Re: Cabin Noise and Muffler

[Greg.Otto@cyrix.com]

Simon,
Can you keep the temperatures on top the engine where the muffler is
mounted down so they don't melt the top cowling?  I know it gets pretty hot
up there without the added heat.  the normal exhaust stacks are in the high
pressure area where the heat is swept out the exhaust fairing or up and out
over the top of the engine dissipating as it goes.

Greg Otto
VELOCITY STD FG
N150GH
McKinney, TX





aegerter@dataway.ch (Simon Aegerter) on 08/10/98 02:45:41 AM

To:   reflector@awpi.com
cc:    (bcc: Greg Otto/CONTRACTOR/DALLAS/CYRIX)
Subject:  Re: Cabin Noise and Muffler




>Is it possible to install muffler in the Velocity in an effort to reduce
>the noise?

Eung:

The Velocity builders here in Switzerland are REQUIRED to install mufflers.
Without them they wouldn't stand a chance to pass the stringent noise tests
that our "FAA" demands. They route the exhaust pipes around the engine to
the top where there is room for a muffler.

The exhaust exits the cowling at the top. This is additional noise
abatement for those on the ground, not necessarily for those in the cabin.

How much the muffler itself affects the noise level in the cabin I don't
know and none of the installations is flying yet. Isn't engine vibration
the most important source of in-cabin noise?

Best
Simon

Simon Aegerter, Winterthur, Switzerland