Deltahawkengines

[ship]

The SFC on a 2 stroke diesel is really not much better than a high CR gasoline engine fitted with EI and FI running LOP

The more correct statement is to say that a crude 2-stroke diesel such as the DeltaHawk is about on par with the most sophistiated gassers.

apples to apples: DH vs. mag Lyco
apples to apples: subaru vs. diesel w/commonrail & EFI.

DH runs .38 using a very simple single-pulse mechanical-injection system with mechanical injection pumps...about as crude as it gets. This is deliberate. Fully electronic common-rail systems were ruled out for the first generation engines to avoid all electrical dependency FWF.

To rv6ejguy's point, the state-of-the-art gassers are using fully electronic ignition and fuel management. Under the same configuration using piezo pulse-width injectors and common rail fuel at 30,000psi, the DH should achieve SFC in the range of .33. As always, testing will tell the tale.

The current state of the art in gas is high .36's; diesels is .27-.28.

 

[rv6ejguy]

The more correct statement is to say that a crude 2-stroke diesel such as the DeltaHawk is about on par with the most sophistiated gassers.

apples to apples: DH vs. mag Lyco
apples to apples: subaru vs. diesel w/commonrail & EFI.

DH runs .38 using a very simple single-pulse mechanical-injection system with mechanical injection pumps...about as crude as it gets. This is deliberate. Fully electronic common-rail systems were ruled out for the first generation engines to avoid all electrical dependency FWF.

To rv6ejguy's point, the state-of-the-art gassers are using fully electronic ignition and fuel management. Under the same configuration using piezo pulse-width injectors and common rail fuel at 30,000psi, the DH should achieve SFC in the range of .33. As always, testing will tell the tale.

The current state of the art in gas is high .36's; diesels is .27-.28.

DHs own data actually shows a cruise SFC of around .42 which is about the same as a Carbed Lyco and their comparison to a Lyco in their data suggests they had a guzzler. Given that even a IO-360 with mags can easily drop below .40 in cruise, I don't see all the hoopla about the DH other than it can burn jet fuel which is not available at lots of small airports. Very few small (mobile) diesels have SFCs below .3. With DH not embracing the latest common rail/ ECU technology, I maintain that their SFCs in the real world are unlikely to be much better than an EI/FI Lyco. If you don't use the latest technology available, you cannot reap the benefits of it. They have much to prove in the fuel consumption and longevity/ reliability areas still. I do wish them well. It is a cool concept and they have stuck with it. Kudos DH.

 

[airguy]

Agreed, they can make better SFC's with some work. But even as crude as the current version is, I am sold on it for two main benefits - I can run standard pump diesel in it for $2.40/gallon, and it's turbocharged to give 100% to at least mid-teens. With the add-on wingtip extensions I can tanker enough cheap fuel to make just about any round trip without having to buy much, if any, Jet A for a top off at my destination. Granted, there may be a small weight/drag penalty to pay for the liquid cooling - but I don't have to worry about supercooling on rapid descent, I don't have to closely monitor the engine to run LOP safely, warmup periods will be nicely shortened in cold weather, and at mid-teen altitude where I like to cruise the high available power will more than make up for the parasitic cooling drag. I'll burn a little more fuel to do so - but at least it won't be $4 fuel!

 

[aadamson]

Agreed, they can make better SFC's with some work. But even as crude as the current version is, I am sold on it for two main benefits - I can run standard pump diesel in it for $2.40/gallon, and it's turbocharged to give 100% to at least mid-teens. With the add-on wingtip extensions I can tanker enough cheap fuel to make just about any round trip without having to buy much, if any, Jet A for a top off at my destination. Granted, there may be a small weight/drag penalty to pay for the liquid cooling - but I don't have to worry about supercooling on rapid descent, I don't have to closely monitor the engine to run LOP safely, warmup periods will be nicely shortened in cold weather, and at mid-teen altitude where I like to cruise the high available power will more than make up for the parasitic cooling drag. I'll burn a little more fuel to do so - but at least it won't be $4 fuel!

