A few weeks ago had an overheating issue caused by not having an air dam which caused the radiator to puke out all the fluid - installed an air dam, new cap 16 psi and thermostat 195 deg.
She's been running perfect and operates around 180 - and never reached more than 200 deg on the hottest days.
Yesterday the gasket on the back of the water pump failed suddenly and leaked a couple of quarts - Napa has a water pump at $372 which seems ridiculously high.
Questions:
I looked at an older thread listed Napa TruFlo part number 43126 which is not valid anymore
What pump are other BB users buying?
What is the GM Part number if known?

I'd prefer not get into belt alignment issues with a universal short pump.

Also - Bearings seem fine I'm thinking a gasket kit.
IDK - Wanted to drive it over the holiday weekend.
Help? Advise?

 

GM part #6260822. https://www.corvettecentral.com/c3-6...7iHYtIYOHrvD9a

 

Thank you

 

Even in my little neck of the woods, there are still folks rebuilding water pumps within a 50mile radius of me. Rebuild the one you've got, especially if it's original. ChevyCool in Phoenix will rebuild it if no one is local to you – they may also have a replacement ready to go.

A GM pump for '74 454 should have #6260822 cast into it, along with a date code.

 

Stewart Components makes some great water pumps for our GM BB engines. I used a cast Iron water pump for many years and had a great experience. They offer different levels of water pumps and their pumps move coolant very well. I should have bought the Stewart Stage 3(?) which was aluminum from the start.

I now have a Edelbrock BB C3 Corvette Water pump in their silver ceramic finish and is a higher flowing performance pump and cools well. The Stewart company had a special way of making the Impeller that flows more water without the cavitation that happens on some performance pumps. The new aluminum water pump weighs far less than the factory style cast iron unit which is always a plus on a big block.

If originality is important to you then you could have that pump rebuilt by some company near home. If better cooling is the goal then buy the Stewart or Edelbrock water pumps. I have a few engine modifications that really push my requirements for a good cooling system.

 

I'm guessing someone out there will have a calculation relating to the increased coolant flow/volume of higher performance water pumps versus radiator cooling ability.
Does higher water pump performance mean higher coolant flow speed - or higher volume of coolant moved?
Is there a calculation relating to how effective a stock (or aftermarket) radiator may be when coolant flow is higher than stock.......perhaps passing too fast through radiator core for incoming cooling air to effectively offer improving cooling of the higher coolant volume?

 

Can't answer the above with scientific calculations or evidence.
I can say I've run both high flow and standard water pumps.
What I personally have found.
Keep in mind I live in tropical Queensland Australia. Where winter temperatures are similar to summer temperatures in the mid western US. And summer temps and humidity are out of this world.
High flow water pumps make zero difference.
Perhaps they move coolant at a faster rate. But then clearly it spends less time in the radiator.
Hi flow thermostats make a difference. A positive difference.
Bigger radiators make a difference.
A extended lower spoiler makes a BIG difference.
But high flow water pumps? Not so much. They work fine.
But the standard flow in my opinion works just a tiny bit better.
Perhaps those engineers that designed these engines had a clue.

 

When playing with the cooling system I like to put thermo-couples on the inlet and outlet hose connections. Then while the engine is running I can see just how effective the radiator is. Varying the flow rates did not make a big difference. Having the right coolant mixture makes a big difference.

If you used 70% water and 30% anti-seize the engine transfers more heat than it does with the 50%water 50% anti-freeze. Then if you want to see even more cooling you simply add a bottle or two of Redline's Water Wetter and the temps will drop even more.

I have an aluminum radiator and before I used a cast iron Stewart's Stage 2 water pump and it did a good job of flowing the coolant. After switching to the Edelbrock Aluminum water pump the coolant is flowing very close to the Stewart water pump. The temperatures did not change much after switching to the newer water pump when watching the radiator's inlet and outlet temperatures.

