Engine Choice… DeltaHawk?

[Utah-Jay]

I am wondering if anyone has thought about going with a Deltahawk engine in the RV-15?

What if any modifications would be needed? I assume a different engine mount. Would the kit cowling fit over the 200HP DeltaHawk engine?

Can you put diesel/jet fuel in tanks sealed with ProSeal?

Thanks in advance for any answers.

 

[rocketman1988]

I am wondering if anyone has thought about going with a Deltahawk engine in the RV-15?

What if any modifications would be needed? I assume a different engine mount. Would the kit cowling fit over the 200HP DeltaHawk engine?

Can you put diesel/jet fuel in tanks sealed with ProSeal?

Thanks in advance for any answers.

Thinking about it, but:

I have been watching the DH for more than two decades and it is STILL not available.

Mods? Many, engine mount, fuel system, cooling system, new cowl...and getting the cowl and cooling system to actually work efficiently is a mixture of art and science.

Some types of pro seal can be used with jet fuel.

IF you get through those things, then consider the 200hp DH is ESTMATED to cost $115,000 without the prop. The 235hp version will be $135,000+ without the prop.

These prices were what DH said when I placed my deposit. Not sure if that will be my path yet, though...

 

[Utah-Jay]

Thinking about it, but:

I have been watching the DH for more than two decades and it is STILL not available.

Mods? Many, engine mount, fuel system, cooling system, new cowl...and getting the cowl and cooling system to actually work efficiently is a mixture of art and science.

Some types of pro seal can be used with jet fuel.

IF you get through those things, then consider the 200hp DH is ESTMATED to cost $115,000 without the prop. The 235hp version will be $135,000+ without the prop.

These prices were what DH said when I placed my deposit. Not sure if that will be my path yet, though...

Thanks for the info. I visited the DH booth at OshKosh and did not know they were not available yet. I just think it is a superior engine and love the idea of FADEC as well. Sure it is more expensive than the IO390, but over time some will/should be recouped via lower fuel prices.

I see you have looked at this a lot more closely than I, so you seem sure the cowling would need to be “massaged” to get it to fit. Is the DH engine larger? Longer? Bigger circumference?

How would the fuel system be different?

Sorry for so many questions.

 

[rvbuilder2002]

Thanks for the info. I visited the DH booth at OshKosh and did not know they were not available yet. I just think it is a superior engine and love the idea of FADEC as well. Sure it is more expensive than the IO390, but over time some will/should be recouped via lower fuel prices.

I see you have looked at this a lot more closely than I, so you seem sure the cowling would need to be “massaged” to get it to fit. Is the DH engine larger? Longer? Bigger circumference?

How would the fuel system be different?

Sorry for so many questions.

Whether the engine fits inside the standard cowling is only one of many considerations.
The DH engine is liquid cooled, correct?
That means you also need to also fit a sufficiently sized radiator inside the cowling as well. Along with making modifications to feed air to that radiator and the oil cooler and the induction system. And then cleanly get all of that air back out again.
And as Bob already mentioned, doing the engineering to make that all work is a lot more than just attaching a couple of flex hoses to the standard air inlets on the cowl. Just the changes required for cooling and induction air is a major engineering project that is way beyond what most home builders would want to take on, let alone all of the other changes that would be required.

 

[IO390]

Fadec? I thought one of the selling points of Deltahawk is that it isn’t fadec. Good old fashioned diesel pump.

 

[Utah-Jay]

OK, you guys have cured me… NO DH

 

[JonJay]

Lots of prior discussion if you do a search.

 

[rocketman1988]

Thanks for the info. I visited the DH booth at OshKosh and did not know they were not available yet. I just think it is a superior engine and love the idea of FADEC as well. Sure it is more expensive than the IO390, but over time some will/should be recouped via lower fuel prices.

I see you have looked at this a lot more closely than I, so you seem sure the cowling would need to be “massaged” to get it to fit. Is the DH engine larger? Longer? Bigger circumference?

How would the fuel system be different?

Sorry for so many questions.

