The International Cessna^® 170 Association

Does anyone out there have any good info on an STC'd tuned exhaust system for the O-300 as installed on a C-170 or early C-172? I have seen reference to "Bertone exhaust" in some ads in Barnstormers and Trade a Plane but cant actually find a product.
Thanks,
Steve B

Steve
Put Bartone and Exhaust in the search box and find more info than you probably want to know.

The Bartone exhaust and Beham exhaust are not "tuned"; they just change the exit points of the tailpipes from through the cowling to behind it. I like the looks of the Bartone exhaust better than Benham, but I went with Benham to lessen the paperwork hassle. Benhams come with an STC, while Bartones require a field approval.

If you really want "tuned" exhaust, put +power +flow +exhaust in the search box, and you'll read some of George's best work. I'd personally stay away from them solely because they are so d****d ugly. Checking PowerFlow's website, they don't seem to offer anything for the O-300 anyway.

Miles

All of the fancy after market exhaust systems that claim fantastic power increases are ridiculous. It would take a turbo supercharger to meet those kinds of results.
When I've asked the guys that have those "Donkey Dicks" hanging out of their cowling how much their static power run up RPM increase was, there is seldom any answer.

BL, Your mind is forgetting that I sent you the stats of my change with a Lycoming 320 in a 172. I didn't buy the Donkey Dink, but opted for their new version that is no different from original. My answer, don't waste your money. I did get much improved climb, with no other changes. You can replace a stock muffler for about $400 compared to the $4,000 for the Power Flow.

The re-visiting of this subject causes me to re-think the situation wherein some owners spend lot's of worry-time on which-a-way the tailpipes should face. They turn them around to face the opening aft in the belief that relative wind creates back-pressure and diminishes engine performance! Ha! If you believe that relative-wind is so powerful a force as to cause trouble to the exhaust-gasses exiting the tailpipes then you have a very active imagination. You might also wish to consider the propellor orientation so that prop-blast-pulses don't interfere with piston-exhaust-stroke-pulses and re-orientate the prop so that they don't interfere.

(The actual orientation is that the cut-end of the tailpipe should face forward/outward in conformity with the curvature of the lower cowl, as depicted in the IPC. This reduces the exhaust deposits on the cowl and reduces the amount of exhaust that is introduced to the cabin via the lower wing-strut/landing-gear attach-area. BTW... don't forget to keep those rubber seals in good condition to avoid CO-poisoning. This possibility is the BEST reason to consider the Benham/Bartone exhaust tailpipes, in my opinion.)

Anyway.... if you believe that facing the tailpipes aft is beneficial.... then you are a candidate for the donkey-genitilia and/or the nuetered-version.