Soundproofing Engine Compartment

jvoelxen · **Joined:** 21 Oct 2006 15:36 **Posts:** 268

I was wondering if anyone had any experience soundproofing the engine compartment. I would like to try to do something but, with all the access hatches, I'm skeptical that any of the readily available soundproofing materials who have any real positive effect. Any experience?

Thanks.

Jim
Odyssey #191

Tortuga's Lie · **Joined:** 27 Oct 2006 10:32 **Posts:** 827

I added the double-density, foil-faced sound insulation available through Defender, 1 1/2" thick. It does a fairly decent job with the airborn noise, but the problem is the vibration noise, which the old Westerbeke has a lot of. You'll need to minimize the vibrations by adjusting the valves on the engine. I sealed the edges of the insulation with the aluminum foil tape found in the HVAC isle at Home Depot. The insulation panels are held inplace with a series of stainless screws and large fender washers, so far they are holding fine. some of the access hatches that are frequently opened, I put protective wood strips to keep the insulation from getting gouged up.
Good Luck, Tom

jvoelxen · **Joined:** 21 Oct 2006 15:36 **Posts:** 268

Tom-

Thanks for the reply. I have a couple of questions, however. On my boat I have the following issues, and I was wondering how you dealt with them:

1) I have zero clearance between the 2 removable access hatches on the port side and the engine. The FW cooling hoses to my water heater are in the way. It dosn't seem possible to soundproof in that area. Were you able to do something at this location?

2) Starboard side of the compartment is also problematic. There is very little clearance between the alternator and that side of the compartment. If I put in soundproofing of any thickness I would have to leave out a significant chunk to get it in and allow for adjustment/removal of the alternator.

3) The forward access hatch: I think I could easily put soundproofing on this but I couldn't seal the 'cracks' since this hatch is removed regularly.

4) Underside of cockpit sole: How far back did you go?

5) Removable panel on starboard side inside locker: Did you soundproof this?

6) Port side of cockpit near instrument panel and the starboard side aft of the hatch: Did you soundproof these areas?

It seems like you're happy with your results, and perhaps I'm making too big a deal of this? You're feedback would be really appreciated.

Thanks.

Jim

Tortuga's Lie · **Joined:** 27 Oct 2006 10:32 **Posts:** 827

Jim,
Aft of the engine, just in front of the hot water heater, I fabricated a removable panel that I was able to insulate which made a fully enclosed engine compartment. The side access panels were tight, but I screwed a plate over-top of the insulation where alternator would rub againist it. The port side has the oil filter sticking out too far. This spot, I notched out the insulation to accommodate it. You most likely won't be able to seal off the bilge, and you probably wouldn't want to in case of flooding anyway. The heater hoses, I was able to notch around them quite successfully where they ran thru the aft panel.
The forward access panel, I used a wooden frame around the insulation as well as the screws and washers to hold it in place. I also used self-adhesive gasket tape around the perimeter to seal it off as well.
Good lick, Tom

jvoelxen · **Joined:** 21 Oct 2006 15:36 **Posts:** 268

Tom-

It sounds like you put alot of thought into your installation and implemented it very well!!! Thanks for the detailed feedback. Perhaps I'll tackle this project during the upcoming winter.

Thanks again.

Jim

jammin · **Joined:** 30 Oct 2006 15:40 **Posts:** 63

Don't forget the engine compartment ventilation duct that opens into the cockpit. If you put your ear to it you will hear a good deal of engine noise. I would like to re-route this to the transom, but it is a future projent.

Also, a lot of noise comes from the air intake. The only reason to have an air filter on a marine diesel is to reduce this noise. Don't know if there is a kit available, but this would also stop a lot of noise.

I found that the valve adjustment and aligning the engine mounts stopped a lot of the vibration.

I have several rolls of marine sound insulation that I got from Sounddown. But it is still in the attic. Be sure you get USCG approved as it will be fire rated.

I want to install a panel aft of the engine to reduce the area of walls affected by the noise source. Then there are fewer square feet of panels to cover. All the large panel areas are sources of transmitted noise.

Hope this helps and good luck,

Jerry
JAMMIN'

Tartan37.com

Soundproofing Engine Compartment

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