Others have answered some of your questions but not the “fuel savings” one.

How many hours would you need to fly at the lower fuel price to make up a $50,000 difference?

 

[JonJay]

The DH Engine would be furnished as a complete FWF package:
Engine, Cowling, Radiator, Engine Mount, Prop, plumbing, harnesses, etc…. basically engineered, test flown, and ready to go. So, factor all of that into the discussion and the price gap narrows. It will still be an expensive option should it come to market.
This has all been discussed in lengthy threads before.
Not for the faint of heart.

 

[lr172]

Others have answered some of your questions but not the “fuel savings” one.

How many hours would you need to fly at the lower fuel price to make up a $50,000 difference?

And who is to say Jet A will always be cheaper. In my area, Diesel is now $1 per gallon more than gas. Jet A is pretty close to diesel. Have to wonder if there a subsidies reducing Jet A price. If so, those can vanish. Maybe it is a tax thing, but that can also change.

 

[JonJay]

I wouldn’t be buying the DH on economy. I am considering it for performance, simplicity, and for something new. Done enough traditional engine stuff and the Lyclones just aren’t that interesting to me.

 

[cjs]

I am wondering if anyone has thought about going with a Deltahawk engine in the RV-15?

What if any modifications would be needed? I assume a different engine mount. Would the kit cowling fit over the 200HP DeltaHawk engine?

Can you put diesel/jet fuel in tanks sealed with ProSeal?

Thanks in advance for any answers.

Utah,

I am currently working with DeltaHawk and SynergyAir on the building and installation of the DH engines on both the RV14 and the RV15.
Lots of incomplete or wrong information on the DeltaHawk engine and installation in the replies to your question.
I'll try to answer your questions as best I can.

First, DeltaHawk's plan is to offer a complete Firewall Forward package for the RV models - - more-or-less plug and play. This is partially to mitigate the fact that most builders don't have experience installing anything other than a standard Lycoming FF package. The pricing DH has been quoting folks is for the complete package. That is, a builder would receive the engine on the mount with all the goodies (starter, alternator, heat exchangers, turbo, etc) mounted and ready to go. The cowling is also included. This seems to be something folks are not properly considering when comparing the DH price to a standard Lycoming installation. I think DH could do a better job messaging this to folks.

Related to this, we are now in construction on the second DeltaHawk RV14 - using our learnings from the first plane to create a completed FF package for the RV14. Incidentally, the first DH RV14 will be converted to a tricycle gear for the purpose of creating a FF package for that configuration. Work on this will likely start in a few months.

Regarding the RV15: We have the wing kit and like others are anxiously awaiting the remainder of the kits so we can complete the build. Our plan is to install the 235hp engine. This is mostly a personal preference as I believe with the additional cargo capacity of the RV15 its not a bad idea to have the extra power. I fly out of mountain strip on my ranch and also want the extra climb capability - especially in hot weather (fortunately, with the forced air induction - turbo/supercharger- on the DH engine, this should be less of a issue than with a naturally aspirated engine).

Yes, Jet/A diesel is compatible with proseal.

A few random comments based on some of the reply posts:

The fuel system is not FADEC - its a mechanical fuel pump system. Very simple and rock solid. No electronic failure points.

Fuel savings, and related: My 70+/- hours flying the prototype DHRV14 showed about a 35% overall fuel savings vs the burn in my Lycoming RV14. The DH is extremely fuel efficient at low speeds - however, at the typical cruise speeds we tend to fly on XC (about 174 kts, 10-12K msl) I was seeing a fuel flow of about 7.2 gph vs 9.9 gph on the Lycoming. As we get the #2 DH RV14 up and flying, I would expect a bit of improvement due to the reworked cowling. And, finally, the DH will maintain full power to about 17K msl. We have yet to collect data to that altitude. It should perform even better up there.

For more info, check the RV14 and RV15 pages. We are updating the threads there as we make progress.

