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DeltaHawk Diesel Makes First Flight to AirVenture
By John W. Conrad
July 26, 2019 - Over a decade ago the developers at DeltaHawk imagined a direct replacement diesel engine for the prolific Lycoming I0-360. The new diesel had to match the size, weight, and performance specifications of the engine it was replacing. They started designing with a blank sheet of paper and the KISS maxim: Keep it simple, stupid.
Now, more than a decade later, they have arrived at what the company describes as "Power Reimagined." This year, for the first time, a Cirrus SR-20 powered by a jet-fueled DeltaHawk engine flew from its factory in Racine, Wisconsin, to AirVenture. The aircraft and engine can be seen at Booth 176 in the aircraft display area.
The engine is a direct-drive, water-cooled, supercharged, turbocharged, two-cycle mill delivering the required 180 hp. And yes, you read that right. The engine is both supercharged and turbocharged. The mechanically driven supercharger provides the pressurized air required to run the two-cycle diesel, and the turbocharger maintains effective power as altitude increases. This setup provides both excellent performance at altitude and also redundancy.
One advantage to the two-cycle diesel is that it has many fewer parts. There are no valves, rockers, camshaft, valve springs, or lifters; no magnetos, no wiring harness, and no spark plugs. The basic engine is elegantly simple. Dennis Webb, director of certification and marketing for DeltaHawk, is fond of quoting Leonardo da Vinci: "Simplicity is the ultimate sophistication."
Another advantage is fuel efficiency. At 65 percent power, the engine burns 6 gallons per hour. Apply that to the 56 gallons of usable fuel in the Cirrus SR-20 and you extend the endurance out to nine hours and change. Realistically, this is well beyond the endurance of most pilots, but the practical value is that less fuel required for any trip means more payload available.
This engine has been a long time coming to AirVenture. Many regulars have stopped by to check on progress, year after year. According to Webb, the turning point came four years ago with the acquisition of major capital funding. This allowed them to expand their workforce from three people to 50. It also allowed them to develop the infrastructure for testing, certification, and production, including advanced computerized engine state testing and simulation that allows them to test parts before the metal is cut. They have a building devoted to dynamometers, both water stabilized and propeller, and have installed a clean room for assembly and equipment that can measure down to 20 millionths (20/1,000,000) of an inch to ensure that all parts are fabricated to exact specifications.
Webb is confident of engine certification within the next few months and said it will exceed FAA requirements. "It is safe and solid and with our testing we won't have any problems," he added.
Now the challenge is getting the engine onto a few airframes. To that end, the company is offering everything from the firewall forward, including engine monitoring package, controls, all engine accessories, custom intake and exhaust systems, propeller, governor, engine mount, and cowling installed for $89,900. That's right. You get your airframe to the Racine, Wisconsin, factory and you will fly away with a turnkey installation.
Jet-fuel powered light airplanes have increased range, increased payload, and enjoy international refueling ability and release from the worry about the long-term availability of leaded gasoline. If you are completing a project, or approaching the time for major overhaul, it may be time for you to consider the future — what the folks at DeltaHawk call Power Reimagined.
"It's been a long road, it's been a lot of hard work, but the rigorous standards we have set for ourselves will pay off," Webb said. "Our customers will be delighted."