Engine bay ventilation

[RedRover]

Does anyone know what size of ventilation grill is required in a rear engine bay to enable the engine to breath properly and not let fumes into the boat via other gaps.? The one i have at the moment is only about 5 inches long by 4 inches high.

[Antares_9]

I would think that's probably OK for a small low revving motor Barry, if that's what the builder put in it should suffice. A quick check would be to run flat out and then open the bay to see if the engine speeds up at all, if the motor is being starved then it should. If you feel the heat build up in the bay is a bit too much you could always fit a bilge blower on a temp switch.

[mbird]

When we bought our boat, Barry, there was no ventilation at all. Being a mid mounted engine, the air was drawn from the bilge. The first thing I did was refitted the crankcase breather to the air filter to help reduce the smell of engine in the boat, and then cut a hole through the hull and fitted a vent approx 8" x 3". No problems at all, and no smells now either.

[RedRover]

When we bought our boat, Barry, there was no ventilation at all. Being a mid mounted engine, the air was drawn from the bilge. The first thing I did was refitted the crankcase breather to the air filter to help reduce the smell of engine in the boat, and then cut a hole through the hull and fitted a vent approx 8" x 3". No problems at all, and no smells now either.

I don't suppose it will do any harm to cut another hole in the hull, after all its about half inch thick anyway.

[goodall_m1]

I don't suppose it will do any harm to cut another hole in the hull, after all its about half inch thick anyway.

Just make sure that the hole is well above the waterline....

And remember its there if you ever tip the boat up on a mud flat.

Clive's disaster thread pointed out the perils of vents that get tipped below the tideline...

Martin

[RedRover]

Just make sure that the hole is well above the waterline....

And remember its there if you ever tip the boat up on a mud flat.

Clive's disaster thread pointed out the perils of vents that get tipped below the tideline...

Martin

Yes,Martin the current hole is well above the waterline and the only reason the water would reach it is if i'm sinking.

[Antares_9]

I don't suppose it will do any harm to cut another hole in the hull, after all its about half inch thick anyway.

I Can't see any harm either Barry, neither can I see the point until you have established the necessity to do so . You have not said what makes you think your motor is starved of air or any other reason why you might think it warrants it.

[RedRover]

I Can't see any harm either Barry, neither can I see the point until you have established the necessity to do so . You have not said what makes you think your motor is starved of air or any other reason why you might think it warrants it.

David there is a smell of diesel everytime i go to the boat (only in the rear cabin) but dissappears when i open the doors and windows.just thought it was lack of ventilation at the rear thats all.

[C.Ricko]

Hi Barry,

With your nice new engine installation I would not expect your engine bay to smell unless you had a diesel leak, check this first, it may just need a wash down if someone had a little slip changing the filters or bleeding the engine?

you only need half a thimble of diesel to make the boat smell..

[RedRover]

Hi Barry,

With your nice new engine installation I would not expect your engine bay to smell unless you had a diesel leak, check this first, it may just need a wash down if someone had a little slip changing the filters or bleeding the engine?

you only need half a thimble of diesel to make the boat smell..

Thanks Clive i'll have a look.but i think when it was in hire the batteries went flat so the auto bilge pump did not come on so the bilges filled up with oil and water from the old leaking engine,then when the batteries were recharged the oil was left stuck to the bilge sides so creating a smell. have been using Bilgex to try and make the smell fresher.

change of post thread to,

like your project coming on nicely cannot believe how much work has been done expect your looking forward to the first voyage next year.expect a lot of people will be taking pictures on the launch trip.

[C.Ricko]

Barry,

they are (were) getting on well,two chippies on there now, they only have tomorrow left to work on it before getting on with work in the shed, though it is just the electrics which need doing now to make her operational and they will get done soon anyway.