Um and what do you do, when in the mid teens, and the oat is 0 or less, and you are using auto diesel? Better plan on using some sore of "anti-gel", *and* you better make sure the engine will not have a problem with it. Also, don't forget, the engine needs to run "low sulfer" as diesel as we all know it is *about* to change. The 2007 and newer autos all have to use it and they *won't* run on the old #2 diesel.

There more to this diesel thing that meets the eye, at least with Jet A, all of the above is taken care of.

 

[airguy]

The reason the auto diesels get cranky about the new low-sulfur diesel is due to the fuel's lowered lubricity giving the old injectors problems. The new injector pumps will handle it, and if operating with an older injector pump a lubricity additive may be needed. As for the fuel temps, you are correct that long cruise periods in cold altitudes might be an issue. A fuel temp gauge would be a requirement, as the fog point of #2 road diesel is -20C. Additives can be used to reduce the pour point of the fuel, but the fog point is what will kill you by clogging the filter, and additives won't affect the fog point.

I'm also still turning over the thought in my head of a small fuel/coolant or fuel/oil heat exchanger, to warm the return fuel line from the injectors on the way back to the tank, to keep fuel temps nice and toasty.

 

[rv6ejguy]

Might want to check the installed weight of the DH. I don't think you will be tankering much fuel with 2 people aboard unless you raise the gross.

 

[airguy]

Might want to check the installed weight of the DH. I don't think you will be tankering much fuel with 2 people aboard unless you raise the gross.

Good point, and it's been considered. My wife hates anything smaller than a 747, we don't (and won't) have kids, so my right seat is for my flight bag and maybe my dog. I'm mostly after fast, economical XC with good performance, and don't need acro. Hence the 9A, versus a 7 or 10.

 

[rv6ejguy]

Good point, and it's been considered. My wife hates anything smaller than a 747, we don't (and won't) have kids, so my right seat is for my flight bag and maybe my dog. I'm mostly after fast, economical XC with good performance, and don't need acro. Hence the 9A, versus a 7 or 10.

If you fly solo XC, no worries. I'd love to see one of these flying in an RV so we can see what kind of numbers it turns in. Keep us posted.

 

[ship]

DHs own data actually shows a cruise SFC of around .42 which is about the same as a Carbed Lyco and their comparison to a Lyco in their data suggests they had a guzzler. Given that even a IO-360 with mags can easily drop below .40 in cruise, I don't see all the hoopla about the DH other than it can burn jet fuel which is not available at lots of small airports. Very few small (mobile) diesels have SFCs below .3. With DH not embracing the latest common rail/ ECU technology, I maintain that their SFCs in the real world are unlikely to be much better than an EI/FI Lyco. If you don't use the latest technology available, you cannot reap the benefits of it. They have much to prove in the fuel consumption and longevity/ reliability areas still. I do wish them well. It is a cool concept and they have stuck with it. Kudos DH.

Not to quibble, but the only diesels making below .3 are massive 2-stroke marine and locomotive diesels.

At this stage of development, DH routinely sees SFC's in the high 30's. This may be "nothing to write home about vs. Lyco", but it should be kept in perspective.

As stated before, DH injectors are single-shot units, and the pump is 100% mechanical. It's about as crude as it can get.....and still it's as good as "real world" Lycoming SFC's. As future generations incorporate common-rail and pilot injectors, SFC's will rapidly drop into the mid 30's.

Hopefully DH will survive long enough to incorporate c-rail, etc.

 

[bumblebee]

I'd love to see one of these flying in an RV so we can see what kind of numbers it turns in. Keep us posted.

FWF is an issue that DH has yet to address, despite several serious offers from myself and others to develop a FWF for RV's.

