I wanted to raise this question with those of you who understand air flow and the air intake needs of a Lycoming motor. My plane is an RV-4 / late model kit, finished in 2006. I recently removed the Carburetor on my engine and replaced it with AFP fuel injection. The engine has chronic surging now and all fuel and electronic possibilities/sources have been exhausted.
After discussion(s) with Don at AFP, he asked me to send in my one-off air box for air flow testing on his equipment. The box is shaped like Van's. But, we decided to try using no filter in the box (expecting more RAM). We just use a flapper bypass to filtered air for ground operation to protect from debris.
Turns out the air box is the probable cause of the problem. Don said the airflow is so turbulent that it shook the room he was testing it in. I never imagined that direct airflow into the box wasn't going to give me extra RAM and more speed, but that thinking was obviously Wrong!.
So, aside from fitting in a thinner KN filter inside the box (smaller vertical space due to FI servo) what do you think would be the best way to address this? Narrow the intake size? Ramp the air 90 degrees directly into the servo? Any ideas greatly appreciated!
Ron
After discussion(s) with Don at AFP, he asked me to send in my one-off air box for air flow testing on his equipment. The box is shaped like Van's. But, we decided to try using no filter in the box (expecting more RAM). We just use a flapper bypass to filtered air for ground operation to protect from debris.
Turns out the air box is the probable cause of the problem. Don said the airflow is so turbulent that it shook the room he was testing it in. I never imagined that direct airflow into the box wasn't going to give me extra RAM and more speed, but that thinking was obviously Wrong!.
So, aside from fitting in a thinner KN filter inside the box (smaller vertical space due to FI servo) what do you think would be the best way to address this? Narrow the intake size? Ramp the air 90 degrees directly into the servo? Any ideas greatly appreciated!
Ron