Raw Water Pump

[dave6330]

I was contacted by the delivery skipper bringing our newly purchased 1979 Pearson 365 Ketch to Alaska for us.  He's currently laid up enroute dealing with an engine overheating issue.  He says there appears to be an electric pump plumbed into the raw water intake system.  Has anyone run into this settup or is it unique to our boat?

[RayNWanda]

I thought we had the only oddball raw water pump. Ours is belt driven. I think everybody else's is driven off the camshaft and mounted on the engine front cover. You do have a Westerbeke W-40 ? Some of these boats got Universals.

[dave6330]

Ours is a Westerbeke.  I'm no mechanic, but I always thought raw water was drawn thru the system by the impeller on the engine itself.  I was a little cornfused when the skipper told me about another pump...

[kevin barber]

I have seen this before.  I met another P365 owner in the keys that had added an electric pump to his cooling system.  He added another seperate heat exchanger as well.  In order to fix his overheat issues, he tried to increase water flow by adding more volume of raw water. 

In my opinion, there are better ways to do this. 

This particular boat was a late model ketch, and had the Universal 5444. 

If this is the same boat, I may be able to help.

[dave6330]

It wouldn't be the same boat, but the problem may be related.  Also, during the haulout for survey it was noted that the oil cooler needed replacing and they did that prior to departure.  I'm thinking that that repair might be part of the issue too, since (apparently) the oil cooler is part of the raw water plumbing.  The engine didn't overheat during seatrials and I'm trying to think of what might have changed...

[EdHouston]

you may want to take a look at my "Making Steam" post I had some of the same heating issues and found a number of causes, not least lots of crud in the exchanger and strainer, also had broken fins in the raw water pump.

My boat has the raw water pump attached to the motor direct drive not electric.

Good Luck

Where is he laid up?

[dave6330]

BARNICALS!!!!  I had barnicals GROWING inside the heat exchanger!!!! 

They pulled the exchanger off the engine, took it in to a local radiator shop to boil it out, rodded it and reinstalled one day later.  Presumbably POLARIS is chugging allong without issues betwix hither and yon.