i gots one of thems . on a sportsman avition waco 30 . it ant what you call power but flys it scale . sounds better if strait piped no it won't hurt it . but a cool engine if you never have 1 lean run or bad fuel they will not work if run lean . don't try to put it in no aerobatic plane unless its a waco . it just dont have power . about like a os 25 la .