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SBC water pump recommendations:

vandelay industries

vandelay industries

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1) i am looking for a water pump that is:

a) Aluminum

b) standard flow. i don't want (and don't think i need?) "high-flow;" Everything is pretty much stock, and the stock cooling system is doing a pretty good job.
UNLESS, using a "high-flow" pump does not put any extra pressure/strain on the stock system; In that case, i may consider a high-flow pump, i.e., Edlebrock 8811 etc.

c) High quality; Money is not an object as long as it is under $300.


2) Now, if #1 cannot be achieved, then what is a good quality stock-type iron pump?
 
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I have been very pleased with both of my Edelbrock water pumps. I don't have tons of years or miles on either, but enough to feel justified by the cost.

I have one big block, one small block. Both standard rotation.

As far as cast iron, I have installed 2 new ones from auto-zone on TBI 350s. So far good results. They aren't made in China like NAPA ones..
 
I've used Edelbrocks as well, very good results with both SBC and BBC units.
 
vandelay industries said:
1) i am looking for a water pump that is:

a) Aluminum

b) standard flow. i don't want (and don't think i need?) "high-flow;" Everything is pretty much stock, and the stock cooling system is doing a pretty good job.
UNLESS, using a "high-flow" pump does not put any extra pressure/strain on the stock system; In that case, i may consider a high-flow pump, i.e., Edlebrock 8811 etc.

c) High quality; Money is not an object as long as it is under $300.

2) Now, if #1 cannot be achieved, then what is a good quality stock-type iron pump?
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Damn, was going to point you here: https://ck5.com/forums/threads/cheap-high-performance-water-pump.326717/ But it looks like they were mis-selling them when I bought mine, I paid $65. Rockauto apparently sells similar/same.

The majority of the pressure in the system comes from the radiator cap, that's why your lower radiator hose doesn't collapse without other issues and hoses fail by splitting. Contrary to some of what you will read/hear, unless the pump cavitates or causes weird flow issues within the block (which I've not read evidence of), the faster fluid is moved through the radiator the better. The physics is absolutely clear on this. High flow/high volume is good, there is no downside, except maybe cost. If the cooling system is adequate to start with, the potential benefit is added cooling system "capacity" if you happen to end up in more demanding conditions...towing, crazy heat, low speed climbing, etc. Also, as your radiator ages it will provide less and less cooling, so more velocity/volume will potentially mitigate some of that loss of efficiency.
 
dyeager535 said:
Contrary to some of what you will read/hear, unless the pump cavitates or causes weird flow issues within the block (which I've not read evidence of), the faster fluid is moved through the radiator the better. The physics is absolutely clear on this. High flow/high volume is good, there is no downside, except maybe cost. If the cooling system is adequate to start with, the potential benefit is added cooling system "capacity" if you happen to end up in more demanding conditions...towing, crazy heat, low speed climbing, etc. Also, as your radiator ages it will provide less and less cooling, so more velocity/volume will potentially mitigate some of that loss of efficiency.
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My understanding of the thermodynamics involved is that the working fluid (water-glycol radiator fluid) needs time to absorb energy from the engine, but not as much time as it needs to dump that energy to the incoming air. This is because of the temperature differential. The higher the temperature differential, the faster the fluid can transfer the energy. So when the fluid comes into contact with the hot engine, the energy difference is high and the heat transfer rate is high. When that same fluid comes into contact with the air, the heat transfer rate is slower so it takes longer to release the heat that is picked up from the engine. Now how fast is too fast? I have no idea.

Not that I really care but that is how it was explained to me....

Sorry to hijack
 
Multiple components, all interrelated...cylinder wall temperature is far beyond boiling point of coolant. Coolant around the cylinders will boil nearly instantly, slowing coolant flow exacerbates that issue, and bubbles do not cool. Speeding coolant flow lessens that effect, as does reducing the incoming coolant temp. Slowing coolant through the radiator means slowing flow through the engine, increasing the outlet temperature of the engines coolant, which means higher temperature back into the engine if radiator efficiency isn't changed.

