1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

[Joe C.]

I have a 1965 327 which is mostly street driven, does not need a "high flow" pump nor an aluminum pump. I subject this car to 7500 RPM shifts at the drag strip 3 maybe 4 times every season. I use a fan blade which corresponds to the TIM&JG in every way, including rivet config. I have broken (snapped) two (2) water pump shafts, both of which were 5/8" diameter. I want to upgrade to a 3/4" diameter shaft using a 3/4" pilot hole for the fan hub. I am fully prepared to drill the fan pulley fan clutch hole to 3/4" from 5/8". I require the heater outlet and bypass nipple pipe diameters to be 3/4" NPT.
With all of that being said, what can you tell me about Chevrolet Performance Mechanical Water Pump 1245892.
Thanks in advance.

[Joe L.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

I have a 1965 327 which is mostly street driven, does not need a "high flow" pump nor an aluminum pump. I subject this car to 7500 RPM shifts at the drag strip 3 maybe 4 times every season. I use a fan blade which corresponds to the TIM&JG in every way, including rivet config. I have broken (snapped) two (2) water pump shafts, both of which were 5/8" diameter. I want to upgrade to a 3/4" diameter shaft using a 3/4" pilot hole for the fan hub. I am fully prepared to drill the fan pulley fan clutch hole to 3/4" from 5/8". I require the heater outlet and bypass nipple pipe diameters to be 3/4" NPT.
With all of that being said, what can you tell me about Chevrolet Performance Mechanical Water Pump 1245892.
Thanks in advance.

Joe------


The part number 1245892 "does not compute". I think that you mean either GM #12458922 or 12458928. Both of these are cast iron small block waterpumps. They were originally cataloged for early 90's small block applications in light trucks and certain rear wheel drive GM passenger cars.

The 12458922 does not have provisions for external by-pass so, since you require that, this pump is disqualified on that fact alone. The 12458928 does have provisions for external by-pass. So, in that regard, it qualifies.

However, the hub spacing on both of the above pumps is incorrect for your application so that pretty much rules out both of the pumps unless you're willing to adjust the hub spacing which I definitely do not recommend. Also, these pump might have metric sized fittings but I am not sure about that.

Let's discuss the basics here for a moment. Your problem involves the fact that you've been using the 1955-70 style waterpump which uses the very weak and problematic 5/8" shaft with associated small bearing. I don't like these, at all. In 1971 GM finally discovered that these waterpumps were a problem and they increased the shaft and bearing size. So, the 1971+ pumps use a 3/4" shaft with the associated "jumbo" bearing size. The 1971+ Corvette pumps use a 3/4" pilot, 3/4" shaft through the bearing, and 5/8" impeller shaft.

I can suggest two other ways for you to achieve what you're seeking to achieve:

1) Use an Edelbrock #8810 pump. This will give you all the strength of the 71+ configuration but with a lighter aluminum pump body and a 5/8" pilot. The 5/8" pilot will allow you to use your current pulleys without modification. I do not recommend over-sizing the pilot holes on 5/8" pilot pulleys with 3" bolt circle bolt holes.

2) Use the 1971+ Corvette waterpump. This will provide you with the 3/4" shaft and jumbo bearing. However, it will have a full 3/4" pilot. To accommodate this I would recommend that you use a 1971+ Corvette pulley set. You will also have to use a 71+ fan clutch and 71+ fan blade assembly.

[Joe C.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

The 8810 looks like a quality pump. It's cast and machined in the USA and that's a MUST. I don't know where any of the others are manufactured. Both openings for the pipe nipples on my factory 326 pump (Corvette application) are 1/2" NPT, correct?

Sorry Joe, I meant to type 12458924. These are the last two pumps listed. Summit doesn't know why what appear to be the same pumps are priced differently. Here's the page I referred to yesterday:

http://www.summitracing.com/search/department/cooling-heating/section/water-pumps/part-type/water-pumps-mechanical/make/chevrolet/engine-family/chevy-small-block-gen-i/pump-finish/natural/water-pump-style-application/short?PageSize=100&SortBy=DisplayPrice&SortOrder=Ascending&N=4294950709%2B4294948875%2B4294948846%2B4294951398%2B4294951379%2B4294947374%2B4294948899%2B4294925571

[Joe C.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

As an important addendum to the original question, does anyone know which of the more popular pump brands are "Made In USA". I realize that this phrase has caveats such as casting, machining, assembly, and materials acquisition.

