Water pumps

[80' 427]

So I will honestly say I believe in running stock until it no longer does the job. I have done this with starters, fuel pumps etc. That said I have a leaking pump on my K30s 454. When I was putting the engine together I could here a rub rub rub noise turning the wp pulley. I pulled the back cover off and holy crap the impeller was like .25-.375 away from the front face and was rubbing on the back cover. I am not sure if some how it moved or if it was built that way. Anyway I pressed it to spec and of course now the seal leaks. It cools great but the leak is getting worse. So the real question is I can see you can get HP water pumps. Will it really make any difference in a nearly stock engine? I have never really had problems but I plan on the sand and do beat the crap out of it. Plus it idles alot on the trail. Otherwise I may just go with a stock remain for $30 from Napa (or a new one for $40).

 

[Fordum]

I had the impeller come completely off the shaft one time. Surprisingly it kept cooling pretty good.
There was nowhere for it to go, and there was enough friction to keep it spinning some.
I had noticed it was running a little hot, and was going to check when the fan blade started touching the radiator.
Shaft just slid right out of the pump, but did not leak a drop.
There was enough shaft left to keep it sealed.

Plus, I helped fix a Firebird that started running super hot after the owner changed the water pump.
Turned out that the reman shop put the wrong impeller on it.

So lots of weird things can happen.

As far as your engine, most of the time the stock pump is more than adequate. I would increase the size of the radiator or change the fan before I would start worrying about the amount of water being moved.

 

[80' 427]

I looked it up and a hp pump is actually only 8 dollars more. I may just do it.

 

[80' 427]

Oh and when I pressed it back together it went HARD.

 

[Fordum]

Sounds like it might be worth it. Any idea what is different? Does it pump more water per RPM, or just have stronger shaft and parts?

The more/faster water, the more horsepower it will take to drive it.

I have had a rough day, so I am a little fuzzy. I know that with air, the horsepower requirements are pretty much cubed.
For example, if you double the amount of air, it takes 2X2X2 or 8X the horsepower.
I don't remember about a liquid, but since air pretty much behaves like a liquid, I suspect its the same.

 

[80' 427]

It just says better impeller but it is new compared to a reman. Has all new parts. I love that a water pump is under $50.

 

[80' 427]

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=TFW44027P_0258178441

 

[Fordum]

That is why I like working on my old 1966 Ford F-600. Water pump is $29, fuel pump, $15.

 

[chulisohombre]

I used a hd one in my 67 impala. It was a pretty tight built high hp engine and. Wanted to make sure it had enough flow to keep it happy. I think it is a better seal and bigger impeller to push more liquid. For ten more bucks why not do it.

 

[dyeager535]

I'd have to look up the parts in the GM manual to see if different ones were offered, but without taking the cover off the back of the pump, you really have no idea what you are getting.

Some will have simple covers riveted to the impeller so that fluid can't "leak" out of the impeller, theoretically moving more water at the same RPM's.

I wouldn't be surprised that for cost or mileage (and maybe very rarely actually for cooling performance) GM ran different size or blade count impellers.

I have an Edelbrock aluminum pump on my bench that has an impeller in it with holes that appear to have been cast that way. Their engineers never answered me if it was supposed to be that way.

Tradeoff of power "robbed" by a pump that works harder vs moving the additional weight of a larger radiator is probably a wash. Moving fluid faster (assuming it's done without cavitation and isn't hitting some other barrier like how much the hoses can flow) will always help cooling.

 

[454Sub]

I run a stock one on my 454 with a 4 core radiator and a 180* thermostat. It can idle in the driveway without the Windstars running and will never get over 200* on a day like today. Its about 80 something here now.

I too go with the stock replacement parts as far as waterpumps, starters, ps pumps, blah blah. Until stock wont do it anymore. Its nice to run stock, as I dont have to order it from Summit and instead can get it from a local parts house.