IMO this is THE biggest stumbling block for DH by not having a flying RV. Who the heck cares about a Velocity? Put the engine on the Chevy of experimentals..... swinging a metal prop in a fast tin tractor will prove once and for all if the diesels will work.

The cooling drag in a tractor configuration will be larger than DH anticipates....as the Subie folks can readily attest.

 

[Captain Avgas]

*by the way...Lycoming gassers use fuel for cooling. This is part of the "diesel is more effecient" arguement.

Patrick N. Garboden
Ozark, MO
RV9-A 942WG
RV9-A 942PT

Would you please elaborate on this theory.

 

[airguy]

It's no theory - by running a mixture "rich of peak", you are supplying more fuel than can be burned by the available oxygen in the cylinder. The result is lower EGT, and some raw unburned (or partially burned) fuel being dumped overboard through the exhaust. Running "lean of peak" injects less fuel into the cylinder than is required to completely consume the available oxygen, meaning all the fuel is burned and there is still oxygen left in the cylinder after combustion. Both LOP and ROP result in lower than "peak" EGT. One side (ROP) you're using excess fuel to cool the engine, the other side (LOP) uses excess air to cool the engine. Air is free, fuel is not - LOP is more efficient. Diesels run inherently LOP by design, as they take a charge of air, compress it, and then inject fuel to produce power. The fuel sprayed into the cylinder is completely burned at all power settings below the "smoke point", meaning it is running lean stoichiometrically - less fuel than available oxygen.

If you see a diesel blowing black smoke, it's injecting more fuel than the available oxygen in the cylinder can support, resulting in partial combustion. The hydrogen in the hydrocarbon chain fuel will preferentially combust and consume the oxygen first, leaving unburned carbon (soot) in the exhaust stream.

 

[Captain Avgas]

It's no theory - by running a mixture "rich of peak", you are supplying more fuel than can be burned by the available oxygen in the cylinder. Both LOP and ROP result in lower than "peak" EGT. One side (ROP) you're using excess fuel to cool the engine, the other side (LOP) uses excess air to cool the engine.

Yes I understand what you're saying but are you advocating the theory that the "excess" fuel when running ROP cools the engine primarily by evaporative cooling. I doubt that's true.

 

[mlw450802]

Yes I understand what you're saying but are you advocating the theory that the "excess" fuel when running ROP cools the engine primarily by evaporative cooling. I doubt that's true.

I think you are correct here. The reason things are cooler when operating away from stoichiometric conditions is simply that flame temperatures are much cooler and power generated is less. Therefore, lower engine temperatures. I doubt that any significant cooling can be attributed to fuel vaporization. I don't know the numbers for avgas but I bet the latent heat of vaporization is no more than a few hundred btu per pound and I suspect that is way down in the noise compared to the combustible energy content per pound.
-mike

 

[airguy]

You're correct, it's the flame temperature that does most of the lowering for the EGT. At a perfect mixture, you'll have the peak EGT with all of the available fuel consuming all the available oxygen. Change the mixture on either side of that, and either the fuel or the oxygen becomes the limiting reagent. You've still got the same amount of fuel being burned if you're rich of peak - all the oxygen is used to burn fuel, but now you've got excess unburned fuel also - so the power produced is not a LOT different. The EGT difference comes about because of the fact that ALL the fuel, not just part of it, burns PARTIALLY (chemically speaking). Some of the partially burned fuel will then burn completely until all the available oxygen is consumed, leaving some partially burned fuel in the exhaust.

The hydrocarbon chain in the fuel during the combustion event will first give up its hydrogen to combust, which burns completely to make water vapor. Then the carbon chain itself will begin to combust, first partially to form carbon monoxide, and then if there is still available oxygen, completely to form carbon dioxide. Oxygen starvation (ROP mixtures) will result in high levels of carbon monoxide in the exhaust. The "combustion" of the carbon monoxide to carbon dioxide adds significant heat to the entire mass of gas in the combustion chamber, so if there is less of that process, the EGT drops. Obviously during LOP operation, fuel starvation is the process that limits EGT.

