Deep Groove Water Pump Pulley

[Ed S.]

I discovered that the water pump pulley on my '64 L76 (non A/C) engine is not the factory original "deep groove" type. What I have is a 2 belt standard depth pulley for a 250-300 hp engine. The "correct" pulley I should have is a (p/n) 3770245 or a 3850141. Both are very rare and used ones are very expensive. Paragon sells a repro of the 245 and it is upwards of $300. At those prices I am not concerned about "originality" or 100% correctness, I just want a pulley that has grooves deep enough to function correctly, no wobble, correct diameter, and aligns properly.

Corvette Central is the only vendor that is selling a moderately priced 2 belt "deep groove" pulley - $89. They are listing it as a 3770245. https://www.corvettecentral.com/62-6...-groove-301245. See the pic -

Does anyone have any experience with this repro pulley? Does it spin without wobble, does it align correctly, is the gauge of metal adequate for the stress it will endure? Opinions / recommendations please.

[Ed S.]

Re: Deep Groove Water Pump Pulley

Well, I took the plunge. In the absence of an affordable solution I ordered the "repro" deep groove pulley from Corvette Central. Before I did I called and talked to a tech rep. Of course he said that they have not had any problems with any that they sold and that they have sold a good number of them. He also said that because they are made "overseas" they check every one they receive. They check the thickness of the metal, measure it, do a visual inspection and then put it on a machine and spin it fast to look for any wobble. I should have it next week. Will let you all know how it fits and works. Hope it functions as good as an original.

[Darryl D.]

Re: Deep Groove Water Pump Pulley

I have repro deep groove pulleys from CC on my 383 in my 57 and they run true.

[Ed S.]

Re: Deep Groove Water Pump Pulley

I have repro deep groove pulleys from CC on my 383 in my 57 and they run true.

Darryl - thanks - that is good to know - a good endorsement. This is a relatively new product for CC, at the price they are asking ($89) it is almost too good to be true and you know how that goes. Thanks again.

[Chris D.]

Re: Deep Groove Water Pump Pulley

With the 250/300 HP engine pulley, how was the alignment with the crankshaft pulley? Deep groove pulley system utilizes a slightly different water pump flange location.

[Ed S.]

Re: Deep Groove Water Pump Pulley

With the 250/300 HP engine pulley, how was the alignment with the crankshaft pulley? Deep groove pulley system utilizes a slightly different water pump flange location.

Chris - you raise a good point, one that I am concerned about. That is something I will check closely. I have the correct harmonic balancer / crank shaft pulley, I also have the correct idler pulley assembly and alternator / pulley & bracket. My water pump is not an original - it is an aftermarket unit - can't determine what the part # is. With these components and the 250 /300 pulley both belts lined up perfectly. I am concerned that a correctly manufactured repro water pump pulley will not line up properly. Thanks for pointing that out - it will get a careful inspection.

[Chris D.]

[Alan D.]

Re: Deep Groove Water Pump Pulley

Chris, recently was helping a friend out with a 67 HP small block car and he had a spacer on the water pump - said it was stock.
However I do not know, was a spacer used on 67 and if so wouldn't that make the need to skip pulling forward? (ie use spacer)

[Ed S.]

Re: Deep Groove Water Pump Pulley

Chris, recently was helping a friend out with a 67 HP small block car and he had a spacer on the water pump - said it was stock.
However I do not know, was a spacer used on 67 and if so wouldn't that make the need to skip pulling forward? (ie use spacer)

Alan, that same thought occurred to me - I've seen "spacers" listed in the catalogs of a few Corvette parts vendors. The link below is for the Paragon spacer. Interesting though, it implies that it is not an original part.
https://www.paragoncorvette.com/p-35...nt-spacer.aspx

Instead, Paragon suggests the spacer should be used to "reinforce" the pulley - implying that metal fatigue may cause the pulley to fail. I don't know if this spacer would resolve an alignment problem, if one exists. I also don't understand why anyone would sell a pulley that is prone to failure and to compensate for that they also sell a reinforcing spacer.

[Alan D.]

Re: Deep Groove Water Pump Pulley

Thanks Ed,
I'm of the opinion that "Paragon suggests the spacer should be used to "reinforce" the pulley" makes no sense at all.
And that was exactly the spacer I saw on the 67.

One other point, I have an original 64FI - the pulley was never replaced, however NO part number is on it. So the one shown in the first thread may be a service replacement (simple enough to hide) or a later part requirement.

[Ed S.]

Re: Deep Groove Water Pump Pulley

Thanks Ed,
I'm of the opinion that "Paragon suggests the spacer should be used to "reinforce" the pulley" makes no sense at all.
And that was exactly the spacer I saw on the 67.

One other point, I have an original 64FI - the pulley was never replaced, however NO part number is on it. So the one shown in the first thread may be a service replacement (simple enough to hide) or a later part requirement.

Alan - the pic of the pulley in the first thread is a Corvette Central repro - in addition to a p/n the letters "CC" are stamped into the pulley immediately after the p/n. The pulley I removed from my car - the one that is for a 250 -300 hp engine has a p/n stamped into it but it is right on the area where the fan clutch bolts to it - so when all is assembled you can't see the pulley p/n. Wondering if you have ever had your pulley off to inspect for a p/n or are you just stating that there is no visible p/n when all assembled.
A

[Alan D.]

Re: Deep Groove Water Pump Pulley

Ed,
Had it off a dozen or so times however never was checking for a pn. Never noticed one, but it may be their. If you can not see it after installled
I would not worry about it. As for CC numbers just fill and paint again.

[Chris D.]

Re: Deep Groove Water Pump Pulley

Ed,
That 3720616 part number is listed as a "reinforcement" for 67-68 327. There's some thought the two different hub locations were consolidated by 66 or 67. I only know what the 63 shop manual shows and the actual dimensions of the Kent Moore Gauge tools specified to set the hubs.

Seeing as that spacer is closer to 1/16" thick than the 1/8" difference in water pump hub locations, I'm not so sure it would get your new pulley properly located by itself. But it might.

Chris

[Alan D.]

Re: Deep Groove Water Pump Pulley

Thanks for PN Chris, yet another detail learned.
Here is some more info.

[Wayne M.]

Re: Deep Groove Water Pump Pulley

Tell me what I've got here ... bought locally from a father/son team with a '64 & '65 (didn't notice the engine horsepower ratings). They were converting them to resto-rods. No part # stamps; notice the outer belt groove seems to be pressed on over the cone formed by the inner belt & hub. (correction) The O.D. is 7_1/16") Tells me I need to change 10 characters for an edit .