Sun 'n Fun 2024: DeltaHawk Engine Update 

IIRC, their website originally estimated about a $15K price tag for the 200hp version.

that's totally nuts!

None of the diesel or electric engines make any economic sense. The purchase price and TBO is just not sensible and i dont see any market comptetition with Lycoming or Continental. This is pie in the sky....😂😂😂

I'm considering buying one of these, so I've looked into the options. Everybody's situation is different, but here's my take... You're quoting the upper estimate price of the engine plus the firewall forward kit. According to Kitplanes magazine, "[DeltaHawk] FWF packages are expected to cost around $100K-$110K including mounts, cooling system and, in some cases, the propeller as well". For comparison, if you buy a YIO-360-M1B from Van's, you'll pay $42K for the engine and maybe $12K for the finishing kit, for a total of about $54K, not including the propeller. So, while the DeltaHawk engine may initially seem pricey, it's essential to consider its unique features. These include turbo-normalization for enhanced power at altitude, significantly better fuel efficiency (40% better than comparable avgas engines), the flexibility to use cheaper and widely available Jet A fuel, reduced maintenance requirements (they claim), and a user-friendly single-level control system, i.e., no mixture control. If you plan to fly behind your new engine for 20-30 years -- as I do -- then the DH engine will pay for itself over time, and the other benefits are just gravy. Also, if SAF ever becomes real, DH is ready to use it immediately, so it's future-proof.

@@ssranon Lets not forget the weight factor. From what I've seen the DH engines are significantly heavier than a Lycoming,. No thanks.

Same. I'm 50 and I have been following this engine basically since going to university to study engineering back in '98.😂

Yeah and now totally overpriced

​@@daszieher- 65 and saw it at Oshkosh, late 1980's if I recall correctly! Might have been the early 1990's!

Yep. Vaporware

@@daszieherSo what’s wrong with it? Is it the engineering, or the economics, or both?

Maybe on your 3rd overhaul you could swap it when they are ready for production

we need to see the thrust bearings. 🚴‍♂ 1:55

I was thinking the same thing.

This is not the same. The Detroit Diesel 2-strokes (the Series 71 and Series 92 are the best known) are a more sophisticated uniflow design, using cam-driven exhaust valves in the head instead of piston-controlled ports for both intake and exhaust.

White Truck experimented with a 2 stroke loop flow V4 in the 50’s or early 60’s. Looper diesels also used in Europe around the same time. Detroit Diesel built a few loopers (2 cylinder if I remember correctly). I can find little info on these. It is likely the loopers did not have the flat torque curve desirable in truck engines.

Considerations for the DH engine: 1. V4 2 stroke has 4 power pulses/rev versus 2 for an IO 360 2. The initial fuel mechanically injected into a diesel takes time to heat and ignite. Meanwhile more fuel is injected behind it. When the initial fuel ignites, the stuff behind does too and this gives a hard hit to the prop. (Electronic injected diesel cars have tamed this.) 3. Jet fuel (and in a pinch diesel) is ubiquitous worldwide whereas avgas isn’t; 4. A 4 cycle piston lifts off the wrist pin at TDC on the inlet stroke..not so on 2 stroke..this means later’s wrist pin is hard to lubricate and presumably solved by DH. 5. A liquid cooled V4 is a much stiffer engine than an air cooled O4. Stiffness considerably affects TBO. So initial $ on a DH, may be made back by longer TBO. To be seen. 6. A liquid cooling installation can be designed with less drag than air cooled (eg P51 Mustang) if the designer chooses to do so (many design trade offs involved) Wish DH success as diesels and continuous high power go well together. New start ups have lots of issues besides design soundness to surmount. We should applaud DHs perseverance.

Thank you! Your comment saved me from having to watch the video and realize that myself.

Sales first, stats later. Which I hate too

If you have to ask you cant afford it lol

It's a worse engine in general.

