TDI in an airplane - the way forward

There are a lot of good swaps on this forum but a VW TDI into an airplane just may be the best yet. We need to really ramp up this effort in the US! The gasoline engines from Lycoming/Continental and all others are essentially garbage. Inefficient, outdated, rough running, and many more unsavory adjectives could be used to describe them. I've been all over these pages now and eventhough we are diesel fanatics I still see people saying "diesel's can't power airplanes, diesels are too heavy, too underpowered, just stick with the gasoline offerings, bla bla bla." IMO diesels and diesel/electric are the future of all transport be it on the ground, water, or in the air! Furthermore here is the proof of just what that little TDI 4 cyclinder can do!

The first one is a Cessna in Europe re-powered by an ALH. (youtube cessna diesel to find it if the link doesn't work)
http://www.youtube.com/watch?v=mgI4vJZZv48&feature=BFa&list=UL78zz1cpVnZg&lf=mfu_in_order

The second is a BEW PD powered conquest out of S. America. (youtube Diesel Conquest)
http://www.youtube.com/watch?v=HeBZ0bj7QS0

These aren't the only ones - another fellow from Finland was featured in an aviation mag (I believe someone might have posted it to the forum) a few years back with an ALH powered kit aircraft. He flew the entire length of Finland without re-fueling! He had approx. 17 hrs flight time available on a tank of fuel. That's more than my C-130 and we carry 62K of fuel!

Truly inspiring stuff!

I have been planning a similar project for some time now (though still a couple years out from build time) with a 2.0 CR TDI in a Zenith CH801.

The VW TDI should be the engine of choice for all GA/Kit Aircraft up to 225-250HP. VW could take over the aviation engine market as well as the auto industry!

Who else is doing this? Pass the word and post the videos!! Let's drive a stake through the heart of 100LL and gasoline for good!!

That was a Finnish guy who TDI'd his airplane. This idea is awesome, I can't agree more. Diesel powered aircraft are nothing new. In WW2 the Russians bombed Berlin from Russia with Large diesel powered four engine bombers. Part of their success was due to the long fuel range.

http://www.deltahawkengines.com/

Or you can order one that will fit in the shrouds.

All for it! would love to have something on floats with a tdi power someday!

I am waiting for someone from Europe to put a Subaru diesel in an airplane.

There are four CERTIFIED diesel engines on the market: the 1.7 and 2.0 Centurion from now defunct Thielert (reduction drive problems killed the company - they sold THOUSANDS of engines first), the 2.0 Austro (installed in Da40 and Da42 Diamond single and twin and the SMA 5.0 direct drive that is STCd in a bunch of airplanes (including C182). The sad part is that when Thielert went under, one of their projects was an Audi 4.2 with PRSD to replace big HP 6 bangers in larger light twins (300-400HP class) and was flying in a B50 (Beech Duke). The up side is that TCM has bought the rights to develop SMA technology to a useful stage - and will start at the 200HP range and go on to the 400 end (this is a modular engine that was designed from the start to be direct drive OR reduction drive, 4, 6 and I imagine (as in HOPE) 8 cyl as well.

I am hoping that before I am too old to hold a medical, I can bolt a pair of 400HP diesel into a Ted Smith airframe (either 680/685 Commander or better yet, one of those AND an Aerostar). If anyone goes 500HP or more (easy with gear reduced, 10 litre SMA design) it would be SO SWEET on a D18S with 232 gal tanks (better yet the 266 gal version with all fuel in the wings).

Agreed the Continental/Lycoming engines are ancient technology, there is one thing that no conversion can top, they are dead nuts reliable.

Scott_DeWitt said:

Agreed the Continental/Lycoming engines are ancient technology, there is one thing that no conversion can top, they are dead nuts reliable.

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SOME light aircraft engines are dead reliable...now (after 70 years of development). There are so many horror stories about genav recips that John Q Public never hears. For DECADES ALL large TCM crankcases failed, as did the re-designed ones. That meant replace the engine (today a $30k proposition). For EVER, TCM couldn't get cylinders right on big engines. NOBODY seems to have been able to make a gear reduced US genav engine that would make it to TBO without an absolute virtuoso performance by the pilots involved (O-300, GO-480, etc.). The Lyc O-320 H2AD was about the most unreliable engine ever built (whereas any other O-320 Lyc is about the best - go figure, but the H2AD had similar cam problems as found in PD VW).

