Mailing List flyrotary@lancaironline.net Message #36159
From: <Lehanover@aol.com>
Subject: Re: [FlyRotary] Re: Engine noise and changes in timeing and mixture.
Date: Tue, 13 Mar 2007 19:21:33 EDT
To: <flyrotary@lancaironline.net>
In a message dated 3/13/2007 2:24:11 P.M. Eastern Standard Time, wrjjrs@aol.com writes:
Enerest, Please note I mis-typed the line and I believe the noise will increase again as the tuning improves. There are many factors here, timing, mixture and exhaust tuning. If all the other factors remain the same I have found that ported engines are usually quieter when too rich. This is anecdotal, I haven't recorded it with a DB meter. My personal explaination is that the cylinder pressures are higher when better tuned and the sudden port opening in a rotary or 2-cycle causes a louder "bark" The rotary is particularly bad in this respect.
Bill Jepson
The over rich rotary sounds dull and a bit less noisy, with a big fire ball on closed throttle.
 
Over lean sounds raspy and sharp but unpleasant. Crackles on closed throttle with little or no fireball.
 
Did anyone hear the RX-8 three rotor at the Mexico city race? Very nice sound. Down on power at 9,000 feet but won the race anyway.
 
Lynn E. Hanover 




AOL now offers free email to everyone. Find out more about what's free from AOL at AOL.com.
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster