Who runs their engine compartment blower constantly while on the water??

[Tahoe 55]

Mercruiser man told me I should do this...

How common is it to have an explosion in and engine compartment?? Especially now with EFI??

 

[Knot Waiting]

Re: Who runs their engine compartment blower constantly while on the water??

I never do. So long as your engine is properly vented and not leaking any fuel I see no reason to continue to run the blower while under-way.

 

[Phantom_II]

Re: Who runs their engine compartment blower constantly while on the water??

I turn on my blower when I start prepping my boat for launch, and turn it off again when I get it loaded back onto the trailer.

It runs the whole time I'm on the water.

And there are lots of other possible ignition sources besides the engines ignition system.


It doesn't cost anything to operate.

 

[Tahoe 55]

Re: Who runs their engine compartment blower constantly while on the water??

Hmmm...

 

[salty87]

Re: Who runs their engine compartment blower constantly while on the water??

i don't run mine all day.

 

[tommays]

Re: Who runs their engine compartment blower constantly while on the water??

It is not at all common when you use the blower and NOTHING goes wrong BUT the whole point is that things CAN go wrong and this provides a saftey net


For the most part engine comparments do not have the passsive air flow they should

You will see seme more costly bost with a grill across the transome allowing lots of natural air flow

On my boat your supposed to do the 3 minutes before startup and anytime your at low speed

 

[a70eliminator]

Re: Who runs their engine compartment blower constantly while on the water??

I always forget to even turn mine on, (new to I/O's) they should have interlocked it with the ignition rather than just an off on switch. But it's all good my engine you can eat off of and my in floor tank vents out the starbird bow, not that it makes it right but some guys are oblivious to whats under the doghouse and plain stupid, I'm going to hang some kind of note on my ignition that says (RUN THE BLOWER!!)

 

[davidfhare]

Re: Who runs their engine compartment blower constantly while on the water??

I run mine *virtually* all the time. If I'm underway at speed for any amount of time I'll cut it off, but when back at slower speeds I have it back on. I run it 4 minutes before starting and a few minutes after cutting the engine off. If anchored and swimming for any length of time it's off.

This was under the advice of the dealership at my checkout.

 

[dvan1901]

Re: Who runs their engine compartment blower constantly while on the water??

I run mine a minute or two before I start it and leave it running while the engine is running and for another minute after I turn the engine off.

 

[Fu-Inator]

Re: Who runs their engine compartment blower constantly while on the water??

I don't use it as much as I should. I usually forget it when pulling off the beach.:redface:

 

[OhWellcraft]

Re: Who runs their engine compartment blower constantly while on the water??

I pretty much run mine all the time, I do alot of water sports with the whole family so there is alot of starting,stopping idleing, etc. Seems just as easy to leave it on plus my crownline has a very tight fitting doghouse over the 350 seems like it helps keep things a bit cooler. If I'm going for a long cruise I will shut it off after I'm underway(if I remember) or if I'm sitting, swimming, having lunch I will turn it off. It CAN'T hurt anything to leave it on unless you forget and run your battery down. Ive also heard it can help lessen the chance of dieseling if its running while in the no wake zone as it helps cool things off.

 

[cmcpherson]

Re: Who runs their engine compartment blower constantly while on the water??

The only time I turn mine off is when I am at anchor and when I put it on the trailer. The way that I look at it is that a burned out blower motor is a lot cheaper than what could happen without it running. Plus, mine runs so quiet that I forget to turn it off.

 

[BillP]

Re: Who runs their engine compartment blower constantly while on the water??

I only use blowers when starting and sometimes when anchored to cool the engine compartment and keep heat from creeping into the cabin. It's rare to hear of a boat exploding while the engine is running. Most gas explosions on boats happen at start up and your nose is the best protection before turning the key. Nobody has mentioned it yet but engines consume fresh air when running and it keeps most engine compartments from accumulating high concentrations of fumes anyway.


bp

 

[danond]

Re: Who runs their engine compartment blower constantly while on the water??

Nobody has mentioned it yet but engines consume fresh air when running and it keeps most engine compartments from accumulating high concentrations of fumes anyway.

bp

Yes - engines consume fresh air, but valve cover hoses fall off, engines run way too rich, leaks happen, sparks happen, etc. The blower is there to account for non-perfect situations. I don't think it's a good idea to suggest that people should bank on things working great all the time.

