Replacement waterpumps

[Dottiesboat]

I need an engine circulation pump for a '99 LTR (Chev 350). The engine uses raw water cooling.
Why can't I use an automotive waterpump with a lifetime warrantee since they seem to only last about two years.

Does rotation direction of the pump matter?

Why do the seals fail at about two years.

Is there an update on the seals?

[NatesGr8]

I believe automotive water pumps are different than boat raw water pumps because they do not self prime and therefore you will not be able to pull any water unless you put your raw water pump below water level. I would suggest sticking with the marine raw water pump. If anyone else knows any different please post it here.

[wesgardner]

Just to clarify things...

There are two pumps - raw water pump (only boats have these)

engine circulation pump - I believe these are a component of the engine and therefore are NOT part of the marinization process (i.e. - you can buy one at an auto parts store)

Dottiesboat - I assume you're talking about the engine circulation pump? as you've stated

Wes

[Engine Nut]

Originally Posted by Dottiesboat

I need an engine circulation pump for a '99 LTR (Chev 350). The engine uses raw water cooling.
Why can't I use an automotive waterpump with a lifetime warrantee since they seem to only last about two years.

Does rotation direction of the pump matter?

Why do the seals fail at about two years.

Is there an update on the seals?

The circulating pump on your engine, belt driven near the top of the engine, is a pump that is unique to the marine industry. It is unique in several respects. The impeller in the pump is generally bronze or some other non-corroding material and is bi-directional, the back-plate is stainless steel - non corroding and the seals are designed to run in raw water not in anti-freeze. A change in the seals on the GM supplied pumps happened two or three years ago and the longevity has improved significantly. It is hard to keep seals in those pumps because raw water does not lubricate as well as anti-freeze. There is typically debris (sand etc.) that goes into the engine with the raw water that is particularly hard on seals as well. If your dealer buys pumps from MasterCraft or Indmar, they should have the improved seals.I can't speak for other circ pump sources.

[André]

Engine nut
Where have you been hiding all those years ???
Man,it's fun to read good ,clean ,understandable answers...
We should start a new thread: "Ask Engine nut ".

[AirJunky]

Ditto what Wesgardner said...... the raw water pump is an electrical pump (on my '94 205) on the port side down by the stringer under the engine.... it sucks water from the intake grate under the boat. The engine also has a circulation pump which in turn has a separate device on the front of it that houses the impeller. I have not heard there is anything different about the automotive & marine circulation pumps, but it's possible the seals could be different as Engine Nut said. But the circulation pump CAN be replaced without effecting the impeller housing.
You might check with http://www.skidim.com on this. They really know their inboards & are great at stuff like this.

[André]

Originally Posted by AirJunky

Ditto what Wesgardner said...... the raw water pump is an electrical pump (on my '94 205) on the port side down by the stringer under the engine....

Electrical pump ???

[Engine Nut]

Originally Posted by AirJunky

Ditto what Wesgardner said...... the raw water pump is an electrical pump (on my '94 205) on the port side down by the stringer under the engine.... it sucks water from the intake grate under the boat. The engine also has a circulation pump which in turn has a separate device on the front of it that houses the impeller. I have not heard there is anything different about the automotive & marine circulation pumps, but it's possible the seals could be different as Engine Nut said. But the circulation pump CAN be replaced without effecting the impeller housing.
You might check with http://www.skidim.com on this. They really know their inboards & are great at stuff like this.

The raw water pump is direct driven off the crankshaft on an Indmar engine. It has a rubber impeller and supplies raw water to the engine. This pump is connected directly via a 1 1/4" ID hose to the through hull pick-up on the bottom of the boat. On some applications, there is a transmission cooler between the water pick-up and the pump and on others the trans cooler is between the pump and thermostat housing. There are no electrical water pumps supplying water to the engine, unless somone has added one for some reason.

[wesgardner]

Hey Engine Nut

Didn't know the circ, pump was different for marine engines....mine's been fine for 15 years....I have replaced my raw water pump, however....

Airjunky, what pump is electrical? Mine are either belt drive (circ.) or crank drive (raw)


Wes

[Footin]

My raw water pump is leaking out the back, is it easier to buy a new pump or take it off and have a new seal pressed in?