[FC] Sound Deadening

[Jim Corey]

Good points, Bob. As I'm now getting more serious about the noise, what you
say makes sense.  But I  will try to preserve the hinged arrangement, but
try to seal and "isolate" the noise transmitting.

J Corey

-----Original Message-----
From: Vairtec Corporation [mailto:Vairtec at optonline.net] 
Sent: Thursday, January 21, 2010 8:48 AM
To: Jim Corey
Cc: corvanatics at corvair.org
Subject: Re: [FC] Sound Deadening

Jim Corey wrote:
> As I said in an earlier response, my Greenie is a work van.  No seats.
Can't have soft
> goods on the floor or walls.  BTW, I hinged my engine cover, with a
recessed
> lift ring and a "stay up" support rod.  Works great.
>   

Okay, let's tackle a few things here.

First, being a work van, "quiet" can only be a relative thing.  However, 
when these trucks were new, they were not objectionably noisy.  So let's 
get back to basics.

Are all the motor mounts and body mounts in good condition?  Even one 
dilapidated body mount can transmit a remarkable amount of noise.

Is factory-style sound insulation present on the underside of the engine 
cover?  It may not look like much, but it contributes.

Is factory-style sound insulation present inside the quarter-panel 
engine cooing air plenums?  Many owners don't even realize that the 
factory glued sound-deadening material here, and that it fell off 20 
years ago.

And finally -- your hinged engine cover is probably contributing.  Most 
owner modifications to hinge the engine cover compromise the seal 
between the cover and its gasket.  My Greenbrier's engine cover is not 
modified, but years ago I learned just how much noise can be transmitted 
by a cover that is not tightly fitted.  All I did was put the cover in 
place without installing the ten screws that hold it down.  Wow, a lot 
more noise!  I put the screws in and things got quieter.

Make sure that your engine cover seals tightly.

--Bob Marlow