Which Water Pump To Get???
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Which Water Pump To Get???
Looking at the various suppliers of water pump for my '96 LT4...how in the heck does one determine which one to get....which ones are junk, which are good?
Is it just the best to go with GM or are these the same, just placed into a GM box?
Prices are anywhere from $85 to $145 for what seems to be the same thing.
Some state higher flow....larger bearing...and so on and so on.....
Is it just the best to go with GM or are these the same, just placed into a GM box?
Prices are anywhere from $85 to $145 for what seems to be the same thing.
Some state higher flow....larger bearing...and so on and so on.....
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
Good question. Most are the same 'ol thing, just a different package.
What IS different and desireble is a hi-flow pump that has a "cast" impeller. That is the efficiency of the pump. Its ability to move water even at idle increases dramatically with a cast impeller.
Look at your alternator. That 'fan' on the front under the pulley is EXACTLY what is inside 99% of all stock water pumps. The pump is designed to simply move water...not pump it.
The stamped impeller will move water,. BUT, when it gets critical when the engine it hot, conditions decrease the margin for error, the stamped impeller is just not good enough.
The cast impeller is a cast or moulded shape more like a turbine or a propeller that is made to push water...move water under pressure. many times more efficient and it is worth the search and the added expense. Find those at many performance stores, some of the vette catalog stores. I have one and it moves water at idle just as good as the stock pump did at 2500 rpm...
huge difference.
What IS different and desireble is a hi-flow pump that has a "cast" impeller. That is the efficiency of the pump. Its ability to move water even at idle increases dramatically with a cast impeller.
Look at your alternator. That 'fan' on the front under the pulley is EXACTLY what is inside 99% of all stock water pumps. The pump is designed to simply move water...not pump it.
The stamped impeller will move water,. BUT, when it gets critical when the engine it hot, conditions decrease the margin for error, the stamped impeller is just not good enough.
The cast impeller is a cast or moulded shape more like a turbine or a propeller that is made to push water...move water under pressure. many times more efficient and it is worth the search and the added expense. Find those at many performance stores, some of the vette catalog stores. I have one and it moves water at idle just as good as the stock pump did at 2500 rpm...
huge difference.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
GM part #88926213 is listed as having a cast impeller.
GM part #12527739 is listed as having a stamped steel...which has a higher price than the cast impeller.
None of the others I have looked at state what the impeller material is.
GM part #12527739 is listed as having a stamped steel...which has a higher price than the cast impeller.
None of the others I have looked at state what the impeller material is.
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
Lanny, for what its worth, I recently replaced my water pump with one from the "water pump man." Supposedly he rebuilds these with American bearings and seals. I have had it on for around 2 months now and drive my 94' daily. It seems to work fine but I think it might be starting to drip a tad from the weep hole and will confirm that tonight.
I too noticed on Rock Auto that the cast impeller AC/Delco pump is cheaper than the stamped impeller AC/Delco pump. I may try the cast impeller Delco if the pump I have now is indeed leaking.
Patrick
I too noticed on Rock Auto that the cast impeller AC/Delco pump is cheaper than the stamped impeller AC/Delco pump. I may try the cast impeller Delco if the pump I have now is indeed leaking.
Patrick
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
I think I have purchased one from this "water pump man"....it lasted about a year and then the bearing was spinning in the pump housing bore....so it hit the recycle pile.
The last one I got was from Checker Auto...now O'Reilly's....but they do not carry the same brand now. This was on my '95 which is now in the hands of John in the San Fran, CA area.
So I am still at a loss as to which to get??????????
The last one I got was from Checker Auto...now O'Reilly's....but they do not carry the same brand now. This was on my '95 which is now in the hands of John in the San Fran, CA area.
So I am still at a loss as to which to get??????????
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
I think I have purchased one from this "water pump man"....it lasted about a year and then the bearing was spinning in the pump housing bore....so it hit the recycle pile.
The last one I got was from Checker Auto...now O'Reilly's....but they do not carry the same brand now. This was on my '95 which is now in the hands of John in the San Fran, CA area.
So I am still at a loss as to which to get??????????
The last one I got was from Checker Auto...now O'Reilly's....but they do not carry the same brand now. This was on my '95 which is now in the hands of John in the San Fran, CA area.
So I am still at a loss as to which to get??????????
