SkyKing
09-13-02, 02:41 AM
Does anybody know who the manufacturer is that makes the outflow valve for the pressurization system as installed in the rear firewall? Ours is a 1977 model. I believe these are the same or similar to the units as installed on the 340, 414 and 421 twins.
The outflow valve has a brown colored phenolic bell-horn protruding into the wheel well area and is mounted at the top of the bottom firewall/bulkhead, just above the safety valve which is all metal.
It appears the control cables that pass through the wheel well area on their way up to the rear engine can rub on the phenolic material if not protected from chafing with a tie-strap, which can cause vibration and small hairline cracks to develop in the bell housing. Has anybody else checked these closely for hairline cracks?
SkyKing
The outflow valve has a brown colored phenolic bell-horn protruding into the wheel well area and is mounted at the top of the bottom firewall/bulkhead, just above the safety valve which is all metal.
It appears the control cables that pass through the wheel well area on their way up to the rear engine can rub on the phenolic material if not protected from chafing with a tie-strap, which can cause vibration and small hairline cracks to develop in the bell housing. Has anybody else checked these closely for hairline cracks?
SkyKing