From watching the video you could do "Sky Writing" too. The operating rpm of a TDI is much more inline with an aircraft engine. The volksplane when I was a kid I believe used a gear reduction from the aircooled engine to spin the prop. I think air boats down here with non aircraft engines do something similar. Maybe I need a TDI airboat? Neat.

rsxrs: The Evans VP could not tolerate the weight of a reduction drive. They were direct drive, and many were built with 1200 engines!!!! My first a/c project was to build a 1500 for a guy who built as a 1200, but the airplane (a bit overweight as was common in those days) would not get off of the ground!

Has anyone tried tooth-belt reductions? Newbie here in the aircraft world, but have seen belt drives work very well in other apps.

Or the tdi engine could be inverted and run direct with dry sump??

The Diamond DA-42 is a great diesel powered plane, I've got about 50 hours in one, truly impressive fuel consumption for a twin. As I recall they set a fuel consumption record for a twin while flying one over to the US from Germany along the "Northern Route" (UK, Iceland, Greenland, etc.)

It's a diesel, but runs Jet/A due to no diesel availability on the ramp in the US.
http://en.wikipedia.org/wiki/Diamond_DA42

awesome!

Ski in NC said:

Has anyone tried tooth-belt reductions? Newbie here in the aircraft world, but have seen belt drives work very well in other apps.

Or the tdi engine could be inverted and run direct with dry sump??

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\Tooth belt drives (timing belt and HTD) have been done, as have V belts, but not in certified engines. I used to build airboat prop drives in timing belt (pre-HTD days) configuration, but to get to the rated power (industrial ratings are WAY more conservative than transportation) the size gets ridiculous. You can make very light and compact drives with HTD, but in any case, the real secret is in getting the torsional damping right. Four and fewer cylinders have a huge torque reversal, and that tears drive systems to bits (and require them to be several orders of magnitude larger than you would think). Look at the size and simplicity of the drive for a Merlin (1650CID, way over 1,000 HP) and compare it with the monster gear drive for a 1.7 litre Benz in a Thielert 135 HP diesel and you will get the point.

IMHO, the neatest and most intelligent way of doing a gasoline powered airplane is a rotary (as in Wankel, not le Rhone Gnome) engine with a Ross PRSU. All overlapping power pulses, three or four planetaries to keep gear size down to minimum (actually automatic transmission parts). Now, if someone would make a nice DIESEL rotary...

As an aircraft mechanic, owner and pilot I have to agree that Lycoming, Continental and Franklin engines are quite reliable. I also realize that there have been a few "horror shows" with certain engines.

One that I'm familiar with is the Lycoming 0-320 H2AD. One day I was doing a pre-purchase inspection on a Cessna 172. By the time I had told the prospective owner about the valve and crankshaft problems associated with that engine, the present owner didn't want to fly it home! I had a friend that had one in his airplane. He was meticulous about maintenance and had the oil analyzed every 25 hours. At 700 hours,the engine was kaput. Most aircraft engines normally go 2000 hours with no problems.

In 3000 hours of flying I never had an engine fail. I did have to shut down the left engine on a Piper Apache twice for two different problems. One was a broken prop governor line and the other time was for a swallowed valve. In both cases, I was able to save the engine from further destruction.

I've had all three brands of engines in dozens of airplanes and most of them have been bullet proof. When you realize that these engines tend to sit for weeks at a time without running, it's amazing that they are reliable at all!

As far as putting a VW 1.9L engine in an airplane goes... it would be really cool. I think that the conversion would be quite costly. You would need to add a gear box, a special prop, liquid cooling and the electronics to pull it off. Has anybody run the numbers to find out the fuel consumption? The Lycomings tended to burn about 9 G.P.H. That gas is now around 6.00/gallon, so if that would give the diesel some "wiggle room".

I'm always open to new ideas and would be interested in following this idea, but could never afford it. I do believe that Cessna offers the 172 with a factory diesel engine now, so it's not exactly far fetched.

