RE: scratch built c130
I tried extending 2 stroke mufflers with tubing on previous models & it lead to trouble. No problems with 4 strokes. Perhaps if you are redesigning the nacelles & mounting the engines sideways you can go back to the standard muffler set up & just tuck them into the side of the nacelle like this. This uses OS FP 40's & OS RC 20's, yes, with air bleed carbs. - John.