Hood insulation: Why? Do you keep it or don't you? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

LT7A · 05-26-2018, 01:11 AM

I posted this over in SquareLand but I figured I would see if I could get input from people that hang out in other parts of the forum since the topic applies to more than squarebodies.

I've had some vehicles with hood insulation and some without. From a high performance mindset, I can't see how it would help. Unless you live way up north in Coldlandia or Coldaska and have a hard time maintaining operating temperature, I don't see how there's a benefit except at initial startup/warmup. I can more easily make a case that it's there just to suppress sound. We all know that NVH is really important to the manufacturers. I would imagine that quiet seems smooth, and smooth + quiet probably help sell vehicles on test drives. Once up to operating temperature, it seems that any insulation would have a negative effect on performance. There is a lot of air going over the top of the hood that could draw heat out of the engine compartment. The closest thing to the hood is typically where the air and fuel are being drawn in. Any drop in temperature in that area sure seems like it would be a performance gain however minimal.

I'm considering pulling the hood insulation out of all of my rigs. I don't mind hearing the motor when it's doing its job. And generally speaking, if it's not revving up, then I don't think it's going to transmit much noise through the hood through the windshield and into the cabin. And I don't mind startling innocent bystanders and woodland creatures when I drive by. What do you guys think: Keep it, add it, toss it?

**mongocanfly** · 05-26-2018, 06:48 AM

my 81 came with the insulation...but it looked crappy...so I replaced it... more for visual than anything

68gmsee · 05-26-2018, 08:20 AM

Some say it's to keep the paint from fading due to engine heat others for noise. Because of the thinner metal used it's probably for both reasons but I see more vehicles with hood insulation that have faded hood paint than I did when they didn't have insulation.

**Clyde65** · 05-26-2018, 04:56 PM

All about engine noise!

toolboxchev · 06-02-2018, 03:06 AM

I ripped that moisture trapping crap outta there. Now I can watch the tune on the engine just by driving down the road!

GASoline71 · 06-06-2018, 12:05 PM

Mine didn't have any from the factory (1972), and I ain't adding any...

Plus... I happen to like engine noise.

Gary

05-26-2018, 01:11 AM	#1
LT7A Registered User Join Date: Oct 2015 Location: PNW Posts: 3,615	Hood insulation: Why? Do you keep it or don't you? I posted this over in SquareLand but I figured I would see if I could get input from people that hang out in other parts of the forum since the topic applies to more than squarebodies. I've had some vehicles with hood insulation and some without. From a high performance mindset, I can't see how it would help. Unless you live way up north in Coldlandia or Coldaska and have a hard time maintaining operating temperature, I don't see how there's a benefit except at initial startup/warmup. I can more easily make a case that it's there just to suppress sound. We all know that NVH is really important to the manufacturers. I would imagine that quiet seems smooth, and smooth + quiet probably help sell vehicles on test drives. Once up to operating temperature, it seems that any insulation would have a negative effect on performance. There is a lot of air going over the top of the hood that could draw heat out of the engine compartment. The closest thing to the hood is typically where the air and fuel are being drawn in. Any drop in temperature in that area sure seems like it would be a performance gain however minimal. I'm considering pulling the hood insulation out of all of my rigs. I don't mind hearing the motor when it's doing its job. And generally speaking, if it's not revving up, then I don't think it's going to transmit much noise through the hood through the windshield and into the cabin. And I don't mind startling innocent bystanders and woodland creatures when I drive by. What do you guys think: Keep it, add it, toss it?

05-26-2018, 06:48 AM	#2
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,662	Re: Hood insulation: Why? Do you keep it or don't you? my 81 came with the insulation...but it looked crappy...so I replaced it... more for visual than anything __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver

05-26-2018, 08:20 AM	#3
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: Hood insulation: Why? Do you keep it or don't you? Some say it's to keep the paint from fading due to engine heat others for noise. Because of the thinner metal used it's probably for both reasons but I see more vehicles with hood insulation that have faded hood paint than I did when they didn't have insulation. __________________ 68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive...

05-26-2018, 04:56 PM	#4
Clyde65 1965 Chevy C10, 2005 4.8L/4l60 Join Date: Aug 2004 Location: DFW Texas Posts: 8,545	Re: Hood insulation: Why? Do you keep it or don't you? All about engine noise! __________________ Clyde65 Rebuild of Clyde http://67-72chevytrucks.com/vboard/s...84#post8338184 69 Aristocrat Lo Liner build http://67-72chevytrucks.com/vboard/s...84#post7561684 *support our troops!*

06-02-2018, 03:06 AM	#5
toolboxchev Registered User Join Date: Jul 2015 Location: 2nd left past the stump on a dirt road. Posts: 2,629	Re: Hood insulation: Why? Do you keep it or don't you? I ripped that moisture trapping crap outta there. Now I can watch the tune on the engine just by driving down the road!



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