Overheating while heeled

[msauntry]

Does anyone know if you can run the engine safely while heeled? Mine started to overheat yesterday when I used the engine to help round a bouy before scudding for home yesterday on the Bay. Water intake was submerged since I was heeled towards it, so I know it wasn't sucking air. I noticed water coming out the back, and it looked like normal flow, but I couldn't be sure, what with a shoal to my lee, a steep chop to sail into, and the boat trying to round up. I can only do four things at once Temperature started normal (160) went up to 200, back down, and back up. When I levelled off briefly between gusts, I thought it helped bring it down, but it went back up again when I was purposely trying to keep it level. Tried lowering and raising rps to see if that helped and it didn't.

Engine ran fine when we got back to Annapolis and temperature was steady 160 heading to the slip. We had also motored for an hour before this incident, also with a steady 160. I'm inclined, no pun intended, to believe that the heeling led to the temperature spike.

Does anyone know if the Atomic 4 can run safely while heeled? Oil pickup tube problems? I didn't check the oil pressure when it happened, but it did have normal oil level when I checked before the start of the trip, approx. 7 hours of engine run time before the incident. I'll double check it when I go back to the boat and see if it is still at the full mark. Engine is installed at the usual upward tilt angle of Pearson Alberg construction.

[agoodman]

I noticed this on my boat last week. we where sailing and I turned the motor on, at this point we were doing approx 7.4 kts with the motor running trying to beat a storm and my temp gauge went to over 180 I think we were going so fast that the intake was not sucking enough water. Our oil pressure was fine. Once we took the sails down and where running level the temp went back to normal.

[msauntry]

I could see how going fast might create weird venturis and such that could prevent water from getting sucked in, but we were only going 4-5 knots at the time and had been motoring around 5.4 knots for an hour before that.

I had used the engine on my last ocean crossing to charge batteries in neutral while the boat was heeled, and this didn't seem to present a problem for it. It is less of a load though.

Any one else have trouble with engine temps while heeled?

Anyone with a good idea of engine internals present a case of why NOT to run an engine while heeled.

[MikeB.330]

Are you fresh or sea water cooled? if you are fresh water cooled maybe your heat exchanger is low on coolant and when heeled was pushing air in the cooling system. it's a long shot but what the heck.

FWIW: I have run the engine heeled many times without any problem at all.

[msauntry]

Raw water cooled, late model engine.

Maybe an air bubble caused this. I'll have to go experiment more.

Flying by the gauges is such an ingrained habit now.

[daveinrenton]

Friends,

Heating up while sailing and motoring at the same time has nothing to do with venturis or anything so exotic. The issue is usually that the boat is heeled over far enough to lift the intake out of the water making it suck air. You will find the condition happening on a particular tack. On my Ericson, it is a port tack since my intake is on the port side of the hull. I was also in a rush on a recent trip and had all canvas up with the motor whirring away when I noticed the heat. I tacked over and the temperature dropped immediately. Putting two and two together, I figured out that the intake got lifted too close to the surface. Note also that it is a pretty powerful vacuum and the boat does not have to be heeling so the intake is at sea level, it just has to be close enough to suck the surface water away leaving only air. The quarter-wave created by the boat moving through the water can also lower the sea level by the intake as the wave troughs. Check where the intake is on your craft and keep the boat flat or heeling in the favored direction if you must sail and motor at the same time.

Keep cool!

Dave

[MikeB.330]

He said that the intake was on the leeward side of the boat so I doubt it sucked air. Or maybe, he forgot what side the intake was located..

Mike

[msauntry]

Nope. Intake is on starboard and I was on port tack, which buries the starboard rail. Intake is pretty deep so I doubt even with the rail buried on stbd tack it would ever see the light of day.
I doubt my boat could ever go fast enough to create venturi problems, but I know some powerboats have special thru hulls to accomodate this problem.

I suspect I have a backpressure exhaust problem.

[Bob.Griffin]

Just a thought, probably wrong, but a port tack would place the water pump (on the starboard side of the engine) a few inches lower than on even keel and the exhaust including the coolant outflow (on the port side of the engine) maybe quite a few inches higher depending on exhaust configuration. Maybe this increase of up to a foot in coolant lift height causes the coolant flow to slow enough (pump has to work harder?) to cause overheating.

Bob (s/v Saga)

[msauntry]

Funny how the mind works. I had thought of this, forgotten about, and remembered again once I saw your reply!

That could very well be it. Each time I've noticed it, its been while heeled to starboard. Since my exhaust plumbing runs on port, that totally makes sense that the extra lift could be causing me problems.
Next time I see it happen, I'll switch tacks and see if the temp goes down.

The suspense is killing me. I can't wait to overheat my engine again!