Mooney Experimental

[Andy95W]

3 hours ago, Rumblestrip said:

You forgot a zero on the end there Andy.  If I have one wish for this decade it's that people would take 30 minutes to research the actual load testing that goes on for modern auto engines, so we could rid ourselves of the FUD being ignorantly regurgitated about durability under load at higher engine speeds.

No Fear, no Uncertainty, no Doubt (like many of my generation, I had to look up FUD.  Interestingly, "FUD troll" popped up.  Hmm.)

But instead of just calling me ignorant, please post the actual load testing results that you're referencing regarding engine durability.

My point this entire time is that despite 80 year old technology, our current engines are remarkable in balancing weight, fuel burn, and reliability.  Please, by all means, show me an engine comparable to the Lycoming IO-360 at 75% power:  150 horsepower at 10 gallons per hour for 2000 hours weighing 300 pounds.

I got my license when the Porsche Mooney PFM was being produced.  I still remember a poster of it at my flight school.  It didn't last.  

Since then, I've heard more rumors than I can count about transfer of automotive engine technology to aviation.  Only 2 have even come close to fruition: the current crop of turbocharged diesels (which only recently have begun to approach- but not meet- the reliability we currently have) and the V8 Orenda conversion for the Aero Commander.  That actually flew, and the engine was actually type-certified, but the resultant airplane wasn't feasible due to weight and other factors.  

http://www.epi-eng.com/aircraft_engine_conversions/orenda_on_aero_commander.htm

Again, please post some data that actually shows:

300 pound engine, continuous 150 HP, 10 gph, 2000 hours.

 (And the IO-360 was actually certified to produce the full 200 HP for that 2000 hours, but at more than 10 gph).

[Joel Ludwigson]

If you really want to go experimental with an engine swap then do what these guys did. It scoots!

https://www.flightglobal.com/aopa-expo-upgraded-aerostar-702p-unveiled-/70709.article

 

https://www.youtube.com/watch?v=5nVTzlDsmME

[lelievre12]

4 hours ago, Andy95W said:

300 pound engine, continuous 150 HP, 10 gph, 2000 hours.

 (And the IO-360 was actually certified to produce the full 200 HP for that 2000 hours, but at more than 10 gph).

Here you go. See attached,

CD155 Continental Diesel.

Weight: 297#

Power: 155HP Continuous

TBO: 2100 Hours.

BSFC 0.353 lb/hp/hr cruise; 0.375 lb/hp/hr max power. (8GPH at takeoff/climbout, 5GPH cruise)

More than enough for your short or medium body Mooney.

More than 1 million flight hours.

 

DS_CMG_2_CD-155.pdf

Edited April 17, 2020 by lelievre12

[Warren]

Its a shame it doesn't have a little more horsepower for takeoff.  My M20k would be pretty lethargic taking of at full weight with only 75% power.  The gross weight might have to be decreased to meet the climb performance requirements.  Especially at my airport with an elevation of 5673.

However, it should have more torque and that, with a more aggressive prop might still work.  The range would be amazing with the extended range tanks and the cost to fly would be significantly reduced as long as the engine is priced reasonably.  I can't wait to see how this goes and what you find for climb performance.

[lelievre12]

6 minutes ago, Warren said:

Its a shame it doesn't have a little more horsepower for takeoff.  My M20k would be pretty lethargic taking of at full weight with only 75% power.  The gross weight might have to be decreased to meet the climb performance requirements.  Especially at my airport with an elevation of 5673.

However, it should have more torque and that, with a more aggressive prop might still work.  The range would be amazing with the extended range tanks and the cost to fly would be significantly reduced as long as the engine is priced reasonably.  I can't wait to see how this goes and what you find for climb performance.

A CD155 will make more power than an IO-360 at 5000 feet. (lapse rate makes for only 25" MP at 5K) and the CD155 has a geared prop which generates more static thrust too.  However your TSIO360 will still beat it everytime at 5K.