The higher flowing water pumps do help in vehicles that like to run hot from my experience. With my L88 compression I have the heat... The cooling system does need the extra help on the BB engine with the thermostat housing at the high point. Radiator caps are supposed to be located at the highest point in the cooling system, on the BB C3 they are not, and this requires some flow to push through the air pockets like the upper radiator hose.

I would love to be able to install a larger surface area radiator, I have a big chin spoiler and heat is always still an issue. My engine's compression MAKES a lot heat, it also makes POWER and that makes the engine a lot of fun to use.

Cooling a car properly requires a lot of factors, not just one "band aid" but many things working together to keep the engine cool. Timing, coolant mixture, radiator type and size, smooth hoses versus the universal type, factory cooling fan or aftermarket electric fans, radiator seals, engine compartment seals and condition of the engine for a few.

 

Guys,
I appreciate all the input.
I spent Friday trying to locate one locally and all I found even after Napa and Orielly's ordering them were wrong. Both didn't have the right dimension to the fan pulley or didn't have the correct dimension to the inlet nozzle.
I took some dimensions in case i find the correct GM Part Number.

After further research the GM part might be - #3992077, if it is i'll confirm dimes to help other in the future.
Or per Barkin grats might be '74 454 should have #6260822
Or I'll call corvette central for their super cool pump - reason I didn't is wanted to drive for the weekend.
Anyway, here's some pictures of what I have.

 

OP Dream Car C3
I've looked at Your pics closely.
Does your 454 have its 90 degree water pump-to-manifold bypass hose in place; or has it been plugged off ?

I'll second the choices from Stewart. Also, Edelbrock's Victor series.
Sadly, it seems Weiand has discontinued most, if not all, of its Team G series.
Victor is more robust than Edelbrock's Performer series. Likewise, Team G more robust than Weiand's Action Plus series.
Supposing Holley takeover prompted Team G demise ? At this rate, perhaps Weiand itself will soon founder.

 

Still have the by-pass - Concerns??

 

What ever you buy, measure the pilot pin in the center of the water pump that is for the pulley pilot pin hole, there are 2 different sizes.
I shop Summit Racing for the best aluminum pump I can afford. They are pricey. If you can find a rebuild kit you can try it but an aluminum one will save some weight off the front of your car. It all adds up eventually. Read the description and make sure its a short pump and is clockwise rotation

 

Good that you retain bypass.

 

It's really not difficult to rebuild your water pump. All you really need is access to a shop press, once you've removed the pump from the engine.

 

Got the pump on reman #386100 AC Delco from Oriely's
for anyone interested - I was able to remove and reinstall the pump without removing the fan - couldn't believe it. Direct drive no clutch though. If you have a clutch not sure.
If anyone wants a picture let me know.

 

If the car started to boil over then the first thing I would check would be the Radiator Cap. I should have mentioned this earlier as it slipped my mind.

Your Radiator cap has to maintain pressure inside the coolant loop. At Sea level the water will boil over at 212* (F), if you put a 16 pound radiator cap on the system, the boil over protection goes up to 261* (F). If your engine just started barfing fluid then I would check the Radiator cap, if more than a few years old replace it. The Radiator cap is an essential part in the cooling system and without the ability to hold pressure in the radiator will boil over earlier than it was supposed to.

Excessive anti-freeze in the coolant can lead to over heating as the anti-freeze does not conduct heat as well as the water. I use 70% water 30% anti freeze in my engine here in the central east coast. Water is so much better at transferring the heat out of the system.

A Bottle of Redline's Water Wetter is always a good thing as it helps remove the heat more effectively.

 

There are TWO water pump shaft diameters.
Early and late C3.
The switch was around 70 or 71 in C3s. (69 in other models) Early cars had a 5/8" pilot.
(The other chevies went to a long wp, C3s never did)
My 72 has a 3/4" dia. pilot shaft sticking out in front of the hub.
Make sure yours does to, and the new one.
Otherwise none of your pulleys, etc, fit right.
Corvette w. pumps are shorter than most other chevies. IIRC they all switched to a long pump in 71.