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DeltaHawk Diesel Engine STC


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Quote: JimR

Doesn't the GO-300 have a 1200 hour TBO?  I wonder what the TBO is of the geared Subaru engines that are flying in the experimental world?  Somehow I doubt that many of them are making it to the 2000 hours that is typical nowadays for the TBOs of many Lycomings and Continentals.  I say this simply because, with some notable exceptions, I see very few homebuilts on the market that have acquired that much time on the airframe, much less the engine. 

Jim  

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  • 2 months later...
  • 4 months later...

I see that Diamond Aircraft has recently installed an Astro AE500 (280 HP w/20,000 ceiling) in their  DA 50 Magnum. Is there anyone still thinking of a diesel conversion? If a STC converstion were $60K and considering that fuel prices are not coming down this may become a viable option.

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  • 8 years later...

Resurrecting an old thread, I went to an SAE meeting this spring that their factory.  The company has a much better financial backing and has grown many fold over the last few years with certification not too far off.  The initial engine will be 180 hp but they intend to have 160 and 200 hp versions to follow.  They engine is a pretty interesting design--2 stroke super and turbo charged.  Being 2 stroke there is no valve train and since it's diesel no ignition system.  Each cylinder has it's own independent injector pump so nice redundancy there.  Potentially it should be very reliable.  It's also liquid cooled so no shock cooling and you'd think improved service life.  It would sure be cool if someone came out with an STC for the J model.  In theory at altitude it would use quite a bit less fuel and be faster since it's turbo/supercharged.  What are the chances we see a STC?

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15 hours ago, marcusku said:

Resurrecting an old thread, I went to an SAE meeting this spring that their factory.  The company has a much better financial backing and has grown many fold over the last few years with certification not too far off.  The initial engine will be 180 hp but they intend to have 160 and 200 hp versions to follow.  They engine is a pretty interesting design--2 stroke super and turbo charged.  Being 2 stroke there is no valve train and since it's diesel no ignition system.  Each cylinder has it's own independent injector pump so nice redundancy there.  Potentially it should be very reliable.  It's also liquid cooled so no shock cooling and you'd think improved service life.  It would sure be cool if someone came out with an STC for the J model.  In theory at altitude it would use quite a bit less fuel and be faster since it's turbo/supercharged.  What are the chances we see a STC?

I would love to see an STC for a 200HP on all C  to J models but I'm not holding my breath.

Placing a 200HP turbocharged/supercharged engine on the front that can burn Jet A or diesel would be good.  However even for experimental I believe the FWF is north of $65k and would probably $75k+ for certified and that would be equal to or greater than the value of many pre-J models and fast approaching the value of many older J models.  You would need to save a lot of fuel to pay for the difference between an overhaul on an IO360 and a Delta Hawk.  Even at 2 gallon per hour savings over 2000 hours to TBO this is $20k savings in fuel.

Now (warning this is pipe dream) if they could get the FWF price in the $40k range then I think you would see some interest in all markets M, P ,& C especially if you could get most of the models up to 200HP.

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Well, I've been waiting for movement on the 200 HP version for the better part of 10 years since my plan was to use it in my RV-10 project.  It's part of the reason the project is on hiatus, because I'm near the point I have to commit to designing a new fuel line system for the diesel setup if I'm going to do it.

Note that diesel needs a modified fuel system, so it would NOT be a simple FWF modification.  Their setup requires a fuel return line (similar to Continental's fuel injection system), so a second fuel line run needs to be installed.  In addition, diesel fuel tanks need to be vented-to-safe, since fuel vapors in a sealed tank can reach the critical fuel-air mix.  So a separate air vent needs to be installed that will ventilate the fuel tank with any light wind, but will obviously not blow out all your fuel when the air is flowing at 150 knots.

It would be pretty funny, though, flying around with only a mixture knob (since there's no throttle).  The design is interesting, too--aside from the weird porting system (instead of valvese), the supercharger is only there for starting the motor, and as a backup in case the turbo fails, so you need some kind of annunciator to tell you if the turbocharger ever fails in flight, since you would not notice an immediate change.

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Keep hope alive.....   - some famous person in history...

