Exhaust systems

aftCG

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Apr 3, 2018
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Recently there was someone posting to the facebook group with exhaust question. The responses were overwhelmingly for one specific place to buy exhaust systems for a Citabria. The format of facebook makes it almost impossible to just sort back through recent posts so here I am:

If you need to replace your exhaust, where do you go?

I'm not sure which planes are affected, but mine on my O-320 has an AD for exhaust system inspection. Does this "aftermarket" exhaust eliminate the AD? Does it produce better power, clear the lower right cowl better, sound better or make me feel taller (or smart for once)?

My left side was a little shaky and had worked its way down until it was riding on the lower left engine mount bolt. On the right side my mechanic was able to weld up the hole and re-drill it for a tight fit but on the left side he needed to obtain a new clamp.

I won't call it good money after bad since I know it will be serviceable when he's done, but I'd like to plan for my next annual and maybe have some new components ready.
 

Bartman

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The earlier 7ECA's have dual exhaust, I think the later ones have a single system. My dual exhaust has two manifolds that feed into two mufflers and one of the manifolds broke off just upstream of the muffler connection. Broke clear off, the muffler was hanging by the hanger, appropriately enough.

Figuring if one broke then the other might too, I took off everything and called the two shops that are probably most well known, Dawley and Aerospace Welding. One of my exhaust manifolds ran too close to the generator and Dawley was willing to work with me to discuss clearance adjustments. Aerospace Welding wasn't.

So I sent everything to Dawley and for (I think) $380 per side they rebuild both manifolds using only the original mounting flanges, all of the pipe and welding was new. They also inspected both mufflers and heat shrouds and found them all ok.

Everything was done quickly and they even discovered when they mounted my old pipes to their jigs that my front manifold wasn't made to spec so the new one automatically had the clearance we needed to keep the generator from getting hot.

It was all reinstalled and fit perfectly. First flight after it was all back together I hit a hawk but even Dawley, as awesome as they were, couldn't help me with that!

Since your exhaust system has an AD it has to be welded by a certified shop. I had that problem back when I had an Aztec, local repair shops couldn't weld my exhaust cracks.

Good luck!
 

aftCG

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You're correct, mine is the old dual exhaust type. The clamps are apparently the challenge right now.
 

Ron86654

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Lebanon, TN
I had to buy a new single muffler/exhaust system for my O-320 conversion. Got it from Dawley, fast service and cost $750.00. And, it fit.
 

Bill Martin

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Nashville,TN
I went the single muffler route in 1998 on my 1973 Decathlon, Went with new cowlings and belly pan to match. This was a big improvement in maintenance and what a much better exhaust note. Bought my exhaust from Dawley (now part of AWI) and other parts from Safe Air Repair (now part of Wag Aero). I think I paid something like $650 for a complete exhaust system and like $160 for a used shroud. Parts cost much more now. Didn't know Ron86654 was so near as I am in Nashville. I was able to do the work myself as a A&P, now have an IA. The muffler now has a crack in the end cap and will require a repair.
 

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Bob Turner

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I have had several end bell cracks. A good welder has no trouble stitching them up - I think I get 200 hours between cracks.

I have not seen an AD that specified a "certified welder." Maybe I need to re-read the one for rhe Dec muffler.
 

aftCG

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Tacoma, WA
Funny, I read backwards through this thread just to find that I started it. Historically I can say that my dual exhaust system needed some kind of welding, refabricated muffler support or clamps every year that I owned it. The 100hr AD seems justified.