Piper PA 28 Airbox Intake Seal

[Hang 4]

This thread https://www.pilotsofamerica.com/community/threads/engine-air-intake.142634/#post-3394261 about a Cessna Airbox seal got me thinking about mine on my PA 28. @Magman mentioned cooling issues if the seal is not tight. My simplistic assumption was any opening in the lower cowl helps cooling. On further reflection, I guess a poor seal could be positive pressure if it faces into the airflow, reducing cooling. The seal between the air filter and the cowl on mine is pretty much shot. This appears to be the part https://www.airpartswest.com/63086_00_seal_Piper_Aircraft_NEW_p/63086-00.htm
It's cheap enough that I may just order it and have my A&P install it.

The actual question, does this opening generate positive pressure in the lower cowl without a good seal and if so should replacing it improve cooling?

 

[Dan Thomas]

As in the Cessna thread, why would Piper spend money and time on that seal if it wasn't important?

 

[Magman]

Commendations to Hang for doing what is necessary to keep his aircraft in top

notch condition.

Dan’s illustration shows why some seals are required.

There are seals and sealants that are often treated with complacency.

Some deal with heat, air, fuel, carbon monoxide and noise.

Tell me what’s not important?

 

[ateamer]

A neighbor was looking at my RV’s engine compartment and pointed out some gaps between the engine and baffles. Very small gaps, less than an inch long and maybe a quarter inch wide. He suggested sealing them with RTV. I did, and CHTs went down by 10 degrees.

 

[4RNB]

https://www.mcfarlaneaviation.com/media/documents/airbox-shroud-seal-assembly.pdf