<VV> Re: Sound deadening

[wblanning at adelphia.net]

---- jwcorvair at aol.com wrote: 

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Hmmm. Very interesting. Did you apply it to the firewall (rear bulkhead) and to the floors as well? 

REPLY: No, I just applied it to the areas in my note, namely inside the rear fender wheel houses and inside the rear frame rails of my 66 coupe.  As far as other sound deadening, I found that the combination of stock engine lid and engine compartment fender insulation gave the best results based on noise meter readings.  Other things I did were to:
- add more insulation over the fender wheels inside the engine compartment against the panel that separates the engine bay from the interior.
- replace the under carpet jute with thicker, heavier material 
- add additional insulation in the rear package tray area including the vertical panel adjacent to the air inlet phlenum
- install insulation under the rear seat
- install thin insulation under the rear interior upholstery panels.

The insulation I used was scavenged out of new cars at the junkyard.  I stripped it out of three cars and the cost was about $10 for all.

In testing with a noise meter, I found that Corvairs are noiser inside while coasting with the engine off than most new cars with the engine on at same speeds.  Thus unless something can be done about sources of noise other than the engine, they will always be noiser than new cars.  I also tested Richard Weidner's 64 coupe with 3.08 gears.  It had about the same noise level as Corvairs with 3.27 and 3.55 gears, but the noise was not as annoying, perhaps because it wasn't as buzzy.  The quietest "Corvair" I tested was Richard's rampside.

I plan to summarize all the noise readings in an article for the Communique in the near future.  One thing that is very important is to have a good rear motor mount.  One that is collapsed and sitting metal to metal transmits a lot of noise into the interior.  Those 66-69 style rear mounts can be failed and not as noticable as a failed 65 style.  In the front of the engine there are several mounts to absorb noise(transmission crossmember, suspension crossmember and others).  But at the rear is just the one.  

Wade