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Under hood insulation

Good luck.

I tried one of the generic glue-on products. Directions required thorough clean and removal of the hood. Cleaned the hood while still on the Burb. Went to test fit the insulation pad (one piece for the whole hood) before I committed by enlisting helpers to remove / reinstall the hood (which would have cost me beer money), only to discover the pad was brittle and started to break-apart. It went in the trash.

Found what looked like some good insulation products that are custom fit for the GMT400, except it is only for the gassers. Discovered the limitation was a ~350*F rated plastic layer held the insulation in place and the turbo surely would have melted the plastic.

So back to the opening of this thread: Good Luck :(
 
iirc LMC truck sells a repop if this in one of their catalogs. I wonder if that stuff is any good. I thing most are held in place by plastic push rivets. if they are placed in areas (not over the turbo) across the center sections for added support?
 
iirc LMC truck sells a repop if this in one of their catalogs. I wonder if that stuff is any good. I thing most are held in place by plastic push rivets. if they are placed in areas (not over the turbo) across the center sections for added support?
I posted on the GMT400 Flaceblook page also.

I haven't got much for responses.
I thought this would be a common thing that lots of people had done already.
I don't want to we waste time ordering something subpar. Or doing the work to find out, I ordered crap.

I didn't even think about the heat from the turbo.

Does anyone run without any underhood insulation?

I'm beginning to think, I'd be better off with nothing, than what I have
 
IIRC, I got both versions from LMC. Did not have the courage to try the better one with the plastic holder. Turbo can give off ~1200*F at WOT when pulling long and hard, and with the plastic rated for about 900*F lower than that, did not feel like playing around. I also had a heat sheild on the turbo, but simply could not get comfortable that it would block enough heat to avoid melting the plastic.

Mercedes has a hood insulation blanket for some of their turbo diesels which incorporates a heat shield above the turbo area. But the Mercedes' hood is smooth on the underside in comparison to the GMT400 which has ribs at angles.

I had considered fabrication of something like the Mercedes design, but got rid of the Burb before that thought turned into any action.
 
Do you seriously think your hood is getting to 350f ?
Paint would be cooked off in a burn mark, right?

Begin with a turbo blanket. Their advantages are known and should drop the under hood temp to same as a gas engine with headers easily.

if just the plastic push pins are still the concerns use sone of the trim sheet metal screws with fender washers in place of the plastic push pins.
 
Do you seriously think your hood is getting to 350f ?
Paint would be cooked off in a burn mark, right?

Begin with a turbo blanket. Their advantages are known and should drop the under hood temp to same as a gas engine with headers easily.

if just the plastic push pins are still the concerns use sone of the trim sheet metal screws with fender washers in place of the plastic push pins.
On a BMW motorcycle. One of the tank side covers had a cobbled affair that was not holding.
I shoved one of these through the hole and fixed that little problem right quick.
The one I had used a 1/4” NC bolt.
 
On a BMW motorcycle. One of the tank side covers had a cobbled affair that was not holding.
I shoved one of these through the hole and fixed that little problem right quick.
The one I had used a 1/4” NC bolt.
I have a box with quite a few of those in it. Different sizes.
Have some of the pop rivot style also. And the big 2 hand pop rivot tool.
I always thought about getting an air riveter for that type of stuff. But never did quite enough of it to justify the cost.

I had enough stuff drug out, when lagging a head pulley at 230' in the air.
 
something else to think about is the stuff they call Lizard Skin... they make a spray on insulation and a sound deadening. I want to try the insulation in the cab of my truck. a gallon of the stuff only is about $100 from Summit. I have heard lots of the classic car guys use both.


 
Same type thread going on over on hummer forum. Hummers are a lot worse for noise and heat coming through than the gmt400.
I wouldn’t be able to find this thread except they literally posted a few hours ago.


One guy posted pics of his really well done complete interior with lizard skin said:
“I did the lizard skin sound and ceramic heat insulation. Laid it on thick and wasn't happy with it so installed the sound matt on top of that.”
Another guy: “Did this help at all?”
“I can’t really say with much accuracy, as it was a number months between doing it and driving again. But no, I don’t think it helped much at all.”

Two of the hummer members that were members here but one kicked off and one of the several guys that quit TTS over the being racist against Jew thing a while back - done amazing write ups on how to, what exactly to use and why. One hummer owner thats not a member here now is a hearing specialist. If I can find the brands and layers they used I will share it but that forum is harder to find stuff on & I’m not good at searching in the first place.

All I remember is using multiple layers with specific types of material is key. Like building an engine- ya can’t just throw random parts and expect good results. You have to match certain components and know which brand has the right stuff. Otherwise ya chase with dollars and hours to get poor results.
 
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