engine room ventilator

[jim rosenthal]

Someone, I can't recall who, asked me to post a few details of this device, as other folks might want to build one. Total cost was less than $100.
I found that when I ran my boat in warm weather, after shutting the engines down, a lot of heat remained in the engine room. Since heat rises, the salon ended up hot as well, requiring running the AC. Also, letting the engine room bake in residual waste heat didn't seem good for the hoses, genset battery, pumps, etc. I decided to install an engine room ventilator.
I used a 110vac squirrel-cage fan that I bought from Allen Machine or Grobans in Boats&Harbors. I mounted it on a board, with a circular cutout for the fan to draw air. A local HVAC shop attached a flange for a hose. The hose, which is six inches wide, goes to one of the side ventilator openings; in my boat these hoses come from the top of the vent and are draped over and run to holes in the deck, through which they dangle into the engine room at the side of the boat. I painted the whole assembly before I installed it, since it is ordinary steel and would rust if not coated.
I installed a timer (one hour, Intermatic, Home Depot), and ran the 110vac cable to a spare breaker on the Hatteras electrical panel. When the boat is out running, and the fan is off, air is free to come into the engine room through the hose and fan cage, it does not seem to block it. When I shut the boat off, I set the timer for an hour. The amount of hot air that is exhausted out the side of the boat is impressive. After an hour it is noticeably cooler. Although the fan is next to one of the engines, it seems to draw air across the whole engine room. Interestingly, it does not seem to draw air more from the same side of the boat; the whole engine room cools down. The installation is so cheap and simple that you could install one on each side of the boat, actually. The motor draws very little current when running- it does not even register on the wattage scale of the shore panel. It is audible, but not loud, and not annoying.
Bigger Hatteras yachts than mine had thermostatically controlled engine room blowers, and fans. This is not as good an installation as the factory did, obviously, but it is simpler and seems to do the job. The salon stays cooler, and the engine room likewise.

[scotty do dah]

Good idea. One other source was through the Grainger Catalog, they sell a 12 volt flange mount unit that screwed right to my original mounts. It moves about 170cfm., sells for about $44.50 ea. It has an approx. flange of about 3"X4". I wired to the original switch on helm on my 1965 50' MY. Grainger' No. that I call is 425-303-8851 or 360-752-0255 hope this helps.
On another subject I installed block heaters in my 8V71's what a difference on cold starts, no smoke. A little difficult to mount under that @#^%$# alternator brkt. & to drill for the plug in, but worth it. And lastly, I just purchased the Racor Crankacase Vent. filters for the engines. One has to use the Open system instead of the closed because of the lack of a turbo to create the vacuum required on the closed unit. Have not hooked them up yet, but will advise anyone out there who is interresed. Also they showed on the instruction sheet, about draining the blower box drains into this filter, which I will probally do later. Note! this filter has to be manualy drained, you do not want the blower box oil runoff to go back into the engine, to contaminated!. Good Luck

[Scott Mather]

Wont's the standard engine room blowers do the same thing?

We have two 12 volt blowers on 1978 37 Sportfish.

Scott,

[jim rosenthal]

I found that the original blower does not move much air. It is a little 3" Jabsco, really a toy. My boat was originally built with gas engines. That blower was really to get gas fumes out of the bilge and I am not sure how effective it was at that even. I added the 110v blower because I thought it would be good to cool the engine room down after operation and the 12v blower wasn't effective. I am not impressed with the 12v blowers you can get through marine supply houses, I don't think they move a lot of air. If anyone knows of a really good one, do let me know.

[34Hatt]

Well most of the 110 fans will move more CFM and will cool it down faster. I just want to point out to owners reading this that if you have gas engines make sure they are Ignition Protected. Most of the 110 fans you buy are not.
Dan

[jim rosenthal]

Good point, and one I didn't think of. I think Graingers does sell 110v fans which can be used in flammable environments, ie ignition protected.

[52 Hat]

I have been noticing the engine heat/fire lite come on during long cruising runs due to excess heat in the engine room. I placed two delta t fans in the air inlets and wired them to the 32volt system. This has eliminated the problem, the fans vork great.

[Traveler 45C]

Did your engines smoke at start up in 70 degree weather? My 8V71N's do after sitting for a few days. I'm seeing white smoke, can't tell if there is any blue in it. I will try running ATF through the injectors to see if it clears up. Block heaters may be in my engines future.

[ttom02]

What is this ATF material? I have the same problem you mentioned with white smoke at start up, and was wondering if there was an additive that could help me clean up the engine. I have 8V92 engines, and normally only run them at 1300 rpm (10knots) for fuel efficiency. I realize this doesn't give them a chance to clear themselves out and have been wondering about alternatives.
Thanks,
Tom

[mike]

atf = automatic trasmission fluid

[Traveler 45C]

-

[Top Shelf]

Or.....just put your blue box blower between the mains and point it up to vent out the top of the engine room hatch. Hang 3 removable towel (3/4" PVC) bars and cool the ER and dry some clothes......

[skammtoo]

Scotty, I also have a 1965 50' MY and would be interested in the filter set up you just purchased. I'd like to clean up the engine rooms and that sounds like it would help.

K8)

[rrob36041]

on your cleaning of injectors problem, try lucas fuel and injector cleaner, available at most auto parts stores, gallon treats 400 gallons diesel, we use it about every 4 or 6 fill ups when moving, smoking is not a problem, only wash transom about every 4 days and then there is no soot on it.