Deltahawk on the Bearhawk

[quesauce]

The 4 place is getting an officially supported new engine in the form of the Deltahawk diesel. I don't know what Mark said to convince them to support experimentals but well done!
Press release.

[tailwind]

How does the weight compare with a 540.

[quesauce]

How does the weight compare with a 540.

The data sheet says 357 pounds dry but including starter, turbo, exhaust, and alternator. So a bit lighter than a 540. But maybe not lighter on the wallet; guesstimates are floating around of $100k firewall forward. But if you can’t get avgas where you are, it might make sense!

[sherrre]

Shouldn't we do the weight comparison with another 180 horse engine such as a 360?

Personally I’m hoping they add two more cylinders and make a 270 horse version but as Kevin mentioned it all comes down to cost.

[jaredyates]

Dennis says it isn't a straight across comparison of displacement due to the very different torque curves. But that is coming from him, naturally. I'm looking forward to seeing one fly so we can get the whole picture!

[sherrre]

I can see the additional torque making the Deltahawk comparable with an 390.

I’m planning to build a Bearhawk 5 so would likely need a bigger engine than the Deltahawk 180.

[svyolo]

More torque at lower rpm would require more blade area/span to take advantage of that torque. The deal breaker is the prop, like Schu said. I was involved in the engine conversion world in automobiles, including putting diesels into former gas cars. They were mostly problematic as the diesel power pulses destroyed transmissions not designed for them. Props are even worse than transmissions. I doubt a prop manufacturer could afford to build (and test properly) a bunch of props for a bunch of applications.

I hope it works out.

[Bcone1381]

In layman terms....the power pulse of a diesel is stronger....more of a "hit" than a "Push". So chances are higher that it gets a metal prop vibrating harmonically like a tuning fork than a Lycoming. So a wood prop can help in that arena. But the Delta Hawk is a two stroke, so more power pulses more often at a lower force is noteworthy, seems like less of a HIT, and needs more research.

Regarding power, its only fair to compare a normally aspirated O-360 against an engine with a turbo charger when they both are being operated at sea-level. I don't know if the Delta Hawk will be underpowered at 8000' and above. I also dont know at what altitude the Delta Hawk power output will equal an O-540, but that data is available.

[sherrre]

Thanks for educating me on the differences with the diesel engine.

Diamond has figured out the propellers for their aircraft so I wonder how much will transfer to other diesel- powered airplanes. Of course they have 4 stroke engines so different power pulses.

[rodsmith]

Diamond uses MT wood/composite props on their jet fuel powered engines.

[Mark Goldberg]

I am hopeful the Deltahawk engine will be a good alternative for the BH community. They have worked awfully hard for a LONG time to get it certified, and other more powerful versions are likely in the future. I am told that this is the first small engine certified since the 1960's. Getting something through the FAA must be incredibly hard. We will know more when Dennis's BH flies.

They have collaborated with Hartzell and MT - so safe props will be available. The price will be less than what some of you have guessed. Let's give the engine a chance to prove itself for our application. We are lucky to have one of the top engineers at Deltahawk willing to install it in the 4 place BH.

[Bissetg]

Fantastic that Bearhawk is at the sharp end of R and D for a modern engine alternative. Paired with a composite CS prop our propulsion could become 21st century technology!

Looking forward to following this with interest.

[Utah-Jay]

Jet fuel is the future, especially as the roll out of unleaded AVGas is non-existent

[sherrre]

As others have said this is great news Mark.

[zkelley2]

In layman terms....the power pulse of a diesel is stronger....more of a "hit" than a "Push". So chances are higher that it gets a metal prop vibrating harmonically like a tuning fork than a Lycoming. So a wood prop can help in that arena. But the Delta Hawk is a two stroke, so more power pulses more often at a lower force is noteworthy, seems like less of a HIT, and needs more research.

Regarding power, its only fair to compare a normally aspirated O-360 against an engine with a turbo charger when they both are being operated at sea-level. I don't know if the Delta Hawk will be underpowered at 8000' and above. I also dont know at what altitude the Delta Hawk power output will equal an O-540, but that data is available.

They claim the critical altitude is above 17.5k It'll make more power than a 180hp 360 any time you're above sea level and it'll make more power than a 540 at around 9000ft.

As far as a different torque curve, at least for takeoff, when you need max power, it's rather irrelevant as they're both making the same torque at 2700rpm like schu said. You don't sit in a less than max power condition in an airplane like you do a car that's accelerating.

[kestrel]

You don't sit in a less than max power condition in an airplane like you do a car that's accelerating.

Oh?! A car will accelerate at less than full throttle?!