'Dog house' insulation...anyone done this?

Rocky_Road

Rocky_Road

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Re: 'Dog house' insulation...anyone done this?

projecthog said:
I am willing to bet that if you run your engine up to operating temperature and take a reading of the engine compartment, you will not see a significant increase in temperature after adding any insulation.

The engine is thermostatically regulated for a range of internal operating temperatures, and will not or should not have a differential of more than maybe 30 or 40 degrees max between idle and WOT.
Most of the heat created therefore will be caused by the increased temperature of the block when running harder and not by the exhaust because it is shielded by water that boils at 212 degrees and even that's not hot enough to set things on fire.

It is different in cars where there is no water cooled shielded exhaust and where the heat is passed off through the walls of the exhaust manifolds and pipes, carried off by air flow through the compartment and out the bottom.

If this were the case in an I/O situation in a boat, then on some boats the rubber exhaust hoses would burn off or the engine cover would heat up and catch on fire very quickly as air flow, other than that of the bilge blower system, is near nonexsistent in the engine box.

Relying on my modest experience in engine rooms on ships, the temperatures there do not "normally" rise above 110 dergrees either as far as I know, even with the air conditioners off. There the engine box is just a bit bigger so you can stand in it.

If there is ample room to install any kind of fuel proof and flame retardant sound proofing without touching any engine parts, there should not be any issues.
I would worry more about the fuel and oil resistance of the stuff you are going to use than the heat affective value.

PH.
Click to expand...

Noted...and I accept your expertise, in this matter.

I'm going to stop at my only local Bayliner dealer tomorrow...on chance that he has one of the new models. I'll snap a picture of the engine cover!
 
A

abj87

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Re: 'Dog house' insulation...anyone done this?

Any insulation you use should be fire resistant. We used this on the diesel on our sailboat it made a significant difference in the noise, and i didn't notice any difference in engine conparmtment temps either. The only downside is that is heavy and expensive. http://store.hamiltonmarine.com/browse.cfm/4,11634.html
 
Silvertip

Silvertip

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Re: 'Dog house' insulation...anyone done this?

Air is being sucked in to feed the engine but it is engine bay air that is being warmed and pulled into the intake. The engine bay itself has inlet and exhaust ports (one normally points forward and one aft so the blower doesn't need to run when underway but I always ran mine.
 
projecthog

projecthog

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Re: 'Dog house' insulation...anyone done this?

abj87 said:
Any insulation you use should be fire resistant. We used this on the diesel on our sailboat it made a significant difference in the noise, and i didn't notice any difference in engine conparmtment temps either. The only downside is that is heavy and expensive. http://store.hamiltonmarine.com/browse.cfm/4,11634.html
Click to expand...

LOL.
Then you could measure your comfort in pounds and ounces. Duplicity in currency if you're British!:D
 
projecthog

projecthog

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Re: 'Dog house' insulation...anyone done this?

Silvertip said:
Air is being sucked in to feed the engine but it is engine bay air that is being warmed and pulled into the intake. The engine bay itself has inlet and exhaust ports (one normally points forward and one aft so the blower doesn't need to run when underway but I always ran mine.
Click to expand...

I thought those vents were mainly for some airflow to minimize the danger of battery and fuel fumes while underway, and the blower for when charging was done while not in motion or to use before you start the engine to remove any possible gas fumes.
Doesn't matter for the engine anyhow as there is enough air sucked out of the bottom to feed it, and if there is no bulkheads that air can come from all the way up in the bow.

But then again most boats do have those vents for just the engine box and in some the blower and the vents work the battery box and engine bay both.

In my bigger boat I had three blowers, one for each engine in the motor hole (and tank area which was aft farther but not sealed off), and one for the battery locker, forward and under the saloon deck. And because of the larger engine compartment I had the half pipes on the port and star sides amid ships.

In any case running the blower(s) can only help to increase clean air and ventilation, I ran mine all the time too.
Nothing wrong with that, I'd rather replace a handfull of insignificant burnouts than a boat.
I had a hatch on the aft deck that was the same size as the old square window fans you'd get in the 70's and 80's. I'd get all puckered up when I hadn't run the engines for a while and would lay that thing down on the hatch and run that full tilt while I went for a coffee and a dognut.

But I'm rambling off course again, Adios,

PH.:D
 
projecthog

projecthog

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Re: 'Dog house' insulation...anyone done this?

Mthieme

If you don't mind El Cheapo fixins :eek:
You can find that silver layered sound proofer and fire retardant stuff at any ol' BIG truck recycling yard, and probably get away with verrrry cheap armfulls of it.

Reason being that the older "Cabover" truck bodies had that stuff everywhere under the doghouse and transmission tunnel, and one cab's worth of insulation would probably do you twice for a boat.
Mind you may have to "carwash" it first but heck, can't see that they would sucker you too much for that stuff.
Maybe they'd even laugh you out the door with a truckload of it.
As for all of that you might even get it new for a decent price from a truck collision outfit.