@@neon_Nomad wow. Presumptuous much?

try a lancair instead

In the video, they mentioned that the water cooling takes care of turbo heat issues. I'm not sure if they also mentioned that the DH doesn't suffer from shock cooling. Hot starts and cold starts are no problem. And it has no mixture control. How is that bad for a flight school?

All 2-stroke engines need either crankcase induction (which is terrible for lubrication and emissions) or a scavenge blower, which is the "supercharger" that they mention. The blower adds complication, but there is no valvetrain.

Is it pressure fed bearing lubrication? Gugen pin life?

@@johanndork5364 Of course it has pressure-fed lubrication.

Any diesel is "single lever" because there is no mixture adjustment.

what about a prop lever

@@phatboizbackyardkustomz9006 Sure... if you have manually controlled prop pitch you have another lever. Since the engine uses a simplistic fuel control, it doesn't have a way to do prop control as well - with a fixed-pitch or constant-speed prop, it's still single-lever.

@@brianb-p6586to be pedantic: it has no throttle and the single lever is a mixture control. 😅

So is 4 stroke tech.

Time before overhaul .How long it lasts .

​@@jamesbarber2882 The TBO, not A TBO, jackass...

@@jamesbarber2882 That sounds like a line from "Airplane."

@@jamesbarber2882 XaviarJS is presumably asking how many hours the TBO is, not what "TBO" means.

I don't think there is a TBO... you likely replace the whole engine, and I could not find any mention of lifetime on the DeltaHawk website.

Yes, crankcase induction can work with a 2-stoke diesel, but it prevents pressure-fed oil lubrication and requires oil injection into the intake air... which would obviously be undesirable.

@@brianb-p6586 I think the skidoo gas direct injection force feeds oil to the crank while the piston, rings and cylinder walls are lubricated by the resulting oil vapor, minimizing the amount of oil out to atmosphere...

@@captarmour that seems really unlikely to work; oil-injection gasoline 2-stokes spray the oil into the intake air.

"Not as efficient"... compared to what? The most efficient piston engines in the world are large 2-stroke diesels.

Was ready to install a Deltahawk in my Tango-2 a number of years ago, but they couldn't deliver; however, I spent a lot of time researching radiator cooling and there are designs that negate drag such that it is not an issue. There is considerable information available from old NACA research documents that I obtained (Kayes and London did a significant amount of research). There are a number of rotary and Subaru powered plane owners that have developed very efficient cooling systems for their planes and have published on their designs. The output of all the early NACA research led to the P-51 cooling system which was said to produce a net positive thrust (not drag) from hot radiator exhaust gases under nominal conditions. The Deltahawk, at the time, was cheaper than a Lycoming, is lighter than a Lycoming, has less moving parts, provides better horsepower at altitude unless you have a turbo Lycoming, has more take-off torque, reduced maintenance (no $50 spark plugs!), and is not slower than a Lycoming powered plane. The deltahawk should provide "significantly" better fuel economy than a gas powered engine as demonstrated by other diesels such as SMA, Thielert, and Continental engines. The only downside today is the inflated cost of any diesel.

@@davewilliams9569 the SMA, Thielert, and Continental engines are all four-stokes. The DeltaHawk is the least effective and efficient form of 2-stroke (piston-ported intake and exhaust). Fuel efficiency of the DeltaHawk can't reasonably be estimated based on dissimilar engines.

@@brianb-p6586I think this is direct-injection, so there is no fuel in the intake air during the time that the exhaust port and the transfer (intake) ports are both open. IOW, it does not push fresh fuel out the exhaust port.

@@backcountyrpilot It is a diesel (compression-ignition engine), so like all diesels it has injection directly into the cylinder, with no fuel in the intake mixture. Pushing raw fuel out the exhaust due to overlap is a problem in gasoline 2-strokes without direct fuel injection, but isn't a problem in diesels of any type... but there are a lot more factors affecting fuel consumption than that.

There was a Twin-Velocity last year at Oshkosh. Go be a cynical troll somewhere else...

@@edcew8236 is that the one that crashed?

@@FlyingNDriving Don't take my word, go look it up yourself.

@@edcew8236 That's not a customer aircraft, it belongs to Deltahawk. Edit: It looks like it hasn't flown since Oshkosh, either.

​@@edcew8236a cynical troll, you say? 😂 Deltahawk have been promising for almost three decades. Their price point is a shot into the bushes, over 100k is just ridiculous. I'd have gone for 50k. I don't see it working.

I thought it was just a simple port(s) opened and closed by the piston. Sleeve valves are a whole new nightmare of complication. See Typhoons(ww2). This does seem a very neat clean design externally. No TBO price weights fuel burn though.

And sell how many? 5? 10?

It would feed into the engine directly through the air valve/throttle body directly or through an intercooler and then into the throttle body and then the supercharger

@@tomg1807 yes they probably intercooler it. But there is no throttle body, because it is a two stroke diesel. So power is regulated by the fuel pump and boost level. I didn't see a waste gate, which also seems weird. And no apparent inlet to the supercharger, which woukd have a hose attachment if it were intercooled

It's all connected in the engine on the stand. The exhaust pipes from the ports to the turbocharger's turbine are obvious. The output of the turbocharger's compressor section goes through a very short pipe, directly into the end of the scavenge blower (which they call "supercharger") housing. _Edit:_ the above is incorrect, as per the following discussion.

@tomg1807 There is no throttle in a diesel, and no intercooler shown on this engine.

@atg197 There is no intercooler on this engine - the turbo compressor is plumbed direct to the scavenge blower inlet. _Edit:_ the above is incorrect, as per the following discussion. With a small turbocharger it will likely be incapable of producing excessive boost for a diesel.

A little more than 22 years. It actually first ran already back in 1997. I think I remember the concept already mentioned in '96. People have been born, graduated from high school and made a pilot's license in the time Deltahawk has been kicking around this idea.

What they call a "supercharger" is actually a scavenge blower, which is what drives induction and exhaust with intake and exhaust piston strokes. The blower is the belt-driven device in the middle of the "V". The turbocharger just adds boost for more power especially at higher altitude - the engine runs fine without it. This is how large 2-stroke diesel engines typically work.

I don't think those old Detroit had turbos feeding the supercharger, or at least our little 6v53 didn't.

@@atg197The 6-71NA I drove just had the normal Roots-type blower, or supercharger. Required for this 2-cycle engine. GM also sold 71 series with a turbocharger in series before the blower. Even the so-called naturally aspirated had a slight above atmosphere pressure charge. I think huge numbers of 6V-53’s were turbo’ed for military vehicle use. The 6-V92 and 8-V92’s certainly were available turbocharged. Again they all had the Roots-type supercharger. Without more information I’d hesitate calling their mechanical supercharger naturally aspirated. GM chose to describe their slight charge this way. Maybe this manufacturer has a couple atmosphere directly off the supercharger. I don’t think there is a practical barrier to this except maybe need for a little more torque from the starter.

@atg197 it depended on whether it was ordered/spec'd as an naturally aspirated or turbocharged. I've worked on both varieties of them. Older heavy machinery would likely be non-turbo, whereas over the road trucks would most likely be turbocharged

huh? The fact that it needs the supercharger to run doesn't mean it isn't supercharged. If you took it up to 25k elevation, where it needs the turbocharger to run, is it no longer turbocharged?

@@vica153 The blower (supercharger) has the primary purpose of creating positive pressure, because the engine doesn't "suck" air in like a four stroke.. It is typically sized to pump the correct volume of air at a relatively low pressure. The turbo is used to increase the pressure into the blower inlet.

Yeah, I feel bad for this company and their investors. :(

The legacy engine manufacturers don't really do us any favors either. I remember when NASA gave away a grant for development of an aero-diesel engine... They ended up awarding the grant to Continental, who used it to "develop" an unworkable engine which they had no interest in ever bringing to market. The entire reason they went after the grant in the first place appeared to be keeping anybody else from getting it.

@@netpackrat Continental has 2 certified diesels with over 5,000 sold and 2.5 million flight hours, so your assumption is incorrect. SMA sold a number of certified engines, but went bankrupt due to high cost economics. However, they are all very expensive relative to a Lycoming! Even the Deltahak will be.

@@davewilliams9569 The current "Continental" diesel engines are actually the Thielert, which has been around for a long time, and which sold quite a few engines before Continental and their current Chinese masters came into the picture, and bought them out of bankruptcy. They are marketed as a Continental but that's only the name that the Chinese have slapped on it for now. The engine I was referring to was the "GAP" powerplant. NASA awarded the grant to Continental to develop and produce it, and what they came up with was similar in some ways to the Deltahawk. It was ultimately not a good engine, and NASA eventually became very unhappy with Continental's performance and pulled the funding from the project. The point of the entire exercise from Continental's point of view seemed to be more about getting the funding, and especially keeping anybody else from using it to produce an engine that would be a threat to Continental's product line.

There are specifications on their website and in a sheet downloadable from that site. This is what they say about fuel consumption: "7.3 gal/hr (27.6 L/hr)at 135 HP Economy Cruise 10.8 gal/hr (40.9 L/hr) at 180 hp" That's 0.054 to 0.06 USgal/hp-hr, 0.36 to 0.40 lb/hp-hr, or 220 to 240 kg/kWh Unfortunately I don't see any indication of TBO or overhaul/rebuild cost, which are critical information.

Get a grip. who says we avoided price? We asked during the shoot and was told a price hasn’t been finalized yet so he didn’t state it. Read our recent coverage in the magazine, where we previously reported DeltaHawk was projecting around $110K for an STC mod kit.

@@aviationconsumermagazine450 you should have said this in the video, and given that estimate... But you purposely didn't... It's sad y'all virulently avoid discussing the most important thing to us.. PRICE

Any extra weight is offset by how much lighter your wallet will be at $60k . LoL 😂

I imagine it would work, but Wankels are horrible fuel pigs in cars, can't imagine it would be any better in an aircraft. Outside of the fact they have poor longevity because they eat APEX seals, because of poor lubrication. Anyone I've ever known with a Wankel powered car typically adds a bit of oil to their fuel to help engine longevity

Poor longevity and the extra fuel Consumption offsets the weight savings

​@@tomg1807a Wankel engine would be best without seals at all. It would have to be run like a turbine and would be best directly coupled to a starter/generator that could bring to the high rpm necessary to idle without seals.

@daszieher Far as I know you can get apex seals made of different materials, not sure how much it would change the longevity of the unit. Considering they're inherently fuel thirsty engines with apex seals, your idea of running it without apex seals I feel would exersabate the fuel consumption issue. I've personally never heard of one running without apex seals, since without them there isn't any way to build compression pressure in the combustion chamber. If you know of one the runs without the apex seals, I'd love to see the video of it running.

Have several buddies with rotaries. Two big issues: as stated elsewhere, very fuel inefficient, and they run very, very hot. You need a lot of radiator. But great HP to weight ratio!

Will be interesting to see if they can pull it off. There is a market for sure.

@@atg197 For an extremely overweight, $100k, 180 hp engine? No.

@@PistonAvatarGuy they want 100k for it??

@@DanFrederiksen For a firewall forward package, apparently.

@@PistonAvatarGuy ridiculous

I'd take my chances with this new engine in heartbeat before ever using a Jabiru. Friends don't let friends fly Jabirus.

Total nonsense comment.

@@galactictomato1434 How many airplanes have you built? How many engine choices have you made?

In 2011 when I sold my SR20, I wanted to replace my engine with a delta hawk engine. 13 years later and it’s still not out 😅