64 Style pulleys on a 68 block don't align

[Dan B.]

I would like try to use a stock 64 Pulley set up (with Power steering) on my engine which is a 68 327 (CE block).

Got 3744043 crank pulley and 3790356 water pump pulleys as called for but the first problem is the crank pulley is back too far (about 1/8 ") behind the WP pulley. I did some checking and verified I have the fourth design Harmonic balancer (66-69) that is 6 3/4" in diameter with crankshaft drilled for a center bolt. I realize the original 64 design was a riveted 6" balancer but was wondering if anyone could tell me if the depth is the same or more. Either way I am 1/8" too far back at the crank using 64 pulleys and would not be able to use the front position for the alternator as original which is what I am trying to achieve.

I was (up to this point) running the deep groove pulleys 37766987 crank and 3770245 WP with this engine using the inner (Rear) groove for the Alternator and outer for P/S and all was pretty well aligned.

One last question, will the early style P/S pulley 3770509 interchange with the later slotted one if the pump has a nut holding the pulley?

Has anyone come accross this that can point me in the right direction. Could not find any info on this in the archives.

Thanks in advance for any help here. Dan

[Joe L.]

Re: 64 Style pulleys on a 68 block don't align

I would like try to use a stock 64 Pulley set up (with Power steering) on my engine which is a 68 327 (CE block).

Got 3744043 crank pulley and 3790356 water pump pulleys as called for but the first problem is the crank pulley is back too far (about 1/8 ") behind the WP pulley. I did some checking and verified I have the fourth design Harmonic balancer (66-69) that is 6 3/4" in diameter with crankshaft drilled for a center bolt. I realize the original 64 design was a riveted 6" balancer but was wondering if anyone could tell me if the depth is the same or more. Either way I am 1/8" too far back at the crank using 64 pulleys and would not be able to use the front position for the alternator as original which is what I am trying to achieve.

I was (up to this point) running the deep groove pulleys 37766987 crank and 3770245 WP with this engine using the inner (Rear) groove for the Alternator and outer for P/S and all was pretty well aligned.

One last question, will the early style P/S pulley 3770509 interchange with the later slotted one if the pump has a nut holding the pulley?

Has anyone come accross this that can point me in the right direction. Could not find any info on this in the archives.

Thanks in advance for any help here. Dan

Dan------

The 1964 and 1968 balancer should be the same dimension from the face of the balancer (pulley mounting surface) to the end of the snout. Some engines used a spacer, though, which installed between the end of the snout and the crankshaft timing sprocket. Curiously, these spacers were 1/8" thick so if you had one installed that would space your balancer out far enough for alignment.

Notwithstanding the above, something does not appear right in your photo. Unless there's some distortion or other aberration due to the photo, it appears to me that your balancer is already spaced too far out.

Regarding the power steering pump pulley, the GM #3770509 is a pulley designed for a tapered shaft pump. Tapered shaft pumps use the special locking nut for pulley retention. 1975 and later pumps used a straight shaft and the pulleys were pressed onto the pump shaft. The tapered shaft type pulleys and the straight shaft type pulleys are definitely NOT interchangeable.

[Timothy B.]

Re: 64 Style pulleys on a 68 block don't align

Dan,

It's also possible the water pump hub is not pressed on the shaft the correct dimension.

If the damper is installed correctly the #043 crankshaft pulley along with the add on #232 crank pulley (power steering belt pulley) should line with the #509 power steering PUMP pulley on the third belt position. If the water pump pulley does not line up in belt positions one and two then I suspect the above condition.

Depending on the alternator pulley installed, you can run the alternator on belt position one or two but the low hp 1964 cars ran it on the #2 position.

[Dan B.]

Re: 64 Style pulleys on a 68 block don't align

[QUOTE=Joe Lucia (12484);676792]Dan------

The 1964 and 1968 balancer should be the same dimension from the face of the balancer (pulley mounting surface) to the end of the snout. Some engines used a spacer, though, which installed between the end of the snout and the crankshaft timing sprocket. Curiously, these spacers were 1/8" thick so if you had one installed that would space your balancer out far enough for alignment.

[QUOTE]

Joe, that's very interesting you say that because with the deep groove pulleys (687 & 245) installed that I got with the motor, they DO line up as is. I was thinking an 1/8" crank spacer (similar to what we use on the C1's) might be the ticket. I've never seen a mid year crank spacer listed anywhere. Yet with the base pulleys, they are off 1/8 inch. The balancer is deffinately on all the way (photo is not the best) and I believe it has never been off the car. I also wonder if since this is a CE motor was it set up as a HP since the crank snout was factory drilled. Thanks for the reply. Dan

[Dan B.]