But further up, things change again. I'm not sure of the critical alt for the TSIO but it's possible that the CD155 may pull more HP at above ~20,000 than a TSIO360 as its not MP limited by vaporisation or detonation in the flight levels. Just a hunch.

Edited April 17, 2020 by lelievre12

[Warren]

3 minutes ago, lelievre12 said:

A CD155 will make more power than an IO-360 at 5000 feet. (lapse rate makes for only 25" MP at 5K) and the CD155 has a geared prop which generates more static thrust too.  However your TSIO360 will still beat it everytime at 5K. I'm not sure of the critical alt for the TSIO but it possible that the CD155 may pull more HP at above ~20,000 than a TSIO360 as its not MP limited by vaporisation or detonation in the flight levels. Just a hunch.

I don't recall exactly where my critical altitude is -- mine has the Merlyn upper deck pressure controller and intercooler upgrades.  I think it is about 20,000.  I don't play much above that level because I am not a fan of the oxygen masks -- it takes a really good wind to make it worth it.  Most of my time is FL190 or lower and I can still easily make full power at these altitudes.  Guys like @gsxrpilot have more experience at higher altitudes.  Maybe he can add some here -- he also as the 252 vs my 231.

[carusoam]

Welcome aboard Lelievre.

Sounds like you have some interesting details to share...

Please add some detail to your avatar data when you get a chance...

Best regards,

-a-

[gsxrpilot]

1 hour ago, lelievre12 said:

A CD155 will make more power than an IO-360 at 5000 feet. (lapse rate makes for only 25" MP at 5K) and the CD155 has a geared prop which generates more static thrust too.  However your TSIO360 will still beat it everytime at 5K.

But further up, things change again. I'm not sure of the critical alt for the TSIO but it's possible that the CD155 may pull more HP at above ~20,000 than a TSIO360 as its not MP limited by vaporisation or detonation in the flight levels. Just a hunch.

As @Warren said my 252 with the TSIO360MB engine will make its full 210 HP all the way to FL230. And it's certified to FL280. It's fast and very efficient at those altitudes. 

[Rumblestrip]

8 hours ago, Andy95W said:

No Fear, no Uncertainty, no Doubt (like many of my generation, I had to look up FUD.  Interestingly, "FUD troll" popped up.  Hmm.)

But instead of just calling me ignorant, please post the actual load testing results that you're referencing regarding engine durability.

My point this entire time is that despite 80 year old technology, our current engines are remarkable in balancing weight, fuel burn, and reliability.  Please, by all means, show me an engine comparable to the Lycoming IO-360 at 75% power:  150 horsepower at 10 gallons per hour for 2000 hours weighing 300 pounds.

I got my license when the Porsche Mooney PFM was being produced.  I still remember a poster of it at my flight school.  It didn't last.  

Since then, I've heard more rumors than I can count about transfer of automotive engine technology to aviation.  Only 2 have even come close to fruition: the current crop of turbocharged diesels (which only recently have begun to approach- but not meet- the reliability we currently have) and the V8 Orenda conversion for the Aero Commander.  That actually flew, and the engine was actually type-certified, but the resultant airplane wasn't feasible due to weight and other factors.  

http://www.epi-eng.com/aircraft_engine_conversions/orenda_on_aero_commander.htm

Again, please post some data that actually shows:

300 pound engine, continuous 150 HP, 10 gph, 2000 hours.

 (And the IO-360 was actually certified to produce the full 200 HP for that 2000 hours, but at more than 10 gph).

I have had long conversations with engineers at Ford, GM, Hyundai/Kia, Toyota and Honda specifically about what their testing procedures are for final validation.  Running an engine for 40 hours straight at max power and max torque are a minimum.  Without pulling out a few bankers boxes full of notes engines can be run for over 100 hours straight for durability testing.

You live in the Detroit area, you must know some engineers you can talk to about validation testing.

As for 80 year old technology still being so prevalent, that has to do with regulations and market size.  After all when you look at the engineering of the DeltaHawk Diesel it's nice, but it isn't that far removed from the old GMC 2 Stroke Diesel motors of the 50's and 60's.  In fact I'd call it 80% the same.  Metallurgy is a little different, DH is a more refined system, but you'd hope for that 50-60 years after the fact.

[Andy95W]

4 hours ago, lelievre12 said:

Here you go. See attached,

CD155 Continental Diesel.

Weight: 297#

Power: 155HP Continuous

TBO: 2100 Hours.

BSFC 0.353 lb/hp/hr cruise; 0.375 lb/hp/hr max power. (8GPH at takeoff/climbout, 5GPH cruise)

More than enough for your short or medium body Mooney.

More than 1 million flight hours.

 

DS_CMG_2_CD-155.pdf 222.55 kB · 5 downloads

I'm completely on board with the current crop of diesels like the CD-155 and the newest Austro.  I would love to put one in my M20C.  

But that wasn't the point of my post.  My point was that I've seen over 30 years of people complaining about how crappy our engines are vs. how wonderful modern car engines are.  And I made an exception for the current crop of turbocharged diesels.

[Andy95W]

46 minutes ago, Rumblestrip said:

I have had long conversations with engineers at Ford, GM, Hyundai/Kia, Toyota and Honda specifically about what their testing procedures are for final validation.  Running an engine for 40 hours straight at max power and max torque are a minimum.  Without pulling out a few bankers boxes full of notes engines can be run for over 100 hours straight for durability testing.

You live in the Detroit area, you must know some engineers you can talk to about validation testing.

As for 80 year old technology still being so prevalent, that has to do with regulations and market size.  After all when you look at the engineering of the DeltaHawk Diesel it's nice, but it isn't that far removed from the old GMC 2 Stroke Diesel motors of the 50's and 60's.  In fact I'd call it 80% the same.  Metallurgy is a little different, DH is a more refined system, but you'd hope for that 50-60 years after the fact.

You made a claim in your original post, I asked for supporting documentation, and you don't have it.  I'm not going to do your research for you.

And it's not just regulations and market size that keeps our 80 year old technology prevalent. Continental has the certified CD-155, Austro has a certified diesel Mercedes Benz converted engine, and Orenda certified a big V8. The reason there aren't a ton of STCs to put those engines into airframes is that either 1.) they bring limitations with them or 2.) it's difficult to justify installing an $80,000 CD-155 into my M20C when I can overhaul my existing engine for $25,000.

Again, our old technology engines are remarkable in meeting so many trade offs so effectively- which was the point of my post in the first place.

[cujet]

One small point about Jet-A that is known by most pilots, but often forgotten: Jet-A is heavier than 100LL. Aircraft operate by weight, and not by gallons. Gallons is simply a purchasing arrangement. That extra 80 pounds of fuel will make a difference, especially when added to the extra weight of a diesel engine. 

Another issue that crops up with aero diesel engines is the propensity to flame out (and not re-start) on descent. This is mitigated by digital engine controls programmed not to allow idle power under some conditions. Of course, this also depends on engine design and compression ratio. Cessna really struggled with this in the SMA diesel 182. A few insiders claim they were unable to overcome the issues. Thielert/Austro seem to have addressed the issue well enough. 

Then there is the additional cooling drag of a liquid cooled engine. Short of some remarkable engineering, aircraft operating at modest speeds will need additional airflow through a "radiator" vs an air cooled engine's "fins". This is due to the lack of significant temperature differential of the liquid cooled engine's radiator and the ambient air. The same number of BTU's must be transferred.  The FAA will require adequate cooling on a stupidly hot day. When a radiator is 200F and ambient air is 105.... Lots of airflow will be required under full power. 

With all that in mind, I truly believe a successful aero diesel will have to be a direct drive, opposed, 6 cylinder, turbocharged 4 stroke and very carefully designed to be as simple and light as possible. Yes, we can make a stupidly complex engine perform well. I promise there is no way to do it cheaply. I'll bet the $ savings in fuel will be the most expensive ever. Those mega complex 300HP+ diesels listed above look to me like they would be exactly $500,000 in today's certified engine market. The FADEC controls, another $100K++. 

