Mustang7

I have a question regarding how much of the cowl do I need to trim to allow enough cooling air to cool the ST75. I plan to install the scale radial kit with the lite ply baffle and in cowl muffler. Everything fits perfectly within the cowl, except there's no opening to allow for smooth air flow over the cylinder head. The rule of thumb is three times the area for exit air as incoming air. Did I miss something in the instructions, or do I just need to cut the cowl (sad since it looks perfect the way it is).

Bax

My Feedback: (11)

Usually, you'd remove a dummy cylinder in the "show" engine for an air inlet. Make baffles so that the air goes through the fins of your engine, and then let the air vent overboard. An air outlet 2 X or more larger is good. You do have to make sure that the air does pass through the engine's fins and not around them.