The International Cessna^® 170 Association

Attached is a picture of the cowling on my 52. At some point in my planes life the engine was changed
from a -145 to a 0-300. When and why the cowling was hacked for the pipes I don't know. I would like to
fix this problem by replacing the pipes and then repairing the cowling. Any guidance with this issue would
by greatly appreciated.

Carl

An excellent method to repair the cowling might be found in the solutions used on the later serials, in which a sliding exit was utilized. See the IPC for that. And even more attractive solution would be to close the exit completely, toss the tailpipes, and replace them with the Bartone tailpipes which exit at the lower cowl opening forward of the firewall. (Contact Member Pat Bartone, found in the Directory.)
As for the tailpipes, you might wish to verify the correct length by contacting AWI (Aerospace Welding Inc., in MN). Charlie Fields might have the info you need. The originals only exit the lower cowl by a couple inches. Longer tailpipes are offered by some aftermarket providers but they lack approval.

Carl, virtually ALL 170s, except those owned by the very meticulous owner who knows better and has time and money to correct it, have worn and reconfigured exhaust openings. Has nothing to do with a change from C-145 to 0-300 as they are identical in regard to the exhaust opening. Has more to do with removing and re-installing an exhaust system that has play and therefor can be installed slightly different each time, and of course new or different parts over the years worn or made to different tolerance added to the system. Then add a shifting cowl and you have a recipe for these holes to be worn in all sorts of directions.

My first 170 had these holes worn so bad that nearly the entire doubler inside the cowl was gone. Didn't bother me in the least and the cowl was easy to remove which is an added benefit.

If it bothers you repair it. I'd think the repair might bother me as much as the wear damage.

Do the mod.

T. C. Downey wrote:Do the mod.

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gahorn wrote:...And even more attractive solution would be to close the exit completely, toss the tailpipes, and replace them with the Bartone tailpipes which exit at the lower cowl opening forward of the firewall...

George,

What is the preferred method to cover the holes up if one were to change to the Bartone/Benham muffler arrangement? Would welding aluminum back in its place cause heartburn with regard to legalities, or is it up to the interpretation of major vs. minor alteration? Making it look like no hole was ever there looks much better than two patches riveted in place.

Any sheet metal man worth his salt can make those holes cosmetically disappear usng a "dime and a dollar" patch, and filler/paint. (2024 aluminum, the alloy used in the cowling, is not easily welded anyway.)

gahorn wrote:Any sheet metal man worth his salt can make those holes cosmetically disappear usng a "dime and a dollar" patch, and filler/paint. (2024 aluminum, the alloy used in the cowling, is not easily welded anyway.)

OMG wash your mouth out.

Yes the cowl lower skins are 2024-T3, and work hardened on the wheel to form them.. do not weld unless you have a heat treatment oven large enough to re-heat treat.

Are the Betone or the Bensham exhaust systems still available?

Carl

Yes they are, I just installed Bartone pipes.

If you want a pair of the slider plates and backers from a 56B you can have them for postage from Canada.

Carl,

Call or email Pat Bartone in Manchester, CT. Last time I talked to him he still has the exhaust pipes in stock. His phone number is listed in the membership directory. You can find it in the "members only" section on the home page of the website. Jim

I used a couple of fabric wing inspection covers to block the old holes in mine; easy to install and they didn't look that bad. This time around, I'll have a new lower cowl fabricated without the holes.

How much is the Bartone STC?

I think I paid $480? But ring Mr Bartone - he is charming. I love mine.

Would the wording of the STC prevent using the tail pipes on a TCM IO-360 vs the O-300?
They both use the same exhaust in a 170 so they'd bolt right up - if allowed.