You can think of combustion as a three stage process - first the hydrogen will go to form water vapor, then the carbon will burn to form carbon monoxide, then the carbon monoxide will burn to form carbon dioxide. That's slightly simplified, but it's essentially what's happening. On a diesel, you won't see black smoke until you've got raw carbon being dumped overboard, meaning the oxygen in the cylinder is mostly consumed by the hydrogen and there isn't enough left to convert all the carbon (black soot) to carbon monoxide (clear colorless). A gasoline engine will barely run at a mixture rich enough to do this, which is why you don't commonly see gas engines blowing black smoke.

 

[WilliamDCat]

If you're interested in published research on EGTs/CHTs/Mixture go to the NASA website and run a search. Fuel (ROP) is more efficient at cooling than water injection! At the same time, extreme ROP conditions, while keeping CHTs in check, can create excessive EGTs because the mixture burns so slowly that it performs less work and the energy is instead retained as heat. While this is not normally a problem with normally aspirated engines it become a problem with turbocharged engines (TIT).

What's this got to do with diesels?

 

[airguy]

*by the way...Lycoming gassers use fuel for cooling. This is part of the "diesel is more effecient" arguement.

Well, I would point out that this entire thread concerns the DH, which is a diesel. We got off track talking about the EGT differences on 100LL engines for ROP and LOP because someone asked about the above quote. The diesel engines are inherently more efficient simply because they (almost) never operate ROP at all - more (or equivalent) power for less fuel.

And turbocharged gas engines will only suffer that problem (extreme ROP) if you are running under very high boost, with no intercooler, and do not use some method of leaning - in which case you're very likely to experience severe detonation before you get to the extreme ROP mixture range due to the high induction temperatures.

 

[RichB]

Bump.

"...it is our hope that builders of different aircraft will get together and develop mounts and firewall forward kits and share the information."

One year later, is there any RV FWF progress? Nothing specific is mentioned on the DeltaHawk site, but they seem to have made the engineering drawings available. Between the engineers, the fabricators, and the watercooled guys already flying, is this not a doable project for the RV community?

 

[airguy]

Very doable. Just not done yet.

I just started my empennage - it'll take me a while before I'm ready to be a test bed!

 

[RichB]

Very doable. Just not done yet.

I just started my empennage - it'll take me a while before I'm ready to be a test bed!

Heh. Maybe I can put something together to sell to pay for my plane?

Hmm. I guess we'd need something like this (K.I.S.S concept):
* A mock-up firewall (I'm happy to knock something up).
* Mock up of the engine (I'll put my hand up for milling this from wood or similar with the CAD files too).
* Subaru / Mazda / etc owners to recommend effective rad locations.
* Design engine mounts to suit (including some basic FEA).
* Mr James to bring forth a suitably efficient cowl to cover it all.
* Mr Catto to design a nice light prop to swing off it.
* A brave soul to test it.

It's gonna be a busy week...

 

[airguy]

Just one point on the prop - a diesel is going to be much happier with a CS prop. I know it adds weight (not to mention a little cost) but the way the diesel operates simply cries out for a CS prop instead of a FP.

 

[1:1 Scale]

I bookmarked http://dieselfirewallforward.com about a year ago, and just sent them an email earlier this week to see if there was any progress at all. I'm nearing the end of my empennage, so I still have some time to "wait and see", but have been brainstorming the cooling installation for a while (as best I can), and I think the inverted V4 configuration will lend itself to a much more efficient cooling setup than we are seeing in most Sube installations.

Also, I've been giving some thought to which version to use. The 160hp, 180, and 200hp all seem to weigh the same, so the natural tendancy is to go for the 200 However, the 180 doesn't have an intercooler (less drag) and will likely outperform a 200hp Lyc at normal altitudes due to the turbo.....Hmmmmm

Of course, it's all dreaming and speculation if we can't get one

 

[RichB]

Just one point on the prop - a diesel is going to be much happier with a CS prop. I know it adds weight (not to mention a little cost) but the way the diesel operates simply cries out for a CS prop instead of a FP.

