Tom and/or Pat. I am really interestd in this plane and watching the build thread with great interest. My thouhgts are towards a DA85 with the canaster exaust, mostly because I would love to try an 85 and the cost and weight savings are so great. I am however having some real problems picturing the heat exhaust for the engine (on either the 100 or 85). I have always been led to believe by "the experts" that the engine exhaust area should be greater than 2-3 times larger than the cowl intake area. I know how the air enters the cowl and from reading other posts understand it should exit out the canister tunnel. But how does it get out after you install the canisters and block the rest of the tunnel with the mount. With your setup as pictured above will it still be necessary to cut an exaust opening in the cowl or will enough air get to the back openings to provide adequate cooling. Sorry if this is a stupid quesiton.