Small block 400, edelbrock heads. New short water pump. Run engine on test stand for about 10 mins and water shot out beteen the pump and block. Changed the gaskets and 5 mins later the bearing went out. Get a new pump from Orallys, engine ran about 10 mins bearing started to lock up. Bought a reman pump , engine ran about 3 mins and pooring water from the back of the pump.:mad:
I have no clue.

Running plain water or coolant??

Plain water in the first two which is why I thought they may have went out, but I all ways just run water when breaking in a new engine.

Update: bearing did go out on the 3th one.

I can't believe that plain water is the cause. :noway:
Maybe a series of bad rebuild water pumps???? All coming from the same parts store George?

I can't believe that plain water is the cause. :noway:
Maybe a series of bad rebuild water pumps???? All coming from the same parts store George?
All from the same store, two new ones, one reman. I have a good used one from a boat that I just put a new engine in that I think I will try tomorrow. All three did not have a hole at the top to oil the bearing but the one from the boat does.
George

Thats hard to believe all three would crap out on your so fast. Fingers crossed though its just a run of bad water pump luck. Hopefully the pump on your boat engine doesn't do the same thing.

George, this does sound strange indeed. I find it hard to believe. You are throwing me a curve with the statement of a oil on the top to oil the bearing. New water pumps have a hole for letting you know of seal failure on the shaft and water will drip out. It's not for oiling the water pump bearing. These have sealed bearings. I havn't seen water pumps with grease or oil fittings on water pump shafts since the 30's and 40 vehicle years. Maybe boats are different. Keep us up to date.

Best Regards

UPDATE: Got the boat water pump on and so far so good. I drove it a round the block.:hurray: Very loud will open hedders. Ran hot about 220.
George

I can't believe that plain water is the cause.
MOST water pumps have seals that will be ruined if they're run with plain water. There must be a lubricant in the coolant to keep the water pump seals happy.

Water-soluble oil or any commercially-available anti-freeze will provide water pump lubrication. I use a can of water pump lube (primary ingredient: water soluble oil) in plain water when I test-fire an engine; then switch to anti-freeze mixed with distilled water when that engine goes into a car.

Beyond that--I'd say the guy got a series of defective water pumps and/or the accessory belts were WAY too tight. Or perhaps an unbalanced fan wiped out the bearings.

I went thru three new pumps last winter on a new motor, all new short pumps from Napa on a small block. Leaking, bad bearing and finally the shaft broke the housing on the last one, running antifreeze and all were new and made in China. The fourth is working but we had to tear it apart and press the hub farther on about 3/16" for proper belt alignment, factory AC and P/S.
cw

Strange...we've run straight tap or distilled water for years in various cars while at the drag strip...tracks don't like to clean up antifreeze...NEVER any water pump issues. :confused: