cowl clearance issues

[kentb]

Now that I am flying, I have found a problem. I have an IO320 with mixture control on the left side of the throttle body. I had to cut a clearance hole in the filter box to allow the control to clear (no big deal) and have switch to the shortest bolt, washer, nut combination to allow the most clearance with the cowl side. I thought that the 1/8 inch clearance would not be enough and sure enough after doing a couple of engine starts/shutdowns it cracked the cowl (sure glade that I painted before first flight). I went ahead and remove some fiberglass from this area before first flight.

Has anyone resolved this problem before?

If a don't hear of a better idea from this group, I plan to cut out more cowl and create a fiberglass bubble in this area.

Kent Byerley
flying.

 

[kentb]

My solution

If anyone else ever faces this issue, I am following up with my own solution.
Where the mixture control rubbed on the cowl I used my drimel tool to cut out a channel for the control to pass through. I then placed on the outside a 1/4 inch layer of styrofome and three layers of fiberglass over the top of that.
After the FG dried I removed the fome from the inside. This gave me about 1/2 inch more clearance then I had before.
After 7 hours of flying I am seeing a small amount of cracking in my blister.
I will be laying more FG over it and then grind out the inside for some more clearance.