What is the advantage of hood insulation?

[Ghoste]

I'm just yanking your chain CP.

[8WHEELER]

I have only run a hood pad once on my 69 I had for one year in 81, I have never had one on a car since, no over heating problems or rubbing air cleaner infact I run the dual plane M1 intake now that is basicaly stock and there is no way the pad would clear I checked that.

I like both looks and yes I sanded the hell on the bottom side of the hood, 5yrs now no paint problems.

Dan

[hemigeno]

when i took my 73 440 apart . i found insulation between the intake manifold and the valley pan from the factory. to keep the engine noise down. Rene

Like this......most of the lo po engines got it

Chris, I had heard that all B/RB engines got the intake silencer - it was supposedly installed to quiet down lifter noise.   I read this most recently in the PCG catalog...

Bet you didn't know your 361-383-426W-440 engine originally had noise insulation between the intake manifold and the pan!   Used on all versions of these engines, silencer package #1879747 is two pieces of fiberglass insulation wrapped in tinfoil, as original.
It is POSSIBLE to install these exactly-reproduced pieces after your manifold is already in place, but it's much easier to do like the factory did.   The pieces were placed on the pan, large piece in front, small piece in rear, then the manifold was bolted in.   These pieces should have engine paint overspray.

[Just 6T9 CHGR]

I read that as well but I have never seen it on a performance engine though

[8WHEELER]

I read that as well but I have never seen it on a performance engine though

Me as well, I have never seen that insulation on an original  HP engine only 67-68-69 350 horse non HP engines out of C-Bodys.

Dan

[Ghoste]

My 68 Road Runner had it.  Still on there actually since I know where the car is.  I was the second owner of the car and I knew the original owner so I can state with certainty that it was original on that 383.

[694spdRT]

I read that as well but I have never seen it on a performance engine though

Me as well, I have never seen that insulation on an original   HP engine only 67-68-69 350 horse non HP engines out of C-Bodys.

Dan

I pulled a non HP 440 out of a '71 Imperial that still had the original insulation also.

[Steve P.]

I pulled a 440 out of a 72' Imperial that had it. It was quite nasty..

[Ghoste]

Now that I think back, my 69 Super Bee had it too.  I have no idea of the pedigree with that cars engine though.  It had been beat hard before I finished it off so I can't imagine it was the original engine.
Super Bee and Road Runner though, maybe they got it?  A nice touch with the unsilenced air cleaner.

[bull]

I'm just guessing here but I think the insulation has more to do with noise control than heat control. Heat always rises of course and insulation would absorb most of the heat that doesn't radiate out the sides and bottom of the engine compartment so I don't think insulation helps reduce heat other than offer some protection to your hood. Maybe if it's 110 degrees out it would protect the engine from heat coming in but I doubt anything will help at that temp. Motion and the fan are the only things that really dissipate hot air in the engine compartment so I would say it's more of a noise thing. If it was a heat issue Mopar probably would have installed heat shields like you see on modern mufflers and cats. If anything I would say insulation would help more in cold weather situations rather than in hot weather. The whole idea is not to keep an engine cool per se, it's to maintain an operating temperature.

[Headrope]

My understanding is that the original reason for the padding was noise insulation. Similar padding is installed on the inside of the firewall, under kickpanels and the carpet - which would seem to keep with the noise insulation theory.

There has been somewhat a debate over the years as to whether or not asbestos was in the original hood padding and firewall insulation material, on some cars. In addition to being flame retardant asbestos is supposedly great at absorbing noise.

To answer your question, though. I personally do not see an advantage in having hood insulation, other than keeping the underside of the hood clean. I removed mine. The engine seems to cool down quicker and the extra half inch of clearance I gained gave me more options when I wanted to play around with carb, intake and air cleaner combinations without needing a hood scoop.

[Charger Steve]

When I completed the restoration on my 68 Charger 3 years ago I put a hood insulation pad on because it had one when it was new. This new pad rubbed on the air cleaner and the A.C. compressor. I cut holes in the pad to "cover up" that probblem but I didn't like the way it looked so I took off the pad. I do not understand why this is. Can anyone explain ?

[Just 6T9 CHGR]

When I completed the restoration on my 68 Charger 3 years ago I put a hood insulation pad on because it had one when it was new. This new pad rubbed on the air cleaner and the A.C. compressor. I cut holes in the pad to "cover up" that probblem but I didn't like the way it looked so I took off the pad. I do not understand why this is. Can anyone explain ?

Did you use the old "dirty rag" loose type of repro pad or the newer molded type pad?  The molded ones hug the contours of the inner hood structure better & do not sag.

[Mike DC]

 
The hood needs to be insulated so your female friends won't burn their bare buns on the sheetmetal at a bad time.  Spoils the mood.