2000golftdigls said:

As far as putting a VW 1.9L engine in an airplane goes... it would be really cool. I think that the conversion would be quite costly. You would need to add a gear box, a special prop, liquid cooling and the electronics to pull it off. Has anybody run the numbers to find out the fuel consumption? The Lycomings tended to burn about 9 G.P.H. That gas is now around 6.00/gallon, so if that would give the diesel some "wiggle room".

I'm always open to new ideas and would be interested in following this idea, but could never afford it. I do believe that Cessna offers the 172 with a factory diesel engine now, so it's not exactly far fetched.

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The diesel 172s were advertised, but not built. They were being developed exactly at the time the Thielert 135HP Centurion gearbox problems (and some engine problems) started to surface - so Cessna wisely dropped the option (done by STC). Thielert MAY emerge from bankrupcy protection one day (they are still operating - but barely and with MASSIVE price increases on everything) and the newer and much more reliable Centurion 2.0 @ 155HP is a direct replacement (not sure what the STCs will allow, though).

To try to develop a 1.9 TDI would be suicidal, at best. It is a HUGE engineering undertaking, and would be more money than just bolting in an Allison 250 turbine.

BTW: While a Lyc or TCM might go 2,000 hrs. reliably, that is not very durable. My best VWTD has over 600,000kms or maybe 8,000 hrs. with some work, but my best DDECII Detroit has 1.6mm kms (million miles = 20,000 hrs.) with NO repair of any kind except accessories. That is both reliable and durable far beyond aviation recip values (but not turbine).

Update to original post

Seems the fellow posted his website for the project. "Huge undertaking" you say....well, someone has done it and it looks factory. "Toothed Drive" PSRU...well here it is. This guy is a true craftsman. http://www.kotinet.com/hamalainen.pekka/ Please take a look as it truly is a work of art - right up there with the most elegant installs I have ever seen.

With fuel prices of all kinds hitting record highs and no end in site, we need great ideas like these in order to simply operate our aircraft. The GA market will die, except for the well-to-do among us, as we simply will not be able to fly our planes with operating costs running so high.

I have nearly 4000 hrs flying experience, much of that single seat and single engine, I can promise you this - based upon the performance of my Jetta Diesels - I will have no issues with emulating what this fine fellow has done by bolting a TDI onto my Zenith and flying it everywhere on "red dyed" diesel.

I wonder if he is using the DMF to help with the torsional issue. That might be key in making the tooth belt hardware live.

Ski in NC said:

I wonder if he is using the DMF to help with the torsional issue. That might be key in making the tooth belt hardware live.

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In the very first pic in the engine pics section I see the DMF peaking out . Looking further in the pics, he must've made a plate that uses the pressure plate bolt holes. I'm going to say that's what runs the belt drive. Either way, I want to buy that dude a beer. That is some truly impressive machine and fab work.

Jpharstrider said:

Seems the fellow posted his website for the project. "Huge undertaking" you say....well, someone has done it and it looks factory. "Toothed Drive" PSRU...well here it is. This guy is a true craftsman. http://www.kotinet.com/hamalainen.pekka/ Please take a look as it truly is a work of art - right up there with the most elegant installs I have ever seen.
With fuel prices of all kinds hitting record highs and no end in site, we need great ideas like these in order to simply operate our aircraft. The GA market will die, except for the well-to-do among us, as we simply will not be able to fly our planes with operating costs running so high.
I have nearly 4000 hrs flying experience, much of that single seat and single engine, I can promise you this - based upon the performance of my Jetta Diesels - I will have no issues with emulating what this fine fellow has done by bolting a TDI onto my Zenith and flying it everywhere on "red dyed" diesel.

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I just realized I commented the link you posted to you on youtube *facepalm*
If I decide to stay in aviation outside of the military, a project like this will be my life goal.

tdi=120 HP reliable until something bad happens dead turbo = 60 hp= not landing on the runway, and weighs toooo much. 4 cyl. 150 lico light and reliable, lot-o-torque, dual mags, dual plugs, no mechanical cooling system. One cyl. dies still 100 hp ish. = landing on the runway.