Agreed, although FP would be simpler and cheaper for prototyping. Perhaps Whirl Wind Aviation would come to the party with a "151D" or "200D" CS prop for prototyping?

I bookmarked http://dieselfirewallforward.com about a year ago, and just sent them an email earlier this week to see if there was any progress at all. I'm nearing the end of my empennage, so I still have some time to "wait and see", but have been brainstorming the cooling installation for a while (as best I can), and I think the inverted V4 configuration will lend itself to a much more efficient cooling setup than we are seeing in most Sube installations.

Also, I've been giving some thought to which version to use. The 160hp, 180, and 200hp all seem to weigh the same, so the natural tendancy is to go for the 200 However, the 180 doesn't have an intercooler (less drag) and will likely outperform a 200hp Lyc at normal altitudes due to the turbo.....Hmmmmm

Of course, it's all dreaming and speculation if we can't get one

I'd guess that they just add more fuel and turn up the boost to get the extra HP, hence the need for the intercooler (on both 180 and 200). 160 HP is a good "worst case" platform, should be less stressed, and is quite a bit cheaper. No intercooler makes a prototype simpler too.

I'm not sure about the cooling, my head tells me FWF cooling (a'la Subaru FWF) is easier, but my gut tells me the weight distribution and aerodynamics might be better if the radiator is further aft on the fuselage. OTOH, I was perusing the Eggenfellner site and saw their liquid cooling E-cowling product. They do one for the RV series already.

The DeltaHawk Velocity page has a bit of info on the cooling requirements. Anyone know the radiator area used on the Eggenfellner kit?

On the topic of engine conversions, this site was a good find...

 

[RichB]

Just thinking out-loud here... has anyone ever tried a P-51 style cooling setup with the radiator behind the seats in the baggage compartment? The benefits are a cleaner nose and better weight distribution. My concerns would be more weight (more coolant, more hardware), structural integrity, and upsetting the aerodynamics with the intake under the fuselage. I also seem to recall that the duct itself may be designed to create lift, will have to do some serious reading.

Result would be FWF kit + fuselage-modification kit. Definitely getting "experimental" here...

 

[TSwezey]

Just thinking out-loud here... has anyone ever tried a P-51 style cooling setup with the radiator behind the seats in the baggage compartment? The benefits are a cleaner nose and better weight distribution. My concerns would be more weight (more coolant, more hardware), structural integrity, and upsetting the aerodynamics with the intake under the fuselage. I also seem to recall that the duct itself may be designed to create lift, will have to do some serious reading.

Result would be FWF kit + fuselage-modification kit. Definitely getting "experimental" here...

I think Ross has some setup like this for his -10.

 

[RichB]

I think Ross has some setup like this for his -10.

http://www.sdsefi.com/air46.htm

Nice work, Ross. Great minds do indeed think alike.

 

[rv4mekp]

Delta Hawk

There is a gentleman named Dean May in our EAA Chapter 1414 (Poplar Grove, IL) who just retired as a captain from United Airlines. He recently bought a Cessna Skymaster which will be converted to a flying test bed for the Delta Hawk engine. I understand he will personally test fly this aircraft with the Delta Hawk installed. Check the EAA Chapter 1414 website for updates.

 

[1:1 Scale]

It's good to see progress on the DH website, but from what people have said here, they may not be too interested in the homebuilt market. I hope they are, but I'm not goiing to pick up the phone and waste their time until I'm ready to cut them a check. But still, inquiring minds want to know!

Just thinking out-loud here... has anyone ever tried a P-51 style cooling setup with the radiator behind the seats in the baggage compartment? The benefits are a cleaner nose and better weight distribution. My concerns would be more weight (more coolant, more hardware), structural integrity, and upsetting the aerodynamics with the intake under the fuselage. I also seem to recall that the duct itself may be designed to create lift, will have to do some serious reading.

