Lycoming Diesel

[woxofswa]

I've heard from a couple of sources that the Lycoming reps at Oshkosh were telling peeps that they will have a 540 sized diesel on the market within a year. That would be my perfect pulse for my expected RV10 project. Anyone have any updates or details? How many would there have to be for Van's to produce a finishing/FWF kit for that application?

[rv6ejguy]

Has Lycoming announced any price target for the engine yet? How about hp and weight?

[groucho]

Drool. I'm buying one. I'm not sure what I'll hang it on, but I need one. General aviation needs new powerplants. I hope this is the one that'll change everything.

[David-aviator]

Originally Posted by groucho

Drool. I'm buying one. I'm not sure what I'll hang it on, but I need one. General aviation needs new powerplants. I hope this is the one that'll change everything.

I don't see how it will change anything....diesel comes out of the same hole as av gas. Lately, its price around here has been higher than regular gas, although it is lower than av gas - but not by much.

The reason these engines have not made it to market is all about economics. The cost of recertifying airplanes is prohibitive. Now if the plug were pulled on av gas, that would make a difference.

Maybe Lycoming knows something we don't.

[groucho]

Originally Posted by David-aviator

I don't see how it will change anything....diesel comes out of the same hole as av gas.

Obviuosly, this whole thing is just pie in the sky for now & I can't make any hard & fast "it's gonna rule the world" comments. There are certainly some drawbacks & as we all know, just because a company talks about releasing something doesn't mean they will.

Jet A isn't available everywhere. So with the current spread of gas pumps, going diesel means you have a more limited set of refueling destinations. There are still lots of FBOs that do sell JetA. At least in my neck of the woods, most airports I fly to sell 100LL & JetA.

All that said, many huge leaps in aviation history have happened because of changes in propulsion. IMHO, military, commercial & general aviation all need new powerplants. Military: I still haven't met a fighter that has enough power. Commercial: improvements of only a couple percent can be the difference between making a profit or not. We're of course not here to solve military or commercial aviation issues. A relatively small improvement in GA engines can significantly change the capabilities of our planes. Tried the difference between a Blended Airfoil & "old" Hartzell prop? ...just an example of what a small change can do.

I'm sure there are several people here that have FADECs, lots that have fuel injection & even more that have electronic ignition. I'd hazard a guess that those who've upgraded their plane to one of these after flying with a bone stock 320 or 360 would have comments ranging from "I can tell" to "wow." Our engines ("our" = those with 320's, 360's & similar) were designed a very long time ago. The cost prohibitive nature of developing & certifying new engines is certainly one driving factor in development. As best I can tell, the O-360 was introduced in 1955. 1955!!! I'd bet that my engine is almost identical to that 1955 model. I guarantee the technology exists to make a better engine today.

A new engine doesn't have to be diesel. There are quite a few companies that are at least talking about their new diesel engines though. A few are:
http://www.zoche.de/
http://www.centurion-engines.com/
http://www.deltahawkengines.com/
Many have followed the progress of these & more...some companies actually have customers with flying engines & others haven't made much ground in years. While designing a new engine is far from trivial, I imagine that a new (i.e. from scratch) Lycoming diesel would be a very tempting powerplant for much of general aviation.

Honda has openly talked about their gas-powered aircraft engine development for several years. I heard a rumor Toyota is also developing a GA engine. Honda recently announced it is building a plant to build it's new jet engine in North Carolina. I haven't heard any news about their piston engine production though. I'd guess that a Honda or Toyota entry into the GA engine market would drastically change the landscape.

In all of this babble, all I'm really saying is that I want an easier to use, more reliable, higher powered, more efficient engine for our airplanes (well, at least my airplane ).

If nothing else, it's fun to talk about.

[KPmarc]

Lycoming said in 2006 that it would have a "heavy fuel" engine on display the next year. 2007 came and went without a peep.

Don't hold your breath.

I will say, however, that we're approaching the economic tipping point for diesels/Jet-A burners in the U.S. Cessna apparently agrees. Until the recent cost hikes on avgas, they didn't make much fiscal sense; now they are starting to.

Don't underestimate the task, either. Go look at the Thielert or SMA installations on certified airplanes. They're complex as all get out, and have vibration signatures that make the prop guys lose sleep. (In fact, I strongly suspect that Hartzell's investment in new composite technologies was based on an expectation that heavy-fuel engines would become more common.) Look at the sophisticated engine mounts on the four-cylinder Thielert...

