I am sure this has been discussed many times but I can not find anythng about it. I want to change my exhaust to the type that comes out of the back of the cowling. Does this require an STC or a 337? I heard that it requires neither and that there was a place to just order the pipes and I would need to make my own brackets. Can anyone give me some help here. I have a 1955 B model (N3407D) with an C-0300 engine.
Ken Nesbitt
Exhaut Mod
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
Ken, you are looking for Pat Bartone's exhaust stacks. Look in the classified section of the Flypaper, his coordinates and price are listed there. You will need field approval. Pat supplies you with drawings for brackets and copies of 337's with the pipes. Oh, if you don't get the Flypaper, you need to join the TIC170A. JD
Both Pat Bartone and John D. Benham have STC's for their slightly differing designs of essentially the same modification. They no longer sell their exhaust pipes with the STC preferring to avoid the liability, and offer them with paperwork to support field approvals.
The major difference I've seen of the two systems is that the Bartone exhausts are supported by brackets on the firewall, and the Benham units are suspended off the lower engine mounts. With either unit, and depending upon your airplane and FSDO inspector, you may have to relocate your gascolator so that it is not directly above a tailpipe.
Both gentlemen may be found in the 170 Assoc. directory. Mr. Bartone in Fla, and Mr. Benham in Tx.
The major difference I've seen of the two systems is that the Bartone exhausts are supported by brackets on the firewall, and the Benham units are suspended off the lower engine mounts. With either unit, and depending upon your airplane and FSDO inspector, you may have to relocate your gascolator so that it is not directly above a tailpipe.
Both gentlemen may be found in the 170 Assoc. directory. Mr. Bartone in Fla, and Mr. Benham in Tx.
Hi Ken, my 54' 170 came with the Bartone pipes with "generic" rubber isolation hangers supporting each pipe from the firewall. The hangers appear to be standard "AutoZone". The gascolater was evidently moved as it is no longer above any of the pipes. As for paperwork....my aircraft came with none. I don't even recall seeing a logbook entry...though I may have missed it during the initial pre buy inspection. I'll go back and check. The pipes are just there, with the original exhaust holes filled and the lip added to the lower cowl. Pre buy inspection turned up no paperwork for the installation so if paperwork is needed for this installation I do not know. The A&P doing my pre buy inspection did not seem alarmed. I do know I LOVE the sound of the pipes 
Said to aid in engine cooling by improving the airflow....I do not know for sure since I did not have the airplane with the original exhaust. Also keeps the cowl free of exhaust tracks
Said to aid in engine cooling by improving the airflow....I do not know for sure since I did not have the airplane with the original exhaust. Also keeps the cowl free of exhaust tracks John, 2734C in Summit Point, WV
We finished up the installation today and it looks and sounds GREAT. However for anyone doing it one note of caution, make sure when moving the gascolator to get your small piece of tubing coming out of the 90 degree bend made prior to attaching your bracket to the firewall. The gascolater does not end up exactly in the center. We had to remove it and reattach it and of course ended up with some holes we had to refill with rivets. Other than that small mistake it went well. I do hope this doesn't take away to much from the originality of the airplane but it does look better and appears to be a much better way to do the exhaust.
Ken
Ken