Doxillas reply shows a different version of a magic (with side exhaust) to the RCM&E version which uses a rear exhaust engine as per Hanno Prettner.

I planned to have the holes as per Rays pics but had to have the front of the cylinder head protruding 1/8" through the cowl as my webra 61 long stroke engine wouldnt fit otherwise. I chose to leave the area behind open for cooling though this isnt visible from the side and it keeps its sleek look.

The exhaust header goes through the first bulkhead via a large hole then up into the top deck . This area is also open into the retract bay. There should be a door on the front wheel but mine was damaged when the retract didnt lock so I left it off (aiding cooling airflow).

The plans also say you should have a slot at the bottom of the canopy to let air in but I didnt bother, assuming I could add this later if needed. Vents to the rear of the turtledeck would draw a reasonable airflow through past the tuned pipe as the plane flies.