Any thoughts on which manufacturers ( e.g.: Weiand, Edelbrock, Stewart, Moroso, Tuff Stuff, Summit, Milodon, etc) meet which of the above phases of "Made In"................

[Joe L.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

The 8810 looks like a quality pump. It's cast and machined in the USA and that's a MUST. I don't know where any of the others are manufactured. Both openings for the pipe nipples on my factory 326 pump (Corvette application) are 1/2" NPT, correct?

Sorry Joe, I meant to type 12458924. These are the last two pumps listed. Summit doesn't know why what appear to be the same pumps are priced differently. Here's the page I referred to yesterday:

http://www.summitracing.com/search/d...9%2B4294925571

Joe------

Yes, your original pump ('326') has 1/2" NPT fittings for both bypass and heater hose.

The GM #12458924 is not a specialty or specifically heavy duty pump. It is actually the replacement pump for 1982 Corvettes. However, it does have the same 3/4" shaft and jumbo bearing size of other HD pumps. I'm not sure that this pump has SAE size fittings. By 1982, a lot of engine peripherals had gone to metric and the singular application of this pump is 1982 Corvette. Even if the fittings are SAE, I fully expect that the bypass fitting will be 3/4" NPT.

Assuming that you were going to go with this style pump, the GM #88926099 would be a much better choice. It is the 1971-81 Corvette waterpump. It has the same shaft and bearing size as the above and it definitely has SAE fittings. However, the bypass fitting is 3/4" NPT. Once again, though, this pump does not have the same hub spacing as your original pump and it only has the 3-1/4" bolt circle on the hub. To use this pump I would recommend using the 1971-82 waterpump pulley, GM #3991423. This will work with your existing GM #3858533 balancer pulley. However, you will also have to use the 1971+ fan clutch and fan blade assembly.

Where are the above waterpumps manufactured? Well, I can almost guarantee that the castings will be of Chinese origin, although the pumps may be of US machining and assembly.

Using the Edelbrock 8810 gets around all of the above-referenced problems and still gets you the 3/4" shaft and jumbo bearing. In my mind, it's the absolute best way to go for you. It will be, essentially, a bolt on installation using all of your existing components. However, the bypass will likely still be 3/4" so all you need to do is to install a reducer in the fitting. These are easily available from most of the Corvette parts vendors.

[Gene M.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

Joe,
Summit and http://performancesst.com/home.php have stainless steel fittings and offer 3/4 to 5/8 and 5/8 to 3/4 conversion for the heater hoses.

[Joe C.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

Joe:
Here are the final three choices:

http://www.summitracing.com/compare

Two of these, you have suggested for my application. The Weiand looks comparable to me. The only consideration is quality/assembly location. I know that Edelbrock and Stewart either have their own foundry or use a US based facility. Weiand, a Holley company, is machined in USA, but not sure of casting and assembly process locations. I am leaning toward the Stewart part, unless I have a valid argument as to why the Edelbrock piece costs an additional $70. Thanks for your help so far.

Gene:
Thanks for the link to bushings. Shouldn't need one with any of these three pumps, but valuable link much appreciated.

************************************************** ****************************
EDIT: So although Summit's website shows the Weiand pump has a 5/8" pilot diameter, Weiand's website shows ALL TEAM G PUMPS USE 3/4" BEARING AND 3/4" PILOT, which brings us back to the original 2 pumps that Joe recommended.

[Joe L.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

Joe:
Here are the final three choices:

http://www.summitracing.com/compare

Two of these, you have suggested for my application. The Weiand looks comparable to me. The only consideration is quality/assembly location. I know that Edelbrock and Stewart either have their own foundry or use a US based facility. Weiand, a Holley company, is machined in USA, but not sure of casting and assembly process locations. I am leaning toward the Stewart part, unless I have a valid argument as to why the Edelbrock piece costs an additional $70. Thanks for your help so far.

Gene:
Thanks for the link to bushings. Shouldn't need one with any of these three pumps, but valuable link much appreciated.

Joe------


That link does not work for me. Please post a link to just the Stewart pump you're considering.

As far as Weiand pumps, I used to like them. In fact, I used one on a small block for years and it definitely has the 3/4" shaft, jumbo bearing, 5/8" pilot and correct hub spacing. I believe that Weiand used to have their own foundry somewhere in southern California. However, I don't know if they still do. Also, my Weiand pump is of conventional configuration. Now, I think all of the Weiand pumps have a "twisted neck" configuration. Maybe it's OK but I don't like it.

[Joe C.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

Joe------


That link does not work for me. Please post a link to just the Stewart pump you're considering.

