Hey Popriv please don,t take it to heart you are and have been a valued contributor here. I thank your question was interesting although I could never hear anything like that with an engine running and my very poor hearing I am often told of strange noises my airplane may make by others of course I never hear it, Darn.

Actually the suggestion by Bozarth above is a very good one while certainly eliminating the noise you are talking about since bubbless tanks use no clunk at all. However a bubbless tank for a very aerobatic airplane can provide far superior fuel flow performance over any conventional tank system. hmm


Good speaking with Ya'll agine

John