Just tryin to get ya squared away.
PH.:D
 
oops!

oops!

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Re: 'Dog house' insulation...anyone done this?

Rocky_Road said:
The aluminum faced sound retarding stuff (eg. Dynomat), will quiet the engine bay.
Click to expand...

dynamat is a completely different product.....dynamat is a very dence rubber liner...kinda like a pool liner

Rocky_Road said:
.
But...there has to be some additional heat trapped in the engine area, and that wouldn't be good in the hot summer days.
Click to expand...

your over thinking this rocky.....the only heat build up you have to worry about is the fact that it will make the air more expancive.....(harder to breath less o2)......but it only by a miniscule amount....the vents in the boat will still circulate the air just fine and replace the warm air with fresh warm outside air.


lowkee said:
What I found in the engine compartment was eggcrate foam!
Click to expand...

eggcrate is great....we use it in recording studios.

lowkee said:
And Bond-o, I really need to find the dumpsters you used! I'm going to need some serious foam seat cushioning soon, and man is that stuff pricey!
Click to expand...

behind furniture stores.....its a 1/4 inch allmost rubbery feeling semi rigid board.

and for cushon foam.....go find an old used couch...!.....it can be as firm or as soft as you want.......but for a boat semi firm is best.

Mark_VTfisherman said:
This used to be available as a fire-retardant product and I even outboards have some stuff like it glued to the motor shroud.
Click to expand...

that tin foil stuff is a good retardant....it should be the outside layer if you use multiple layers......if you use the egg crate foam....that works best as an outside layer.....but it is not fire retardant

a70eliminator said:
I don't think it would effect the engine's running temp.
Click to expand...

its not the running temp but what the engine breathes

Silvertip said:
Air is being sucked in to feed the engine but it is engine bay air that is being warmed and pulled into the intake.
Click to expand...

on racing day.....it is a big thing to get air from any where but behind the radiator.......on a boat you will only see a little performance loss....(barley noticable) on a hot day....the air is exchanged by the vents that tip was talking about
 
SKEETR

SKEETR

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Re: 'Dog house' insulation...anyone done this?

I used a 1" thick closed cell foam and coated it with good ol' home depot duct sealant. It was a grey goo in a tub, think it was henrys. Applied it with a trowel about 1/8 thick. Claims to withstand heat up to 500 deg. Nicely sealed corners and joints as well.
 
Rocky_Road

Rocky_Road

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Re: 'Dog house' insulation...anyone done this?

Surffx said:
anyone ever try this stuff?

http://www.silentrunning.us./index.html
Click to expand...

I actually like the 'press' on this one...sounds like just what I could use.

Can be brushed on. The video demo on the link tells it all, as to how well it works. Coast Guard approved. You can decide just how much sound deadening you end up with (layers can be added, after a test run).

Goes to the head of my list...!
 
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abj87

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Rocky_Road

Rocky_Road

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Re: 'Dog house' insulation...anyone done this?

abj87 said:
cant help you on that one but the stuff i posted before was peel and stick.
Click to expand...

Yes it is, abj87...thanks for the link!

I am going to avoid any product with a metallic liner...I can't 'shake' the feeling that this would increase my engine bay temps, with my small (Mercruiser 3.0L) engine setup.

Still kicking this around...!
 
mthieme

mthieme

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Re: 'Dog house' insulation...anyone done this?

projecthog said:
Mthieme

If you don't mind El Cheapo fixins :eek:
You can find that silver layered sound proofer and fire retardant stuff at any ol' BIG truck recycling yard, and probably get away with verrrry cheap armfulls of it.

Reason being that the older "Cabover" truck bodies had that stuff everywhere under the doghouse and transmission tunnel, and one cab's worth of insulation would probably do you twice for a boat.
Mind you may have to "carwash" it first but heck, can't see that they would sucker you too much for that stuff.
Maybe they'd even laugh you out the door with a truckload of it.
As for all of that you might even get it new for a decent price from a truck collision outfit.

Just tryin to get ya squared away.
PH.:D
Click to expand...

Thanks, not too many of those nearby though.
I was thinking of trying a sheet of foil backed foam insulation - for houses.
 
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grego

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Re: 'Dog house' insulation...anyone done this?

rocky road. the airbox is designed for max airflow. If you want to dampen sound, use rigid insulation, NO! thicker than the original insul. Cut ridig. styrofoam for top cover about 1/2" smaller than actual size. Cut sides long and angle cut top edge at angle so they wedge into the 1/4" space around top cover. You can buy glue and fiberglass resin at auto parts store, styro cutter from e-bay $10.00. cut,styro as close as possible,glue in before or after you apply resin and aluminum one sided tape to cover seams.
 
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