Bilge blower

Thresher

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Bilge blower. At least I think that is what it is called. I have an electric extractor fan in my boat that not suprisingly extracts air from the engine compartment out through the transom.

But why? What's it for? I don't care how hot or smelly it gets in there.

Brendan.
 
Its to stop you from going BOOM!!!! when you turn the ignition key if there is build up of explosive fumes .

Regards

Terry
 
ITs to cut down on the latent heat of the engine and all its ancilliaries, that way your engine and everything in there will last longer, in the perfect world the engine would have its own external intake and you would have an intake fan sucking air in through a seperate ventand flooding the engine room with cool air and an exhaust fan sucking the hot air out, remember as well that fans cut down on heat being radiated into the rest of the boat through the sides of the engine box
 
Thanks, I thought it might be something like that.

So, I should switch it on when the engine starts to get hot or when it is a very warm day?
 
If your engine breaths from inside your engine box, an extractor fan sucking out of the engine box, is as much us as an ashtray on a harley, when the engine is running it pumps a lot of air. Switch it on before you start the engine, then switch it off, it wont draw air out with the engine drawing air in. Switch it back on when you stop, to draw hot air out of the compartment. As was said above, for an engine room extractor to work, the engine needs to draw air from outside the engine compartment.
 
Bilge sucker.

My Volvo 2002 is about 1/2 litre or so (probably a bit more but it's a good round figure).

At normal cruising I do 2,500 rpm, and its a 4 stroke so for 1 out of two cycles the valves are closed and not drawing fresh air. Therefore 1,250 times a minute it shifts 1/2 litre of air, or times by 60, 37,500 litres per hour.

Twenty strokes on the manual pump in the morning will clear the bilges of anything heavier than air lurking down there.

I would suggest the engine can look after itself, provided you can keep it fed with enough fresh air.
 
As previously said it stops an explosive mixture developing in the engine compartment, mostly found on petrol engine instalations. Diesel is very unlikly to produce an explosive fuel/air mix at NTP (normal temperature & pressure). I think on a petrol engine you should run the bilge blower for a few min before starting the engine.
Trevor
 
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