Rich, we're thinking on the same page, but I'm thinking inside the box (cowl) From what I've been reading, the Meredith Effect (creating thrust) will be pretty minimal at RV speeds, but if we can get close to zero drag, that's good enough for me

 

[rv6ejguy]

I'm currently flying an aft mounted supplementary rad set on the 6A which made a big difference in cooling. For heavier engine installations, the aft mounted rads should be more efficient and keep the C of G more reasonable. There can be issues with other cooling air and exhaust impinging on the rad inlet on an RV so these things need to be considered as well as piping- external or internal.

The aft rad scoop is probably best placed near the C of G to reduce potential pitch change from aerodynamic influences.

 

[Transporter]

Radiator Scoop

Related to this thread: the Stewart S51 Mustang replica also uses a rear-mounted radiator. Terry Gerber's S51 (here at KLXT) has a big-block Chevy (with four blade prop!); the radiator scoop looks like it might be close to the size needed for an RV since this is a 3/4 scale design.

For photos see http://www.terryair51.com/gallery.htm

FWIW: If you've got the $$ this plane is for sale ($275K)-beautiful plane.

 

[RichB]

Very nice. The mini-mustang intake could be a good starting point. I found this fullsize spitfire replica kit for too. Back on topic, yeah, the standard exhaust location could be an issue... We don't want to fill the radiator with exhaust fumes if that's avoidable. All of the liquid cooled warbirds run side exhausts, so that might be a possible solution.

As for progress, I've got the IGES and STEP models loaded up on my machine, but need a few days to consult with the milling machine operator about stock and tool sizes etc. And I talked to some CFD (computational fluid dynamics) guys about running a simulation on an model of an RV-7A last night. Looks like that will be doable.

Cheers,
Rich

 

[RichB]

Velocity sized radiator inside a scaled-to-fit "mini mustang" scoop. No idea if it'll get enough air, plus it needs an oil cooler, etc. Gotta start somewhere, and CFD will show what's up pretty quickly.

 

[Mike S]

Where did the exhaust pipes exit on a P-51.

Same Q for the cooling air that comes off of the engine----after going through the cylinder and head fins

 

[N941WR]

Good picture Rich but what about airflow that far back in all attitudes. Also, if you look close at the P-51 "dog house", its opening is not flush with the bottom of the fuselage; it actually stands off a little bit with a vertical splitter in the center. I believe this was done for boundary flow reasons.

The Mustang heat exchanger has to be one of the most studied radiator set ups ever made. There is lots of good info about it out there.

 

[RichB]

Where did the exhaust pipes exit on a P-51.

Same Q for the cooling air that comes off of the engine----after going through the cylinder and head fins

Yup, P-51 exhaust was out the side of the cowling. There's a small intake up-front too, so I guess a bit of airflow was taken in and out... small off-center cowl outlets might be a work-around.

Good picture Rich but what about airflow that far back in all attitudes. Also, if you look close at the P-51 "dog house", its opening is not flush with the bottom of the fuselage; it actually stands off a little bit with a vertical splitter in the center. I believe this was done for boundary flow reasons.

The Mustang heat exchanger has to be one of the most studied radiator set ups ever made. There is lots of good info about it out there.

I was aiming to put the radiator behind the seats, as the duct is raised up into the fuselage, but I'll double check the position. I don't know about airflow at altitude, I figured that'll be something to check out in simulations. It's hard to tell from the pic, but there is a small gap here too. Anyway, I've adjusted the location of the duct a bit (might need to refresh the browser to see the new pics)

I've been sifting through a bunches of documents, and those old war engineers sure did some cool stuff for their day... Any pointers you could recommend?

 

[John Courte]

Nice 3D model!

Sorry to threadjack, but Rich, where did you get that 3D model from?