Craig

 

[rocketman1988]

The DH Engine would be furnished as a complete FWF package:
Engine, Cowling, Radiator, Engine Mount, Prop, plumbing, harnesses, etc…. basically engineered, test flown, and ready to go. So, factor all of that into the discussion and the price gap narrows. It will still be an expensive option should it come to market.
This has all been discussed in lengthy threads before.
Not for the faint of heart.

That is NOT what I was told when I placed my deposit…Prop not included in the $115k/$135k price.

Maybe it has changed?

 

[peredavi]

I am wondering if anyone has thought about going with a Deltahawk engine in the RV-15?

What if any modifications would be needed? I assume a different engine mount. Would the kit cowling fit over the 200HP DeltaHawk engine?

Can you put diesel/jet fuel in tanks sealed with ProSeal?

Thanks in advance for any answers.

 

[rocketman1988]

Utah,

I am currently working with DeltaHawk and SynergyAir on the building and installation of the DH engines on both the RV14 and the RV15.
Lots of incomplete or wrong information on the DeltaHawk engine and installation in the replies to your question.
I'll try to answer your questions as best I can.

First, DeltaHawk's plan is to offer a complete Firewall Forward package for the RV models - - more-or-less plug and play. This is partially to mitigate the fact that most builders don't have experience installing anything other than a standard Lycoming FF package. The pricing DH has been quoting folks is for the complete package. That is, a builder would receive the engine on the mount with all the goodies (starter, alternator, heat exchangers, turbo, etc) mounted and ready to go. The cowling is also included. This seems to be something folks are not properly considering when comparing the DH price to a standard Lycoming installation. I think DH could do a better job messaging this to folks.

Related to this, we are now in construction on the second DeltaHawk RV14 - using our learnings from the first plane to create a completed FF package for the RV14. Incidentally, the first DH RV14 will be converted to a tricycle gear for the purpose of creating a FF package for that configuration. Work on this will likely start in a few months.

Regarding the RV15: We have the wing kit and like others are anxiously awaiting the remainder of the kits so we can complete the build. Our plan is to install the 235hp engine. This is mostly a personal preference as I believe with the additional cargo capacity of the RV15 its not a bad idea to have the extra power. I fly out of mountain strip on my ranch and also want the extra climb capability - especially in hot weather (fortunately, with the forced air induction - turbo/supercharger- on the DH engine, this should be less of a issue than with a naturally aspirated engine).

Yes, Jet/A diesel is compatible with proseal.

A few random comments based on some of the reply posts:

The fuel system is not FADEC - its a mechanical fuel pump system. Very simply and rock solid. No electronic failure points.

Fuel savings, and related: My 70+/- hours flying the prototype DHRV14 showed about a 35% overall fuel savings vs the burn in my Lycoming RV14. The DH is extremely fuel efficient at low speeds - however, at the typical cruise speeds we tend to fly on XC (about 174 kts, 10-12K msl) I was seeing a fuel flow of about 7.2 gph vs 9.9 gph on the Lycoming. As we get the #2 DH RV14 up and flying, I would expect a bit of improvement due to the reworked cowling. And, finally, the DH will maintain full power to about 17K msl. We have yet to collect data to that altitude. It should perform even better up there.

For more info, check the RV14 and RV15 pages. We are updating the threads there as we make progress.

Craig

As I said above, that was not what I was told by the guy who verified my deposit…prop not included. Then again, it’s been awhile since they took my deposit, so maybe it has changed…which would be good.

Still not sure that I want to lay out that kind of money but at least I have a place in line…

 

[JonJay]

That is NOT what I was told when I placed my deposit…Prop not included in the $115k/$135k price.

Maybe it has changed?

I stand CORRECTED. ( figured I yell back )
cjs already chimed in….
I wouldn’t hold too much out on price as we will see it if/when they come to market.
Doesn’t matter. It won’t influence my decision, unless it’s a major change in their estimate.

 

[rocketman1988]

I stand CORRECTED. ( figured I yell back )
cjs already chimed in….
I wouldn’t hold too much out on price as we will see it if/when they come to market.
Doesn’t matter. It won’t influence my decision, unless it’s a major change in their estimate.

Yeah, the price tag is eye watering, and I was told it was an estimate as you can't buy one at the present. Having watched the DH for more than two decades, it would be a surprise if it was actually available for purchase when my -15 is ready for it.

Time will tell.

 

[JonJay]

Yeah, the price tag is eye watering, and I was told it was an estimate as you can't buy one at the present. Having watched the DH for more than two decades, it would be a surprise if it was actually available for purchase when my -15 is ready for it.
Time will tell.

I am dubious also. However, I was in the lighting industry and watched Alan Rudd, the “new” money behind DH, do amazing things. He has invested over $100M in the operation “relatively” recently.
Will it go forward now? As you say, time will tell.

 

[Jjackh10]

And who is to say Jet A will always be cheaper. In my area, Diesel is now $1 per gallon more than gas. Jet A is pretty close to diesel. Have to wonder if there a subsidies reducing Jet A price. If so, those can vanish. Maybe it is a tax thing, but that can also change.

Pretty sure state and fed taxes hit diesel pretty hard. That's why "offroad" diesel is considerably less when you can find it.

 

[rvbuilder2002]

It is good to hear that DH is going to do all the engineering and will provide a complete ready to install FWF.
With the current policy at Vans to not allow any kit part deletion’s, the price difference delta from installing a Lycoming will be even bigger from all of the unneeded expensive finish kit parts, unless Vans partners with DH to offer a special deal.

 

[Rick RV-4]

Can someone verify if the DH is a TBR (time before replacement) engine as opposed to one you can overhaul? And yes, I do realize many or most of us will never put 2,000 hours on our engines, but was just curious.

 

[msires]

Their current sales information is that it can be overhauled, and the overhaul is simpler/cheaper than a Lycoming/Continental. No cam, no valves, replaceable sleeves for the pistons, etc.

 

[msires]

I think part of their problem now is that 'Perfect is the enemy of good'. The money men aren't pushing them to get it done, so the engineers will continue to modify it until the heat death of the universe.

 

[JonJay]

It is good to hear that DH is going to do all the engineering and will provide a complete ready to install FWF.
With the current policy at Vans to not allow any kit part deletion’s, the price difference delta from installing a Lycoming will be even bigger from all of the unneeded expensive finish kit parts, unless Vans partners with DH to offer a special deal.

I was told they are already working with Vans for this to be an “option”, but, this is all just so much chatter until we actually see a deliverable product.
Again, if someone is trying to cost justify this, I doubt it will pencil.

 

[Mrk]

Craig,

Can you comment on the fuel system for the DH, especially the fuel return and how DH recommends this is handled in the 15.

I got the wings with the slow build wing option, and before I assembled daytime, you can verify in the daytime observation. There is no movement after this daytime just

 

[Mrk]

Ignore the last paragraph, dam auto correct.

Mark

 

[rvbuilder2002]

Again, if someone is trying to cost justify this, I doubt it will pencil.

I agree
I would imagine that every sane person has some level of spending limit though when comparing one choice vs another so the potential doesn’t seem unreasonable discussion.

 

[bigmikeh24]

I think for a lot of us, it’s going to be a race to see if you can get a DH. Install it in your -15 and still have the cognitive ability to fly it….

 

[Dirt911]

For me 100ll is logistically a pain. So I’m not going to use the io-390 (had a discussion with lycoming at Oshkosh…even if I had the thunderbolt build a low compression 390, it won’t work).

So the DH would be cool, if I could really run diesel. Jet A is logistically worse than 100ll, I’d have to fly to a big airport and talk to controllers and everything…

So now I’m looking at the AC aero 390. Liquid cooled cylinders with more modern combustion chambers. Should be fine on 91 octane and make good power. If I chicken out on the development part of figuring out how to make that work it’ll have to be some kind of io-360, or 370.

Unless Rotax announces a higher HP engine to expand their line…

 

[TShort]

I think for a lot of us, it’s going to be a race to see if you can get a DH. Install it in your -15 and still have the cognitive ability to fly it….

Or a race to get a -390, based on recent discussion of lead time / availability...

 

[Aircraft Specialty]

We are waiting to see what the final configuration of the RV-15 looks like and have already received many inquiries on SDS/EFII/Deltahawk installs. We are involved in the prototype installations for the RV-14 Deltahawk setup. Right now there isn't enough information available on the -15 but whatever engine configurations builders end up using our their -15 builds, Tom and I plan on helping to "Hose" you.

 

[AeroEngineer]

(had a discussion with lycoming at Oshkosh…even if I had the thunderbolt build a low compression 390, it won’t work).

I don't want to derail this thread, but: Can I ask; Why won't it work? I've heard of low-compression 390s that can burn mogas (I think it was in the context of a Glasair Sportsman...), I thought that sounded like an appealing engine.

AC aero 390. Liquid cooled cylinders with more modern combustion chambers. Should be fine on 91 octane...

I had to Google that one!

Unless Rotax announces a higher HP engine to expand their line…

There is always Edge Performance... Their souped-up Rotaxes get up to at least 185 hp and apparently some go over 200. I have heard stories of less-than-great reliability but those were all a while ago so, who knows.

 

[tow_dog]

There is always Edge Performance... Their souped-up Rotaxes get up to at least 185 hp and apparently some go over 200. I have heard stories of less-than-great reliability but those were all a while ago so, who knows.

AFAIK, all of the various aftermarket souped up Rotax 4-cylinders are limited in their max power setting to something like 5 minutes. Max continuous power is about 135hp

 

[Utah-Jay]

Utah,

I am currently working with DeltaHawk and SynergyAir on the building and installation of the DH engines on both the RV14 and the RV15.
Lots of incomplete or wrong information on the DeltaHawk engine and installation in the replies to your question.
I'll try to answer your questions as best I can.

First, DeltaHawk's plan is to offer a complete Firewall Forward package for the RV models - - more-or-less plug and play. This is partially to mitigate the fact that most builders don't have experience installing anything other than a standard Lycoming FF package. The pricing DH has been quoting folks is for the complete package. That is, a builder would receive the engine on the mount with all the goodies (starter, alternator, heat exchangers, turbo, etc) mounted and ready to go. The cowling is also included. This seems to be something folks are not properly considering when comparing the DH price to a standard Lycoming installation. I think DH could do a better job messaging this to folks.

Related to this, we are now in construction on the second DeltaHawk RV14 - using our learnings from the first plane to create a completed FF package for the RV14. Incidentally, the first DH RV14 will be converted to a tricycle gear for the purpose of creating a FF package for that configuration. Work on this will likely start in a few months.

Regarding the RV15: We have the wing kit and like others are anxiously awaiting the remainder of the kits so we can complete the build. Our plan is to install the 235hp engine. This is mostly a personal preference as I believe with the additional cargo capacity of the RV15 its not a bad idea to have the extra power. I fly out of mountain strip on my ranch and also want the extra climb capability - especially in hot weather (fortunately, with the forced air induction - turbo/supercharger- on the DH engine, this should be less of a issue than with a naturally aspirated engine).

Yes, Jet/A diesel is compatible with proseal.

A few random comments based on some of the reply posts:

The fuel system is not FADEC - its a mechanical fuel pump system. Very simply and rock solid. No electronic failure points.

Fuel savings, and related: My 70+/- hours flying the prototype DHRV14 showed about a 35% overall fuel savings vs the burn in my Lycoming RV14. The DH is extremely fuel efficient at low speeds - however, at the typical cruise speeds we tend to fly on XC (about 174 kts, 10-12K msl) I was seeing a fuel flow of about 7.2 gph vs 9.9 gph on the Lycoming. As we get the #2 DH RV14 up and flying, I would expect a bit of improvement due to the reworked cowling. And, finally, the DH will maintain full power to about 17K msl. We have yet to collect data to that altitude. It should perform even better up there.

For more info, check the RV14 and RV15 pages. We are updating the threads there as we make progress.