Looks like the Cessna has a fixed-pitch prop
Generally engine oil is used in a constant Speed Prop, so maybe the builder didn't figure that design issue out. It could require another STC.
A continental or Lycoming 6-banger might weigh as much the TDI engine but then there's also the liquid cooling equipment needed.
An oi leak could be catastrophic in terms of the turbo and CS Prop all dependent on engine oil.

Cool idea though.

I beleive that it is the Cessna 182 that is sellig in a diesel.

http://www.flyingmag.com/aircraft/pistons/cessna-182-jt

I'd have to take slight issue with the bit about the aeroengines being garbage, they are actually pretty good for the job they are required to do, to the point that the majority of car engines (with the additional decades of refinement, fuel injection and the rest) actually struggle to even make as good of an aircraft engine as they do. Alot of compromises go into the making of an aircraft engine, in part the reason why there are not a rash of brand new aircraft engines to replace them all over the market... I don't have them memorized offhand, but I remember discovering that in the past when researching auto engines in cars is all. The sustained power outputs they offer for the weight which they have, and the efficiency at those power outputs is actually pretty reasonable - they only have to do steady state cruise afterall, and modern car engines haven't offered massive improvements to that for most of what i've been aware of.

Issues to consider are the lifespan of diesels at high CONSTANT power outputs (would a Jetta engine last if it puts out 200hp all day long for thousands of hours before overhaul?) vs weight among other things (and 300lbs is not at all light for an aero engine, considering that a Lycoming 360 weighs 258lbs for a _5.9liter_ engine with 180hp constant, a rule of thumb for a competitive aero engine is 2hp per 3lbs for a 24/7 competitive power rating), an excellent testbed for that would be marine engines in particular an outboard which are similarily run at high outputs and need to be light in weight.

That said I totally share the passion for aerodiesels. Other than the Zoche and one other maker I can't remember the name off I wasn't even aware of others working on aerodiesels let alone flying them yet...

I'd planned to "someday" build a homebuilt aircraft myself and if a diesel could show notable improvements in SFC, reduced maintenance needs, or longer engine lifespan i'd be all for it. Would love to see how they work long term/after thousands of hours of flight time... any aircraft of my own is probably a good decade off yet I still research and dream in that direction for when I can afford flight school.


To Ski In NC, they've used belt drives on the 4.3 vortec v6 conversions, see beltedair.com They have other advantages like absorbing certain harmonics and torque loads without transfering them directly to an engine like they are in direct drive engines.

Midnight: there are a PILE of people working on aero diesels. The second from the homebuilt-experimental-maybe-one-day-certified bunch is Wiksch in the UK. they have quite a few engines in airplanes over the last 10 years.

Thielert has a lot of experience (literally thousands of engines with over a million hours) with certified production versions of 1.7 and 2.0 M-B automotive diesels in aircraft. There were some difficulties with the 1.7, but the 2.0 seems to have worked out fairly well, but reduced continuous output to 135HP from the original target of 155 or something like that. Most would cruise at 80% for a constant 110HP. His best former customer, Diamond, has built their own 2.0 automotive based engine which is certified at 170HP for a constant 140HP at cruise.

Just out of interest: VW has a huge marine engine division, so there is a LOT of experience with auto engines running constant high HP - and they will outlast a Continental or Lyc by a considerable margin.

There are even developments of the SMA 305 licensed to Continental (who figured out that they really had to go outside to find out how to build an aviation diesel). that engine was originally planned to go direct drive, reduction drive, 4 and 6 cylinders (a reduction drive SMA 460CID engine would be far over 400HP). Continental will be heading in the same direction. The SMA is the one certified in the C182T. As a 5.0 litre @ 230 HP, it will START with TBO around antique gasser times, but should end up at least double the TBO as they prove out.

While Thielert is working on certifying 3.0 and 4.2 Audi based conversions, the most promising engine is from EPS in Wisconsin. They have a dedicated aero horizontally opposed CGI block using BMW 4.4 heads (and I assume pistons) that will run around 350HP. Prototype has been running for a while - and it is a very intelligent design (integrated radiators, all kinds of neat stuff).

