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Water pumps, which one ?

MrMarty51

MrMarty51

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Location
Miles City, Montana
Rock Auto shows the AC Delco pump.
Part No. 8892690
Price on that is $100.79
The other favorable choice is the GM Original.
Part No. 88894035 or Part No. 12456231
Price on that one is $189.79
Trying to decide which pump would be the better unit for longevity.
The GM original pump has the same first part No. that @Will L. Listed in another thread.
I do have the NAPA pump that I installed on this engine about 8 years ago and it was functioning just fine.
I do believe that if there is a warranty period on this new engine that there will be the need for a new coolant pump and possibly even a radiator flush.
I’ll know more when the enjun is delivered.
There most likely will be a list of must do items to keep everything correct.
 
88894035 and the 8892690 are supposed to be the same unit that was made at the two different plants. Afaik the 8892690 is the one still being made for new GEP going into hmmwvs.
They were done as a casting number for some inhouse basis is my understanding.
But maybe a call to Delco’s tech support and ask them any difference in details to verify would be good.

On this topic, I’m torn because I bought a pump years ago and it has sat on the shelf all this time. I excepted to have it running long ago, now wondering if the seal might have dried up and be better to not run at this point…
 
Long as I’m putting this much into the truck, a new coolant pump wont hurt that much more.
@Will L.
I too have a new pump on the shelf that’ll never get installed.
Thats one of those higher volume, higher pressure pumps that Leroy sells.
And thank You for the information on the numbers.
 
From a 2008 MaxxTorque article on the topic of 6.5 engine cooling, “Testing [of multiple pumps] proved that
coolant flow was reasonably equal – side-to-side – only at low RPM.”

The conclusion of the testing showed GM Pump part number 88894035 (97 and later) was the one that provided the more balanced delivery from passenger to driver side along with a higher flow volume, roughly 98GPM. 48+% delivered to the passenger and 51+% driver’s side at 2500RPM. The 1996 and earlier pumps flowed 75 GPM and delivered closer to 22% pass. 76% driver side at 2500RPM

FWIW, I’ve yet to see a validated test showing the magical, mythical 150gpm from GM.

A couple of excerpts from the Spring 2008 MaxxTorque article:
6.5L Water Pump
“A more recent investigation focused on coolant flow-conditions in the cylinder block and heads. Testing proved that
coolant flow was reasonably equal – side-to-side – only at low RPM. As the engine speed was raised, the flow
increasingly favoured the driver‟s side of the engine. In testing a 1995 model engine with factory issue (low-volume)
flange type water pump, the coolant flow was biased 76 percent on the driver‟s side when the engine was at 2500
RPM. This bias in flow, combined with high engine load conditions, can have a detrimental effect on passenger-side
cylinders. The factory issue, low volume coolant pump used on 1992-96 engines was found to produce approximately
75 GPM at 2,500 RPM. Again, only 24 percent of that flow moved through the passenger side of the engine….

At the conclusion of an exhaustive evaluation, we had determined a clear and decisive winner in the factory service
replacement water pump: part number 88894035. This GM pump proved to be vastly superior to all others in terms of
bias with a much improved and nearly equal coolant flow, side-to-side at 2,500 RPM. This represents a tremendous
improvement in flow to the passenger side under heavy operating conditions. This represents a tremendous improvement in flow to the passenger side under heavy operating conditions. Where the flow rate on the passenger-side had been a paltry 22 GPM with the ’97 high volume flange type pump, the 88894035 pump provided 48 GPM!”
 
MrMarty51 said:
Now that is a lot of information. Takes the question right out of which pump is best for the serpentine belt driven pumps.
Thank You very much @Paveltolz
Click to expand...
Happy to help.
jrsavoie said:
I thought there were 2 pumps that were the same. The only difference being, one pump had a spin on fan and the other a bolt on fan
Click to expand...
Correct. There are bolt on and spin on fan models but, during the testing, the Spin On one (GM 88894035) produced the best results for the article.

Apparently they tried an improved GM pump w/ bolt on fan from 98 w/ dual T-Stats. While it flowed more at 94GPH vs. the older 75GPH pump, there was no improvement in bias between passenger and driver's sides.

Heath used to sell a 'Balance Flow' kit that utilized the rear passages to try to improve the driver/passenger bias but, the new GM Pumps made it all moot given the price points. TurbineDoc used to run it. It could be seen in some of his reference pictures in the stickies. However, with all the busted links and failed picture transfers when the stickies were updated, I don't know if they're still visible so here's one I saved from his thread on relocating the OPS.
OPS relocation.jpg
 
Big T said:
If that is a true AC Delco unit from RockAuto, then it’s a good price. Otherwise, go to AC Delco store on Amazon.
Click to expand...
Here is what all is on the way.
When I did a highlite and copy, then pasted it into the RA search function, this is the pump that it came up with.
I hope it is as good as the AC Delco unit.
It was quit a bit over the price of the AC Delco pump.
IMG_0640.jpeg
 
Paveltolz said:
Happy to help.

Correct. There are bolt on and spin on fan models but, during the testing, the Spin On one (GM 88894035) produced the best results for the article.

Apparently they tried an improved GM pump w/ bolt on fan from 98 w/ dual T-Stats. While it flowed more at 94GPH vs. the older 75GPH pump, there was no improvement in bias between passenger and driver's sides.

Heath used to sell a 'Balance Flow' kit that utilized the rear passages to try to improve the driver/passenger bias but, the new GM Pumps made it all moot given the price points. TurbineDoc used to run it. It could be seen in some of his reference pictures in the stickies. However, with all the busted links and failed picture transfers when the stickies were updated, I don't know if they're still visible so here's one I saved from his thread on relocating the OPS.
View attachment 89827
Click to expand...

I have one of those kits sitting around if someone had a use for it.
 
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