I'm breaking in the new engine on my new plane now. (Yes, I finished the plane. I'll post about it once it flies... probably this week.) The augmenter tube rings loudly, particularly at certain RPMs, like a wind chime. What is the simplest, lightest way to quell the ringing metal? The tube is 4.5' long, 2.5" diameter, .035" wall, 6061-T6.
For those who aren't familiar with the term, an "augmenter tube is a tube or pipe through which the exhaust gases from an aircraft reciprocating engine are directed." Mine is open on both ends, not sealed to the muffler's tail pipe. In fact it doesn't even touch the muffler at all. The tail pipe just blows into the open end. I'm using it to route the oily exhaust down by the right main gear tire.
My previous plane used a short augmenter tube to keep the oily exhaust off the reduction drive belt. The tube doesn't get all that hot, so it could be wrapped with rubber or something.
I was thinking of wrapping it tightly in a few places with neoprene rubber sheeting, held on with cable ties or hose clamps. I don't want to add more weight or bulk than necessary, particularly since it is in my view and would add drag. Does anyone have any experience with this, or suggestions for possible solutions? It would be easy to try different things.
Another idea I had would be to clamp a length of 1/2" by 1/16" thick aluminum angle to it with some hose clamps. The angle could be located so it doesn't add any drag or obstruction to view.
It may ring less as oil and carbon build up inside over time. But it's very loud at certain RPMs now.