The temperature differential cylinder wall vs. coolant and ambient air vs coolant is also much, much greater. The coolant in the engine does not need time to absorb heat because the differential is so high. It needs to be removed as fast as possible to eliminate boiling. This is also a reason that some sort of bypass is designed into all normal automotive engines I'm aware of, at least modern ones...coolant is plenty cold, but without circulation it still boils where it is needed most. (FWIW, bypass is accomplished via the heater hoses on trucks such as ours where generally there is no shutoff valve)

If you could isolate radiator coolant flow velocity from engine block flow, then it would work. But you can't, because the pump determines flow rate through the entire system, assuming the thermostat is fully open. Unless you already have an overheating problem, the effect of slowing or increasing coolant flow would be nearly impossible to determine unless you exceeded the capacity of the cooling system by doing so.
 
The system is under pressure to help diminish the boiling at the cylinder.

And small block water pumps have a bypass built in, it's the extra hole by one of the mounting bolts. Big block has a bypass hose.
 
Pressure definitely helps, adding somewhere around 45* to the boiling point, but I was a bit disappointed never having been able to find a good measurement of the exterior cylinder wall temperature. Combustion temp is approximately 4000*, but that certainly doesn't mean that's what they head/cylinder wall temps run at.

Is it the pump or the block casting? Vortecs went external, supposedly that was a change to the block. With a heater hose out of the intake, and no shutoff valve, it's got a bypass. ;)
 
Well I don't have knowledge past a TBI 350. (And I plan on skipping past the '96-'99 engines)
I believe.....that the block and the pump match with the bypass hole. And of course, now I want to go look to be certain, but I don't have one apart to look at....
 
I'd just get a reman unit from the parts store.

Last one I got from O'Reillys cost like $20 and it had a pretty nice coat of black paint on it. Cast iron unit with a lifetime warranty.

Never had any issues with the remans.
 
handloader90 said:
I'd just get a reman unit from the parts store.

Last one I got from O'Reillys cost like $20 and it had a pretty nice coat of black paint on it. Cast iron unit with a lifetime warranty.

Never had any issues with the remans.
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It's not like the GM waterpumps had any particular issues (nor did these trucks cooling systems in general seem to, all stock), and the cheap ones should be fine for a standard application. You'd almost certainly be fine with a standard unit. Larger, more powerful engines are where you would definitely want to take any advantage possible.

With a properly operating thermostat, you could have the most efficient cooling system on the planet, the engine is still only going to run at approximately the rated temp of the t-stat. It would just be able to do so with much more load than a less efficient cooling system.
 
handloader90 said:
I'd just get a reman unit from the parts store.

Last one I got from O'Reillys cost like $20 and it had a pretty nice coat of black paint on it. Cast iron unit with a lifetime warranty.

Never had any issues with the remans.
Click to expand...


Same Here, specially for his application, otherwise it's a want not a need, and that's perfectly fine.
 
I installed a rebuilt motor in a Camaro I once owned, 427. I forgot to install the thermostat. Thought it would be fine, I'd get to it later. Nope. Got hot as hell. Without the thermostat, the coolant was rushing through the engine, apparently not moving slowly enough through the radiator to let it do its job.

I just installed a cheap NAPA water pump in my Blazer, works great so far.
 
Green Monster said:
I installed a rebuilt motor in a Camaro I once owned, 427. I forgot to install the thermostat. Thought it would be fine, I'd get to it later. Nope. Got hot as hell. Without the thermostat, the coolant was rushing through the engine, apparently not moving slowly enough through the radiator to let it do its job.
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This is one topic I've never seen discussed and solved/explained away. It's mentioned often enough that I don't doubt it happens. But I've also personally seen the exact opposite. No thermostat and the car would never get beyond luke-warm, no matter how hard I pushed the engine/car. Other than the older vertical flow radiators (not cross flow or new vertical flow) all the GM cooling systems I know of from the late 60's through to at least late 90's (or later) operated the same, so it's not going to be make/engine that is the difference, or component design. The same cooling system design will see some overheat without a thermostat, others never heat up. Both are experiencing "extra" coolant flow.

I'm not going to say it doesn't happen, but the reason cannot be too fast coolant flow (within our parameters). More flow=more cooling. PDF page 7 here has a nice, easy to understand graph demonstrating the same, in a controlled experiment: https://www.researchgate.net/profil...ormance-Evaluation-of-Automotive-Radiator.pdf

Billavista says essentially the same thing, in a pretty simple to understand article: http://www.pirate4x4.com/tech/billavista/Cooling/
When a thermostat is removed and an engine overheats, but doesn't when a thermostat is installed, something else is going to cause the overheating, other than an increase of coolant flow, but of which I have no clue. I have seen one theory that it may be caused by the lower hose collapsing, which I can see as being potentially possible, if engine temp isn't increasing enough (due to lack of thermostat) to build appreciable pressure.
 
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I've seen engines ruined by running without a thermostat,they never warmed up enough to boil off condensation in the crank case and run warm enough to let the computer go into full loop...vehicles used for shorter trips suffered the most from this..

The 400 SB I had would boil over in 5-10 miles until I discovered it had no thermostat..I put a 195 temp one in it and the only time it ever overheated after that was when I tried going further than 10 miles with the plow on it...fixed that issue by manually locking the fan clutch "on" by taking the coiled spring on it off its tab and flipping it 180 degrees and putting it back on the tab again..sounded like a hoover vacuum cleaner and it did reduce power some,but it ran cool as a cucumber after that...in the spring I'd switch the spring back to its normal position..

Personally I do not see a need for any super flow high capacity water pumps --as long as the radiator is clean and big enough the engine should stay within its normal operating range with factory components...my theory is if it overheats due to towing ,you either need a lighter trailer or a bigger truck,your just overloading it..
 
I ran the Edelbrock high flow aluminium wp on my 400sb, worked well. Issue I had was the seal leaking (had 2 leak). I used it because my motor ran hot, it did help.

After the second ones seal went out, I replaced it with a standard cast iron unit. Engine ran 15-20° hotter. Ended up being a tuning problem.

My take on it is, if you need a high flow wp on anything but a race engine, you have other problems that need to be addressed first. It should be a last resort.
 
Figure I've seen quoted is that coolant will drop about 10* through the radiator. I don't have an IR gun to check that out, but as with everything, there are variables that affect that.

The one easy way to look at it is that if you have a theoretical high flow water pump that moves twice as much fluid as "stock", then you've effectively doubled the size of the radiator. Some of the manufacturers tout better low RPM flow, which I can see helping at slow speeds, high ambient temps, and AC.

That's what I find interesting about GM's strategy with the truck big blocks and diesels...the amount of surface area of the radiator exposed to airflow doesn't change a whole lot. The AC condenser cutout is a fixed size, and about the size of the small (17" tall) radiator. It seems to me that they were as interested in increasing the amount of coolant available as they were airflow over it. Yes, the shroud covers the whole back side of the radiator, but the "inlet" to radiator airflow is much smaller. It obviously works, perhaps since the extra width is on the inlet side, due to the higher fluid temp at that side, it was able to shed heat fairly well, even with minimal airflow compared to the center of the radiator where airflow would be greatest, but fluid temp will be less.
 
Wow---this thread has gone in directions i wouldn't have imagined; Not complaining because i'm learning. Jus sayin'

Anyways, if i could interrupt for a sec for an update:

What happened was i decided to cheap out and replace the back cover gasket---and i did this with it still on the engine. Yes, it is possible with a 10mm ratchet wrench, and patience. i am not a large guy and not being overweight also helps (although i use to be overweight and this may be a separate topic in The Lounge section). i used Permatex's The Right Stuff and it works great.

Well, it turns out it WASN'T the back cover gasket---it was the weep hole after all. So all that work, wasted. Although i did learn that it IS possible to replace that gasket with the pump still on the engine.
a) i AM NOT happy with Advance Auto Parts water pumps. In all fairness, i do not remember if this was the budget line or a higher priced unit, but it only lasted for about 4 years and much less than 20,000 miles.

So, i went with the Edlebrock 8811 which was in-stock at the local PepBoys---because i need it done by Monday morning (normally i order form Jeg's/Summit etc). i just want to confirm that the plug that goes into the top of the pump (normally for the heater hose) is NPT thread?

Continue on!
 
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The factory plug on the "short" water pump was NPT,either 3/8" or 1/2",I forget which..
Not sure if aftermarket pumps still used pipe threads,I would assume they did..

You must have the patience of Job to replace the back cover gasket without taking the pump off...its only 4 bolts to remove it,and a few more to loosen the belts (if it has V belts)...
I remember replacing the water pump on my '72 K5 on the side of a busy highway years ago,it took me about 20 minutes..not my favorite place to do major repairs,but it was either fix it right there,or pay $200 to get it towed 50 miles home..
I had the new pump with me,and was on my way to my parents house to replace it,the weep hole on the original was dripping for about a week ,when the bearing decided to suddenly grenade during the ride home--the fan grazed the radiator,but didn't make it leak..
 
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