Here is what Al had to say about his exhaust setup (no pictures). He also says more info should be in the “archives” if anyone has them? My files only go back to about Feb 2011. Is there an archive somewhere of all messages? I also see another message where Al sold his plane after about 200 hours and it still was running the 20B. Wonder where 755V is now?
M
“My 20B got 265 hp at 6300 rpm on the dyno with the tangential muffler and secondary resonator. With 9.0 : 1 rotors and normally aspirated that’s not all bad.
But perhaps more importantly I now have 213 hour on the inconel tangential and 321 SS secondary; and they are still in good condition. And it is reasonably quiet.
Al G
From: Rotary motors in aircraft
Sent: Monday, July 20, 2020 11:45 AM
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: [FlyRotary] Al Gietzen - 20B Exhaust System
Does anyone have any of the drawings from Al Gietzen's exhaust system as it was installed on his Mazda 20B Velocity (N755V.)
Tom Mann
Long-EZ N200LZ (in construction)
Velocity N951TM