 

 

EDIT: I wanted to add that both 100LL and Jet-A have essentially the same energy content by weight. Talking about GPH needs to be changed to PPH, for a real world comparison. A diesel may get better MPG, but the advantage starts to dissipate when we talk about pounds of fuel consumed (we fly by weight) . Remember, engine efficiency is measured in Pounds fuel per HP per hour or Grams fuel per KWH. 

Edited April 19, 2020 by cujet

[EricJ]

12 hours ago, cujet said:

With all that in mind, I truly believe a successful aero diesel will have to be a direct drive, opposed, 6 cylinder, turbocharged 4 stroke and very carefully designed to be as simple and light as possible. Yes, we can make a stupidly complex engine perform well. I promise there is no way to do it cheaply. I'll bet the $ savings in fuel will be the most expensive ever. Those mega complex 300HP+ diesels listed above look to me like they would be exactly $500,000 in today's certified engine market. The FADEC controls, another $100K++. 

The Germans were making successful diesel engines for aviation applications from about ninety years ago.    The Brits took it up a bit after the war but I think they mostly got displaced by turbines.

Bring back the Jumo diesels! 
 

 

[cujet]

The Jumo 205 had a BSFC of  0.38 pounds of fuel per hour per HP produced, which is exactly the same as an angle valve IO360 Lycoming running lean of peak, with electronic ignition. Remember, we fly by weight, not gallons... Furthermore, like other aero diesels, it did have some operational quirks and was not an ideal powerplant. The thought that we can do better today should be tempered with the fact that aircraft engine engineers really did know what they were doing. It's no surprise we still use technology pioneered in the 1930's. It was designed to accomplish a particular task. That being light weight, reliable and efficient power. Ever wonder why our cylinder heads are screwed on to the barrels? In the '30's it was far more reliable than head gaskets and head bolts, it was light and allowed efficient heat transfer. 

 

[EricJ]

1 hour ago, 1980Mooney said:

Imagine flying a J with an additional 161 lbs hanging forward of the firewall.  

You mean a K? 

 

[cujet]

Just a thought experiment, but why not take an existing, conventional aircraft engine design and alter it for diesel operation. A Conti 520, with smaller pistons, say 4 inches, 4 valve mono-block 3 cylinder + head assemblies (possible as a single casting on a diesel due to the flat combustion chamber head surface) , liquid cooling and dual turbochargers that mount directly on the head, on a integral log exhaust manifold. Limit it to 225-250HP and 2500RPM. There would be some difficulty in avoiding connecting rod interference, but it may be possible. Drive an injection pump from each of the magneto pads. Use 2 injectors per cylinder for redundancy. 

This would keep crank, case and rod stresses within limits, allow the use of standard engine mounts, prop governors, and props, etc, and keep development costs down to "top end" related components. 

[lelievre12]

1 hour ago, cujet said:

Just a thought experiment, but why not take an existing, conventional aircraft engine design and alter it for diesel operation. A Conti 520, with smaller pistons, say 4 inches, 4 valve mono-block 3 cylinder + head assemblies (possible as a single casting on a diesel due to the flat combustion chamber head surface) , liquid cooling and dual turbochargers that mount directly on the head, on a integral log exhaust manifold. Limit it to 225-250HP and 2500RPM. There would be some difficulty in avoiding connecting rod interference, but it may be possible. Drive an injection pump from each of the magneto pads. Use 2 injectors per cylinder for redundancy. 

This would keep crank, case and rod stresses within limits, allow the use of standard engine mounts, prop governors, and props, etc, and keep development costs down to "top end" related components. 

I did the math on that and this is basically a good idea. The longer stroke of a diesel engine means the piston bore can be smaller so that the BMEP and peak pressure loads on the crank can be reduced to 'acceptable' for the 'stock' VAR 520 crank.  Another 'trick' to reduce these loads is to use common rail injection so that the peak loads can be mitigated by introducing fuel in a programmed amount (not all at once). So the question of whether the bottom end can handle the revised cylinders does work. When I look at the SMA Diesel, that looks to me to be their approach.  Of course the harmonics would still be hard to manage and a fully strain guage instrumented crank would be needed to assess what/where counterweights would be needed. Still a big engineering job.