Re: 64 Style pulleys on a 68 block don't align

Dan,

It's also possible the water pump hub is not pressed on the shaft the correct dimension.

If the damper is installed correctly the #043 crankshaft pulley along with the add on #232 crank pulley (power steering belt pulley) should line with the #509 power steering PUMP pulley on the third belt position. If the water pump pulley does not line up in belt positions one and two then I suspect the above condition.

Depending on the alternator pulley installed, you can run the alternator on belt position one or two but the low hp 1964 cars ran it on the #2 position.

Tim, that was my first thought, but the HP pulleys do line up and it appears that with the correct alternator fan and pulley, the water pump pulley (356) would align. Dunno gonna have to keep at this. If the riveted balancer (1st design) and the pressed (2nd design) depths are identical, then it would appear my only option would be to space the balancer to agree with the other 2. Problem is I don't have the early P/S pulley or add on yet, so I cant use them for a tie breaker.

Additionally, the water pump hub face to the water pump mount flange measures approximately 5 5/8" which I believe is correct.

[Cecil L.]

Re: 64 Style pulleys on a 68 block don't align

I'm pretty sure the fan hub on the waterpump should be 5 11/16. If your CE block is drilled for the balancer bolt, chances are pretty good that it is a HP......a peek in a spark plug hole with a borescope should tell you, or check the lifter travel for L-79 specs. Either way, shouldn't affect the setback of the balancer.
I seem to recall that some later crank pulleys had a reinforcement spot welded to the backside to prevent cracking. I know there were several TSB's addressing the installation of the waterpump pulley reinforcement to prevent cracking but they weren't welded and were'nt that thick.

[Joe L.]

Re: 64 Style pulleys on a 68 block don't align

Tim, that was my first thought, but the HP pulleys do line up and it appears that with the correct alternator fan and pulley, the water pump pulley (356) would align. Dunno gonna have to keep at this. If the riveted balancer (1st design) and the pressed (2nd design) depths are identical, then it would appear my only option would be to space the balancer to agree with the other 2. Problem is I don't have the early P/S pulley or add on yet, so I cant use them for a tie breaker.

Additionally, the water pump hub face to the water pump mount flange measures approximately 5 5/8" which I believe is correct.

Dan------


5-9/16" is the correct dimension for the 1968 pump from the face of the hub to the base of the flange. However, some earlier pumps (like the 1964 from which your pulleys were obtained) could have been 1/8" different.

By the way, the deep groove pulleys were used with special high performance applications. For these applications there was no add-on, "3rd groove" balancer pulley used. These applications usually used a "drop-down" cast iron pulley and one of the belts traversed the balancer, waterpump and power steering pump pulleys. The other belt traversed the balancer, water pump, and alternator pulleys.

[Dan B.]

Re: 64 Style pulleys on a 68 block don't align

Thanks Joe, sounds like I am in the ball park. If anyone with a 63 -64 can supply an accurate pump hub measurement, that would be a help in solving this. I've come accross some pumps pressed in an additional 1/8 " but can't say where they came from.

[Cecil L.]

Re: 64 Style pulleys on a 68 block don't align

Thanks Joe, sounds like I am in the ball park. If anyone with a 63 -64 can supply an accurate pump hub measurement, that would be a help in solving this. I've come accross some pumps pressed in an additional 1/8 " but can't say where they came from.

From March. 65 CSN:

[Dan B.]

Re: 64 Style pulleys on a 68 block don't align

Cecil, thanks for the great reply, it would appear you have found the answer to using the early pulleys on a later motor!!!! Now it makes sense why the later pulleys aligned and the early ones did not.

Amazing how you come up with these documents thanks so much for your efforts. Regards, Dan

[Timothy B.]

Re: 64 Style pulleys on a 68 block don't align

Dan,

I don't want to confuse things more but if the deep groove pulleys line up why not just use the cast iron power steering pump pulley #720, as this will line with the second belt position.

[Dan B.]

Re: 64 Style pulleys on a 68 block don't align

Tim, right you are. My current set up works fine with the forward position used for P/S. Spent some time today working on getting a better alignment for the Alternator. Found 2 problems, first the "F" bracket had a slight bend in the front which I was able to straighten on the bench. Second, Bubba had apparently shortened the sleeve bushing just enough to allow the Alternator to be cocked to the side. I made a new bushing, and reassembled and now it's laser straight. It's all back together with the later pulleys and everything is tracking properly. Decided to hold off removing the Water pump at present and will gather the necessary parts and do this as a Winter project so I can get back on the road.