Spent quite some time planning and taking measurements trying to workout the design of the Cowl Flap system. I've decided to have two moveable flaps on the bottom (roughly patterned after the Tom Moore fixed-flap design). Each flap will be about 13 inches long and about 9 inches wide at the opening, and taper to a width of 6 or 7 inches at the hinge. They will open 4 inches downward yielding an additional 72 square inches of exit area. A rotatable shaft will be mounted horizontally, ~5 inches from the bottom of the firewall and there will be two actuator arms 4 inches long with linkages attached to each flap (two each to eliminate flap flutter in the slipstream). The Electric actuator will be mounted above this on the right side of the firewall and connect downward to a single arm on the shaft. As the Electric actuator extends, this rotates the shaft extending each cowl flap at the same time. More planning is required, but at least I can put in the order for the electric actuator from dcactuators.com.