Craig

Craig, that is a million for that information. I thought the DH came as a plug and play, I was unaware of the cowling being included. The cowling is a huge hurdle with regards to building time.

 

[Dirt911]

I don't want to derail this thread, but: Can I ask; Why won't it work? I've heard of low-compression 390s that can burn mogas (I think it was in the context of a Glasair Sportsman...), I thought that sounded like an appealing engine.



I had to Google that one!



There is always Edge Performance... Their souped-up Rotaxes get up to at least 185 hp and apparently some go over 200. I have heard stories of less-than-great reliability but those were all a while ago so, who knows.

When I talked to the lycoming guys at Oshkosh, I asked them that very question. They said "it's just physics, can't make that kind of power without the higher octane "

So I smiled and nodded and walked away.

It's obviously not a physical limitation, I've got a 2 liter engine in my car that makes 315 horsepower on 91 octane. It's a mere engineering problem, and clearly lycoming isn't interested in solving that problem.

So if someone else can figure it out, I'll buy their engine.

To get this back on topic...for those that are really ready to go with the DH, how do you feel about the problem of not having any experienced mechanics available? I'm a so-so mechanic at best, so I would think that I would need help to troubleshoot but there won't be anyone that has any experience with these things...

 

[Alphalpha]

When I talked to the lycoming guys at Oshkosh, I asked them that very question. They said "it's just physics, can't make that kind of power without the higher octane "

So I smiled and nodded and walked away.

It's obviously not a physical limitation, I've got a 2 liter engine in my car that makes 315 horsepower on 91 octane. It's a mere engineering problem, and clearly lycoming isn't interested in solving that problem.

So if someone else can figure it out, I'll buy their engine.

To get this back on topic...for those that are really ready to go with the DH, how do you feel about the problem of not having any experienced mechanics available? I'm a so-so mechanic at best, so I would think that I would need help to troubleshoot but there won't be anyone that has any experience with these things...

You can't compare a liquid cooled engine to an air-cooled engine. It is just physics. At some Brake Mean Effective Pressure (BMEP) fuel will detonate. Octane ratings are a measure of the fuel's resistance to detonating. BMEP is affected by compression, compression heat and resident heat. BMEP is also one of several factors used to calculate output power. So there is a direct correlation between octane limitations and maximum power output for any given amount of cooling capacity. And air cooled engines can only cool so much without adding a lot of weight.

I can also assure you that if you keep your 2 liter auto engine at 315hp output continuously it will not last very long. Auto manufacturers do not rate their output power the same way aircraft engine manufacturers do. In the latter they must rate it at the maximum it can put out continuously, indefinitely. It probably won't make TBO at that setting but it will run continuously.

 

[JonJay]

To get this back on topic...for those that are really ready to go with the DH, how do you feel about the problem of not having any experienced mechanics available? I'm a so-so mechanic at best, so I would think that I would need help to troubleshoot but there won't be anyone that has any experience with these things...

Legitimate concern. I do my own wrenching and, thus far, the factory has been very approachable. I am hopeful they will have appropriate service info for us DIY types.

 

[Dirt911]

You can't compare a liquid cooled engine to an air-cooled engine. It is just physics. At some Brake Mean Effective Pressure (BMEP) fuel will detonate. Octane ratings are a measure of the fuel's resistance to detonating. BMEP is affected by compression, compression heat and resident heat. BMEP is also one of several factors used to calculate output power. So there is a direct correlation between octane limitations and maximum power output for any given amount of cooling capacity. And air cooled engines can only cool so much without adding a lot of weight.

I can also assure you that if you keep your 2 liter auto engine at 315hp output continuously it will not last very long. Auto manufacturers do not rate their output power the same way aircraft engine manufacturers do. In the latter they must rate it at the maximum it can put out continuously, indefinitely. It probably won't make TBO at that setting but it will run continuously.

