Just to add to the discussion, or maybe confusion, I have an extra balancer from a swap meet many years ago. Measures 8" dia and 1 3/4" wide with 12 - 1/4" holes drilled outside of the 3 radial arms that support the hub. Key way appears to be 3/16" wide.

173 is stamped on the front of balancer and "F1 6.2" is cast into back side of the radial arm nearest the key way. So in almost all respects it fits the criteria mentioned in these post; HOWEVER, there are no fins cast into the inner part of the balancer.

Any opinions/comments about these markings and absence of fins?

Larry

[Jack H.]

Re: Harmonic balancer 62 FI

Anton-----


The GM #3817173 balancer is the original and correct piece for all 1962-68 SHP 327. The version used through at least 1965 had a hub with 12 fins.

The timing cover for both 1962 and 1963 with SHP was the same.

Keyway was 3/16" wide.

That does bring up a question I've had for a while. I know the fins disappeared with service replacements, but were some later production units missing the fins also? The above suggests the answer was "yes". I'm particularly interested in a 1967 L79 application.

[Anton S.]

Re: Harmonic balancer 62 FI

Thank you Joe

[Joe L.]

Re: Harmonic balancer 62 FI

Just to add to the discussion, or maybe confusion, I have an extra balancer from a swap meet many years ago. Measures 8" dia and 1 3/4" wide with 12 - 1/4" holes drilled outside of the 3 radial arms that support the hub. Key way appears to be 3/16" wide.

173 is stamped on the front of balancer and "F1 6.2" is cast into back side of the radial arm nearest the key way. So in almost all respects it fits the criteria mentioned in these post; HOWEVER, there are no fins cast into the inner part of the balancer.

Any opinions/comments about these markings and absence of fins?

Larry

Larry-----


I believe that the fins ceased sometime in the 1966 model year, probably late in the model year.