perkins cooling system

[Capt Dan]

I have a P-4-107 and a question about engine exhaust cooling.* After the salt water has done it's duty to the heat exchangers and oil coolers there is a T in the line before it enters the exhaust riser.** This allows part or maybe most of the salt water to exit thru a thru hull at the water line in the side of the hull.** With back pressure from the diesel, I am not sure any water would ever make it to cool the actual exhaust line.

Any help?

 

[Sunshine Rick]

I had a W30 Nomad w/Perkins 4-107 awhile back that had that arrangement. It had a gate valve in the line that went directly overboard, and I think the idea was you could close off the gate valve just enough until you had adequate cooling in the exhaust line without excessive backpressure.

Fast forward several boats later, I now have another W30 Nomad w/Perkins 4-107, but the overboard line is not there. There is a thru-hull where it used to go, but now all the water goes into the exhaust. The riser is now a simpler Vetus unit, so maybe that makes a difference, but I can't see that there is any problem with all the water going through the exhuast hose.

 

[Capt Dan]

Thanks for that, as I suspected.* I may just remove that extra thru hull and pipe the excess water into my PSS shaft seal, where I expect* less water will go, due to back pressure from being 3 feet below the surface, even tho there is some discussion that at 7 knots, the PSS needs no extra cooling water.

So many thru hulls on the W-30's.* Good to get rid of another.

Where do you cruise?* I am in Maine.

 

[Capt Dan]

I may also split the line that heads to the PSS, and run a reduced line into one of the cockpit drains, where I can see at a glance that I have cooling water flowing.* If I see steam,* know I have a problem.* Not my idea, I have seen it on a friend's boat.

Dan