Piper Goes S/E Diesel.

[Ex FSO GRIFFO]

From Avweb...

"Piper Unveils Diesel Archer.


In what appears to be the major product introduction of the Aero show in Friedrichshafen, Piper Aircraft announced Wednesday that it begin marketing a diesel-powered Archer, the Archer DX. The aircraft is certified under an STC developed by Piper and Continental Motors and it will have Continental’s Centurion 2.0s, a 155-horsepower variant of the base engine developed by the former Thielert Aircraft Engines and acquired by Continental last year. The airplane is slated for delivery in the first quarter of 2015, according to Piper CEO Simon Caldecott, who expects it will create a new market for the company, rather than canabalizing sales of Lycoming-powered Archers. Piper see the DX as a global aircraft, but expects some sales in North America.

[Ozgrade3]

I cant see any flying school even looking at it.

Its costs $60,000 more than the standard archer, and the gearbox requires replacement every 600 hrs. It is also lower performance than the Avgas aircraft.

Sorry Mr Piper, you will have to do better than that.

Now if EPS did a 4 cylinder version of their flat 8, that might be a goer.

[onetrack]

Interestingly, there's some seriously different claims for this engine in the PA28.

One site say 22.1 l/h at a speed of 110 KTAS (70% power, 6,000 ft.), and a pretty leisurely climb rate to 6,000', of approximately 658 ft/min ... yet another says 18.11 l/h, with no speed mentioned (might be throttled back to 90kts?), and a more interesting climb rate of 830 ft/min.

A TBO of 1200hrs isn't particularly impressive - and there isn't too much to get excited about overall - apart from being able to rob a construction site for fuel, when you're stuck. :E

One also has to ponder the amount of stresses inside a pretty ordinary, automotive-based, L-4 design 2.0L engine, that's producing a constant 155HP, too. :suspect:

Technify Motors GmbH - News (http://www.technify.de/typo3/index.php?id=530&backPID=530&tt_news=1919&L=1)

Centurion 2.0 S | Aerojet Baltic (http://aerojet.cc/en/engines/centurion-20-s)

[27/09]

onetrack: One also has to ponder the amount of stresses inside a pretty ordinary, automotive-based, L-4 design 2.0L engine, that's producing a constant 155HP, too.

I'd have to agree. Interestingly the original 1.7 L Theilert engine (which these are a direct derivative of) produced 135 HP but due to reliability issues was replaced with the 2.0 l engine producing 135 HP. One wonders how reliable the 2.0 L engine will be at the higher rating of 155 HP?

Unfortunately the only market where these will be attractive is one where there is no Avgas what so ever.

[Wally Mk2]

I guess it's like everything we humans tend to do when it comes to change, we struggle mostly at the idea of change as we are a species of comfort & familiarity:-)
Took a while to educate the gen public towards diesel powered cars at first, noisy, underpowered & messy costing more. If you got the product on yr hands it was awful, greasy & smelly but now every man & his automotive dog are making diesels with outstanding results.

Give it time, that's all we have left these days, time to ponder about the good 'ole days:)


Wmk2

[VH-XXX]

It won't be a constant 155 hp, there would be a time-based limit. No engine as far as I know is approved to operate continuously at its' maximum horsepower.

155 hp is only 114 kilowatts, not an overly powerful engine however being diesel should give good torque figures. There are lots of 2 litre diesel cars and commercial vehicles out there pumping out figures higher than that.

[Old Akro]

Sorry Mr Piper, you will have to do better than that.

Piper are just utilising the engine that's available. Don't blame them for Continentals engine.

A TBO of 1200hrs isn't particularly impressive

If I recall correctly, this is a TBO that Theilert started with. The intention was to increase the TBO as engines approached that time in service. However, by then Theilert was in trouble and it didn't happen. I think I recall press statements by Continental that they will increase the TBO. By the time Piper launches the aircraft in 12 - 18 months things could be different.

155 hp is only 114 kilowatts, not an overly powerful engine

Its the torque that counts. Conventional avgas aircraft engines don't make impressive power either, but the specific torque of Continental / Lycoming engines is quite impressive. Look at the specific torque instead.

[Wally Mk2]

'XXX' I think you will find that yr comments re max power limits only apply for certain engines. The basic Lyc O320 for Eg can run flat out all day(in fact I think that's a req for running in a new donk, but don't quote me) providing it doesn't exceed certain parameters such as prop RPM Cyl head temps etc. I don't recall seeing a max power time limit in any of the basic machines I used to drive a 100 yrs ago:-)
Our resident engine guru 'Jaba' would no doubt be able to provide volumes of info regarding such engines:)

Wmk2

[43Inches]

The document provided states maximum "permanent" output at 155hp, I assume this would be another way of saying max continuous power.

