TommiM

iTrader: (19)

There is thread around here that was started about an ac delco water pump for an evo8 that was an exact fit and much cheaper. Having heard great reviews about it, and ac delco being a very reputable brand, imo. I decided to order one for my new build. Well it finally arrived and I wanted to take a few shots of it so you folks can take a look at it and compare to an oem unit.


One obvioius design was that the oem has one extra blade and are longer, vs the ac delco which has a beefier center section, wider blades, but one less blade. Hard to see in the pic but also the opening behind the blade seems larger in the oem unit. The oem also has a polished section on the ring behind the impeller vs. the ac delco which is all just cast finish... Very curious to get any feedback from long term users of this pump. Any differences in coolant temps?

(ignore the tape and gasket material)
ac delco left, oem right

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Here is a closer look of the smoothed finish area behind the impeller of an oem waterpump.


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here is a closer look of the rough casted finish area behind the impeller of the ac delco unit.


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here is a pic of the slightly different design of where the pump outlet o-ring seal would fit into. Here is the ac delco. They decided to use grooves cut into the center


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And here is my oem one. Its hard to tell in the pic cause its used, but instead of cutting out grooves in the middle, the whole area is cut for the seal.


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On the exterior fitment looks dead on. the center flange on the pulley sticks out more but that shouldn't be any issue with anything rubbing in front of it. The flange itself is much beefier, as you can see by the smaller clearance between the housing and flange. Not a problem as I would opt for the beefier version imo.


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All in all it looks like a nice piece. Because of having a different blade design I am curious about feedback from folks have been using this pump on there evo compared to an oem one.

mrfred

iTrader: (50)

nice post and comparison. coolant temp data at idle and at high power for stock vs ac delco would be helpful.

TommiM

iTrader: (19)

Never did get anything like that logged while my old one was on but ya, that information would be nice to see.

TommiM

iTrader: (19)

Heres a little update on this. Today I was able to look at the differences between the gasket supplied with this pump vs. an oem one.


Here is the gasket supplied with the ac delco pump. Notice the gasket area between my fingers and how it partially covers that water port.


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Here is an oem gasket. Notice how the oem goes around the port completely. (sorry for the blurry pic)


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The oem gasket also feels and looks to be a little more durable.
The pump itself still seems like a great deal and should work fine, I personally would recommend to buy an oem gasket instead though.

I don't know how much of an issue it would really cause to use the ac delco gasket, but overtime I could see water breaking down the gasket right there, causing not only debris in the coolant system but also possible gasket failure.

TommiM

iTrader: (19)

Bump for an update. Now that I have evoscan I am able to log info. No issues with this pump. Been driving it tuned at 25 psi, making 340hp/350 ft lbs on E85. Cali weather has been averaging about low to mid 80s. Evoscan logs show coolant temps average about 198ish. usually go back to 192 and sometimes spike to 203, but then will drop back to low 190s soon after according to the logs. Havent seen anything stay above 203 on the street driving which also has lots of stop and go. No track reviews yet.

twabtoxer

iTrader: (39)

Thanks for the write up! Looking forward for further updates

420a-t

iTrader: (15)

I just bought my gates brand new waterpump and decided to take some pics next to my oem waterpump I bought two years ago from the dealer for $225 or so. The Gates one I bought from rockauto.com for $36.79.

They look almost identical besides some of the stamps and numbers on them. The gasket and o ring are included as well. I would use an oem gasket though, seen above as to why.

I will not be buying anymore oem waterpumps if I can get the gates ones this cheap, and have a good reputation as well.

Not trying to threadjack, just figured I'd post some more info on different ones out there

TommiM

iTrader: (19)

Thanks for posting those pics up. This makes it even better to compare three different brands, Gates, AC delco, and OEM. The difference in impeller design is interesting. Im curious if the ac delco will have less tendency to aerate coolant spinning at higher rpms. Im averaging about 182 deg F while Im crawling through Cali traffic. WHen I driving spirited, even on hot days, the most Ive seen it spike to was 203 deg F. No data yet on temps at the track. Although I have had the idea to drive through the Grapevine as that seems to put extra stress on vehicles' coolant systems.

EVOkeeper

iTrader: (1)

my theory as why the blades would be differetn is because when a large manufacturer like ac delco makes a part, they have a database of blade dimensions that other cars use for water pumps, and if this dimension is equal,close or matches in most aspects, then they just cross match the item in to the evo pump instead of having to make one specifically for it.
i.e. enlarging the inner bore of the blade assembly to fit an evo pump if a close match is available is cheaper than to recreate a blade assembly just for the evo pumps. so a blade with lesser fins made the cut.

It reduces production costs and increase profit, and Im sure that small changes wont be detrimental, considering the basis to make a pump function is pretty simple, and these are the factors as why aftermarket pumps are cheaper. the OE pumps are engineered for that application, and that application only in most cases so that translates to higher production costs and its the consumer who pays for it.