I don’t really want to get too far off topic but I also have a horizontally opposed air/oil cooled car from the 80’s that makes 230 hp on 3.2 liters, about 195 cubic inches. Sure, it turns faster, it has electronic injection and spark. Point is it’s really not physics. Lycoming, or anyone else could design an engine that makes more power from less octane, but not one that is exactly like their current engine. I guess that’s my point. I don’t disagree that this engine with its combustion chambers probably needs 100ll. But it’s not a moon shot to make 230 hp from 390 cubic inches of displacement on unleaded gas.

 

[Alphalpha]

I don’t really want to get too far off topic but I also have a horizontally opposed air/oil cooled car from the 80’s that makes 230 hp on 3.2 liters, about 195 , cubic inches. Sure, it turns faster, it has electronic injection and spark. Point is it’s really not physics. Lycoming, or anyone else could design an engine that makes more power from less octane, but not one that is exactly like their current engine. I guess that’s my point. I don’t disagree that this engine with its combustion chambers probably needs 100ll. But it’s not a moon shot to make 230 hp from 390 cubic inches of displacement on unleaded gas.

Ok, well, per basic physics, power = force x distance / time. In this case force is torque, times revolutions per minute as efficiently described Mr. Newton. Due to not breaking the speed of sound aircraft propellers and crankshafts typically can't go much beyond 2700 RRM. So they can't make power through RPM unless they are geared. Gearing adds a lot of weight, complexity and they often limit life of the system for a variety of reasons. Because of physics you cannot scientifically compare automotive technology with airmotive technology. So in the auto example, if using 5400 RPM is producing twice what an aircraft engine can do... and 3.2 liters times 61 cu/in per liter equals 195 cu/in times two for the doubled RPM equals 390 cu/in. But, while the work being produced is close, the BMEP in the slower engine is going to be a lot closer to detonation because the double sized combustion chamber probably has a much lower ratio of cooling fins to BTU's burned than your car and because it is producing the power through bigger bore versus RPM. Load your car engine to 2700 RPM at full throttle and see if it gets hot.

The other aspect as I said above, which is physics, your car is running at 230HP about 2% of the time. The O-390 can run at 215HP 100% of the time. I have the strongest confidence if we ran your car's engine at 230HP continuously it would not last very long. Auto manufacturers only give peak, short term HP ratings.

The idea that this is not physics is preposterous. If Lycoming could make a ten pound engine that produced 400 HP on one gallon of 87 octane fuel per day... they would produce it and put all their competition out of business. Physics says they can't. The only way they can make more power is to make it bigger. Which they already have. I would much sooner go with a 540 in the -15 than a new tech diesel if I wanted more power simply because it will be much longer than my lifetime before the "new tech" is broadly supported in the aviation industry.

Given that the airplane was designed around 215 HP and Vans has yet to design an underpowered airplane I'm not convinced more power is a valid motive for going with a different engine technology. Having something cool and unique certainly is a reasonable motive. Another motive is there are many parts of the world where avgas of any kind is not possible but diesel is. If this were my case I would strongly consider Continental's jet-A line which has been flying for a long time outside of North America. https://continentaldiesel.com/ The website shows 12 million flight hours so far.

 

[Dirt911]

Ok, well, per basic physics, power = force x distance / time. In this case force is torque, times revolutions per minute as efficiently described Mr. Newton. Due to not breaking the speed of sound aircraft propellers and crankshafts typically can't go much beyond 2700 RRM. So they can't make power through RPM unless they are geared. Gearing adds a lot of weight, complexity and they often limit life of the system for a variety of reasons. Because of physics you cannot scientifically compare automotive technology with airmotive technology. So in the auto example, if using 5400 RPM is producing twice what an aircraft engine can do... and 3.2 liters times 61 cu/in per liter equals 195 cu/in times two for the doubled RPM equals 390 cu/in. But, while the work being produced is close, the BMEP in the slower engine is going to be a lot closer to detonation because the double sized combustion chamber probably has a much lower ratio of cooling fins to BTU's burned than your car and because it is producing the power through bigger bore versus RPM. Load your car engine to 2700 RPM at full throttle and see if it gets hot.

