Keeping the noise down

[boybach]

I've just added a bunch of insulation to the cockpit floor and firewall. I used 1/4" cork sheeting first (cos I had about 100sq ft of it in the
garage) followed by some Amazon sticky foam stuff. Together, they effectively raised the floor level up about 3/4".
I'm sure there are fancier/pricier and no doubt "better" ways to do it, but what I did will definitely cut down on engine noise enough for my needs.

So I started thinking about the "other" engine compartment - the Onan.

Back of my coach retains the original Palm Beach arrangement, rear dinette with fold down beds. The Onan's house is under the driver's side seat and
the "roof" is plain, un-insulated fiberglass. Seems to me I could shut that sucker up quite a bit adding some sound deadening material to the
fiberglass areas under the driver's side bed and possibly behind the wall too.

Anyone done this? Good results?

Larry
--
Larry - Victoria BC -

1977 Palm Beach 40,000 miles, PO said everything working but forgot the word NOT. New Atwood fridge, water heater & furnace. New SS exhaust system,
6000w Onan, Iota Converter, R134A A/C, New fuel lines & heat exchange hoses

 

[Carl Stouffer]

I lined my Onan compartment with some material I got from Jim Bounds. It is Mylar faced with two layers of foam with a sound barrier between them.
It is glued to the inside of the compartment and screwed in a kind of quilt pattern with self tappers and fender washers.

It did improve the sound level inside the coach.
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member

 

[Jim Hupy]

I used closed cell foam and covered that with a sound deadening foil backed
material that felt a lot like lead. It is made for hot rods to deaden
sounds from exhaust systems, etc. It is heavy but really effective. It
quieted that Onan down a lot. Can't remember the trade name. Summit has it,
as well as other suppliers.
Jim Hupy
Salem, Oregon

> I lined my Onan compartment with some material I got from Jim Bounds. It
> is Mylar faced with two layers of foam with a sound barrier between them.
> It is glued to the inside of the compartment and screwed in a kind of
> quilt pattern with self tappers and fender washers.
>
> It did improve the sound level inside the coach.
> --
> Carl Stouffer
> '75 ex Palm Beach
> Tucson, AZ.
> Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive,
> Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American
> Eagles,
> Solar battery charging. GMCSJ and GMCMI member
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>

 

[Matt Colie]

We have a BF (4kW) in a 23 and things are different.

I wanted to line the Onan box with some loaded foam that I had, but there was not room over the top of the unit for it to be there and not be
interfering with things. I dropped that plan.

Matt
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

 

[sgltrac]

I used a sandwich layered foam/high density rubber material from a company
called soundown. They do marine acoustic materials. Since my onan box was
galvanized steel sheet metal and little else I removed it and made a wooden
box out of 1/2” plywood with 2”x2” boards cut in half length wise to create
triangular reinforcements of the sheets. Soundown had a foil faced material
which was screwed to the inside of the box.
If you do not have room inside the box the material could also be place on
the outside.

Sully
Bellevue wa

> We have a BF (4kW) in a 23 and things are different.
>
> I wanted to line the Onan box with some loaded foam that I had, but there
> was not room over the top of the unit for it to be there and not be
> interfering with things. I dropped that plan.
>
> Matt
> --
> Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL,
> GMCES
> Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum
> Brakes with Applied Control Arms
> SE Michigan - Near DTW - Twixt A2 and Detroit
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>

 

[john r. lebetski]

My 77 compartment has factory glued in foam lining. Assuming it is fire retardant as dangerously close to exhaust manifold. It is charred from heat.
Check the fire rating of anything you add.
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[boybach]

I'm planning on doing everything from inside the coach.
The fold down bed can be raised to get access to the top of the Onan's fibreglass "box" and the back of the box cam be accessed by removing the trim
below the fold down bed. I didn't fancy getting inside the Genny drawer and trying to clean it up enough to get some insulation to adhere.

I won't be able to get quite as much covered up but some will definitely help I would think.

Larry

--
Larry - Victoria BC -

1977 Palm Beach 40,000 miles, PO said everything working but forgot the word NOT. New Atwood fridge, water heater & furnace. New SS exhaust system,
6000w Onan, Iota Converter, R134A A/C, New fuel lines & heat exchange hoses

 

[boybach]

My onan compartment is also insulated like yours but I added the cork layer plus improvised with jigsaw 3/8" foam flooring cut to size under the fold
out bed and between the closet and the side of the Onan house. I still could do the gangway front, which would be the back of the power drawer but
testing it right now, those panels o just covered have already quietened down the Genset considerably
If I get over a temporary attack of the lazies, I might to the front but for now, not bad at all.

Larry
--
Larry - Victoria BC -

1977 Palm Beach 40,000 miles, PO said everything working but forgot the word NOT. New Atwood fridge, water heater & furnace. New SS exhaust system,
6000w Onan, Iota Converter, R134A A/C, New fuel lines & heat exchange hoses