Brief Description: Fitting the Cowl; Installing the Hinges
The RV cowls use piano hinges as attachment fasteners. Before I install the engine, I decided to install the hinges on the forward-fuselage/firewall so I would have adequate access to use a rivet squeezer to install the rivets. The hinges come with an aluminum 1/8” diameter pin that you have to replace with a .090” steel pin to accommodate the curves down the side of the fuselage. The instructions tell you to shim all the hinges on the firewall to accommodate the cowl thickness at the interface of the fuselage and cowlings. I have to cut all these shim pieces manually and grind them down to fit the firewall flanges. After I got the hinges installed, I didn’t like how much effort it takes to remove the hinges by pulling the hinge pins through the cowl oil fill door opening. After a bunch of research, I ordered a complete cowl fastening system using a new product called “Skybolt VLoc Cowling Fastening System” which eliminate the hinge pins altogether. These new, improved fasteners are supposed to keep the cowl from bulging inflight because they have an interlocking support system you rivet onto the cowling, much like the hinge pins. I hope they work well. They are not cheap! In any case, removing the cowls will be easier than pulling the pins. All these pictures are from the Skybolt Website.