As far as Weiand pumps, I used to like them. In fact, I used one on a small block for years and it definitely has the 3/4" shaft, jumbo bearing, 5/8" pilot and correct hub spacing. I believe that Weiand used to have their own foundry somewhere in southern California. However, I don't know if they still do. Also, my Weiand pump is of conventional configuration. Now, I think all of the Weiand pumps have a "twisted neck" configuration. Maybe it's OK but I don't like it.

Not sure if I like it either. Looks gimmicky. I would think that ribbing in-line with the shaft axis would be better. Certainly more conventional. Although it would be logical to think that the "twisted" ribs might prevent fatigue across two axes rather than across the shaft axis. Seems to me that a casting would have a tendency to split along the shaft axis if subjected to vibrational (bending) loads.

I think that the link I gave you "times out" after awhile, so try this link:

http://www.summitracing.com/search/department/cooling-heating/section/water-pumps/part-type/water-pumps-mechanical/make/chevrolet/engine-family/chevy-small-block-gen-i/pump-finish/natural/water-pump-style-application/short/pilot-diameter-in/0-625-in/water-pump-rotation/clockwise/quantity/sold-individually?N=4294950709%2B4294948875%2B4294948846%2B4294951398%2B4294951379%2B4294947374%2B4294948899%2B4294928596%2B4294925667%2B4294925669%2B4294951810&PageSize=100&SortBy=DisplayPrice&SortOrder=Ascending

and look at the three "checked" pumps toward the bottom: the 22103, 9222 and 8810.

[Joe L.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

Not sure if I like it either. Looks gimmicky. I would think that ribbing in-line with the shaft axis would be better. Certainly more conventional. Although it would be logical to think that the "twisted" ribs might prevent fatigue across two axes rather than across the shaft axis. Seems to me that a casting would have a tendency to split along the shaft axis if subjected to vibrational (bending) loads.

I think that the link I gave you "times out" after awhile, so try this link:

http://www.summitracing.com/search/department/cooling-heating/section/water-pumps/part-type/water-pumps-mechanical/make/chevrolet/engine-family/chevy-small-block-gen-i/pump-finish/natural/water-pump-style-application/short/pilot-diameter-in/0-625-in/water-pump-rotation/clockwise/quantity/sold-individually?N=4294950709%2B4294948875%2B4294948846%2B4294951398%2B4294951379%2B4294947374%2B4294948899%2B4294928596%2B4294925667%2B4294925669%2B4294951810&PageSize=100&SortBy=DisplayPrice&SortOrder=Ascending

and look at the three "checked" pumps toward the bottom: the 22103, 9222 and 8810.

Joe-------


I think the Stewart pump would serve your purposes just fine. Functionally and specification-wise, I think it's equivalent to the Edelbrock pump. However, I've got to admit that if it were me, I'd probably go with the Edelbrock pump even at its higher cost. Edelbrock has absolutely great quality. It might be a dumb thing to do but I'd probably still do it.

[Joe C.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

Joe-------


I think the Stewart pump would serve your purposes just fine. Functionally and specification-wise, I think it's equivalent to the Edelbrock pump. However, I've got to admit that if it were me, I'd probably go with the Edelbrock pump even at its higher cost. Edelbrock has absolutely great quality. It might be a dumb thing to do but I'd probably still do it.

Thanks for all your help, Joe.
Sometimes there's no doubting the old adage: "you get what you pay for".
I know that Edelbrock has been around for a long time. I don't know very much about Stewart, but I'll probably buy the Stewart piece.

Here's something to ponder re the old adage above:
Sometimes if you take a chance, you can be rewarded when "biting" on a suspiciously low price. I liked a pair of AFR aluminum heads and almost bought them when someone steered me to an outfit called "ProFiler". My first thought was...............geez, what a stupid name and a lame play on words. I did my due diligence and afterwards bought the ProFilers at a 40% savings. Fully cast, machined and assembled in the USA. Very high quality pieces which flow same as or better than the AFR heads.

PS: Kevin Stewart is recommending I expand the pilot hole in the pulley and use the 22203 pump which he says is stronger than the 22103. He feels that the pulley hub wouldn't be weakened to the extent that it would offset the gain in strength due to the beefier pilot. He maintains that the stress riser created at the 3/4" to 5/8" transition point causes dual diameter shafts to fail much easier than full 3/4" shafts.

