Great Southern Insulation Generator Sound Shields

mobocracy

Active Member
Jun 29, 2014
541
United States
Boat Info
310 Sundancer
Engines
350 Mag & Bravo III
My 2007 310DA came with a Kohler 5ECD but no sound shield. The admiral thinks it's way too loud and I'm inclined to agree. The noise is worst in the cockpit and it seems to be just the sound of the engine running. The noise at the exhaust port is entirely tolerable and seems quite quiet and even in the cabin it's not that bad. Strangely in the water you can't hear it all (I don't make a habit of allowing swimming while its running due CO, but I wanted to make sure it wasn't totally annoying anyone anchored nearby).

I called Kohler and found they actually still make the original sound shield for this generator and got the part number (GM41781-KP1) but googling that part number brings up a really unpleasant price, like close to $2100 and I want to guess that installing it involves more than I have the skills to do.

In looking for solutions, I stumbled across Great Southern Insulation:

http://stopthesound.com/generator-soundproofing/soft-generator-cover/

I called them and was quoted a price of $1250 for the kit (metal frame with velcro-attached panels and exhaust fan), which is still a lot but less of a lot if it makes running the genny more tolerable, especially to the admiral. The catch seems to be that in order for it to be effective (and I think even mountable), I would need a platform under the generator for both attachment of the frame and for sealing the base of the panels to prevent sound leakage. I'm pretty sure mine is just mounted to a drip pan than spans the stringers. I haven't looked closely, but I suspect I could fit a sheet of marine plywood under the drip pan without re-doing all the hoses and wiring but it would probably require some effort and a winch to lift it enough. The bonus of a wooden platform might be more vibration dampening and more yet if I added some rubber bushings.

Anyone had any experience with this product or installation or other clever ideas for quieting an unshielded generator? My other cheaper idea is just more insulation inside the engine compartment (obviously the right kind meant for engine rooms), although I suspect that there's just too many places for noise leakage for this to be all that effective.
 
I have a sound shield just like that on my diesel genset. I think it helps and it's easy to service the generator as the panels removed easly. I would recommend it.
 
1.2 boat bucks is real money. I'd be tempted to DIY this before spending that kind of coin. I'd first buy some "SoundDown" for the underside of your engine room hatch, maybe some forward of the generator. If that doesn't help enough I'd consider the platform idea, something DIY. And if that doesn't help....buy a Westerbeke. ha.

I'd bet much of the benefit from these kits they sell is in the platform, not as much the panels. I wonder if there is a cheap way to put some rubberized mounts between the Kohler and the hull. Lifting that thing is going to be a huge PITA.

On second thought - just get a louder stereo and be done with this madness!
 
1.2 boat bucks is real money. I'd be tempted to DIY this before spending that kind of coin. I'd first buy some "SoundDown" for the underside of your engine room hatch, maybe some forward of the generator. If that doesn't help enough I'd consider the platform idea, something DIY. And if that doesn't help....buy a Westerbeke. ha.

I'd bet much of the benefit from these kits they sell is in the platform, not as much the panels. I wonder if there is a cheap way to put some rubberized mounts between the Kohler and the hull. Lifting that thing is going to be a huge PITA.

On second thought - just get a louder stereo and be done with this madness!

I think the platform would be anywhere from a total PITA to just slightly tricky, depending on whether you could lift it just enough to slide the platform under without disconnecting everything and have enough room on the edges of the platform to bolt it down to the stringers on the edges of the platform (ie, not require full access to the platform). The PITA factor grows a lot if you have to lift the generator out completely and disconnect everything to mount the platform, more so still if you found you had to shift the generator laterally to accommodate the platform.

Once again I lack the photos I wish I had, but I think there's enough room on the edges of the generator mounting area in my 310 that a platform with 1" edge exposure for attachment to the stringers might be possible, and if only 3/4" lift was required to slide the platform under the generator it might be possible to do it without disconnecting everything. I'm curious if I could get away with 5200 for attaching the platform vs. through-bolting it to the stringers, although I suspect making it removable is a good idea.

The biggest obstacle really seems to boil down to no way to lift the generator without an external hoist. Maybe it's possible to rig some kind of block and tackle with a post spanning the engine room and supported on the sides of the boat, I think the generator is only 250 pounds.

I also am more dubious of the added engine room insulation as accomplishing much. I think there would be a lot of generator noise escaping through vents and resonating inside the engine room.
 
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Read the linked thread from several years ago. Some of the noise is vibration and is hard to eliminate. I quieted down mine with a 2 stage muffler.

http://clubsearay.com/showthread.php/45547-What-can-be-done-to-quiet-a-Kohler-generator

MM

I read through it, but honestly I don't find the exhaust noise to be a major contributor to the overall noise problem, at least not based on what I hear at the exhaust port. And in that thread people with a sound shield seem pretty satisfied with the noise level.

I think I have the space for a sound shield, it's just the complexity of retrofit, mostly based on the lack of an existing platform under the generator for mounting it.
 
why not just add another layer of sound proofing insulation to the deck instead of trying to reduce the sound of the genny?.....it would still make the same amount of noise you just would not be able to hear it as much......might prove to be easier....not sure if the extra weight would be a problem for the ER hatch lift......

maybe just using a very thick rug or carpet on the deck with a thin layer of soundproofing underneath may work as well....

cliff
 
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why not just add another layer of sound proofing insulation to the deck instead of trying to reduce the sound of the genny?.....it would still make the same amount of noise you just would not be able to hear it as much......might prove to be easier....not sure if the extra weight would be a problem for the ER hatch lift......

cliff

I go back and forth about this. I'm not sure how much noise reduction it would actually accomplish given the engine room venting on either side of the cockpit. I also think that the generator noise gets sort of amplified by resonating the uninsulated portions of the engine room interior, turning the entire engine room into kind of drum head. I think to be truly effective, the generator noise needs to be more completely contained to avoid the secondary "drum" effect.

Maybe insulating more uninsulated surfaces in the ER would be beneficial to muffle the noise better, but I'm not entirely sure how practical that is (spaces you can't reach, possible water absorption, etc).
 
Sounds to me as you're convinced of the way to do it. Now you just need to pull the trigger. Let us know how it goes.
 

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