This morning While topping off Batteries to go flying. I decided to take a closer look and found that you will be able to use the JC-28 in the Sbach without much trouble. As it turned out I took more then I needed to on the top of the smile. I didn't need more clearance in the corners of the smile. Remember that when you guys are doing yours,
This is the first step in mounting the engine. Centering it up to the Spinner.I didn't have the right size on hand so I had to improvise. I used a smaller one centered it and drew a pencil mark around it so I can keep it Visually centered while I cut clearance for the cooling fins. On My 50cc planes I found that you need around 1/4 in of clearance between the finns and the fiberglass or the vibration is going to shake the glass and the finns together and will crack there.
First I put a black marker line for an outline to go back to. I used an Execto blade to carve some of the glass away then went by hand with a file to get it closer to what I needed. This is just roughed in and I used a round and a flat file to get what I wanted. Now I'll finish the edges with sand paper when the time comes. Have other clearances to cut first.