Aftermarket engine upgrade offers additional power

aftermarket kitLooking for a little more power to shorten that already awe-inspiring takeoff roll? An AirCam owner recently completed the addition of an aftermarket engine cylinder and piston kit, and the results are impressive. The “big bore kit,” as it’s referred to increases the bore of the cylinders and pistons offering a gain of an estimated 10-12 horsepower.

The upgrade was performed on the right engine first, leaving the left engine as a fair basis for comparison in single engine performance at gross weight. The airplane weighed in at 1061 lbs empty, gross weight 1680 lbs. Flying at Sebring with a density altitude of 1700, we were immediately impressed by an improvement of 150 ft/min in single engine performance. The standard Rotax 912ULS engine averaged a single engine climb rate of 240 ft/min at gross weight, while the aftermarket upgrade averaged a single engine climb rate of 390 ft/min. The increase in power was noticeable right from the start, even requiring pitch adjustments to the prop to prevent an overspeed.

Lately I’ve been weighing in at 195 lbs. Later in the same week with both engines retrofitted with the aftermarket kit, I flew solo with 3/4 tanks of fuel and was off the ground in 80 ft. Climbing from 500 ft. on a 2700 ft. density altitude day was just as impressive… 2000 ft/min! With a passenger and loaded at gross, takeoffs were nearly as remarkably short, and we averaged a 1600 ft/min climb.

It’s worth noting that we don’t know how the aftermarket engine upgrade will affect engine life or oil consumption, but its safe to assume a decrease in TBO and and increase in oil consumption. If you’ve got a new set of engines, be aware that the retrofit is not affiliated with or approved by Rotax.