What cause I/O failure? Horsepower or Torque?

[mylesm260]

Re: What cause I/O failure? Horsepower or Torque?

I've been rocking an automotive water pump in my 4.3 vortec for 3 seasons now in fresh water only.

It leaks a TINY little bit, but is otherwise okay.

 

[MikDee]

Re: What cause I/O failure? Horsepower or Torque?

About 16yrs ago I needed a water pump for my 888 Mercruiser 302 Ford/188hp, and being I was at the Merc dealer for other small parts I figured I'd give them more business so I asked the guy how much is a new water pump for an 888 Mercruiser? He said $325! I said what's it made of Gold? Forget it, I then went to the local auto supply, & got a rebuilt generic pump for a Ford 302 V8 for $29.95, and figured I could replace it once a year, for 10yrs at that rate! But the joke was on me, because I couldn't mount it, the automotive heater hose outlets were hitting the block So, out they came, and I epoxied a couple of metal plugs in the holes, and used it.

One of the most expensive items on a marine water pump is the stainless back plate! Again, about 12 yrs ago I needed a water pump for my 350/260hp Merc, and the marina owner offered to get me one for $150 Then he said, if I get it without the stainless backplate, it's only $80, so take it off your old pump, & put it on the new one, so I did! By the way, both an auto, & marine, pump had the same cast impeller, if I remember correctly.

 

[fabrimacator21]

Re: What cause I/O failure? Horsepower or Torque?

I see...


I can't imagine why the automotive pump wouldn't fit... maybe ford used different blocks or it was the wrong pump...

Everyone I've talked to is telling me that the marine pumps have stainless impellers which is really only needed if your gonna be in the ocean. That is the expensive part, at least thats my guess. It's not easy to make impellers, especially out of stainless. I think I'm gonna take my chances with a duralast pump from autozone... 32 bucks with a lifetime warranty. How can you go wrong? Do I need a heavy duty pump for a marine motor though? I've heard the marine water pumps move a little more water then automotive pumps. The HD pump is only 20 bucks more.

 

[MikDee]

Re: What cause I/O failure? Horsepower or Torque?

The generic 302 V8 auto pump had two extra spouts on it for the heater hose, and would not sit flat against the block without hitting them, I had to remove them, maybe a different model 302 pump would have bolted right up, but I had no way to find out. All I know is, I tried to get the same year auto pump as the boat engine, I think it was a 1973'.

The 350 V8 pump that I got, I had to put the stainless back plate from my original pump on, so it came with the impeller exposed, and it had the same cast impeller I had on my original Mercruiser pump, I was surprised neither one seemed like stainless to me?

 

[fabrimacator21]

Re: What cause I/O failure? Horsepower or Torque?

Well it could have been just a cast impeller... but I know the mercruiser/omc chevy pumps come with stainless impellers. It may just be a stainless alloy that still ends up being cast.