“We just finished our 200-hour-test program on this engine and it performed extremely well under some really punishing conditions,” said Jay O’Donnell, a professional pilot and FAA-designated engineering representative who founded Corsair Aircraft Engine Co. in Colorado Springs, Colorado, to address some of general aviation’s most persistent problems: high engine acquisition and operational costs, the expense and uncertain future availability of leaded avgas, antiquated technology, and operational complexity.
“This engine shows that we really can improve aircraft performance, sharply reduce costs, and get rid of leaded avgas all at the same time.”
O’Donnell began flying and became a civilian flight instructor in the 1980s. Back then, he taught in “worn-out trainers built in the 1960s,” and then left general aviation when he became an airline pilot. After a 20-year absence, he returned to GA to teach his daughter Maggi to fly and was appalled to find the same airplanes he instructed in 30 years ago are still being used for that purpose.
“They were ratty and worn out then,” he said. “They’re even worse now.”
O’Donnell said GA must piggyback off the automotive industry where engines and electronics are mass produced in order to meaningfully reduce costs. Auto engine conversions have a terrible track record in GA, however, and despite decades of hope and promises, none has been successful in the marketplace. (Remember Porsche engines in Mooneys? Or Toyota’s Lexus engine, which was FAA certified but never put into production?)
The difference now, O’Donnell said, is that auto engines are lighter, more fuel efficient, more reliable, and more powerful—so they can run at a fraction of their rated power in aircraft. That’s a big difference from previous versions, which had to run close to flat out to produce the power required for flight.
“This engine is rated at more than 500 horsepower,” O’Donnell said. “But we’re only using a maximum of 220 horsepower. The fact that it’s basically loafing all the time increases its reliability and longevity.”
The Corsair V-8 engine is produced by General Motors, and similar aluminum-block models are used in Camaros and Suburbans; marine versions are in speed boats and yachts; and other models run power generation stations. The Corsair V-8 turns just 3,200 rpm at full power, and a gear reduction drive slows its Sensenich fixed-pitch propeller to an efficient rate.
“This engine is rated at more than 500 horsepower,” O’Donnell said. “But we’re only using a maximum of 220 horsepower. The fact that it’s basically loafing all the time increases its reliability and longevity.”
The Corsair V-8 uses unleaded auto gas including E-85 (which contains 15 percent ethanol). The engine has two independent electrical systems (normal and auxiliary) and two batteries for redundancy. If the single alternator or a battery fails, the engine can run for at least one hour on the other battery. Like a car engine, however, it needs electricity to keep running.
The Corsair V-8 engine with its liquid cooling system and two radiators is about 50 pounds heavier than traditional air-cooled aviation engines producing similar power. The second electrical system adds another 70 pounds.
With synthetic oil and unleaded fuel, O’Donnell recommends oil changes at 200 hours instead of the normal 25 to 50 for aircraft engines burning leaded avgas. He claims operating costs are about 60 percent less than traditional aircraft engines, and parts are much less expensive and more widely available.
O’Donnell said he plans to pursue a supplemental type certificate (STC) for installing Corsair V-8 engines on Cessna 172s as a retrofit, and he said future projects include putting them (and constant-speed propellers) in Cessna 182s, 185s, and 180s as well as other utility airplanes and piston twins. He plans to market the Corsair V-8 system to flight schools and overseas operators where avgas is unobtainable or prohibitively expensive.
I came along on a demonstration flight of the Corsair V-8 engine at the company’s home base at the Colorado Springs Municipal Airport (elevation: 6,200 feet). The first things you notice in the cockpit are the absence of mixture and carburetor heat knobs and the presence of a push-button starter.
The engine springs to life instantly when the starter is engaged, and it responds quickly to throttle adjustments. O’Donnell said the onboard computers actually slow the engine response to avoid the high torque and P-factor that can result from a too-quick application of full power (such as a student pilot performing a go-around).
Switching the key position from normal to auxiliary power tests both electrical systems, and the pilot can move between them manually or let the onboard computer system do it automatically.
Takeoff acceleration was quick despite a 7,000-foot density altitude, and the airplane climbed at an impressive 1,000 fpm with two aboard, half fuel, and more than 100 pounds of ballast meant to keep the airplane near its maximum gross weight.
“That’s about twice the climb rate you’d get in a brand-new 172,” O’Donnell said.
A pair of intentional go-arounds with the flaps set at 30 degrees showed smooth and rapid throttle response and quick acceleration that required pitching the nose up within a few seconds to avoid exceeding flap speed—something I didn’t anticipate in a normally aspirated 172 at high elevation.
The propeller on the Corsair V-8 spins in the opposite direction as those powered by Lycoming or Continental engines, so the pilot applies left rudder during takeoff and climb. Approach and landing at 65 knots felt normal for a heavily loaded Skyhawk.
The Corsair 172 is currently registered in the experimental category (market survey, research and development, and crew training).
O’Donnell said he is convinced a modern automotive engine is the right fit for GA right now.
“Electric propulsion looks promising, but it isn’t ready for prime time,” he said. “Traditional aircraft engine manufacturers don’t have the economies of scale that come with mass production. Taking a modern automotive engine and adapting it for aviation seems like the right answer.