Hood blanket... literally? (engine compartment thermal insulation) - Page 6 - Fuel Economy, Hypermiling, EcoModding News and Forum

FastPlastic · 11-22-2008, 11:04 PM

So I was going to put on the weather stripping I picked up the other day. But turns out it decided to snow today. So I decided to take this opportunity to do a little test. When I was cleaning off my car I stuffed as much snow as possible in to the cracks around the hood. After my 4.5mile trip a large circle had melted on the center of the hood. And the cracks across the front and passenger side of the hood. The drivers side had only started to melt. 15min later I went out and checked it again and all of the cracks were clean and the hood had melted completely. I also noticed you could still feel a small amount of heat coming out of the cracks even on the driver side.

I'm going to try again tomorrow to put the weather stripping in. Can't wait to see the difference.

Sean T. · 11-22-2008, 11:49 PM

How much is that Peel & Seal stuff at Lowe's? I have a HD right up the street and Lowe's is about 10 mins from school, but if it's cheaper at Lowe's I'll wait and pick it up when I'm out there.

Christ · 11-23-2008, 01:33 AM

wonder why the snow stuck to one side longer than in the other side?

You don't have a longitudinally mounted engine, so the only other explanation would be the exhaust manifold...

I wonder, if after sealing the hood, it wouldn't be beneficial to divert some of the heat from one side of the engine compartment to the intake side... it might help to preheat the air going into the engine. I'm not sure what other benefit you would get from it, other than a uniformly heated area under the hood...

Obviously, the header area is going to be hotter than the rest of the engine bay... I'm just wondering if you can make it so that there's less of a difference between areas.

trebuchet03 · 11-23-2008, 02:59 AM

Quote:

Originally Posted by Sean T.

How much is that Peel & Seal stuff at Lowe's? I have a HD right up the street and Lowe's is about 10 mins from school, but if it's cheaper at Lowe's I'll wait and pick it up when I'm out there.

Cheap! A few dollars for something like 25'

Depending on thickness and such of course

Christ · 11-23-2008, 12:03 PM

The only uncool thing about Peel & Seal is that it's made of butyl rubber with asphalt for filler... that means that on hot days, the stuff can/will leave an asphalt smell in your car.

I've never gotten a strong enough smell that it couldn't be covered up by a simple air freshener, and obviously, this only applies if you use it for sound/heat barrier inside the car.

EDIT:

That kinda makes it sound like I'm picking on Peel & Seal specifically, but I'm not... ANY product with asphalt filler in it will do the same exact thing.

Funny · 11-23-2008, 02:54 PM

Quote:

Originally Posted by 93Cobra#2771

By the way, there is a much better alternative to Dynamat, at a fraction of the cost. It is called "Peel and Seal" and is located at Lowes and Home Depot in the roofing section. It is a super adhesive product, about 1/4" thick, used to seal gaps in roofing. It has a reflective aluminum laminated to one side and is identical to Dynamat (I have used both). I insulated the entire roof and floor in my escort, primarily for sound deadening purposes. An added bonus is it keeps it from getting near as hot inside in the summertime while baking in a parking lot. And it is MUCH less expensive than dynamat.

Just as a side note, I would like to get it in much larger sheets to accommodate the large, semi-flat potions inside the engine bay, so I searched and came up with this: 36" x 33 ½' for $135.86 including S&H
If my math serves me correctly, that is 12.5 square feet for the 6" x 25' at $1.01/sq. ft. and 100.5 square feet for the 36" x 33 ½' at $1.35/sq. ft.

Just in case someone wanted to get it shipped to them...

FastPlastic · 11-24-2008, 04:00 AM

I decided to hold off another day on the weather stripping so I could get myself a baseline of how fast the engine cooled off after shutting the car off. I included 5 different measurements with varying outside temps and durations. It should be enough to give me an idea of how much of an improvement it's making.

FastPlastic · 11-25-2008, 03:55 AM

Had time today to install the weather stripping. So far I haven't driven enough to find out how much of an improvement it is. But I did find that after very little warm air can be found coming out of the gap. I'm working on charting the results and will post them as soon as I can. The next step will be finding something to insulate the hood itself.

Before

After

Before

After

Christ · 11-25-2008, 03:59 AM

Have you made sure that the weather stripping is making contact all the way around?

For small areas that aren't, you can heat it up and pull it back up a bit, add a small strip under it, and press it back down.

Looking forward to the result.

FastPlastic · 11-25-2008, 04:06 AM

Quote:

Originally Posted by Christ

Have you made sure that the weather stripping is making contact all the way around?

For small areas that aren't, you can heat it up and pull it back up a bit, add a small strip under it, and press it back down.

Looking forward to the result.

It's about as close as it's going to get. The sides make good contact but the front was difficult. I had to skip over the latch and there is a lip on the front that kinda zig-zags a bit. So it's not perfect but defiantly an improvement over before.