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LS3 - It's not just for Corvettes


Blue on Top

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As an update (~10 hours into this thread), thanks for all the great input!  Keep it coming!

1) I'm surprised the aero gurus on here haven't complained about a water-cooled engine.  Yes, it adds drag :(

2) I'll also come clean in that I know the person that headed the Toyota engine certification.  He lives within a mile of me.  (yes, certificated aviation is a really, really small world).  It's not all roses ... nor is/was the Orenda engine.

3) I also have inside information on gear boxes (AutoPSRUs).  He has been a good friend of mine for years.  We trade stories often.

The goal of this "study" is to see if we can produce power at a much lower cost than is the current industry standard.  It will help all of us if flying were cheaper … and safer, too.  Thanks!!! 

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4 minutes ago, McMooney said:

imagine a liquid cooled, direct injected, coil over, electronic ignition engine in our mooney.  

could even have heat without risk of co poisoning

now that I think about it, each coil in my car is independent, lose 1 or 2 i'm down power but things keep turning.   doesnt' sound horrible

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12 hours ago, Blue on Top said:

From experience, the diesels are VERY heavy, and they are not low cost!  I'll leave it at that.

With all due respect, but this seems to be a very US-centric view.  If that is the only/main target market, that's fine, but I understand (not know first-hand, mind you) that the ability to burn Jet instead of AVGAS is in high demand elsewhere.

So this is the engine you want to be the piston side of the hybrid?  I like!

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17 hours ago, kmyfm20s said:

It would be exciting to see the use of an electric turbo charger to turbo normalize our engines. High altitude takeoffs and en route climb performance at the flip of a switch with no pressure on the exhaust system:)

https://www.forbes.com/sites/samabuelsamid/2019/10/17/garrett-electric-turbochargers-headed-to-production-in-2021/#6df60865180at

This something I have worked with, so I thought I would add a little to this.  E-turbos are already in Formula 1 race cars.  In the trickle down of technology, that experience is leading to the passenger car applications.   I do not expect an aircraft application to make sense. 

E-turbos make the most sense for applications with lots of power cycling where turbo lag is a concern, and  bonus if there can be extra energy to capture.  This is much more automotive profile than an aircraft profile.  There is an even less common case of needing high boost at partial power when exhaust energy is not sufficient.  This can occur in massive ship diesels that may need to run partial power (slow steaming) for sustained periods, but would like to get the total efficiency back from full boost.  In aviation with effectively constant power settings (sustaining for more than a few seconds), a standard turbo works really well, and scavenging the energy from the exhaust is very efficient.  The e-turbo will also bring support hardware in the form of controllers and batteries, and require a higher DC voltage than our planes have.

-dan

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1 hour ago, tmo said:

With all due respect, but this seems to be a very US-centric view.  If that is the only/main target market, that's fine, but I understand (not know first-hand, mind you) that the ability to burn Jet instead of AVGAS is in high demand elsewhere.

So this is the engine you want to be the piston side of the hybrid?  I like!

Thanks, @tmo.  I agree with you on the fuel costs versus aviation fuel.  Does an automotive fuel solution work for European countries?

Although the total, full to-TBO/TBR-time costs may be lower with a diesel engine, the initial costs will not be, but that might be a good financial tradeoff (purchase price on business jets are a minor factor compared to hourly operating costs).   Fuel is also heavier, but a tradeoff of less quantity could pay off too as less fuel is burned per hour.  The Mercedes diesel was not designed to run at 100% power for long durations nor was the gearbox.  TBR times on both of those are currently low, with the gearbox being half the time of the engine.  A turbocharger is also required, which is also an issue when it goes.  Depending on the diesel, there may not be enough power to maintain flight.  Another failure mode that has to be accounted for.

We need to keep looking for options.  And kissing frogs. :)   Thanks, Ron

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22 minutes ago, Blue on Top said:

I agree with you on the fuel costs versus aviation fuel.  Does an automotive fuel solution work for European countries?

When talking price yes, automotive fuel works wonderfully.  Especially if you allow the ethanol-laced fuels typically found at the pumps (the Petersen STC does not, which severely limits its usefulness in current times).  For the likes of me it would be perfect - literally half off.  There are people base their purchases on the ability to burn automotive fuel.  FWIW, there allegedly is a STC to put a Rotax engine (think ultralights / LSAs) on a C150.

With automotive fuel, do remember about possible vapor lock issues, which AFAIU are specific to airframes (also noted by Petersen when talking about why their STC covers one airframe but not another).

When talking fuel availability at major airports automotive fuel (mogas) probably doesn't help any, with Jet-A1 being the only thing that is available, period.  I believe that is the situation in Asia and Africa as well.  Do keep in mind I'm not basing this on actual first hand knowledge, but on things I've read / heard from others, some of which might have been biased by virtue of having spent money on the Thielert engines.

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Check this out  https://www.mby.com/gear/cox-powertrain-cxo-300hp-the-worlds-first-300hp-diesel-outboard-engine-has-landed-99662

 

338 HP diesel that delivers max torque in the range our props operate in...  The weight is high, but keep in mind that includes the lower end of the outboard.  Those weight a LOT so I suspect the weight of the engine alone is 150+ lbs lighter than that.

it is COMPACT for its power.... Someone get on getting it certified!  Should be a shoe it since it would be running well below the 3000 RPM redline.

 

EDIT:  looks like it would need a gearbox to drive a prop and deliver the full HP.

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1 hour ago, Austintatious said:

Check this out  https://www.mby.com/gear/cox-powertrain-cxo-300hp-the-worlds-first-300hp-diesel-outboard-engine-has-landed-99662

 

338 HP diesel that delivers max torque in the range our props operate in...  The weight is high, but keep in mind that includes the lower end of the outboard.  Those weight a LOT so I suspect the weight of the engine alone is 150+ lbs lighter than that.

it is COMPACT for its power.... Someone get on getting it certified!  Should be a shoe it since it would be running well below the 3000 RPM redline.

Lots of discussion on the need for a replacement to our traditional engines and for a number of reasons most significantly high cost of manufacturing and fuel availability. I agree with the comment that our traditional engine does the job it was designed to do very well. I don't know why they are so expensive to manufacture other than the stupid product liability that is needed to protect from ambulance chasing attorneys. The other is because of the environmental battle against the lead in our fuel making it so hard to get outside of North America. All other forms of internal combustion engines have been designed to operate with un leaded fuel but this is not going to happen without major design changes to the cylinder heads and computer controlled ignition and fuel injection. 

In response to the diesel outboard well I do know that the lower unit on my v6 Mercury is no where near 150 pounds. One of the biggest complaint that the out board consumers had when environmental requirements forced the use of 4 strokes was the additional weight of these engines. Not as big a deal on a boat but still has an impact on WOT performance on their respective hulls. As for what would be a great engine for an airplane my favorite would be a V6 or 8 cylinder 2 stroke. These motors are designed to run a 100% power for long periods develop high torque at lower rpm and are super light because there is no valve train needed. With fuel injection along with oil injection run very clean on unleaded auto. And since their is no valve train the engines are extremely compact which would allow for the needed water cooling so you would not have a big areodynamic penalty since the engine is so much smaller there would be room to provide air to the radiator. As for life span my 1986 Mercury still makes max RPM and has never been overhauled. It also has redundant ignition systems since being at sea with a dead engine is arguably just as bad as losing one in flight.

 

 

 

 

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9 minutes ago, bonal said:

Lots of discussion on the need for a replacement to our traditional engines and for a number of reasons most significantly high cost of manufacturing and fuel availability. I agree with the comment that our traditional engine does the job it was designed to do very well. I don't know why they are so expensive to manufacture other than the stupid product liability that is needed to protect from ambulance chasing attorneys. The other is because of the environmental battle against the lead in our fuel making it so hard to get outside of North America. All other forms of internal combustion engines have been designed to operate with in leaded fuel but this is not going to happen without major design changes to the cylinder heads and computer controlled ignition and fuel injection. 

