On Mon, 8 Sep 2008 10:53:44 -0700 (PDT),
wrote:

On Sep 8, 1:33*pm, (Richard Casady) wrote:
On Mon, 8 Sep 2008 08:31:27 -0700 (PDT), wrote:
Normal IC aircraft engines aren't muffled, and the back pressure has
an affect on them if you try to.

Most, maybe all, of the planes I have experience with have had
mufflers. Includes radial engines from the thirties, and the usual
Piper, Beech, and Cessna planes in use from the forties on. Still
loud, every one of them.

Casady

From what loogie suggests, the engines may not run if muffled too
much. Is there ways to do it? Could these boats be made to be somewhat
sane? I know that with our bikes there are trick pipes that are very
loud, but several private tracks we frequent won't allow them. Guys
have to change pipes and rejet to ride there, but it can be done... I
don't think there is a lot of reason for a pleasure boat to be so
loud, although I do not have problems with loud vehicles in sanctioned
races, with proper permits and such...

They require mufflers on sprint cars at many tracks.

Casady

On Sep 8, 2:14*pm, (Richard Casady) wrote:
On Mon, 8 Sep 2008 10:53:44 -0700 (PDT),





wrote:
On Sep 8, 1:33*pm, (Richard Casady) wrote:
On Mon, 8 Sep 2008 08:31:27 -0700 (PDT), wrote:
Normal IC aircraft engines aren't muffled, and the back pressure has
an affect on them if you try to.

Most, maybe all, of the planes I have experience with have had
mufflers. Includes radial engines from the thirties, and the usual
Piper, Beech, and Cessna planes in use from the forties on. Still
loud, every one of them.

Casady

From what loogie suggests, the engines may not run if muffled too
much. Is there ways to do it? Could these boats be made to be somewhat
sane? I know that with our bikes there are trick pipes that are very
loud, but several private tracks we frequent won't allow them. Guys
have to change pipes and rejet to ride there, but it can be done... I
don't think there is a lot of reason for a pleasure boat to be so
loud, although I do not have problems with loud vehicles in sanctioned
races, with proper permits and such...

They require mufflers on sprint cars at many tracks.

Casady- Hide quoted text -

- Show quoted text -

Same with MX racing with N.E.M.A.. they have a sound check before
races but the levels are high. It is some of the private tracks where
they are more strict. Like I said, the NEMA races are sanctioned and
within the zoning and other guidelines as agreed with the local
communities.. But they do have limits.. My question is, is it possible
for these airboats to run at all within tolerable noise levels, or do
the engines just make that impossible? If so, maybe they need to find
an alternative power source, or a more suited tool.. Just because
something works, doesn't mean it's the best tool for the job. Who
hasn't used a screwdriver as a prybar

On Mon, 8 Sep 2008 11:25:07 -0700 (PDT),
wrote:

On Sep 8, 2:14*pm, (Richard Casady) wrote:
On Mon, 8 Sep 2008 10:53:44 -0700 (PDT),





wrote:
On Sep 8, 1:33*pm, (Richard Casady) wrote:
On Mon, 8 Sep 2008 08:31:27 -0700 (PDT), wrote:
Normal IC aircraft engines aren't muffled, and the back pressure has
an affect on them if you try to.

Most, maybe all, of the planes I have experience with have had
mufflers. Includes radial engines from the thirties, and the usual
Piper, Beech, and Cessna planes in use from the forties on. Still
loud, every one of them.

Casady

From what loogie suggests, the engines may not run if muffled too
much. Is there ways to do it? Could these boats be made to be somewhat
sane? I know that with our bikes there are trick pipes that are very
loud, but several private tracks we frequent won't allow them. Guys
have to change pipes and rejet to ride there, but it can be done... I
don't think there is a lot of reason for a pleasure boat to be so
loud, although I do not have problems with loud vehicles in sanctioned
races, with proper permits and such...

They require mufflers on sprint cars at many tracks.

Casady- Hide quoted text -

- Show quoted text -

Same with MX racing with N.E.M.A.. they have a sound check before
races but the levels are high. It is some of the private tracks where
they are more strict. Like I said, the NEMA races are sanctioned and
within the zoning and other guidelines as agreed with the local
communities.. But they do have limits.. My question is, is it possible
for these airboats to run at all within tolerable noise levels, or do
the engines just make that impossible? If so, maybe they need to find
an alternative power source, or a more suited tool.. Just because
something works, doesn't mean it's the best tool for the job. Who
hasn't used a screwdriver as a prybar

As soon as you start enlarging the airframe to accommodate large
effective mufflers, they will starting impacting speed and range.
They will have weight regardless of any drag penalty. Earplugs or
radio headsets are much cheaper. During the SEA war games, the CIA
had a powered sailplane with effective mufflers and a zillion blade
low speed prop and which was nearly silent.

Casady