The really cool thing is the amount of energy that can be stored in a gallon of diesel fuel...

The next coolest thing... availability...

third... no lead...

I think I have a better chance of mounting a turbine on my Mooney....

Best regards,

-a-

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On 10/1/2019 at 2:27 PM, jaylw314 said:

diesel fuel tanks need to be vented-to-safe, since fuel vapors in a sealed tank can reach the critical fuel-air mix.

Must not be terribly hard — look at all the JetA planes and helicopters around and few of them are spontaneously combusting. 

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Diesel is less volatile than gasoline so I would think venting would be less critical.

It appears likely the engine will be certified in the reasonably near future.  I think the question is if someone will get an STC for Mooney's and of course the cost.  I've heard it will be in the $60k range but that's some speculation. 

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53 minutes ago, marcusku said:

Diesel is less volatile than gasoline so I would think venting would be less critical.

It appears likely the engine will be certified in the reasonably near future.  I think the question is if someone will get an STC for Mooney's and of course the cost.  I've heard it will be in the $60k range but that's some speculation. 

Look at what it costs to buy a new IO-360 from Lycoming, and expect to pay more. Don't look at Exchange or Overhaul pricing, look at what it costs to call up and buy a brand new one with --zippo!-- to give in exchange other than good old fashioned cashola.

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4 hours ago, Jerry 5TJ said:

Must not be terribly hard — look at all the JetA planes and helicopters around and few of them are spontaneously combusting. 

I assume aircraft that use JetA or diesel are designed with a fuel tank venting system.  The tricky part is retrofitting a plane (or a kit design) with a fuel system designed for gasoline.

I have to admit, though, I don't know if such a venting system is required by regulation or type design for, for example, turbine aircraft.  It's recommended by DieselHawk and may simply be out of an abundance of caution

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1 hour ago, marcusku said:

Diesel is less volatile than gasoline so I would think venting would be less critical.

It appears likely the engine will be certified in the reasonably near future.  I think the question is if someone will get an STC for Mooney's and of course the cost.  I've heard it will be in the $60k range but that's some speculation. 

Gasoline fuel tanks are "sealed" to safe.  "sealed" means that there is only one vent to allow air in when you use fuel, so there is no air circulating into the tank when fuel is not being used.  This allows gasoline to evaporate into the air in the tank, and it will reach saturation after a few minutes.  At that point, there is enough gasoline in the air that the fuel-air mixture is too rich and will not ignite.  If you leave a tank open, the fuel-air mix will be leaner and might be able to ignite.

Diesel fuel is so less volatile that in a "sealed" tank, it will never reach saturation, but it might reach the point where the fuel air mix is capable of igniting.  Having more than one vent will prevent this possibility, since having even a little bit of air circulate in the tank will make it impossible for the fuel-air mix ever to get rich enough to ignite.

That's the theory, anyway.

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1 hour ago, jaylw314 said:

I assume aircraft that use JetA or diesel are designed with a fuel tank venting system.  The tricky part is retrofitting a plane (or a kit design) with a fuel system designed for gasoline.

I fly a plane originally designed for gasoline that now uses JetA.  The tank vent design appears to be the same now as it always was.  

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Delta hawk has been a year from certification since I started flying.  So far the only diesel engines I've seen or aircraft were reworked car engines.  I'm with Jose, if manufacturers really want the business of the emerging world make the damn engines work with Mogas.  A lot of them do already.  Mogas is available everywhere.

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6 hours ago, steingar said:

Delta hawk has been a year from certification since I started flying.  So far the only diesel engines I've seen or aircraft were reworked car engines.  I'm with Jose, if manufacturers really want the business of the emerging world make the damn engines work with Mogas.  A lot of them do already.  Mogas is available everywhere.

Most Diamondstar DA42 twins have diesel engines.   Many if not most of the big recip drones are diesels (many of them from Lycoming)

Most of the "mogas" STC conversions require 100% gasoline, not the ethanol-blended gasoline that comes out of most pumps.   The "mogas" that is required to run in most of the STCs is pretty much unobtanium in most of the country.

Jet A is far more available at airports, which is what the diesels burn.

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