water flow

[WayWeGo]

If you are chasing an overheating problem, an infrared heat gun can help you follow the water circuit and see where the temperature increases.

[Big D]

Given that the OP mentioned it's a dual pocket pump, we have to assume he's referring to the raw water pump and not the circ pump. It should also be noted that if it's a dual pocket pump application, in every such 440 application I've dealt with, they've never had a circ pump. I've only seen circ pumps on 440s with single pocket pumps. Has anyone seen an original unmodified OEM 440 dual pocket application with a circ pump? Just curious for personal knowledge.

This may seem like an over simplified question but we shouldn't assume anything; did you replace BOTH impellers in that pump? Had a friend that "replaced" his impellers but didn't know there were 2 per pump so he continued overheating. Don't know how he missed the second impeller but he did!

The condition of the inside of the pump affects its efficiency. If the top and bottom ends are badly scored she won't pump properly. If the cam is badly worn, output volume will be reduced considerable. One should always inspect these areas when replacing impellers.

[WayWeGo]

We have 440s with aftermarket Sen-Dure fresh water cooling. Their system is a bit different in that the raw water pump is a single pump and the engine mounted circulation pump is replaced by the belt driven dual pump that is normally seen on a raw water application. Raw water comes from the single pocket pump directly to the heat exchanger and onto the exhaust elbows. The manifolds, engine oil coolers and transmission oil coolers are all fresh water cooled through the dual pocket pump.

I have the installation instructions if anyone would like a copy.

[prowlersfish]

Given that the OP mentioned it's a dual pocket pump, we have to assume he's referring to the raw water pump and not the circ pump. It should also be noted that if it's a dual pocket pump application, in every such 440 application I've dealt with, they've never had a circ pump. I've only seen circ pumps on 440s with single pocket pumps. Has anyone seen an original unmodified OEM 440 dual pocket application with a circ pump? Just curious for personal knowledge.

This may seem like an over simplified question but we shouldn't assume anything; did you replace BOTH impellers in that pump? Had a friend that "replaced" his impellers but didn't know there were 2 per pump so he continued overheating. Don't know how he missed the second impeller but he did!

The condition of the inside of the pump affects its efficiency. If the top and bottom ends are badly scored she won't pump properly. If the cam is badly worn, output volume will be reduced considerable. One should always inspect these areas when replacing impellers.

Good info , Good point on the pumps .

[Footeloose]

Sorry, Prowlerfish, missed your question about the pump. Yes, it is the dual lmpeller, 4 hose pump, & I do have the intakes on the bottom, & discharge on the top. Thanks for the interest.

[Footeloose]

Oh yes, I did replace both the impellers, & I agree that there is no circulating pump as we know it on the engine. Just a note though, I was reading/studying the cooling section of the manual & noticed they were talking about a circulating pump in the raw water cooling section. That threw me, but then realized I DO NOT have a circulating pump on these 440's. Next time I crack open my pump, I will give it a VERY thorough inspection, but I do think it's in decent shape. Thanks for all your thoughts & suggestions. Dave