From what I've read online the 135hp fitted to the Warriors reportedly "feels" like it's 135hp relative to the normal O-320 160hp. The basic weight is increased on the aircraft considerably and cruise performance down around 10%.

With an engine life of 1200 hours it would cost more including offsets of fuel costs to operate than the Avgas engine. It all depends on what happens at 1200 hours as well, overhaul, re-manufacture or replace? With the new O-360 you would get a couple of useful cheap overhauls out of it or a reduced price factory exchange.

[Ozgrade3]

Its not the TBO that is of concern, it is the gearbox 600 hr gearbox inspections .....in Germany that would kill us. We do 18,000 hrs a year.

In interesting article from 2008, it doesn't seem much has changed.

Thielert's Flawed Economics (And Why the Company Knows It)

By Paul Bertorelli | May 29, 2008

The war of words between Diamond Aircraft and Thielert Aircraft Engines continued this week, reaching a low arc at the Berlin Air Show. Bruno Kubler, who heads the firm overseeing Thielert's insolvency, used the forum to blast Diamond for what Kubler claimed was a disinformation campaign aimed at making Diamond customers "massively insecure." Why Diamond would want to do this is baffling, since it has on its hands some 800 distressed owners of airplanes equipped with Thielert diesel engines.

Diamond is engaging in a degree of brinksmanship, but given what appears to be Thielert's disastrous economics, who can blame them? The usual strategy in situations like this is for the companies involved to play footsy behind the scenes to work out a deal acceptable to all of the distressed parties. Unfortunately, Kubler's numbers appear to be so far off the mark that I don't see how this is possible.

This week, I took some time to put a sharp pencil on how Kubler's prices will reshape the economics of the Thielert Centurion line. I developed this data on my own from the Kubler-derived prices and my totals don't precisely agree with Diamond's, which it released in Wednesday. But my research does confirm that Kubler's prices raise the engine operating cost about six fold.

Further, the new prices raise the direct costs of operating the diesels to four or five times that of a gasoline engine. In fact, minus the fuel, Thielert diesel costs outstrip those of operating a turbine engine, such as Pratt & Whitney's PT6 or even a small jet engine. Why? Thielert still requires 300-hour removal and inspection of gearboxes, plus numerous other expensive parts. Furthermore, all these components have to be shipped back and forth to Germany for service and inspection. Shipping alone comes about $600 per inspection event.

This onerous maintenance load was one complaint owners had about the Thielert 1.7 Centurion. Thielert responded to this with the new-and-improved Centurion 2.0, which would double the gearbox inspection interval to 600 hours and increase the engine's time between replacement (TBR) to 2400 hours. But Diamond and owners complain that the documentation doesn't support this and they're still required to do the 300-hour gearbox removals. This is roughly the equivalent of yanking the transmission out of your car every 3000 miles and sending it back to the factory. Moreover, if the 2.0 really is a 2400-hour engine—and no one seems to know if it is or it isn't—the entire thing has to be shipped back to the factory for inspection at 1200 hours, costing $4000 in shipping alone. One flight school with three Twin Stars told me that it's probably more sensible to just replace the engine at 1200 hours rather than shipping it back to Germany.

As the late Everitt Dirksen famously said, you're talking about real money here. When you add everything up, Kubler's numbers just don't make sense. The rational way to examine this—if there's anything rational about any of this—is to compare the lifecycle costs of a Thielert 2.0 against a Lycoming at time of replacement. The numbers follow here. One point: On many Thielert parts, owners have the choice of new or inspected, which is basically a used component within service limits. The parts listed below aren't elective replacement—you have to replace them to keep the engine serviceable.

Cost of replacement engine: $51,150 Inspected gearboxes (3): $23,500 ($47,118 new) Shipping: $1800 High pressure pump: $1412 ($5550 new) Rail valve: $651 Feed pumps (3) $1255 Clutch (3) $1443 Clutch shaft (3) $1200 Alternator: $1426 ($2985 new) Scheduled labor $1800 Unscheduled labor $5000 Total: $90,637 Hourly engine (1200 basis): $75.53 Total hourly with fuel: $101.03

For unscheduled labor, I used 10 percent of the cost of the engine, based on owner surveys we've conducted. These numbers, by the way, represent the absolute best case and assume that no additional parts other than those scheduled will be required. Further, owners complain that the labor for gearbox changes is higher than Thielert said it would be, but I've used the lower number anyway to give Thielert the benefit of the doubt. But these numbers are almost certainly too low.

If new parts rather than inspected parts are used, the total comes to $119,952 or $99.96 for the hourly engine reserve or, when you add in fuel, $125.46. Oh, and double that for a DA42 Twin Star. This total may be sustainable in Europe and the U.K.—although I doubt it—but it's a non-starter in the U.S. But remember, the Centurion diesel is a world engine, not a U.S. engine.