In response to the diesel outboard well I do know that the lower unit on my v6 Mercury is no where near 150 pounds. One of the biggest complaint that the out board consumers had when environmental requirements forced the use of 4 strokes was the additional weight of these engines. Not as big a deal on a boat but still has an impact on WOT performance on their respective hulls. As for what would be a great engine for an airplane my favorite would be a V6 or 8 cylinder 2 stroke. These motors are designed to run a 100% power for long periods develop high torque at lower rpm and are super light because there is no valve train needed. With fuel injection along with oil injection run very clean on unleaded auto. And since their is no valve train the engines are extremely compact witch would allow for the needed water cooling so you would not have a big area dynamic penalty since the engine is so much smaller there would be room to provide air to the radiator. As for life span my 1986 Mercury still makes max RPM and has never been overhauled. It also has redundant ignition systems since being at sea with a dead engine is arguably just as bad as losing one in flight.

 

 

 

 

Ohh absolutely a 2 stroke would be awesome... TBH, I am surprised it has not been done.  The only issue I see is that you need a super reliable way to get the oil into the fuel.  If that oil delivery system fails, that is BAAAD!  In the 2 stroke boating world the saying goes "Pre-mix or be TOAD"   I have a 1983 90 HP mercury that runs like a top STILL!  Tower of power all the way!

It would be interesting to see just the bare engine weight on that motor.  It would need to be less than 500 LBS to make sense.  I like the idea of no Ignition to fail.    Perhaps some versions of a 2 stroke Diesel is the ultimate in simplicity and reliability.

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I think my V6 150hp Mercury weighs around 320 pounds and that's the total weight including everything the power head the housing lower unit and trim and tilt hydraulics as well as the bracket that hangs it to the transom.  Actually the oil injection is extremely simple and reliable it also has a backup oil supply that provides around 30 minutes reserve in the event of a main system failure that has a built in warning horn to advise the operator if there is a failure. Also, these engines often sit for long long periods of time with no use and suffer no detrimental effect. Ad to that we all worry about corrosion these engines are designed to operate in salt water can't think of a more hostile environment than that and continue to run year after year.

edit, a two stroke diesel would be nice not needing an ignition system but as I said before my Mercury has redundant electronic ignition systems. Marine design has some serious safety concerns just like aviation 

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4 hours ago, tmo said:

With all due respect, but this seems to be a very US-centric view.  If that is the only/main target market, that's fine, but I understand (not know first-hand, mind you) that the ability to burn Jet instead of AVGAS is in high demand elsewhere.

I think it's in high demand because people are abominably stupid.  Most GA engines and aircraft will happily run car gas so long as it hasn't booze in it,  and car gas is nearly universally available.  The only reason it isn't at airports is that no one yet uses it.  But any airport is going to have a car gas station not far away.  The only reason folks aren't promoting it is most people can't think outside the box at all.

Instead of trying to adapt heavy diesel engines people should start using GA aircraft with auto gas STCs.  There are lots of them, and if they started making inroads internationally there'd be a lot more.  Using the diesel is trying to fit a square peg in a round hole.  Hell, the Mooney M10 would probably have been a roaring success with e Rotax engine.  As it is they tried to muscle in a diesel and it sits in a warehouse never to be made.  The damn things just don't work, they never have.

I recall a TV show about a Danish woman flying her taildragger to Afghanistan.  She had a couple gas cans, and when she landed she'd go on the hunt to find super unleaded.  She never failed.  If anyone had any sense that's the way they'd go.  There are already lots of aircraft and lots of engines.

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Yeah, I think it is somewhat more complicated than that, but thanks for your view, @steingar (I do mean it sincerely).

What it comes down to is that there are many places around the world where 100LL is not available and Jet-A1 is.  The reason for this is of secondary importance, it just is.

