LOUD engine blower

[Parsons]

This brings up another question, the placement of the engine compartment intake. Mine is down very far in front of the shaft log behind the transmission, essentially in the bilge. This is probably a good design for eliminating diesel fumes, which I'm not worried about, but not for reducing heat. Ideas?

 

[Head Sail]

This brings up another question, the placement of the engine compartment intake. Mine is down very far in front of the shaft log behind the transmission, essentially in the bilge. This is probably a good design for eliminating diesel fumes, which I'm not worried about, but not for reducing heat. Ideas?

If the reason your trying to get rid of heat is for comfort, you can open your hatches turn on AC or a boom tent. Your engine is designed to withstand the heat it generates under normal operating conditions. Is running the blower to cool the engine specified by the manufacturer?

 

[Ralph Johnstone]

This is probably a good design for eliminating diesel fumes, which I'm not worried about, but not for reducing heat. Ideas?

This is the BEST possible area for supplying cooling air to the engine. The air has been pulled across the bottom of the hull which is the coolest surface in your boat.

 

[Meriachee]

Loud. May I introduce you to the Westerbeke 18. I'll bet there isn't a blower in this category that you could ever hear above the racket this little red monstrosity makes.
If you like somewhat disturbing thought that it's about to propel a rod through the hull, this is the engine you want.

 

[Ralph Johnstone]

If you like somewhat disturbing thought that it's about to propel a rod through the hull

............................. kinda like the pistons are swapping cylinders ?

 

[jssailem]

Meriachee.. I'll call your Westerbeke and raise you the 1973 4 cyl Perkins 4.107. This baby can stop your bride from talking when in the salon under power.

 

[Meriachee]

That's about right. It does have one great use, you can quickly find any loose fitting within 100 yards.

 

[jssailem]

Only when they are loose enough to rattle over the din of the engine. But usually that is just enough time to find a wrench and secure the fitting before it escapes to the peace and quiet of the briny deep.

 

[capta]

This is the BEST possible area for supplying cooling air to the engine. The air has been pulled across the bottom of the hull which is the coolest surface in your boat.

Most small craft engine space blowers I've encountered remove air from the engine space, not bring it in. As one moves up in HP, number of engines, turbos and a more sealed engine room, it becomes necessary to supply more air to the engines than they can pull in, and folks use intake fans in for that purpose.

 

[Bill Roosa]

Have you considered passive venting? If there are vents to let air in then all you need is a vertical section of tube to let the hot air out. Put a cap on it to keep the rain out and your set. Alternately you could use an engine driven fan but that would require some serious reworking of things in the engine compartment
Good luck

 

[Ralph Johnstone]

Most small craft engine space blowers I've encountered remove air from the engine space, not bring it in.

I think Parsons is looking at where his air is being sucked from (using neg. pressure) rather than being delivered from (using pos. pressure). I don't think you'll find a cooler air that what comes out of the bilge area.

 

[Parsons]

Correct Ralph. Like most production boats I've seen, I've got a blower fan that exhausts from the engine compartment to a cowled vent on the transom. In my case (unlike some boats I've seen), mine is wired to the engine-key switch, and then through another engine panel switch (which is always on), so whenever the key is on, the blower sucks. It's a nice arrangement, but I wondered if the intake location would be more effective in another location, such as near the top of the engine compartment (hot air rises, and all that). I think that the compartment is 'leaky' enough that the diesel is not starved for air, but their is another 4" hose to another cowled vent to supply air as well.

 

[Ralph Johnstone]

but I wondered if the intake location would be more effective in another location, such as near the top of the engine compartment (hot air rises, and all that).

Now I see, I think. Sometimes hard to tell who's sucking on what and where.

I installed my suction to pull from the top of the engine like so ..................

............... with the idea of pulling from the hottest air. However, when running the engine with the cover off, you get to see just how much wind there is with the alt. fan and belts flying. I think it's pretty much like a small scale hurricane in there when the cover is back on. Probably doesn't matter where the suction hose pulls from as long as it's as far as possible from the air inlet into the engine cavity.