I aquired a used SU-31 with a Saito 150S engine. The cowl was perty beat up and I wanted to change the engine setup so I ordered a replacement cowl Lighting fast service from Cermark and three or four part days to get the cowl openings cut and the cowl mounted. I took it to the field this morning and the engine started right up, but after a bit of time on the bench tuning and what not, when I shut it down, there was a very strong odor of overheated paint. It was the balck covering on the Saito engine that I smelled.

After a typical problem solving session at the field, I left wondering if I had enough air exit vents in the cowl. The design put the big, what I thought at first was an air exit right up to the belly pan on the wing. The old cowl I took off had aproximatly the same number and size holes cut it it as the new one, and I cut out the bottom of the rectangular cast in the bottom of the cowl for additional air exit.

Have any of you with this plane done any modifications to allow for better airflow through the cowl? I've been considering cutting open the leading part of the belly pan and then cutting some long slotts in the bottom of the pan for an air exit. Any thoughs on this???