Saildrive Cooling problem

[TonyS]

I think that the water intake in the saildrive actually sucks the water out of the seawater cooling system when sailing fast. I have been trying to understand the delay in the flow switch closing which is situated under the Vetus antisyphon valve. The pipes are now clean and see through and you can see the water dissapearing. If the boat is heeled a lot, lowering the seawater filter then I believe it sucks all the water out and leads to impeller failure. Or can there be another mechanism or hypothesis?

 

[starboard]

Not sure of your question??...I have a Volvo MD5B driving a 110 leg. I have no problem as stated but dont fully understand the question!! Surely if you are heeled that much there is sufficient wind to sail and not use the engine, after all its a sailing yacht!!! I never resort to the engine till my sailing speed drops to 2kts, and only then if in a hurry!! Then again the old girl is 27 years and like to give it some TLC.

Paul.

 

[TonyS]

What I thought I was saying was that when "sailing" not motoring, the water is sucked out of the seawater cooling intake situated in the saildrive by the forward motion of the boat through the water.

 

[polantom]

I'm not an engine expert so please excuse me if this is wrong but does it matter if there is no cooling water when the engine isn't running?
Surely as long as the water flows when you are under power then it is ok? /forums/images/graemlins/confused.gif
Does the engine overheat at all?

 

[alldownwind]

Assuming that you mean the cooling system has the water sucked out of it when sailing, and therefore when you re-start the engine the impeller runs dry for a few seconds, I wouldn't worry. Still enough dampness around to lubricate it, I'm sure. (ooh what have I said /forums/images/graemlins/ooo.gif)
Anyway, if you've slowed down before you start the engine, taking sails down or the wind has dropped, the water probably runs back into the system anyway.