Fascinating... well I hadn't done any updated research on aerodiesels in YEARS so I shouldn't be surprised that i'm surprised I guess. But there's also a difference between working on and just about ready for production and certification - homebuilts are cool, but I wasn't aware of commercial aerodiesels that you could drop in at competitive power to weight ratios at the time. If you want to give a more canononical list to track down i'd be very interested.

Any opinions on how well a Jetta based aeroengine would stand up for constant HP loads? It's one thing to build an engine off something very expensive, i'd love to see something on the more affordable end of the scale. Mind you affordable versus a $30,000 Lycoming or something is somewhat relative, but I used to follow Fly5k (the group trying to build safe reliable flyable aircraft for $5000 all up with about half budgeted to the engine) so i'd be more interested if you could churn out something reliable for alot less.. I always have better things to be spending money on when it's available. >_> The 300lb weight of the engine sort of forces 200hp if you can get it to stay fairly competitive, i'm aware they do 150 or more stock but I wonder whether they could put out even 150hp for 3000hrs between an overhaul that is... I just dont know/i'm not a VW expert, other than i've heard these are the more reliable category of small diesels as it is.

I'm an especially big fan of indirect engines, I know they aren't the in thing, but they are by all I can tell more suitable for the viscocity differences of straight veggie oils and such and for a long time i've been trying to cross-breed projects with ecologically oriented ones since oil independance from the middle east seems to be a necessity of our future and if anyone shows the way it will be small home experimenters in all likelihood - i'd like to have an SVO fueled airplane.

A VO-fueled airplane sounds like a horrible idea for multiple reasons, the first of which is gelling.

Maybe if you literally mount the radiators in the fuel tanks...

But, even then, the fuel system on the IDI VWs is a very close relative of the one on older TDIs, and we know veggie oil destroys it in short order.

Your best bet is to convert the veggie oil to biodiesel, rather than try to run an engine on it directly. But, still, gelling will be a huge issue, you will need significant fuel heating.

I think you might be best off with a 2.0 16v 170 hp PD engine. The fuel system in that engine is extremely tolerant of low lubricity fuel (like Jet-A) as it uses engine oil to lubricate the high pressure components, unlike either the older VE or especially the newer CR systems. The valvetrain on the 16v PDs is robust, as it uses roller rockers, unlike the older engines (the VEs were fine with flat tappets, the 8v PDs have serious problems and are picky about lubrication (and as I understand, sustained high RPM operation worsens the problem), the CRs also have roller rockers). Engine internals are already as beefed up as they get on this family, just about. It won't be cheap, though.

As far as factory engines... the main choices are the Thielerts (formerly 1.7, now 2.0 Mercedes-derived), the Austro Diesel AE300 (2.0 Mercedes) and AE500 (3.2 I6 Steyr), and the Continental TD-300 (aka the SMA SR305-230, a dedicated aerodiesel), as far as I know.

Let me know if anybody needs a standalone Commonrail 2.0 TDI at 50 degrees incline that would be ideal for an airplane!

Greg
Boxeer.com

Since this thread seems to have come back from the dead, maybe time to update the aero diesel scene a bit.

Thielert of course went TU, but were bought by Continental who are now in turn owned by Chinese. The Thielert 2.0 engine is in production with 135 and 155 versions. Continental took a license to use the SMA 305/230 technology and develop their own direct drive air cooled, but that seems to be going nowhere. You can buy certified 172 Cessnas (STC) with the liquid cooled 2.0 engine.

Diamond had to develop their own engines when it came to Thielerts's problems (mostly with reduction drive system - thus why I have to point out how critical that component is), and their Austro brand has been doing very well indeed at 170 HP output. Both Centurion (Continental) and Austro are based on 2.0 Mercedes auto engine architecture. Again for those thinking of a TDI VW in aircraft use, take a look at the reduction drive on both of these engines, and remember that trying to get it right bankrupted Thielert (engineering company that made a bunch of F1 engine stuff)

Lycoming denied any interest in diesels, but word finally leaked out that they have been producing an inline 4 banger (DEL 120, 205HP takeoff, 180hp continuous in cruise, 350 lbs) that has been flying in RPVs and may autonomous drones for years. Liquid cooled.

