Lessee here, Darrel.
If I remember correctly, my Cessna 150 had a vacuum system. The pump
was part of the O-200 engine. It had an air/oil separator to keep oil
from gumming up the works. Just using the vacuum of the manifold, like
that Chevy truck, may not be the best practice for gyro instruments.
The pulsations from the intake cycles may cause instability on the gyro,
and unreliability of the instrument. Just when you don't need it!
Venturies don't have to be that large, especially if only powering one
instrument. And it could be mounted on the bottom of the plane, rather
than out in frount of God and everybody.
The list may have better ideas regarding vacuum systems.
Percy in Portland<<attachment: winmail.dat>>
