Thielert Diesel

[No4]

Thielert Diesel

 

http://www.centurion-engines.com/index.htm

 

The Thielert diesels are becoming quite popular. They are offered new in some Diamond aircraft, as a retro fit for pipers and cessnas, and will be available for homebuilts.

 

They come in two sizes,

 

1.7 135hp 4 cylinder water cooled turbocharged 135 kg complete with reduction drive and constant speed propeller drive $19,500

 

4.0 310hp V8 twin turbocharged 285 kg with psru and csu $48,000

 

The engines are certified conversions of Mercedes Benz auto diesels.

 

They run on any mix of jet fuel and diesel.

 

In identical aircraft an IO-360 uses 9.5 gph, whilst the thielert uses 5 gph. The range increased from 570nm to 750 nm. Speeds are the same at 130 knots.

 

The lack of total horsepower in the 1.7 is apparently made up for by the high torque throughout the rev range, which leads to a similar horspower at cruise rpm in respect to the lyc. The V8 is due to be standard in the Gippsland Airvan, a plane similar to a Cessna 206

 

I used to dream about Mercedes making a V8 aero diesel, and now it's come true! I believe these engines are the future; efficient, low cost fuel, greatly reduced fire hazard, no ignition, probably very reliable.

 

Still pretty keen on the V10 Volkswagen (400hp)and Volvo 5 cylinder(230hp) aswell.

 

 

 

[mlefebvre]

It looks like a great option for economical and efficient operation. I wonder how you handle the JetA/Diesel mix? How would you decide what ratio to use? Does it imply that it can be 100% either? I am considering increasing the range of the aircraft and this deffinately is a boost if it comes through for the experimental market as described. How does the price compare to a Lycoming? How about weight differential?

 

Marc

[No4]

Any mix of Jet Fuel / Diesel, ie 100% one or the other. Jet A1 is dearer, possibly less calorific, but contains some chemicals to prevent gelling at low temp. Diesel is less expensive, has lower quality control, and is more prone to gelling.

 

I think a Thielert 1.7 is less expensive than a Lycoming, and it includes a constant speed prop.

 

The weights are very similar, I think.

 

I plan to make my Cozy a two seater with long range tanks, 300 knots cruise at 25,000 feet, 1500 nm range, using either the VW V10 or Mercedes V8, it should consume 16.5 gph or less

but we shall see!

 

[LargePrime]

One thing I never see mentioned is this is a first generation TDI diesel. Current diesels (automotive) are nearing 3rd generation and have doubled the HP per cubic inch. The 1.7 with a little coaxing could easily add 40 HP (different ECU chip and bigger injectors).

 

Long term a new head with individual injector pumps could add 100HP. At some point you have to start looking at what else needs replacing.

 

Another thing I love is this is a high quality automotive engine conversion. I belive you can go down to the DC dealer and buy a new crank and pistons. Thats got to make overhaul and rebuild less expensive.

[marbleturtle]

If they would do a turbo 6 cylinder, I would rethink the rotary. My Father had an assortment of MB diesels that lived between 250,000 and 700,000 miles before he traded up. As long as the engine had a mechanical fuel pump, all the electronics or accessories could die but the engine would keep pumping. Definate "get you there and back" appeal.

 

Mercedes quality has taken a dump since the eary 90's, but since they spend most of their effort fiddling with the gas engines, I would still trust the current MB diesels.

[kumaros]

If they would do a turbo 6 cylinder, I would rethink the rotary. My Father had an assortment of MB diesels that lived between 250,000 and 700,000 miles before he traded up. As long as the engine had a mechanical fuel pump, all the electronics or accessories could die but the engine would keep pumping. Definate "get you there and back" appeal.

 

They finally do, both MB and VW are producing V6 turbodiesels, both 225HP at 4000RPM, 205HP at 2800RPM, flat torque curve from ~ 1500RPM to 2800RPM. Feast your eyes:

 

http://www.germancarfans.com/news.cfm/newsid/2041216.002/page/2/lang/eng/mercedes/1.html

 

http://www.germancarfans.com/news.cfm/newsid/2041117.004/page/1/lang/eng/volkswagen/1.html

 

 

Mercedes quality has taken a dump since the eary 90's, but since they spend most of their effort fiddling with the gas engines, I would still trust the current MB diesels.

 

True, even German automobile magazines lament the low reliability of modern German cars, most problems, however, tend to lie in their complicated electronic gadgets. German metallurgy still rules, although all German car manufacturers did have some problems with their Bosch diesel pumps.

 

Kumaros

[crosswindaviator]

Ive been flying the Thielert Diesel engine on 2 different aircraft,

 

have experienced MASSIVE engine problems due to Gearbox overtemps and mainly FADEC issue's,

 

Im in love with the Cozy and im reading thru this to find out what the better engine would be... but im not very convinced it should be this diesel... although I must say, it was a lot of "engine childhood" troubles, but still, have had to many pans and know of 3 full engine shutdowns in the last 12 months

 

 

edit, Im talking about the 135 hp version

[Air Ambulance]

Hey Crosswind,

 

Could you give more details? Which Thielert were you flying? 2.0? 4.0? We're looking into a Cessna 206 with a TAE 4.0. We're still in the "fact finding" stage.

 

Thanks

[crosswindaviator]

hi,

 

yup, it was the light version 135 hp.

 

not the 4.0

 

do note that all these troubles were in the very young stages of these engines, I as far as I know there hasnt been to many issues with it...

[gontek]

I like the potential of these diesels, and am glad they are an option. That being said, the centurions probably have a higher installed weight. Also Jet Fuel is more dense, therefore fuel economy is at the expense of higher weight and heavier fuel. Jet fuel may be cheaper and easier to come by in the future than 100LL, but fuel prices can change, and likely will to ensure uncle sam still gets his "fair share". I see you guys are in Europe so that is a big difference from in the states.

 

One other thing to point out is that I don't know that these eat standard diesel fuel, but they do burn Jet Fuel or Kerosene using the Diesel Cycle, as opposed to Otto Cycle. The biggest thing I'd consider when choosing my engine is TBO and overhaul cost - well basically lifecycle cost. If these diesels have very high TBO they could very well pay off in the lifecycle, but that remains to be seen. I think it is interesting to hear about Gearbox and FADEC issues. The gearbox is a drawback I have heard of. The FADEC problem I have not heard of and would be a much bigger issue to me if I start hearing about FADEC failures.

[KeithO]

Just remember that the Automotive engine that this started out as was rated 90hp. There is very little on the engine other than head and block that is left over from the original engine. The crank and cam and fueling system, manifold, turbo etc are all new developments by Thielert (these guys earn most of their money building formula racing engines).

 

The engine is an alloy casting and I think that for a reasonable TBO it is already maxed out. Also, there is no real "TBO". They talk about TBR (time before replacement). When the time is up, the engine is replaced complete. No components are overhauled at all. Very much like a turbine engine, except that TBR applies to modular components, so one does not neccersarily have to replace the whole engine in 1 go.

 

The fuel load for a given range will be a lot lower than for a similar power gas engine, simply because the burn rate is so much lower. So in an apples to apples comparison, a gas powered airplane would always have to carry a heavier fuel load that one equipped with the Thielert diesel. Jet A and Low Lead fuel are both taxed a lot less in the USA than in Europe. The low lead fuel is very highly taxed and in low supply in Europe, thus they have great economic benefits in that market when using diesel instead.

[Phil Kriley]

I've seen no indication that Thielert intends to make engines available to the experimental crowd - in fact, I've read company statements that they are specifically NOT interested in the expiremental market.

 

Has this official company position changed recently? If so, it's news to me, as I would be very interested in one of their engines for my Cozy.

[Marc Zeitlin]

I've seen no indication that Thielert intends to make engines available to the experimental crowd - in fact, I've read company statements that they are specifically NOT interested in the expiremental market.

 

Has this official company position changed recently? If so, it's news to me, as I would be very interested in one of their engines for my Cozy.

See:

 

http://www.centurion-engines.com/

 

Click on the 2.0 engine, then "Kitplanes and Experimentals".

[Phil Kriley]

Right - available to kit manufacturers - not directly to builders. So we still can't get one for our planes.

[Marc Zeitlin]

Right - available to kit manufacturers - not directly to builders. So we still can't get one for our planes.

That's very different than saying that they're not interested in the experimental market. Should Vans start marketing these engines, that would be 1/2 of the experimental amateur built market :-).

 

At any rate, if ACS decided to market them for the COZY, then they'd be available to us. It's hardly obviously a lost cause.

[Phil Kriley]

Not a lost cause - I still have my hopes up! By the time I'm ready for an engine, maybe it will be an option. But at this time the engine is not available to those of us with Cozy's. That's all I was trying to say.