LOUD engine blower

Nov 26, 2008
1,966
Endeavour 42 Cruisin
My engine blower is very loud. Very. Typical 4" tube style marine engine blower. Are they all like this? Are some quieter than others? Would like to keep it running after we drop anchor to evacuate heat but it is obnoxious.
So who makes a quiet engine blower?
Thanks
 
Jul 12, 2011
1,165
Leopard 40 Jupiter, Florida
Depends on what you mean by 'loud'. They all make a whooshing sound, typical of a small fan that is operating at high speeds. The ones that are still good do not rattle, squeak, or have mechanical noises. Like all mechanical things, they will radiate noise more if they are rigidly attached to an amplifying drum head. You could try sound insulation, such as inserting 1/4 inch rubber stock on the mounting bolts to keep the vibration away from the hull. I see that Jabsco makes a line of centrifugal fans with about the same 250 CFM rating that may be quieter, but I have not heard one on a boat yet. They are much more expensive (4x).
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
... Would like to keep it running after we drop anchor to evacuate heat but it is obnoxious....
How about letting the engine idle for a few minutes- like you should anyway- to let it cool down.
 
Nov 26, 2008
1,966
Endeavour 42 Cruisin
How about letting the engine idle for a few minutes- like you should anyway- to let it cool down.
We take around 10 to 20 minutes at idle speed to check out a spot, drop anchor and set. I don't know about your boat but my engine room is very warm for several hours after extended motoring.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
...I don't know about your boat but my engine room is very warm for several hours after extended motoring.
Maybe a second blower is needed even during motoring, would be a good preventive idea.? Are you sure the vent hose is not blocked/crushed, and making the motor whine from starvation?
 
Nov 26, 2008
1,966
Endeavour 42 Cruisin
Maybe a second blower is needed even during motoring, would be a good preventive idea.? Are you sure the vent hose is not blocked/crushed, and making the motor whine from starvation?
Blower is so loud it is easily heard above the engine! So we never run it.
 
Nov 13, 2013
723
Catalina 34 Tacoma
Aren't these sealed? Haven't looked at taking it apart but may be worth a shot. Worst thing is I trash it!
Anyone have experience servicing these?
An electric motor in a marine environment for years is bound to be problematic. Mine makes a loud squealing noise so I never use it. From what I've read, diesel fumes are not combustible like gasoline fumes. Just have to be careful and not store propane or any combustible gas in the cabin. Most people are aware of that danger. I don't know many who use them and haven't heard of any boats exploding recently.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
It's probably mounted in such a way that it's transmitting vibratory energy to a part of the structure, as Parsons mentioned. And, it could be it has worn bearings, which is the sonic noise generator.
 

capta

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Jun 4, 2009
4,766
Pearson 530 Admiralty Bay, Bequia SVG
I like a loud blower. Just like I prefer hearing my fresh water pump operate. These noises are the safety factors on our boats. If the engine space blower makes too much noise to forget that a high draw piece of machinery is operating, I am unlikely to deplete my batteries accidentally. I can't count the times I've become aware of problems with my fresh water system because I could hear the pump cycling when it shouldn't be.
 
Jun 8, 2004
2,841
Catalina 320 Dana Point
They are sealed and less than $20 not worth trying to lube for a little extra life.
I tried them all trying to determine which was quietest and one was a little less annoying, unfortunately I can't remember which.
 
Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
Blower is so loud it is easily heard above the engine! So we never run it.
We had the same problem when I installed our new blower system. We couldn't stand it on the first cruise as it was much louder than the engine. I pulled the wires from it after the first half hour.

The intended purpose was to remove heat for the alternator cooling and to also remove heat while the engine cooled down after running on a scorchingly hot afternoon when we were preparing for a night at anchor.

My two design errors were:

1. I used a Shurflow Yellowtail 3" blower. Screams like a banshee from the get go. I saw mention here that a forgotten production boat was using Detmar blowers. Tried the two of them side by side and the Detmar was quieter.

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2. In the original design, I also used an aluminum drier vent which conducted the sound beautifully. Drove anyone near the boat nuts.

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I substituted a rubberized fabric hose from Defender.

3 in Hose From Defender.JPG


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The fan exhaust .....................

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..................... is now quieter than the engine.

Check your assembly and if it uses either of these items, you may be able to reduce the noise.
 

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jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
I like a loud blower. Just like I prefer hearing my fresh water pump operate. These noises are the safety factors on our boats. If the engine space blower makes too much noise to forget that a high draw piece of machinery is operating, I am unlikely to deplete my batteries accidentally. I can't count the times I've become aware of problems with my fresh water system because I could hear the pump cycling when it shouldn't be.
That makes sense. Wire a siren to the blower, just so there's no doubt. Loud pipes save lives.
 
Nov 26, 2008
1,966
Endeavour 42 Cruisin
There is loud and then there is LOUD. The blower is louder than the engine. A gentle hum will be more than plenty to remind me it's running.

Ralph, thank you for that info, I will look at detmar.
 
Jun 9, 2004
615
Catalina 385 Marquette. Mi
My 3 banger Yanmar is so quiet...any blower would be louder.
 
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Apr 8, 2010
1,942
Ericson Yachts Olson 34 28400 Portland OR
We are on our second Attwood 3" 'turbo' blower, in about 25 years. I can hardly hear it whirring away over the sound of the diesel. It's there, but not obnoxious. (all pretty subjective, really)
We run it all the time the engine is running -- to help cool down the engine compartment which also benefits the alternator.
One other part of the equation to keep in mind is that the original spiral wire vinyl hose has a definite life span. Look for places where it is cracking and brittle after about 10 to 15 years. It's continually moving a lot of heat, which is the enemy of vinyl.
Replacement of the hose is pretty inexpensive, tho.
 
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Oct 2, 2008
3,807
Pearson/ 530 Strafford, NH
We had a 4" flange mount which was loud and went to an in-line which was also loud but cheaper. We run ours full time while motor sailing which knocks down the heat in the engine room when we finally anchor. Then we have a small 12V fan with a suction cup we can put anywhere we have an outlet.

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