
Design an inverted V-4 piston engine, run it on jet fuel as a diesel, and do your polite Wisconsin best to be a disruptor in the general aviation aircraft engine world. That might be the mission statement for DeltaHawk, builder of the FAA-certificated DHK180A4.
As the piston-engine aircraft world grapples to embrace no-lead gasoline and phase out 100LL, the DeltaHawk approach, using lightweight diesel engines that do not burn gasoline, offers an intriguing alternative for some aircraft owners and manufacturers.
During EAA AirVenture Oshkosh 2024, DeltaHawk CEO Christopher Ruud revealed that the company is collaborating with Italian general aviation manufacturer Vulcanair to find ways to power Vulcanair’s airframes with DeltaHawk’s diesel engines.
Officials from the two companies are working to put the DHK180 diesel in Vulcanair’s V1 aircraft design. The V1, looking very much like an Italian interpretation of a Cessna 172, currently uses a Lycoming IO-360 engine.
Ruud touted the V1 for its record of no FAA Airworthiness Directives (ADs), and no landing gear incidents, something noteworthy for a training aircraft in which hard landings may be expected.
Vulcanair revealed earlier this year that it is establishing a U.S. manufacturing facility for the V1.0 in Elizabethtown, North Carolina.
The collaboration with Vulcanair follows other collaborations announced earlier this year, including one with Piper Aircraft to power Seminoles with the diesel engines, Van’s Aircraft and its RV-14, as well as Bearhawk, where the diesel DHK180 engine is expected to enhance altitude operation, range, and cost of operation.

According to Dennis Webb, DeltaHawk’s director of marketing and certification, the company is using new engine block technology that makes its diesels stronger, 70 pounds lighter, and easier to manufacture.
Webb added the company makes firewall-forward packages that can be useful for experimental and production aircraft. Evolution of the design includes improved aerodynamics on the engine’s heat exchanger, he said.
At DeltaHawk’s plant in Racine, Wisconsin, the company has an engine test stand that is sophisticated enough to run unattended, providing more test hours in less time on the calendar, according to Webb.

He added that DeltaHawk’s survey of aircraft types people would like to see matched with the diesel engine has received more than 1,000 responses, with many naming classic general aviation models.
Webb said possibilities exist to extend the range of electric aircraft with a hybrid diesel and electric arrangement.
He also is enthusiastic about DeltaHawk’s powerplant growth.
“We have more powerful engines coming,” he said. “It’s very scalable — four-cylinder, six-cylinder, eight-cylinder.”
While the world grapples with how to get the lead out of aviation gasoline, DeltaHawk has its own answer — don’t use gasoline.
For more information: DeltaHawk.com
Price is not the only factor. Check out my article in Cessna Pilots Magazine, which delves deeply into the economics of the DeltaHawk engine. It’s posted on the DeltaHawk Facebook page.
Delta Hawke engines purpose built and direct drive should be a better prospect than modified auto engines which have never been a long term solution.
The Delta Hawkes short crankshaft should reduce torsional vibration .
It will be interesting to see the price of a FWF installation.
It seems to me that this diesel engine is probably being targeted, no pun intended, at the military and govt market. Drone warfare is the future. Look no further than the new types of drones currently being employed in Ukraine. A reliable small aircraft engine that burns diesel is going to interest a lot of govts/militaries that have been doing everything they can to convert every combustion engine practical to diesel fuel for decades. Any GA manufacturer or homebuilt business they can develop will be just the very tip of a large potential iceberg.
The thing I find very curious is that they refuse to utter the words “two stroke”. Looking at photos it sure looks like like one. They talk about less parts and weight, but don’t explain why. Coming from a motorcycling background I have no problem with two strokes. I wonder why they avoid the term like the plague. My 2 cents.
Seriously? If you look at the DeltaHawk page in Facebook, there are videos of the CEO and marketing director talking specifically about the impact of a two-stroke engine.
A nightmare of complexity. And in the experimental (amateur build) market. Yeah, right.
