So, I just recently read that on the 170/172 with the O-300, that the mitered cut on the exhaust pipe should face forward(follow the contour of the cowl?. Does anyone have any experiance with this or know for sure????? If that is true, mine have been backwards for several years.

Mine are the opposite, but I've seen lots both ways. Does it say why?

Gump

I have seen them both ways. I just checked a photo of mine and they follow the cowl, ie, angled with the opening towards the front.

GumpAir wrote:Mine are the opposite, but I've seen lots both ways. Does it say why?

Gump

It says that facing the miter aft, creates a suction. That makes sense, but that seems like a good thing for scavenging exhaust gases. My airframe IPC shows the cuts forward.

Mine used to face forward:



Now they face back - Bartone STC:

Pipes cut at 30 degrees facing forward and rotated out word 15 degrees, upper cut about 1 to 2 inches from cowl, if the pipes are cut too short exhaust will enter the cowl. This makes the exhaust gas go out and away form the cowl surface and fuselage, if installed the other way you will see exhaust stains on the cowl and may get exhaust in the cabin.

Are there any pipes that improve the power of the 0-300?

Saw one yesterday that the slash cuts were oriented 90 degrees left and right.

UngaWunga wrote:Are there any pipes that improve the power of the 0-300?

Yeah, pipes that come out of an O-360.

Mine have the slash to the rear, like yours, Jared--although mine do come from the O-360 conversion. It is actually a slightly modified Mooney dual exhaust system, which my IA says is a whole lot more efficient than the usual single pipe O-360 exhaust system. I can tell you that it's noisy, and I'm told that when I take off, it's louder than most O-360s at 2700 rpm. I've never heard it from outside, myself.

Cary

I guess I will plan o pn switching them around. Mine have been extended slighty. Not sure if that has anything to domwith it or not.