Engine exhaust

[Luvjet]

After looking at a lot of 170's I've noticed that the exhaust openings have no rhyme or reason to which way they face. My plane has one that faces forward and one that faces sideways. I can't help but think that the back-pressure would not only lower the efficiency of the engine but may be even hard on the system. I know they are every where. Is it just that maybe they have been repaired many times through the years or does it matter which way they face?

[Brad Brady]

I have seen stacks pointed in several different directions. I realy don't know that it maters....that's an engineer's area. Ideally the back cut should be pointed rearwards. I think most irregular stacks are from people just using what they had at the time, regardless of the direction of the back cut.....Brad

[jrenwick]

The photos in my '56 owner's manual show the stacks cut parallel to the contour of the lower cowling, and protruding only about an inch. FWIW

[N2255D]

Try looking here for the answer.
http://www.cessna170.org/forums/viewtop ... ing#p41758

[Luvjet]

Thank You! I guess I should leave the pipes the way they are. This board is incredible.