TCM unveils diesel project
 

Continental Unveils a Diesel Project

:ok:

About time too !

Good to see Americans recognizing that there might be a problem with burning Avgas :ok:

Looks like a panic response to the problem with burning Avgas, seeing as how it's just a rebadged SMA SR305-230

I seem to remember that quite a few years ago there were big headlines when NASA gave TCM (and another engine manufacturer) a lump of money to develop a diesel engine. I don't know what happened with that project although I believe like others they were having problems lubricating the diesel pump with avtur.

Does anyone else know any more?

Brilliant bit of kit. Electronic control but mechanical injection at constant 2200 rpm. Unlike the insane common rail system used by Thielert, loss of electrical power is a non event. Wish I could afford one. :{

As regards lubrication of mechanical injection pumps, the problem is to do with the design of the pumping mechanism. Bosch pumps use in line pistons or rotary swash plate operated pistons, both of which tolerate avtur (or central heating oil) Other designs use cam operated rollers which can wear rapidly. The common rail system does away with mechanical pumps, but ensures loss of the engine in the event of electrical power failure. Not a good set up when a broken alternator drive belt means a forced landing.

Their own design, from a few years ago, is better and was a 4 cyl 2 stroke, with an electricaly augmented turbocharger.

The SMA 4 stroke is to heavy and produces high torque pulses that hammer the prop.
I would not touch it with a barge poll.
TCM have been in the engine business to long to believe in new designs.

2 stroke diesels are a better way to go.

See this from Ecomotors, an opposed piston engine with a single crankshaft and an electrically augmented turbocharger.

Advanced Propulsion Technologies, Inc.

Good power to weight ratio, simple design and with very low vibration.

Eurocopters are investigating using them in future machines.

Gemini Engine

Yes two stroke diesels seem very promising. But many small firms have become victims of the financial crisis. Nothing has been heard recently of the three cylinder supercharged two stroke Gemini. (More than 100 HP and the same weight as a VW 70 hp.)

Anybody looking at doing an "Aero Baby Deltic diesel"

Two Stroke, Good power to weight ratio, smooth:8

Socata did a lot of work on the SMA 4-cyl engine some years ago, and abandoned it due to insurmoutable vibration issues, reportedly. There is an F-reg TB20 flying with it.

I am suprised that Conti did not develop their own engine. They gave the appearance of having a design all ready and waiting for the market to be ready for it.

Diesel......dont hold your breath!
 

Ho ho ho yet another diesel that is set to take GA by storm and yet we hear that this engine has the same vibration problems that seem to turn up with all diesels.

The diesel power pulses are a problem when turning a propeller and so without a big damper the things seem to shake them selfs to bits.

I would put my money on the Lycoming FADEC mogas engine hitting the market long before a re-walmed SMA engine

Well, that is a 100% sure bet.

Reciprocating diesel aero engines are surely a blind alley?

The sensible way forward is for a small, turbine engine. The problem though would always be the cost.

In the future it is much more likely that small turbines will become a 'blind alley' except where the power requirements are so large that a more efficient prime mover cannot be used.

They are horribly inefficient and the justification for wasting that quantity of fuel is going to be very difficult to make for aircraft of small to medium size. They are also as you note very expensive so highly unlikley to devleop much further.

Diesels do offer the potential for much more efficient engines - but in aircraft simply making a diesel variant of an existing configuration is not going to work.

Try picking up the 'dual mass' flywheel fitted to virtually all modern diesel car engines - makes your eyes water - and they are there to ensure that the engine drives smoothly and does not trash the transmission.

If Deltahawk last the course they may be pointing towards the answer. Wilksch seem quite a way from it - finally re-designing the internals so that they can afford to actually make the engine. Most of the rest have fallen way the wayside.

Once someone gets a workable configuration then I'm sure others will follow.

Quite why TCM have decided to buy in the SMA 'technology' baffles me at the moment...........

I was under the impression that Diesel Air Ltd - Diesel Air Limited - who have handballed their project to the Americans.... namely, DeiselTech LLC - FTI Diesel Tech, L.L.C. - DAIR-100 - have an entirely workable and highly satisfactory engine design in the form of the opposed piston, twin crankshaft engine.

http://i44.tinypic.com/f1iqom.jpg

The DAIR engine principle has been around for a long time... Rootes made a successful truck diesel engine in the form of the 2 stroke, supercharged Rootes TS3. However DAIR's idea is simpler than the Rootes truck engine with its complex cranks to a single crankshaft.
I personally feel that some further development of the DAIR engine will produce a winner. However, they need to up the size/no of cylinders, to make it attractive to anything but LSA, as it stands at present.

TCM seem to be getting dragged kicking and screaming into the diesel market, and taking the lazy way out, by not designing up something new, revolutionary, and exciting... which is quite achievable in this day and age.
There are plenty of new technologies and designs that are competent enough to provide a vastly superior and technically advanced engine... but no-o-o... TCM are too conservative to even consider that approach..... :rolleyes:

When all's said and done, Packard had a viable diesel aircraft engine in 1929... and it would have still been around, if the chief engineer and promoter hadn't met a premature end in an aircraft crash. That, and the Great Depression, are about the only reasons the Packard diesel died... because when the designer died, the engine died with him.

At present, it appears to me that the Zoche,Thielert, and even the much-touted Austro AE300 still leave a lot to be desired, by way of improved design; simple, low-cost construction; and modest hourly running costs.

Diesels WILL be the way of the future in aero engines - their major advantages in superior performance at high levels, economy, simplicity, higher resistance to temperature extremes (once running), are all factors that make them the route to go down.
Don't forget, that at one time, diesels were sneered at, in trucks and tractors, and it was predicted they would never be able to produce a viable truck or tractor diesel. It did take over 2 decades... but Clessie Cummins showed 'em.... :)

Like I've been saying, the future has to be hybrid:

1. Drive aircraft with electric power.
2. Power them with fossil fuel primary movers until the power storage has been solved.

Just as an example - A rough running diesel engine without a flywheel to make it stable is no problem for a generator - it can be as rough as it wants. The combo of a generator and an engine is also less than a engine+flywheel+transmission, so it's not even a weight issue anymore.

Better still - get a free piston generator diesel and you can eliminate most of the weight for crankshafts and bearnings and housings:

Free Piston Power Home

Junkers did it in 1932 with the Jumo:
Junkers Jumo 205 - Wikipedia, the free encyclopedia

867Hp at 2,800 rpm for 595 Kilos weight 2 stroke diesel

I have heard said, that but for the advance in fuel technologies with high octane allowing higher compression ratios and supercharging of petrol engines that happened in the 1930s, that we would all be flying diesels like this now. This engine was up with the best in its day.

The Science Museum have an example - ask them why it is not on display!
Jumo 205http://upload.wikimedia.org/wikipedi...05_cutview.JPG


Jumo 205 cutawayTypeDiesel aero-engineManufacturerJunkersFirst run1930sMajor applications*Junkers Ju 86

• Blohm & Voss Bv 222

Developed fromJunkers Jumo 204