Noise abatement- UPDATED

"Old-Busted-Hotness" (old-busted-hotness)
03/11/2020 at 13:13 • Filed to: None

So the Love Boat’s “Super Luxury Sound Insulation” was getting really ragged, falling out and generally making a damn mess, so I got rid of it about a month ago. About an inch of loose-woven fiberglass with a thin fabric facing. I wanted something that would keep engine heat from melting the wax on the hood, so I stopped at Lowe’s and got a roll of this stuff:

One roll was just enough to cover the hood. And for 20 bucks it’s a lot cheaper than Dynamat or any of the knockoffs. And you know what? It totally works. This thing is Rolls-Royce quiet now. Unlike the factory insulation, this stuff damps noise that the hood itself makes.

I put some in the rear quarters as well. Any large panel can act as a drumhead. Fortunately the roof is already taken care of by Ford.

You could use undercoating or bedliner, too. But this is neater and will reflect heat much better.

Also, I put the Ansens back on. You’d think the T/As with their chunky block tread would be noisy, but they’re not. Random size blocks FTW.

UPDATE:

Did a hood-insulation experiment to find the ignition point of the foil/foam duct insulation I used.

Experiment 1: Stuck some to the inside of the lid of my propane space heater. Directly exposed to flame, it started smoldering right off the bat, at 300 degrees.

Experiment 2: Sat it on the outside of the lid, foam side up. Started smoldering at 289 degrees. The lid was at 450.

That’s far enough above the engine’s operating temp to call it safe.

DISCUSSION (16)

SBA Thanks You For All The Fish > Old-Busted-Hotness
03/11/2020 at 13:33

What’s the temp spec? It’s for heating systems, but I’m curious what the under-hood specs are.

MoCamino > Old-Busted-Hotness
03/11/2020 at 13:37

I’ve been planning to use this very product on the floor of my El Camino after I take care of some rust issues in the floor. Is the foam closed-cell? My biggest concern for use on the floor pan is whether it will absorb and retain water. I know DynaMat and the related products that are marketed for such use are arguably better, but they’re also too darn expensive.

Old-Busted-Hotness > MoCamino
03/11/2020 at 13:56

Definitely closed cell, the stuff is pretty dense. I don’t think it will soak up water, but I haven’t really tried. The foil isn’t real tough, so you might tear it up some on a floorboard, especially in the heel area.

Old-Busted-Hotness > SBA Thanks You For All The Fish
03/11/2020 at 13:59

Ain’t no specs, and no fire rating on the package . I figure if it catches fire, I’ll have learned a valuable lesson. But I don’t think it will. Even in summer, the hood doesn’t get egg-frying hot. Ford used a similar foam on the HVAC plenum, but with no foil. I don’t really think there will be a problem.

lone_liberal > Old-Busted-Hotness
03/11/2020 at 14:02

I wonder if reinforcing it with a little handyman’s secret weapon (duct tape) would help in areas like that?

SBA Thanks You For All The Fish > Old-Busted-Hotness
03/11/2020 at 14:08

Yeah, I was just curious. I have no idea what the car companies model for temps under there. Please keep us posted-- I have an old Alfa 164 with that blanket pretty well disintegrated under there.

MoCamino > Old-Busted-Hotness
03/11/2020 at 14:26

Once I have the floor fixed and the insulation down, I’ll put the carpet back in, so I don’t think it will be a big problem. With that said, liberal use of some duct tape or perhaps a second layer in the heel area would be wise.

Chariotoflove > SBA Thanks You For All The Fish
03/11/2020 at 14:39

I was wondering this as well, and also whether this layer would appreciably raise the operating temp of the engine in hot weather.

SBA Thanks You For All The Fish > Chariotoflove
03/11/2020 at 14:41

I need to do something about that Alfa. The P/O had used duct tape to patch it up and the adhesive really out-gasses something noxious since it’s drooping down onto the engine. Smells horrific. It all needs to go and be replaced with something.

Chariotoflove > SBA Thanks You For All The Fish
03/11/2020 at 14:52

Oh no, duct tape is magical for so many things, but so obviously not for this. It can’t take the heat. What a dumb thing for him to do. Yeah, you need to fix that. I hope this insulation fits the bill. Nice to have someone else being your guinea pig.

Old-Busted-Hotness > Chariotoflove
03/11/2020 at 19:33

Probably not. It only has an R value of 3, which has to be less than the 1" of fiberglass that came OEM.

Also, there’s a lot of airflow through the engine compartment. Lots of openings in the core support, and the radiator is approximately the size of a garage door. No belly pan.

Chariotoflove > Old-Busted-Hotness
03/11/2020 at 19:33

Yeah, makes sense.

Old-Busted-Hotness > MoCamino
03/11/2020 at 19:36

A thin sheet of aluminum between the carpet and the foam would do the trick, too. Tape it right to the foam. Or a piece of luan. You’d be surprised how heavy your foot is, and the heel of your shoe, even a tennis shoe, has a sharp edge.

MoCamino > Old-Busted-Hotness
03/11/2020 at 21:20

Oh definitely. I am glad you mentioned it - I will definitely put in some reinforcement.

Old-Busted-Hotness > SBA Thanks You For All The Fish
03/12/2020 at 09:11

See update. TL;DR: ignition point 289 degrees

SBA Thanks You For All The Fish > Old-Busted-Hotness
03/12/2020 at 12:53

Thanks!