Race Director
Joined: Feb 2003
Posts: 11,672
Likes: 20
From: Lake Wylie SC
Have you considered an electric water pump? I went that route 6-7 years ago and it works so much better than the OEM pumps. Meziere (sp) makes a very good pump, just go with their HD pump. Benefits: no weep hole leaks on your Opti, it only takes about 30 minutes to change if you need to (I've got over 20K on mine). Works best at idle in the summer with the A/C on. Plus it frees up a few extra ponies. You also eliminate a possible oil leak where the shaft comes through the timing cover. Just something to think about.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Yep I have been considering going to an electric water pump, however they are over 3 times the cost and probably effort as well. Not sure how much longer I will keep this car....does not get much drive time any more. Just turned over 58,000 miles yesterday...('96 LT4)...so it is not really economically justified to go to the electric water pump. But then again...where the Corvette is concerned...are things ever economically justified???..LOL...
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Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
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From: Green Valley Arizona
I would not go with an Airtex brand just because of the bad history regarding their fuel pumps.
The Bosch unit is no longer available at Rock Auto for some reason.
I will likely go with the Delco unit I guess. Have not ordered yet.
The Bosch unit is no longer available at Rock Auto for some reason.
I will likely go with the Delco unit I guess. Have not ordered yet.
Pro
Joined: Dec 2011
Posts: 626
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From: Austin, TX
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
I'm sorry to say you are wrong
http://www.rockauto.com/catalog/x,ca...,parttype,2208
http://www.rockauto.com/catalog/x,ca...,parttype,2208
The second time I was allowed to put into the shopping cart, but shows zero stock.
Race Director
Joined: Jan 2005
Posts: 10,641
Likes: 13
From: Slidell Louisiana
I love my mez HD. Allowed me to use a SBC double roller timing chain, I can cool the car off with engine off, makes burping easy, and it end's a potential oil leak too.
Folks talk about how at high rpm the stock pump pumps a higher gpm, but I only have about 4 gallons of coolant so IMO 50gpm should move the coolant through the system a couple times a minute when things are warmed up and working hard. Its been in since 2006 without issue.
Mike
Folks talk about how at high rpm the stock pump pumps a higher gpm, but I only have about 4 gallons of coolant so IMO 50gpm should move the coolant through the system a couple times a minute when things are warmed up and working hard. Its been in since 2006 without issue.
Mike
Race Director
Joined: Feb 2003
Posts: 11,672
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From: Lake Wylie SC
Yep I have been considering going to an electric water pump, however they are over 3 times the cost and probably effort as well. Not sure how much longer I will keep this car....does not get much drive time any more. Just turned over 58,000 miles yesterday...('96 LT4)...so it is not really economically justified to go to the electric water pump. But then again...where the Corvette is concerned...are things ever economically justified???..LOL...
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
For those that have gone to an electric water pump....what is done with the water pump drive? Is the front cover removed and the drive parts taken out and then a plug is put into the front cover?
Is this plug easy to find?
You guys have me leaning towards the MZ...
Is this plug easy to find?
You guys have me leaning towards the MZ...
Race Director
Joined: Jan 2005
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From: Slidell Louisiana
MIke
Last edited by aboatguy; Feb 24, 2013 at 08:37 AM.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Stock impeller?
Does anyone know what the stock, OEM water pump impeller is; cast iron or stamped steel?
Could everyone with a 96 LT4 go remove their water pump and take a look at the impeller and post what it is?
Could everyone with a 96 LT4 go remove their water pump and take a look at the impeller and post what it is?
Le Mans Master
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From: Akron Ohio
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Race Director
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From: Color my life with the chaos of trouble.
I was lucky enough (sarcasm) to have quite a few on my '96 track car. There are a LOT of differences between brands. The best I saw was by ACDelco, I believe with a GM Performance Parts branding. The differences are much more than the impeller itself. The cheap pumps that I saw had 1 set of bearings as opposed to 2 with the Delco pump. The shaft itself was also a much lower grade steel. Even the pump bodies were a much better made part. I'm a professional nerd for a living (quality engineer) and those things really stick out to me. There is no way I would ever go with 1 of the cheap units. This is a case where I have seen first hand that you get exactly what you pay for.
As for going electric, that was my eventual approach. The Meziere is a great pump and had no problems keeping things where they needed to be even in some extreme environments with an engine that made a LOT of heat.
For the front drive, I left it exactly like it was. Some feel the need to plug it, but I always carried a spare mechanical pump with me so I wanted to be able to install it in a hurry if I had to. I never saw any ill results from it.
Last edited by RedLS1GTO; Mar 1, 2013 at 11:50 AM.