73silververt

Rebuilding the original engine for my 73. Bumping it up a little, mild cam, 20 over with flat top pistons, heads completely rebuilt. Engine & heads #matching, restored original carb, restored original tach drive dist w/pertronix upgrade. Going for stock look with exception of headers, better performance. Ive got the original water pump, cant decide to rebuild, or replace and upgrade? is there an upgrade? Car is not restored to exact, will never be judged just trying to keep close to original as possible.

63vette427

I had my original water pump rebuilt but am using a Stewarts Stage 2 on the car now. I use it combined with a Dewitts Radiator and have had no issues. The combination keeps my big block at 180 degree. I'm happy with the Stewarts and will only use my original one when/if I have my car judged..

Mike Ward

You can spend tons of money on pumps, but they're not 'upgrades'. The stock pump has at least 35% more flow than required. More is not better.

MelWff

some water pump choices, aftermarket companies like stewarts use a disk on the impeller to improve flow

http://www.summitracing.com/search/y...d=water%20pump

Jeff_Keryk

I use a Flow Kooler and a AC (7 blade I think) fan. Everything else stock right down to the recored Harrison radiator.
No issues...

donyue

I have an Edelbrock 8812 water pump on my 427 Dart SHP SBC.

I can't say how it compares to stock, but it works fine with my engine and the Dewitt's rad and electric fans.

Gale Banks 80'

Probably the biggest up grade would be to use an Aluminum Pump to save weight. If a higher flow pump was used it would only cause less heat transfer and overheating. If it did have higher flow then that would mean it would suck more HP turning it.

c3_dk

I just bought Edelbrock 8810, but only due to going to hydr roller cam in my 355

riverracer au

i used a "EDELBROCK ALUMINIUM HIGH VOL SHORT WATER PUMP CHEV SB CORVETTE 3/4" SHAFT ED8812" on my 350 '72 rebuild.

just had to machine the bolt bosses down a little bit for the a/c bracket to fit / line up properly.

7T1vette

"Better" pump means more work done by the pump...which means more heat generated and more fuel used to power the pump. You don't want any more pump capacity in the car than is needed by the car. Otherwise, you've wasted money on the pump and will continue to pay more for having it.

If the engine you build is going to produce more heat, then the WHOLE cooling system needs to be re-engineered. All of the cooling system components are designed to work together. Change only one component and you are just screwing with the system.

If your car is going to be a street machine, you don't need an upgrade to the cooling system (if yours is in good condition). If something does need to be replaced, replace it with a similar product.

Street Rat

I'm sold on the Stewart pumps. That was the only pump that would keep my 468 cid Chevelle cool during the hot Texas summers. If your not having cooling issues go with the stock AC Delco pump. My .02.

jb78L-82

100%

I used the OEM GM water pump along with th OEM 4 core brass radiator for the 78 L-82 for 30 years and the car simply would not run below 200 degrees no matter what i did-that was the low temp with a high of 235-240 with AC on VERY hot days.

The super efficient combination for the car was a Stewart Stage 2 aluminum water pump and a Dewitts aluminum radiator and the L-82 NEVER ran cooler-never in 37 years of ownership. With my newly rebuilt L-82 355 and the Stewart/Dewitts combo the engine has never run even remotely hot. I did not have to upgrade anything on the cooling side-that is what happens when you run a super efficient cooling system.

BTW-the usual errant remarks by some about the GM water pump being perfectly adquate for most C3's is simply false-maybe other cars of the era but the C3's always poised cooling issues, especailly the High HP engines with AC. The difference in HP draw between a Stock GM pump and the super efficient aluminum water pump is esentially zero...the increased flow is mostly due to a more efficiently designed impeller.

Mike Ward

The usual errant remarks about the pump being inadequate come from people who have usually made TWO changes at the same time - one of which was responsible for any drop in temperature, the other with neutral effect.

If there's one thing GM got right it was cooling system flow rate. There's no evidence to show otherwise.

It's worth noting that the OP made no mention of any increase in coolant temp as a result of his engine mods. Not sure what problem he's trying to fix other than believing all the hype about aftermarket stuff.

Jeff_Keryk

Actually, a replacement pump can improve cooling; if the pump is going south, or the radiator is partially blocked.
Just sayin'...

jb78L-82

Nope again..put the Stewarts Stage 2 aluminum pump and the Dewitts aluminum radiator on the L-82 original engine at 2 different times-not at the same time….as for GM getting the cooling right on the C3 corvettes, tell that to the BB guys with overheating issues with the OEM motor and the 77-79 L-82 guys with cars that ran at 225 degrees totally stock brand new with Temps hitting 235-240 on the highway with AC on. The problem was not the water pump and brass radiator but the smog 882 heads that caused the engine to run HOT for emissions. GM recognized the cooling issue with the L-82's in 79 by adding an auxiliary electric cooling fan inside the fan shroud for the L-82's with heavy duty cooling in 1979 AND changed the 12 0'Clock position on the 79 temp gauge to 220 instead of 200 on previous years. The only way I could get my 78 L-82 to run sub 200 temps consistently was with the Stewarts water pump and the Dewitts aluminum radiator..that is a fact.

My comments are based on real world personal experience, not theory...

Mike Ward

Your examples of GM getting it right or wrong or fixing it was NOT related to the pump- as you have pointed out.

Thanks.

Your efforts to design 'out' what GM designed 'in' is a different discussion.