G
Geoff
So I went flying today to test my newly-installed gear leg fairings and upper intersection fairings. Much to my surprise, the engine made a noise I've never heard before in this plane. At higher power settings (above about 19" MP) the engine was making a pulsing sound. It sounded *exactly* like flying a twin with the props out of sync. Varying the MP between 19" and 24" sounded exactly like moving the prop control slightly on one engine of a twin.
I can only guess that this is some sort of exhaust pulse. However, I didn't make any changes between this flight and the previous flights except to install the gear leg and upper intersection fairings. I'm just not sure it sounds reasonable that these fairings would alter the airflow along the bottom of the fuselage enough to cause an exhaust pulse where none existed before. By the way, there is no floor or other vibration -- just the pulsing sound.
I have some turndowns that Larry Vetterman gave me. I've flown when them on and off and didn't notice much difference. They're presently off, but I plan to put them back on and see if the pulse thing goes away. I'm using the standard Vetterman exhaust, TMX IO-360, vertical induction.
Any other ideas?
Thanks.
I can only guess that this is some sort of exhaust pulse. However, I didn't make any changes between this flight and the previous flights except to install the gear leg and upper intersection fairings. I'm just not sure it sounds reasonable that these fairings would alter the airflow along the bottom of the fuselage enough to cause an exhaust pulse where none existed before. By the way, there is no floor or other vibration -- just the pulsing sound.
I have some turndowns that Larry Vetterman gave me. I've flown when them on and off and didn't notice much difference. They're presently off, but I plan to put them back on and see if the pulse thing goes away. I'm using the standard Vetterman exhaust, TMX IO-360, vertical induction.
Any other ideas?
Thanks.