The Delta Hawk engine has been flying for at least 15 years now. Not much of an inroad into aviation as yet. As previously mentioned, any manufacturer that is going to “disrupt” the GA engine market has to have an engine priced similarly to an after market Lycoming or Continental, or one of the Lyc or Cont clones and similar or less expensive cost to overhaul. The majority of GA aircraft built in the US are being built in hangars and garages, not by Piper or Cessna. Build an engine priced to compete in that market, and then we have something to talk about. Sell it to Cessna, Piper, or Cirus, and it becomes something the wealthy can brag about, but nobody else will own for the next 20 years and runs a strong chance of becoming a morphodite. Anyone remember the Porsche engined Mooneys?
Kent hits the nail right on the head – if the engine is too expensive, it is DOA.
Piper/Cessna etc. won’t be interested because they’d have to recertify the aircraft type certificate and for the few hundred aircraft they are currently producing, it makes no economic sense. The only way in for the Delta on these aircraft is by STC. Again, bring money, lots of it. If someone is considering a repower on their legacy GA airplane, they will most likely take the easy way out and rebuild the engine they have. Delta would have to present a really compelling case for the conversion.
On experimentals, yes, there’s a market, but the Delta has to be at least reasonably competitive with Continental and Lycoming, and remember that these engines are available used for considerably less than new – so Delta is competing with used Continental and Lycoming engines. Remember that not everybody buys (or can afford) a brand new engine for their homebuilt.
Delta’s real market is manufacturers who incorporate the engine in their new aircraft, such as the Vulcanair. The manufacturer has to buy SOME engine, so the decision to use a more advanced engine like the Delta Diesel is a viable choice.
An engine maker that is disruptive is Jan Eggenfelner of Viking Engines. He wisely uses commodity auto engines as a basis for aircraft engines that cost much less than the legacy ones, and often make use of low-cost, high-quality, volume produced spare parts available at any auto parts store. Perhaps DeltaHawk can join forces with him to produce an affordable diesel in the 100-150 hp range.
I’m not sure Eggenfelner’s efforts actually register as “disruptive” in the market, at least not in a positive way. For one, his efforts with the Subaru-based engines went so poorly that he walked off from the whole company he built around that (and his own name) to rebrand with the Viking label, built around Honda engines. (Perhaps the Viking effort is going better; I don’t know. However, anecdotal evidence suggests there may not be much daylight between this effort and previous one.)
And, if building aircraft engines based on automotive engines and designs is the measure for being “disruptive” here, then he is quite late to that party. (Consider all the folks using Corvair and Volkswagen engines, for instance, among lots of others.) And he’s not particularly original (auto engine with a reduction drive); that’s been done to (sometimes literally) death.
Then, in terms of market penetration with the automotive-based-in-aircraft-application route, I’m fairly confident he hasn’t topped the Diamond/Austro Engine success. He’s likely also behind Thielert (now Continental) with their Mercede-based Diesels by the same measure. And, perhaps most importantly, I also haven’t yet seen evidence showing his products are either more reliable, or meaningfully cheaper in the long run, much less both.
It would be more disruptive if its cost were comparable to similarly powered Lycomings from 10 years ago. Diesels are not exactly new though. They were first used on airships and aircraft in Germany a century ago. Many Diamond Aircraft are powered by Austro diesel engines. Continental has offered their diesels (previous Thielert) engines for 10-20 years. Price is everything – if they are too expensive, the are DOA.
I agree that, from a broad perspective, using a compression ignition engine in an aircraft isn’t new. However, what is kind of “fresh” with the Deltahawk is that it is a two-stroke diesel, rather than a four-stroke. I find that approach pretty intriguing on its face; it would seem to have a number of advantages going for it in this application. Also, the Deltahawk design avoids much of the dependency on complex electronics that comes with adapting a modern automotive engine, which has a chance to improve weight, complexity, and installed volume. But, you are spot on about price; it won’t matter if it is the best design ever conceived if it is so expensive that the old tried-and-true is still cheaper.
Nice engine, nice build, super far off in regard to what it is allowed to cost to be of any market value