The other aspect as I said above, which is physics, your car is running at 230HP about 2% of the time. The O-390 can run at 215HP 100% of the time. I have the strongest confidence if we ran your car's engine at 230HP continuously it would not last very long. Auto manufacturers only give peak, short term HP ratings.

The idea that this is not physics is preposterous. If Lycoming could make a ten pound engine that produced 400 HP on one gallon of 87 octane fuel per day... they would produce it and put all their competition out of business. Physics says they can't. The only way they can make more power is to make it bigger. Which they already have. I would much sooner go with a 540 in the -15 than a new tech diesel if I wanted more power simply because it will be much longer than my lifetime before the "new tech" is broadly supported in the aviation industry.

Given that the airplane was designed around 215 HP and Vans has yet to design an underpowered airplane I'm not convinced more power is a valid motive for going with a different engine technology. Having something cool and unique certainly is a reasonable motive. Another motive is there are many parts of the world where avgas of any kind is not possible but diesel is. If this were my case I would strongly consider Continental's jet-A line which has been flying for a long time outside of North America. https://continentaldiesel.com/ The website shows 12 million flight hours so far.

I think we talking past each other. You’re saying that there is no further engineering possible to improve lycoming’s io-390. That they are on the edge of what is physically possible. I disagree, but I’m not really interested in that.

I’m saying that something different is needed, and lycoming isn’t interested in innovation or engineering. So hopefully rotax or delta hawk, or ac aero or some company will step up and offer something different.

 

[bertschb]

...lycoming isn’t interested in innovation or engineering.

Probably because they have a 3+ year wait list for their 75 year old design.

 

[ATC_RV8OR]

Probably because they have a 3+ year wait list for their 75 year old design.

Or the more likely reason, regulators have created a financial hurdle. It’s too expensive to clean sheet a new engine design for a type certificate. Overall demand even with a 3 year wait is not great enough to justify the capital investment in innovation.

 

[tspear]

So they can't make power through RPM unless they are geared. Gearing adds a lot of weight, complexity and they often limit life of the system for a variety of reasons.

Somehow Rotax does it.

The other aspect as I said above, which is physics, your car is running at 230HP about 2% of the time. The O-390 can run at 215HP 100% of the time. I have the strongest confidence if we ran your car's engine at 230HP continuously it would not last very long. Auto manufacturers only give peak, short term HP ratings.

Depends totally on design. Here is an example of an automotive engine that can do it, and lasts much longer than that O-390:

It all comes down to engineering.

Or the more likely reason, regulators have created a financial hurdle. It’s too expensive to clean sheet a new engine design for a type certificate. Overall demand even with a 3 year wait is not great enough to justify the capital investment in innovation.

Lycoming has offered I2E for a number of years. How many here have actually ordered one?
The reality is owners and pilots like to complain about the FAA being a roadblock.
But the reality is pilots and owners are the larger problem; and in the experimental space the FAA effectively has no play here.

Tim

 

[ATC_RV8OR]

Somehow Rotax does it.

Depends totally on design. Here is an example of an automotive engine that can do it, and lasts much longer than that O-390:

It all comes down to engineering.



Lycoming has offered I2E for a number of years. How many here have actually ordered one?
The reality is owners and pilots like to complain about the FAA being a roadblock.
But the reality is pilots and owners are the larger problem; and in the experimental space the FAA effectively has no play here.

Tim

It was $115,000 as an experimental version in 2010. Can’t say that is a viable option. They are much too proud of it.

Lancair: Evolution and Revolution

July 2010 — For the past few years piston-engine giant Lycoming has been developing a new engine, the TEO-540-A1A. The designation is meaningful: It is a

www.flyingmag.com

 

[Alphalpha]

It’s purely economics. Why invest that much into bringing a product to market that only a few in North America will buy. Continental never marketed their diesel engines in NA because they knew the real market is those areas where diesel is the only available fuel.

Until airframe manufacturers start installing them in new units on a large scale, well the reliable dinosaurs will reign.