Water pump specs straight 8

[2carb40]

Anyone know what WATER PUMP gpm is for Buick straight 8? THANX! in advance for specs not guesses.

[1939_Buick]

mis post

Edited August 11, 2022 by 1939_Buick (see edit history)

[Bloo]

All I can say is if you find it somewhere else, please post it to this thread.

[2carb40]

I will be researching and will post any findings, Thanx for responding!

[MCHinson]

The 1937 Buick Service Presentation booklet and the 1937 Buick Engineering Features book designed to disseminate technical information to Buick Dealership mechanics both have a bit of information about water pumps, including a detailed diagram instructions for rebuilding them, but  they do not have any specifications about how many gallons per minute the water pump is supposed to pump. My suspicion is that you would have to find some original Buick engineering documents and I don't think they still exist. 

[Mark Shaw]

The answer will be a range of flow, not a specific GPM.

Flow characteristics will vary primarily with RPM and back pressure from the radiator. 

I suggest you search for a performance curve online that is close to the size of your pump.

You will find that there are too many variables to arrive at the specific GPM for your pump.

 

[Bloo]

4 hours ago, MCHinson said:

The 1937 Buick Service Presentation booklet and the 1937 Buick Engineering Features book designed to disseminate technical information to Buick Dealership mechanics both have a bit of information about water pumps, including a detailed diagram instructions for rebuilding them, but  they do not have any specifications about how many gallons per minute the water pump is supposed to pump. My suspicion is that you would have to find some original Buick engineering documents and I don't think they still exist. 

In my opinion, the impeller face clearance, tip clearance (to the breakwater) and back clearance would all be very interesting things to know. Especially the face clearance, as I believe it to be the most important by far.

 

GPM, as @2carb40 wants, could be specified at a given RPM into open air, or through a specified orifice. I think that would be most useful for bench testing. Offhand I don't recall ever seeing a specification like that for any car.

 

[Buick35]

I'm curious as well because my 35 has two styles I have to choose from.The one on it now is the more modern type without the packing nut.I also have the older version.Both have been rebuilt.

[Mark Shaw]

20 hours ago, Bloo said:

GPM, as @2carb40 wants, could be specified at a given RPM into open air, or through a specified orifice. I think that would be most useful for bench testing. Offhand I don't recall ever seeing a specification like that for any car.

• Commercial pumps for irrigation or domestic well pumps typically run around 80% at the peak of their performance curve. 
• The overall efficiency of an automotive water pump is quite low and therefore not worth the trouble of making impeller clearance to factory specs.   
• The relatively crude impellers used in most older engines could never come close to those efficiencies.   
• Keeping the radiator and engine cooling channels free of corrosion and debris should be the primary concerns in preventing overheating.

I worked for one of the world's largest industrial pump and valve manufacturers for almost 30 years.  I suggest not wasting time trying to find exact specs to make such crude pumps perform incrementally better than they were designed to perform.

[Bloo]

Good to see someone who knows pumps in the thread. I sure don't, but have been reading a lot lately. I'm not as much interested in making a pump incrementally better, as I am in making sure I've not made it monumentally worse. I don't know what @2carb40 is up to but I suspect something similar.

 

On these semi-closed impeller pumps we see a lot of in cars, the clearance of the blades on the open side of the impeller seems to be a big deal. Some (1970s?) Fords, anecdotally anyway, have a problem with rebuilders putting in impellers that don't fit tightly enough to do the job. Studebaker had a problem like this in the early 60s and released a bulletin with all the clearances that needed to be held. Maserati had a mid year change sometime in the 80s that changed the impeller depth. If you get it wrong one way, the impeller bottoms out and scrapes or won't spin. If you get it wrong the other way, The impeller is too far away. The car just boils over constantly and nobody can figure out why because the parts fit and look like they belong. Pontiac V8s, some of them anyway, have a replaceable sheet metal stamping, with the tolerance that implies, forming the part of the pump body that the open side of the impeller runs against. As you might imagine sometimes they need bending to fit properly. Matt Harwood set the endplay to the book spec on his Lincoln pump and inadvertantly moved the impeller further away rather than closer. It stopped pumping altogether. He did eventually bench test that pump. I think in most cases you would never get to that point, but If I had some unsolvable overheating problem I would sure consider it.

 

[2carb40]

I will be researching and will post any findings, Thanx for responding!

THANX for all the replies! My ultimate and decidedly unscientific, but observable test was to put long enuff radiator hose on to divert exit water over the driver's side front fender also a hose that rose vertically on the inlet side on the passenger side to be able to replenish cooling water discharged(hopefully), by the pump, which worked to my satisfaction, as I wanted a good flushing strategy for the engine after derusting with Evapo- Rust. Two things were accomplished with one stone, as it were, I could watch not only pump out flow, but also see how clear the outflow became as I was flushing to be as sure as possible I wasn't contaminating a 'fresh' radiator repair. After assuring myself that was accomplished I hooked up the radiator and let the engine idle with 85 air temp. The temp gauge I installed held a steady 185 after approx 20-30 minutes of Idling. I'm feeling confident that at road speed it should be even better, (he said somewhat hopefully!).