If my engine is running, so is my blower.

 

[bhammer]

Re: Who runs their engine compartment blower constantly while on the water??

I open the cover and turn on when I prep the boat. Close the cover and the blower stay on unless I tie up or anchor down.

 

[SooLineRob]

Re: Who runs their engine compartment blower constantly while on the water??

I'm a really new boater, so I relied on my owner's manual ... and added alot of time to what is required, being on the cautious side...

I run mine and verify proper operation from arrival/prep time at the ramp, until clear of the no wake zone. I'll shut it off when engine is above fast idle (cruising RPM's/10+ MPH), and turn it back on during fast idle or less, and run it for five minutes after engine stop and before engine re-start.

When the boat is laid up in the garage between runs, I leave the engine cover open to prevent fumes from building up from the engine and batteries charging.

 

[Boatist]

Re: Who runs their engine compartment blower constantly while on the water??

I turn mine on as soon as I board the boat then lower the outdrive, walk back and smell the output air.
If it smells normal I start the engine.
Then I start the kicker motor and let it run 30 seconds while the last crew member gets on board.
Shut the kicker off and raise and then get under way.
Once we get up on plane I shut Blower off until the next time we get ready to start up. Even then if the wind blowing 15 mph or more do not use the blower.

The question that should be ask is how many bolwer are set up right.
I would say about 50 percent the do not have the blower set where it does any good. My boat was not right when I got it from the factory.

Every boat should have 4 hoses.
#1 goes from low in the bilge under the engine to the blower then out of blower on to the rear faceing cowl. This hose should come from as low in the bilge as possible but not so low it could get blocked by bilge water.

#2 goes the same as number 1 but not thru the blower. So from low in the bilge to a second port on a rear facing cowl.

#3 and #4 come from the foward faceing cowls to a point high in the engine carpartment. Best if higher than the flame arester.

Idea is to bring in fresh air above the flame arester and force any heavy than air gas fumes down to the bottom of the bilge where they are sucked out by the bilge blower at low speed and calm wind. At higher speeds and wind the #2 hose will suck more air out than the hose with the blower.

 

[QC]

Re: Who runs their engine compartment blower constantly while on the water??

I am with Bill P on this. Blower to start and then it's off. Regardless of whether it is a perfect situation or not, the engine is always pumping in fresh air. How does a leak change that? How does a valve cover hose off change that? Why do I care about a valve cover hose off as far as a blower is concerned? No matter what, you are still exchanging air if the engine is running. Stick your face over the intake and jump on it once and then tell me that your blower is making any significant difference. Yes it pulls air from the bilge if the hoses are correct, but I still believe the level of air exchange while running is so much higher that all of the air under the cover is active while running. There may be a case for the blower while idling, but certainly not while on plane. That big hole in the middle of your engine is not "passively" exchanging air. Waaaaaaaay active.

I agree with Boatist on the hoses though, but I would bet less than 10% are right.

BTW, I have failed a blower by leaving it on accidentally once. It sucked a small price tag in with some adhesive on it and it stuck the blades. Blew the fuse, but I couldn't figure out the problem until I got her home. Now I have a spare, worked fine once I got the sticky thingy out.

 

[cmcpherson]

Re: Who runs their engine compartment blower constantly while on the water??

No good reasons not to run it all the time though, now are they...

 

[BillP]

Re: Who runs their engine compartment blower constantly while on the water??

I only posted how I do it to answer the original post so don't assume I meant not to run the blower whenever you want. My post was only meant to bring attention to the fact of when most explosions happen and that air is exchanged in the bilge when the engine is running.

I'll add this...If you run blowers full time be aware that melted blowers (there goes your spark protection) happens WAY more often than explosions from gas fumes. Have any of you examined your blower lately? It's another live electical circuit that can short, start fires or ignite gas fumes. Never heard of "valve covers popping off" but they wouldn't make fumes for explosions.The only thing they could do is let oil go in places that might ignite it. A blower would fan the flames so it would be wiser to shut the blower off if a fire started.

Even the smallest fuel leak while running will quickly overcome the blower and engine cfm anyway. Put about 10 drops of raw fuel in an open container in your bilge (don't start the engine on this one please) and see how long it takes for the blower to evacuate the fumes. I tried it 30+ yrs ago in a bottle cap and strong fumes stayed until the gas evaporated.

bp