Yvon Cournoyer wrote:

Good evening Perry,
Your project is very interesting. I hope you will continue informing us
about your results.
I can assure you that MY 13B is LOUD at 5500 rpm, even with a muffler. I
use earplugs under the headphones to protect my hearing and my sanity. My
engine is installed "right side up" which puts the exhaust and muffler
just ahead and almost under my feet.
Is your engine "right side up" or "plugs up"?
Paul suggests the pusher prop fan acts to break up the noise, maybe it is
the combination of duct, smaller diameter prop, engine installation and
present rpm that results in less noise.
When alone in your craft, I suppose that you sit up front? That would be
a little farther from the engine, admittedly not much so.
Cordially, Yvon

Paul a écrit:

You need to build one of those tangential mufflers Yvon.
Makes a even a front engine rotary as quiet or quieter than
a C172.

Paul
 
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