 

[rv6ejguy]

Rich, I like your ideas. With the Deltahawk being turbo, the exhaust pipe can be easily moved somewhere where it won't impinge on the rad inlet. You can have soot down the side of the fuselage!

The rad duct needs to have internal angles of less than 7 degrees to prevent separation of the flow or have guide vanes. If the rad will be partially mounted inside the cabin, a fair number of structural mods would be required.

I believe for ground cooling, the inlet area needs to be at least 30 square inches even for a diesel with its lower heat rejection. You'll probably also need a movable exit door to aid flow on the ground and trim drag in cruise.

On my 6A CFD model, pressure is actually low across the bottom of the fuse from the spar to almost the TE of the wing. How much difference this makes is unknown as dynamic pressure is many times higher at the rad face in flight.

A 2 row rad with around 120 inches of face area and 2.5 inches thick should do the job if you have a good duct design.

 

[1:1 Scale]

Rich, I like your ideas. With the Deltahawk being turbo, the exhaust pipe can be easily moved somewhere where it won't impinge on the rad inlet. You can have soot down the side of the fuselage!

I vote for staight up out of the top of the cowl with a flapper on the end

 

[Mike S]

I vote for staight up out of the top of the cowl with a flapper on the end

Just be sure to get it higher than the windshield.

Soot on the tail-------no big deal. Soot on windshield------big deal.

 

[RichB]

Sorry to threadjack, but Rich, where did you get that 3D model from?

It's the RV-7A model for X-Plane 8, made by Tracy Walker. I think I retrieved it from www.x-plane.org sometime last year.

 

[the4ork]

ive thought alot about running a diesel in a -4

i drive an 82 turbo diesel jetta that i have done some engine mods to.. 150hp 1.6L... it gets 50+mpg!

often thought about using one as an a/c engine, but they are way too weak for a prop i think, especially if any aerobatics were involved.

is the deltahawk going to be beefy enough for occasional aerobatic flight?

whats everyones hunch on this engine over the next 3-4 years?

 

[Mike S]

I first say this engine at OSH in either 91, or 95.

There was a static display of the prototype at that time, in addition, there was a Velocity minus wings taxing around with one.

Zipping forward to now, I still dont know of any that have flown.

Not much of an answer to your question, at least not a direct answer, but you should be able to draw your own conclusion.

FFIW, I would love to see this, and a lot of other (Inyodine for one) new tech engines succeed in the real world.

 

[skelrad]

Flying in a Velocity

I'm not sure if there are any customer engines flying, but Deltahawk has had an engine flying in a Velocity since 2003.

http://www.deltahawkengines.com/article00.shtml

Brandon

 

[Mike S]

Thanks

Brandon, that is good news.

The engine on the linked site appears to be from production castings, as I recall the engine I saw long ago had a lot of parts like the water jacket and manifolds welded up from sheet metal.

They list 3 flying planes now-----things must be looking up.

 

[rv6ejguy]

What's Taking so Long?

I worry if any engine that takes 10+ years to get to market will ever be truly affordable or actually even get there- Zoche, Orenda, Deltahawk, SMA, Theilert etc. When they throw in the certification process, that is usually the end of it right there as costs go through the roof and those costs are passed on to the customer. The only thing that may save the Deltahawk is that there is military interest in it. This has been good for Rotax (which did not need help) and for Thielert which did need more capital because they were so far in the hole from development and warranty costs.

Bringing more $30K+ engines to the experimental market is not what is needed, we need new designs which are reliable and fuel efficient at a lower cost than a Lycoming. Then these companies will do well. I don't see too many savvy people dropping $50K for a new design based on promises- although Thielert sucked lots into that vortex. So maybe there are suckers born every minute.

I see Mistral is working on several designs now and trying to certify them. I wish them well and hope they have deep pockets. I just don't understand engine builders trying to work on several engines simultaneously AND trying to certify them. Talk about a cash flow crunch. Get one done, release to the experimental market, make some money to certify it if desired THEN start the next version.

