The International Cessna^® 170 Association

Hi ... question. In removing my exhaust system I noted that two of the exhaust inlet tube clamps on each side of the engine are rubbing into the intake manifold elbows. It appears the exhaust inlet tubes where the clamps rub have been dished slightly to provide clearance ... not enough though to prevent the rubbing. 1) Is this normal? and 2) if not, what is the fix? Regards, Lee (N1967C)

http://cessna170.org/forums/viewtopic.php?f=24&t=13115

My clamps have been ground out a little to provide clearance.

Good idea ... I should have thought of that! R/Lee

The proper clamps have a flat spot bent into them to clear the intake elbows.

I will look at the clamps carefully ... good info. If the clamps are wrong, they will be replaced! Thanks ... R/Lee

Even with the correct clamps it is sometimes necessary to grind a dished-out section to provide clearance. This is due to the vagaries of cylinder mfr'g and mounting. (Even reinstalling the same cylinder in it's previous position can re-locate it a few thousands-of-an inch as it settles into a different position on it's studs. Adding the repositioning of exhaust risers, etc. can contribute to a tight fit.)

None of my clamps have a flat spot bent into them ... I am calling AWI in the morning to order some hardware and will check with them about the clamps. By the way, AWI was superb with their service ... my new mufflers arrived two days after ordering in perfect shape ... well packed. The enclosed Cracker Jacks were a nice gesture! I did get a 15% discount for 170 Association membership. R/Lee (N1967C)

I talked to AWI a few minutes ago ... their clamps are not ground in any way ... I will do some work on mine to get a proper fit. That said, I needed some more hardware (nuts and bolts) for three clamp sets and the exhaust pipe clamps ... they are sending them gratis! AWI has my vote ... superb customer service and they are fast! R/Lee