GSJames

The wing was easy, the fuselage for a radial engined airplane is HARD! For the last several days I have been making various test drawings trying to meet the 3/4" cylinder head exposure rule without interference between the muffler and the cowl and then still be able continue the body aft in order to meet the 12.5 sq in and 5" height rule. So far, I haven't been able to do it and keep a scale outline that I personally think to be acceptable. One possibility might be to make the cowling elliptical in cross section instead of circular, it wouldn't be correct, but at least it would meet the rules and keep the same theme. Then the rest of the fuselage contours would be able to match the scale outlines. Another possibility would be to make "troughs" in the cowl to meet the 3/4" head exposure requirement and to clear the muffler. Troughs are allowed by the rules.


It just occurred to me that if I were able to add a 1/4" muffler stand-off extension that the problem would be solved. Not being very familiar with Q-40 engines, I don't know if such a part exists and if it would screw up the engine timing. Either Henry, Mike or Dub would probably know. Has this ever been done? Would it work. Is it legal, or would it screw up the timing? Inquiring minds want to know...