[cujet]

2 hours ago, lelievre12 said:

I did the math on that and this is basically a good idea. The longer stroke of a diesel engine means the piston bore can be smaller so that the BMEP and peak pressure loads on the crank can be reduced to 'acceptable' for the 'stock' VAR 520 crank.  Another 'trick' to reduce these loads is to use common rail injection so that the peak loads can be mitigated by introducing fuel in a programmed amount (not all at once). So the question of whether the bottom end can handle the revised cylinders does work. When I look at the SMA Diesel, that looks to me to be their approach.  Of course the harmonics would still be hard to manage and a fully strain guage instrumented crank would be needed to assess what/where counterweights would be needed. Still a big engineering job.

BMEP related stresses on the lower end (rods/bearings/crank) would be managed mostly by piston size reduction. The TSIO 520 may have a MEP of near 200psi at peak torque. The higher BMEP of turbodiesel engines necessitates a reduction in piston area to keep stress levels the same, hence my guess that going from the TSIO's 5.25 inch piston to diesel conversion's 4 inch piston (about a 58% reduction in surface area, or about 300 cubic inches) means that operation at up to 345psi BMEP is within reason without adding stress. Numbers close enough to start exploring. We can also limit stresses by limiting torque at any given RPM, or by simply operating the engine at just one RPM, say 2500. 

The conversion of a six cylinder engine helps reduce the harmonics the prop and crank flange are subject to. The 4 cylinder SMA engine really needs a wood or composite prop for this reason. 

Remember, aero diesels are not asked to generate huge torque numbers at RPM's just above idle, like transport or industrial engines are. So there may be no need to explore the stress generating 450psi BMEP range that we see in modern diesels. 50 cubic inch diesel cylinders are large enough to be inherently efficient, and BSFC numbers would likey be at or above 3.3 pounds of fuel per HP per hour (no pie in the sky guesses here) (good but not great numbers, at about 14% more efficient than an angle valve IO360 w/elec ign) . Anyway, it's just a thought experiment and it seems that 250HP is possible, without excess stress, it does illuminate some of the shortcomings noted above, namely a less than ideal power to weight and power to size ratio. 

 

 

 

Edited April 21, 2020 by cujet

[McMooney]

Hmm can we start with this, little heavy prob like 400lbs but 200+ hp  between 2000 and 3000 rpm

unfortunately there is no way this would ever make sense to do, cry.

[carusoam]

Any idea how much torque Mooney engines produce?

Best regards,

-a-

[EricJ]

15 minutes ago, carusoam said:

Any idea how much torque Mooney engines produce?

Best regards,

-a-

200 hp at 2700 rpm means 389 ft-lbs at 2700 rpm.   Don't know what the rest of the curve looks like, though.

 

[McMooney]

If 200hp an Io-360 a1a. Would be about 380@2700

[afward]

10 hours ago, EricJ said:

200 hp at 2700 rpm means 389 ft-lbs at 2700 rpm.   Don't know what the rest of the curve looks like, though.

Per the operator's manual, page 3-36 (page 68 of the PDF), it's a relatively flat torque curve (see the sea level section).  Peak is probably just above 2600 RPM, but not by much; best guess is that it's basically at peak between 2550 and 2725 and falls off slowly on either side.  For all practical purposes, any cruise setting will be in the power band, no matter what it is.

[Ibra]

On 4/20/2020 at 4:55 AM, 1980Mooney said:

You point out "Remember, we fly by weight"....which is why this engine died out.  It's a heavy beast with dual crankshafts

True but on a tiny plus side you may get a higher speed certification with that one (cruise speed about 33 wing loading and VNE +40% above) 

Obviously, no idea if you can make those speeds with that engine and there are better places to store weight than engine (making structure stronger )