I fabricated an engine winterization kit by taking a mold of the cowling cooling air intake with e-glass and West Sytem epoxy. I bonded on styrofoam to the mold and hot wired the styrofoam to the desired profile followed by three more layers of e-glass, sanding everything smooth and painting the engine inlet cooling air reducers to match the aircraft paint scheme. I added a few anchor nuts to the cowling for quick removal and installation of the winterization kit.
Cooling air inlet reducer for cold weater operations