engine cowl

[Ray Kouns]

question to those that have put an io360 engine in there cozy how
much trouble or aterations did you have to make with the off the
shelf cowl from feather lite if any?

[Wayne Hicks]

Ray:

I'm double dipping here since I gave a similar yet brief reply on the Cozy email group.

Assuming you start with Featherlite cowls, the top cowl will fit an IO-360 just fine. You'll have to modify the bottom cowl because it's shape with hit against such things as the fuel injection unit, intake pipes, and sump. It all depends on the type sump you have.

I know of 4 builders off hand who are using the IO-360.

Brian DeFord used the Featherlite cowls. He fabricated a new scoop onto the bottom of the lower cowl to clear the fuel injection unit. He did this quite easily (?) by applying pour foam to the outside bottom of the cowl, sanding the foam to shape, and glassing 3 plies of BID inside and out to create a new scoop. The scoop sits 1 inch lower than the original cowl. See his website for pictures and text. He also modified his top cowl to raise it to meet his taller-than-plans firewall. But the mod wasn't done because of the engine.

Norm Muzzy and I have the IO-360-A3B6D engine. We got our cowls from AeroCad. Their top cowl is identical to the top cowl from Featherlite and it fits fine. Their bottom cowl started out as a Featherlite clone, but was reshaped to fit around a B sump. Since we don't have B-sump engines, the lower cowl impacts the aft starboard intake tube. Norm got around this by moving the top/bottom cowls aft by an inch or two. (I don't remember how much.) He essentially extended the cowl lips off the turtleback further aft than plans before fitting the cowls. You can see his pictures on his website.

I have not completed the fit on my lower cowl yet. Besides what Norm did, there are two other options -- (a) add a blister to the cowl so as to make room for the intake pipe; and (b) have the intake pipe reshaped to clear the cowl. After talking with Norm, I'm almost certain I will go with "B" and just reshape the intake pipe. The blister would be ungainly and would be quite ugly.

Eric Westland is the other fellow who I talk with frequently that has an IO-360. But unfortunately, I don't know what cowls he used, and I don't know what he modified to get them to fit. Maybe you can ask him directly.

If I were to do it over again, I'd just buy the Featherlite cowls and make the lower cowl mods myself. While I can't speak to the workmanship of Featherlite cowls, I found the workmanship on the AeroCad cowls to be rather lacking. While the Aerocad cowls look great when delivered in their pristine white mold release, the layups had plenty of air voids and their bottom cowl didn't even align properly with the top cowl. This is especially true at the exhaust openings. You'd think they'd match up, right? I'm now having to reshape the exhaust openings and I'm having to open up the air voids and fill them. So I'm having to do even more cosmetic work than intended just to make them look decent.