Having an engine built. what water pump do you recomend for a 77 ?
l48? any part numbers?
thanks

 

i bought a stewart aluminum for small block chevy , the short one . be good

 

You might consider the Stewart Components Water Pumps...I installed the P/N 33103... ' 71 - 82 'Vette High Flow Pump they are available from the major racing product catalogs, or Stewart Components direct.... My '77 does not even get to the 195 mark. and it is rebuildable. The best possible information is available at their web site www.stewartcomponents.com Take Care!

 

while you're at it , maybe ordering one of their hi- flow thermostat .bee good

 

Anyone have a part number?

are these better than gm stockers?

 

what's wrong with the stock waterpump?
They work well and are very reliable.

Unless you are racing the car and concerned about saving every possible ounce of weight in which case an aluminum waterpump would have some weight advantage what do you hope to gain by going with a fancy, aftermarket, racing style waterpump.
These are mainly designed to eliminate cavitation at very high RPM's for racing purposes - are you planning on driving the car with sustained high RPM's in the 7,000, 8,000, 9,000 RPM range?

 

The reason that I selected the water pump is for the increased coolant flow rate, With the stock water pump it just was not flowing enough through the engine, for the radiator to perform it funtion at low R.P.M. such as stop and go city driving. Now, all the cooling system components are what I would consider " balanced " ...

 

makes me wonder what other changes you might have made in the cooling system or the motor at the same time that helped cure any low speed cooling issues you were having.
The reason I say that is twofold:

1. most aftermarket "racing style" hi-flow water pumps as I've mentioned are designed for high RPM coolant flow in sustained 8000-9000 rpm ranges. In most cases the impellars are LESS efficient than stock OEM water pumps impellars at normal street usage rpm's. This is not really a design flaw but simply that they were designed to operate at and work best at higher RPM's.
The waterpump is rarely ever the cause of cooling system issues (overheating, running hot, etc) unless it's an old, original, very well used unit that the impellar has been worn away from corrosion.

2. In your case you mentioned issues at low speed with cooling problems. In most cases a low speed cooling problem is related to airflow management or ignition timing problems. High speed (highway driving) cooling issues are typically caused by radiator, restricted air or coolant flow.
since your issue or concern was low speed cooling you are dealing with airflow or ignition timing, not coolant flow so using a high-flow water pump for fixing a low speed cooling issue is counterproductive, especially since the racing style waterpumps are less efficient at lower RPM's and could actually make the situation worst.

Now, before I get completely flamed to death here let me say that I'm not against any aftermarket parts, BUT, I think too often people just start looking in the pretty colorful catalogs and see all these cool parts and many times figure that a "racing" part that works on a racing motor must be good so it would work great on my car too. Not always the case.
In most cases the stock OEM parts work best. They work as designed and are reliable and were engineered as part of the "system". To just randomly swap in a different part with different specs and in many cases what was designed for a different usage can be conterproductive and actually not work as well as how the stock part may work.

Now, the OP simply said that he was building a new motor to replace his L48. He did not state what he was having built, what size, what HP is planned, or even how he plans on using it. For all I know he may be having built a 800HP supercharged motor for dragracing in which case forget everything i've said and by all means go with the SW high-flow waterpump. On the other hand if the OP is just having a nice motor built for normal street usage than I stand by what I've said so far.

 

I use the stock Delco water pumps with no problems. As Barry said, sometimes the high flow ones can be counter productive.

 

Well, I just can not speak for most folks needs and driving conditions, I do not have any concerns about the operation of the complete drive train on my car. It took me about a month or more to decide on the water pump that would address the equal cooling of the heads and "wash" the heat from the engine so, that the heat exchanger could preform.....better. So, for my enviroment of 115 to 120 degree days , I feel that my system is now matched to my specific requirments.. another reason, I select this specific pump was because of the bearings and shaft seal ....Growing up in the Hydraulic, Pneumatic and Fluid Power Industry in the Desert Oilfields , we kinda know how, and what will control unwanted heat. and I was just not comfortable with replacing , what I consider a weak link in the system, with one just like it. The pump that I replaced was in normal operating condition... and was only acting as a flow regulator. And yes, I have upgraded the complete system. The hydrogen sulfide and other related gasses are rather harsh on some metals around these parts. " If it can't do it...it can't stay." I do hope that timgman gets the water pump that will solve his concern. Take care!

 

barry . i run that set up ( stewart pump , 180 degres hi flow thermostat , a general fit aluminum rad and a flex-a- lite electric fan ) You know sometime , we got very humid and hot temperature north of the border and a lot of traffic sometime 100 farenheit and being blocked for long hours and my set up never let the temps going over 190 degres . beside that , there's any place better to get rid of some weight and in conclusion , the flow is adequate and there's no such thing as to much volume or to high a flow . if the flow to rapid to cool the heath in the rad then it is to rapid to remove the heath in the engine , everything is always relative . that's my 2 cents be good

 

This worked for me, A team"G" aluminum weiland #925-9220, make sure you order the shim kit for some reason beyound my patience level everything lined up but the a/c belt.

Note - Its cheaper to ship an alum. pump then a stock cast pump
I got mine from jeg's

Good luck
JRL

 

A stock water pump will be fine. Why spend more for something that is not really needed.

Yes Stewart makes a fine water pump both in aluminum and iron depending on model. But for a stock build it is not really needed.

If you would like to increase the stock water pump flow there is a simple way to do it. There used to be a kit for t his but I have not seen one in a long time I think because it is too simple to make lol.

Simply remove the back cover and take a piece of sheet steel and cut it round close to the diameter of the back of the pump say within 1/8 of an inch and simply rivit it to the impeller and then close it back up. It will increase the flow of the pump.

 

SHAKERATTLEROLL, I believe the company that originally made that conversion was called Flowkooler. The need arose because GM changed the way they made their water pump impellers. Years ago they used to use cast iron impellers and then went to sheetmetal but with no backing plate on the impeller. The waterpumps with the sheetmetal impellers didn't flow as well as the others. I believe you can still buy these kits and they do work.