Finding auto fuel without booze in it can also be non-trivial and non-deterministic (no guarantee that the next batch will be the same as the previous one, because the norms allow between 0 and N% of various additives, not just ethanol) - even in the US, whereas Jet-A1 just is what it is, always, the big guys make it so.

All that said, of course there is nothing wrong with designing a GA device just for the US market, it is the largest in the world by far, I was just trying to point out the challenges (or perhaps opportunities) outside of the GA paradise you all have there.  Hell, Rotax did it for the EU ultralight market, and is doing well.

I wish my TSIO-360 was allowed to drink auto fuel, but it ain't so...  One liter (0.2641729 of a US gallon) of AVGAS at my field costs $2.70; 100 octane unleaded is $1.45.  Yes, I know the octane rating is counted differently for avgas and car gas, and differently in the US and the EU car gas as well.  </rant off>

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28 minutes ago, steingar said:

I think it's in high demand because people are abominably stupid.  Most GA engines and aircraft will happily run car gas so long as it hasn't booze in it,  and car gas is nearly universally available.  The only reason it isn't at airports is that no one yet uses it.  But any airport is going to have a car gas station not far away.  The only reason folks aren't promoting it is most people can't think outside the box at all.

Instead of trying to adapt heavy diesel engines people should start using GA aircraft with auto gas STCs.  There are lots of them, and if they started making inroads internationally there'd be a lot more.  Using the diesel is trying to fit a square peg in a round hole.  Hell, the Mooney M10 would probably have been a roaring success with e Rotax engine.  As it is they tried to muscle in a diesel and it sits in a warehouse never to be made.  The damn things just don't work, they never have.

I recall a TV show about a Danish woman flying her taildragger to Afghanistan.  She had a couple gas cans, and when she landed she'd go on the hunt to find super unleaded.  She never failed.  If anyone had any sense that's the way they'd go.  There are already lots of aircraft and lots of engines.

Only if you don't mind detonation.

And of course actual car gas with ethanol instead of mogas, will also do a number on even those aviation engines that have a mogas stc.

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2 hours ago, aviatoreb said:

Only if you don't mind detonation.

And of course actual car gas with ethanol instead of mogas, will also do a number on even those aviation engines that have a mogas stc.

Hence my point about significant cylinder head design changes. It's amazing how much performance we get from modern engines running on the crap they sell at the pump. I wonder what would be possible if we could get 103 or 105 octane at the pumps like the good old days

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I'd love a turbo diesel,  they put out power/torque at just the right range, more efficient but are unfortunately god awful expensive.

If there was one available near the cost of a replacement io-360, I'd be first in line. 

You see the specs of continental and diamond turbo diesels, something in the 200hp range would burn approx 7 to 8 gph which sounds perfect for my mooney.

little math,  that would probably take me >1000 miles and be cheaper to operate.

 

i sent an email to cont. regarding their turbo diesels, they didn't even bother to reply.

 

so, next best thing would be prob be a modern auto fueled engine, that CAN support current fuel, ethanol included.

seriously, my car runs 340 hp on 87 octane gas. booze, no booze, water, whatever

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1 hour ago, McMooney said:

I'd love a turbo diesel,  they put out power/torque at just the right range, more efficient but are unfortunately god awful expensive.

If there was one available near the cost of a replacement io-360, I'd be first in line. 

You see the specs of continental and diamond turbo diesels, something in the 200hp range would burn approx 7 to 8 gph which sounds perfect for my mooney.

little math,  that would probably take me >1000 miles and be cheaper to operate.

 

i sent an email to cont. regarding their turbo diesels, they didn't even bother to reply.

 

so, next best thing would be prob be a modern auto fueled engine, that CAN support current fuel, ethanol included.

seriously, my car runs 340 hp on 87 octane gas. booze, no booze, water, whatever

What ever happened to delta hawk diesel - it seemed perfect.

Your car doesn't operate at 20,000 ft at 340hp and for that matter it doesn't put out 340hp for more than a few seconds.  And it doesn't expect to sit for a month with ethanol in the fuel.  87 octane would make my tsio520nb explode - literally.

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