RED in Europe is developing a 300 HP V6 (continous 280). I mention them as they already have ESA certification for the V12 500 HP (480 cruise) 700 lb. aircraft diesel. Credible bunch!!!!

Since we are in Europe, have to mention that the long certified SMA 305/230 has now been taken into a new STC upgrade for 182 Cessnas by Soloy. They set a world record at Oshkosh this year, flying non-stop from the WA home to WI, and hanging around for another hour aloft before landing. Problem is: this is a $230k STC!!!!!!! There will be a 260 HP version of this engine in that same airframe for another $30k later this year. Their SMA460 6 horizontally opposed, air/oil cooled 6 banger at 350+HP and up is very near certification.

Now that we are at the mid size twin engine range, have to mention EPS in Wisconsin. They have been in test flight programme for a few years (none other than Dick Rutan as pilot) and are also VERY near certification. Also 350/400HP range. this is an opposed 8 cyl engine with a CGI block, liquid cooled but with integral radiators on the cylinder heads (thus no external plumbing). Because 8 cylinders, very low level torsional issues - has been tested with a few aluminum props and proclaimed to be smoother than 6 cyl gasser.

So, now you have seen where the big boys are looking to fleece our pockets for 6 figures minimum to add a diesel to an airplane. How about down at the world of homebuilts, LSAs and little certified airplanes? Anything there? Well, as it turns out, yes. Remember the Junkers Jumo aircraft diesels? What, you weren't around in WWII? Well, they were opposed piston, 2 crank engines that Germany flew. A company called Superior Air Parts - who build so many parts that they have offered complete Lycoming engines for homebuilders for years - took on a project called Gemini diesel. These are 100HP supercharged and 125 HP with added turbocharger engines heading for certification some day, flying for quite a while.

I STILL have a license 8 years after this thread started, and I STILL do not have a diesel powered airplane. If I could afford it, I would consider a C182 from Soloy, but this is going to be a half mil for a 260 version. If I could put a Gemini 125 under STC into a Diamond Katana, I would be flying that tommorow. In Canada, I could even go owner maintenance if I could get an engine from Superior.

I really love the 'near certification' or 'very near certification' language used to describe new engine projects in general aviation. Apparently, from looking at the wreckage of chapter 13, chapter 11, and completely dead companies that were very near certification, this terminology is a clear display of the 90-10-90 rule. That is, the design, engineering, manufacturing of prototypes, acceptance, starting of a test program, getting the FAA to promise to work on it, getting the work done, going through any number of test, re-engineer, re-manufacture, test again scenarios, and getting to that 'very near certification' point will take at least 90% of your funds, provided you have a budget measured in cubic $$. Getting past that last 10% hurdle will take the other 90% of your funds (meaning: at least 80% more than you'll ever raise).

Seriously, the herculean effort of trying to get a new engine certified these days explains very well why we aren't seeing any new engines making it to the certificated airplane engine market.

And the fun part is this: even if you manage to get an engine certificated, you still need to get a certificate for each and every airplane model you want to install it into. So if you want to install it into an airplane, and want to change anything about that engine compartment, you'll need to certify it yet again.

I think the GA market is going to evolve into foreign manufactured airframes and experimentals, with the latter taking the largest portion. And companies like Deltahawk, well, there aren't really companies, there's only Deltahawk. The only reason they've survived this far is with sales to the military who don't really need FAA certification to fly a drone. They have expended all the resources of several well-heeled investors, and the only reason they've survived is by selling the company to someone else (the Ruud family if my memory serves). Yes, they have made some very small fortunes, by starting with very large fortunes.

But that is the way it is with airplanes.

I want to build one, someday. But I'll probably be forced to content myself with rebuilding a Corvair engine (which compare very favorably with the similar offerings from lycosaur engines), and if I want to really jazz it up figure out how to do a blown direct injected 2 stroke with liquid cooling. A wankel will be fun to work on in the spare time, if I can figure out how to do a reduction drive that doesn't weigh more than a substantial boat anchor like the Ross unit does.

Or maybe I'll just rescue TDIs, turn them into trucklets, and go feral pig hunting to feed the family.

Cheers!

PH