More to ponder. I remember hearing about hub reinforcements used on some earlier model Corvettes. I'm thinking of either trying to buy one of those, or make a reinforcement plate and weld it on if I decide to expand the pilot hole.

[Joe L.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

Thanks for all your help, Joe.
Sometimes there's no doubting the old adage: "you get what you pay for".
I know that Edelbrock has been around for a long time. I don't know very much about Stewart, but I'll probably buy the Stewart piece.

Here's something to ponder re the old adage above:
Sometimes if you take a chance, you can be rewarded when "biting" on a suspiciously low price. I liked a pair of AFR aluminum heads and almost bought them when someone steered me to an outfit called "ProFiler". My first thought was...............geez, what a stupid name and a lame play on words. I did my due diligence and afterwards bought the ProFilers at a 40% savings. Fully cast, machined and assembled in the USA. Very high quality pieces which flow same as or better than the AFR heads.

PS: Kevin Stewart is recommending I expand the pilot hole in the pulley and use the 22203 pump which he says is stronger than the 22103. He feels that the pulley hub wouldn't be weakened to the extent that it would offset the gain in strength due to the beefier pilot. He maintains that the stress riser created at the 3/4" to 5/8" transition point causes dual diameter shafts to fail much easier than full 3/4" shafts.

More to ponder. I remember hearing about hub reinforcements used on some earlier model Corvettes. I'm thinking of either trying to buy one of those, or make a reinforcement plate and weld it on if I decide to expand the pilot hole.

Joe------


I don't know that I agree with him on the shafts. However, if I were going to go with the full 3/4" shaft, then I'd use the 1971+ waterpump pulley, GM #3991423. You'll also have to use the 1971+ fan clutch and 1971+ fan blade assembly regardless of whether you use an enlarged pilot hole original pulley or the 3991423.

By the way, the only Chevrolet applications that ever used a 3/4" pilot were 1971-82 Corvette and some MD/HD trucks. All others, including all 1971+ applications (all of which used the 3/4" shaft and jumbo bearing) used a 5/8" pilot.

The reinforcement of which you speak is GM #3720616. It's still available from GM. However, it would need considerable re-work to be used as I think you are considering.

[Gene M.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

Hey Joe C,
I've been following this post and wonder why you are not signing up for Edelbrock 8810 pump as it has everything you want. Is the flow thru it not good or what?

[Joe L.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

Joe:
Here are the final three choices:

http://www.summitracing.com/compare

Two of these, you have suggested for my application. The Weiand looks comparable to me. The only consideration is quality/assembly location. I know that Edelbrock and Stewart either have their own foundry or use a US based facility. Weiand, a Holley company, is machined in USA, but not sure of casting and assembly process locations. I am leaning toward the Stewart part, unless I have a valid argument as to why the Edelbrock piece costs an additional $70. Thanks for your help so far.

Gene:
Thanks for the link to bushings. Shouldn't need one with any of these three pumps, but valuable link much appreciated.

************************************************** ****************************
EDIT: So although Summit's website shows the Weiand pump has a 5/8" pilot diameter, Weiand's website shows ALL TEAM G PUMPS USE 3/4" BEARING AND 3/4" PILOT, which brings us back to the original 2 pumps that Joe recommended.

Joe------


Here's an Edelbrock 8810 for 170 bucks. It's new but it's out-of-box. You probably won't care too much about the box, anyway. After you install the pump, you'll most likely just throw the box away.

http://www.ebay.com/itm/Edelbrock-Victor-Series-Aluminum-Maximum-Flow-8810-Water-Pump-Out-Of-Box-/331750426495?hash=item4d3dddc77f:g:8xEAAOSwoydWkTPg&vxp=mtr

[Joe L.]

Re: 1965 SBC Water Pump Severe Duty:Joe L or Any Other PN/Spec Expert

Joe------


Also, a correction to an earlier post of mine. I have found that the Stewart 22203 (with full 3/4" pilot) uses a hub spacing which is the same as 55-70 Corvette waterpumps (i.e. 5-5/8"). Therefore, you cannot use the GM #3991423 which I referred to earlier. There is, thus, no GM pulley which will be a direct fit for your application. If you use this pump, you will have to modify your existing pulley by enlarging the pilot hole to 3/4". However, I do not recommend doing this. If you decide to go this way, you MUST ensure that the enlarged hole is PERFECTING concentric with the existing hole.

If you choose to use your existing fan clutch, which I do not recommend, then you will also have to enlarge the pilot hole to 3/4". Once again, you MUST ensure that the enlarged hole is PERFECTLY concentric with the existing hole.