Hanging one of these on the firewall of an RV-10 is going to make putting a rotary or a fuel cell engine seem like popping new AAs into your Maglite.

[sierradelta]

My perfect power plant choice would be a diesel....imagine converting it to biodeisel and running SVO.

Goodness then I could power my SVO Ford truck my SVO Agriculture Tractor and my SVO plane on the same fuel....That is a dream because I can produce my own fuel at home.

Oh technology can you please hurry up and make my dream come true!

[SvingenB]

Originally Posted by David-aviator

I don't see how it will change anything....diesel comes out of the same hole as av gas. Lately, its price around here has been higher than regular gas, although it is lower than av gas - but not by much.

The reason these engines have not made it to market is all about economics. The cost of recertifying airplanes is prohibitive. Now if the plug were pulled on av gas, that would make a difference.

Maybe Lycoming knows something we don't.

A diesel engine will run on both jet fuel and diesel. Both these fuels, or at least one of them, can be found everywhere, even at the most remote places on the planet. Avgas is an exotic mix that only GA use, and much more highly refined than mogas. An airplane burning avgas needs a seperate infrastructure for storage and transport, while an airplane burning diesel don't, it can use existing autodiesel or jet insfrastructure. What I find strange is why avgas is so cheap in the US, and diesel/jet is expensive. Diesel is much less expensive to make, transport and store than either avgas or mogas.

I just hope someone will make an an ordinary air cooled turbo-diesel without all the expensive and unreliable gears, clutches, Common Rails, FADECs etc.

[rv6ejguy]

Where I fly mostly, neither jet nor diesel fuel is available at the airport so this would need to be addressed either by tankering, choosing routes based on fuel availability or installing diesel/ jet tanks at these smaller airports. I don't see the latter happening until many of thousands of diesel engines are being used in aircraft. At the present rate of diesel engine introduction and the current costs, this won't be for some time.

Diesels have a long ways to go IMO before they become a reasonable choice for weekend fliers like most of us on this forum are.

Bumming a ride into town with a few jerry cans to get diesel is ridiculous.

For flight schools and those making long trips to major centers, diesels make more sense if reliability gets up there with Lycoming engines. Thielert engines have not shown that to be true in service unfortunately.

[airguy]

You'll begin to see large(r) numbers of homebuilders with 75-gallon built-in fuel tanks in the bed of a pickup, an extremely common sight in West Texas and other farming communities where it's often very handy to have a mobile diesel pump, even if it's of limited capacity. I honestly cannot count the numbers of people I know that have a 75 or 100 gallon diesel tank with electric pumps in the back of a gasoline-fueled pickup. Between that and extended-range fuel tanks to tanker fuel for shorter round trips, much of your fuel availability problems would be resolved.

I, too, believe that the efficiency of a water-cooled turbodiesel is going to become more and more attractive (and thus see more usage) for small aircraft within the next 10-20 years, eventually becoming commonplace.

Originally Posted by David-aviator

The reason these engines have not made it to market is all about economics. The cost of recertifying airplanes is prohibitive. Now if the plug were pulled on av gas, that would make a difference.

Exactly true - but we don't have to certify the engine - nor the airplane - we just have to make it work to our satisfaction. The market will follow any lead proven to be viable.

Originally Posted by SvingenB

I just hope someone will make an an ordinary air cooled turbo-diesel without all the expensive and unreliable gears, clutches, Common Rails, FADECs etc.

Not likely with air cooling - it's been tried before and is just not practical. Air cooling means the thermal variation between ambient temperature and running engine is quite large - meaning you have a large amount of thermal expansion to deal with, which requires loose tolerances to allow the engine to operate without physically seizing itself up during operation. Loose tolerances encourage high oil usage (quart every 4-6 hours, anyone??) and make it more difficult to seal the piston within the cylinder properly for high compression, which is an absolute necessity for a diesel. Additionally, air cooling limits the rate at which heat can be rejected to atmosphere (temperature differential and surface area), which can severely impact the amount of power that can be extracted from a small engine without overtemping the cylinders. It's simple mathematics that allows us to extract more power from a given displacement with water cooling versus air cooling. You'll have a larger radiator (and associated cooling drag) to deal with, but you can get a much high power output for a given engine size and weight. At some point it becomes advantageous to pay the weight and drag penalty and use water cooling. Is that point within our useful aircraft engineering envelope for 2- and 4-place aircraft? Dunno - but I'm betting we find out within the next 10 years.