Sound insulation?

[Flat57]

Getting ready to start putting a 57 cab on a 85 suburban chassis with 6.2L. I want to make sure the vehicle is quiet enough. What is the best material(s) to keep the diesel noise in the engine compartment? I'll have everything apart in the cab, so access to the firewall, floor, celing will be easy. Does it help to insulate the underside of the hood? Looking for suggestions. smile.gif

[Dieselboy]

I like Dynamat. It's expensive, but you get what you pay for. Be strategic, go for covering the thinnest areas first like the outer door skins and ceiling. Then move to thicker spots like the flooring and inner door skins. Do the firewall, front and back, and tranny tunnel, too.
http://www.oliverdiesel.com/images/dynamat/installed.jpg

[john8662]

Dieselboy,

wow, that looks cool! nice idea!

[cschneider]

Honestly Dynamat does not do all that much to knock down noise tranmission. It's purpose is to seal against rattles and resonance. Dynamat is an expensive version of the asphalt based roofing material you can buy at Home depot. The only way you can really knock down sound is to convert the wave energy into heat. Foam and vinyl barriers do this well and some new sythetic polymers (quietcoat) do the job as well. I would not waste my money again on Dynamat or anything of the like. I have been less than satisfied with the results. Defintely put sound proofing on the underside of the hood, that helps tremendously. Please feel free to email me for more detail, I have tried it all.

-Chris

[grape]

look up lizard skin sound deadening in a google search.

[Flat57]

Chris, I'll have to take you up on your offer for help when I get ready to do the sound deadening. I used some stuff like quite coat and lizard skin on my 73 Vette, but since I also put in a ceramic based matt and new carpet, I don't know which did what. I do know that I put dynamat-like stuff (ice and water from Home Depot) in my Ford diesel, and it didn't make any difference at all on the engine noise. It did reduce road noise a little bit. I'll also look into the sound deadening foam, that might be the ticket. I think that is what they put in acoustic chambers to absorb noise.

[gavio]

Here's a link to a page that does a pretty fair job of explaining the different types of materials used in different areas: quiet ride (http://www.quietride.com/acoustisheild.html). It's good reading to get some ideas for how to plan it. Their prices for the actual materials are pretty high, though, so it's worth further research once you understand what you're doing.

The best prices I found at the time I started my project were from b-quiet (http://www.b-quiet.com/), but that may have changed since so look around.

I can't report on the results yet as I have not had the time to do my van yet - the stuff is still sitting here in boxes waiting......

And here's a link to pretty cool set of pages that really goes into a do-it-yourself approach to sound reduction in a VW microbus, which is a formidable sound control problem indeed - I got a lot of ideas from reading this: heat, rust and noise in VWs (http://www.shagadelic.org/VW/info/gmbulley-soundproof/)

Hopefully some of this will help you get started.....as i've come to understand it, it really requires a pretty comprehensive approach to get truly meaningful results, but since you're starting from a bare body, I expect you could do quite well.

Good luck with it......

Gavio

[cschneider]

I have quite a bit of acoustic foam with 1lb vinyl barrier that I bought to do my suburban (a little bit more aggressive than Vcomp on B-Quiet's site, but same construction). I had originally thought of putting it everywhere and also bought enough for a friend's blazer. He sold the blazer and I scaled back my project so now I have over $500 dollars worth of this stuff that I probably won't use. I would love to get rid of some of it, so if anyone is interested, email me. Just make sure not put any foams or vinyls in the engine compartment. The fire danger is too great. For that I had to get a melamine/vinyl composite which is obscenely expensive. Unless you want a $300 underhood mat, just use the factory stuff, it will knock down enough noise without breaking the bank.

[a5150nut]

I had a 66 Chevel SS 396 and I put waffle carpet pad and a short, dense shag carpet in. Shure did quit that thing down.

[Jgreemo]

I used the asphalt based pads from JC Whitney. They are 10"x13" and for 40$ you get a box of 12. I found you do not have to cover the entire floor to stop it from resonating so a couple of boxes can go a long ways. I followed that up with the aluminized foam padding and a new carpet kit from LMC truck. Definitely a lot quieter and I haven't even made it to the doors or roof yet.

Dynamat works great around the dash and speakers but can be pricey for Suburban square footage. The sheeting from JC Whitney works fine, especially if you put it into a warm oven before rolling in on. Just don't leave it in there.

Jon

[Flat57]

Thanks for all the good info. I will check out the JC Whitney stuff. I also like the ideas in the VW bus website (I like his humor too ;) ).

Monday we are going to get the engine running and start removing the body to replace it with the '57. Any idea if suburban parts sell well on ebay?

smile.gif

[Ratau]

The black glass wool like insulation under the hood on my Blazer is falling apart and I have to replace it soon. Could I spray something on to keep the fibers together?

Danie

[cschneider]

It depends on what you're selling. I'm always doing searches for suburban stuff but there isn't a whole lot left I need. Put it up and see what happens. If it's a silverado/sierra classic, I'd be interested in some real nice, original door panels.

[84 Convert]

Hey , flat57, I might be interested in some of your parts for my crew cab. Maybe post what you want for them over in the classified forum.

Gregg

[Flat57]

OK.

We're hoping to get the body pulled tomorrow. It may take longer than that though. I looked at it, and a lot of the parts are pretty rough, so there may not be that much salvagable. The dash looks OK, the door panels are fair, the seats are shot, etc.

[Stray Cat]

Ratau, To hold together the sound/heat barrier on my Suburban, I sprayed it with "Rubberized Undercoating". There is an Asphalt based spray (that never completely sets), and a more expensive rubber based spray (that does set)...make sure you use the "Rubber" stuff for this application! On my Blazer, it was beyond saving. I removed it and replaced it with the aluminized sound/heat barrier. It works fine, also.