I think engine guys often get carried away with passion for their design. Eventually the reality of solving all the problems sinks in but by then they have run out of money. Many of these companies need a better business plan before they start.

I see MPS is now selling their EJ25 based FF packages as a rival to Eggenfellner's but the price is still too high IMO. Unless you roll your own conversion, it is hard not to look at a Lycoming first these days.

 

[the4ork]

so are they available for purchase? the 180hp version

 

[Msletten]

I just don't understand engine builders trying to work on several engines simultaneously AND trying to certify them. Talk about a cash flow crunch. Get one done, release to the experimental market, make some money to certify it if desired THEN start the next version

I believe this was DeltaHawk's original plan, but then the FAA changed the rules regarding UAV engines.

As you mentioned, DeltaHawk has received much attention from the military -- primarily for use in UAV. The FAA, however, now requires any UAV flying in US airspace must use a "certified" engine. If DeltaHawk has any hope of breaking into the military UAV market, it must now get it's engine FAA-certified.

Regards,

Mark

 

[flybill7]

Tough Business

When I first started building in early 2004, DeltaHawk was marketing in my area. I listened to one of their spokesmen a couple of times at a EAA Chapter meeting and an RV get-together. I thought their concept was reasonably compelling, although I was new to this building your own airplane stuff. Here it is four 1/2 years later, I'm almost done building my plane, and their diesels still aren't on the market. It's obviously very difficult to establish a new GA powerplant.

 

[breister]

It is my understanding that DeltaHawk has a government contract in-hand for UAVs, which is putting pressure on them to complete their certification.

They did an initial "production run" of about 30 engines, but I think after that they changed either their primary manufacturing partner or their terms with that group. In that timeframe is when they got the gov. contract, and promptly dropped any interest they had in promoting the experimental market in lieu of the guaranteed money. Once they certify (or if?) they will probably want to provide engines to whoever they can sell to, but that is not guaranteed (Thielert would NEVER sell to the experimental market).

If you are really interested in the latest poop, I suggest you just call them. I spoke to them a few years back, and they were happy to spend a little phone time telling me about their journey.

 

[bumblebee]

It is my understanding that DeltaHawk has a government contract in-hand for UAVs, which is putting pressure on them to complete their certification.

Where did you hear this?

They did an initial "production run" of about 30 engines, but I think after that they changed either their primary manufacturing partner or their terms with that group. In that timeframe is when they got the gov. contract, and promptly dropped any interest they had in promoting the experimental market in lieu of the guaranteed money.

The government doesn't "guarantee" any money unless they are explicitly funding a development effort. All "USgovernment" UAV's are currently built by private contractors who are not in the habit of paying for something that isn't ready for prime time. Thielert provided test engines to the major UAV builders but could never prove satisfactory reliability. Rotax is the only piston engine currently flying in production UAV's flown by US.

If you are really interested in the latest poop, I suggest you just call them. I spoke to them a few years back, and they were happy to spend a little phone time telling me about their journey.

Their website hasn't changed in years and the "display" at OSH is as stale as ever. What evidence does anyone have that DeltaHawk is moving forward at all?

Obtaining FAA certification on an "engine" is relatively simple. Obtaining the PMA certificate (production manufacturing) is an entirely different animal PMA kills 80% of all certification efforts. And THEN one must obtain a certification for the "combinations", i.e. prop/engine/airframe INCLUDING flutter and vibration testing. VERY costly and VERY time consuming. "Combo" certification kills 99% of all FAA certification efforts.

Despite the hype, there are very few UAV's flying compared to Experimental aircraft. Total flying UAV population is measured in "hundreds" worldwide.

With the demise of Thielert, a certificated diesel UAV won't be coming to a dealer near you anytime soon.

If DH were smart (no evidence yet) they would get an RV flying, fly the **** out of it (3000hours) and THEN market the engine. Forget FAA.