Here's how a Lycoming IO-360 compares. It's apples to apples, because this is the engine Diamond uses in its DA40 Star, which also has a diesel option.

Lycoming IO-360 REM

Cost of replacement engine: $25,160 Top overhaul at mid-time: $8000 Unscheduled maintenance: $5000 Total: $38,160 Hourly engine (2000 hours basis) $19.08 Total hourly with fuel: $59.58

For the Lycoming comparison, I added a top overhaul that this engine is unlikely to need and I used unscheduled maintenance of 20 percent of engine cost, twice what I used for Thielert. Even with this lopsided comparison in favor of the Thielert, the Lycoming's costs are a little more than half of the Thielert's. They begin to break even at an avgas cost of around $9 a gallon. But, of course, if avgas costs that much, so does Jet A, so they never break even.

In some ways, the better comparison is between the Thielert Centurion and the Pratt & Whitney PT6, say the dash 114A used in the Caravan. It's a 675-HP free turbine engine with a 3500-hour TBO and overhaul costs in the $85,000 to $130,000 range. The Aircraft Bluebook Digest recommends a $37.14 per hour set aside for the PT6, or half what it takes to the fund the Thielert Centurion and without the onerous 300-hour inspections.

How could the industry have missed such breathtakingly screwed up economics? The companies involved missed it—Diamond and lately Cessna—missed it and we in the press (including me) absolutely glossed it over. In 2005, I visited Thielert's factory in Lichtenstein, in the former East Germany, and we went over the economics of this engine. I never got a clear explanation of how the power-per-hour pro-ration based on a 2400-hour engine was going to work. It seemed too expensive. How was Thielert going to make a go of it long term with all those built-in service costs? Persistent dumb ass questions led me to understand that the initial engine was a loss leader funded by investors who thought the model would turn the corner with sufficient volume and, once the engine had proved itself, the inspections would go away and TBO would increase.

They haven't. And that's what's killing this engine, more than anything else. Shipping perfectly good gearboxes back and forth to Germany is lunacy, as is removing them from the engines every 300 hours. Owners I've interviewed have told me there are problems with clutches, but the gearboxes themselves have proved durable. There's good evidence that this is true, because Thielert offers an "inspected" gearbox for half the price of a new one. But half price is still $7800, plus shipping, and you need to do that three times to get to the Centurion's tender 1200-hour TBO. Seventy-eight hundred bucks to inspect a gearbox? It's an aluminum case, some bearings and a couple of gears. How can that require $7800?

In my view, the inspections were probably built into the model not just as a prudent and admirable step toward proving durability, but also as a profit center to fund the rest of this engine's expensive recurrent maintenance needs. Logically, there's nothing wrong with that concept, as long as going forward, the customer benefits from the proven reliability and cost decrease.

Oddly, both Thielert and Kubler seem to be aware of this, but maintain that Germany's bankruptcy laws force them to run the company on a basis that shows no loss. This morning, Thielert spokesperson Christoph Moller e-mailed me this note:

"At the moment, due to German insolvency law, Mr. Kubler cannot produce any losses and must ask Thielert's clients for prices which meet the company's current expenses. We know, of course, that the new prices for replacement and inspection of parts are a burden for many of our and Diamond's clients. As you know, Mr. Kubler's aim is to find a long-term investor who will provide significant investments in order to push forward the Thielert engine technology which in fact is the future of the aircraft engine industry. To ensure long-lasting relations to his clients this investor will presumably establish a sustainable warranty and guarantee scheme which will improve the current situation significantly. There is a great possibility that this will include considerable efforts to advance Thielert engines especially in terms of prolonging the engines lifetime which in fact is not where it should be at the moment. This will reduce the inspection times and, by this, the costs for owners considerably then."

I take Moller's point, but it's difficult to see how this will make the business viable. In essence, the message to customers is this: pay us five to seven times what you expected to pay and, if we show no losses, we can turn this thing around and you'll maybe pay less later...if you don't mind buying expensive engines without warranties. To me, this looks like a negative feedback loop. The more you input rising prices, the less revenue you generate and the more you have to raise prices until a single customer pays $4 million for a gearbox and clutch. (Warranty extra.)

And if Thielert hopes to find investors to fund a business running on these rules, they'll need nerves of steel and be willing to pour in a pile of money for several years just to gain of glimpse whether it can be profitable. It seems unlikely that customers will stand by and fund what I view as a fiasco, nor should they be expected to. Thielert and Kubler can blame German bankruptcy laws if they wish, but the current strategy seems to serve no one—not creditors, not customers and not the industry.

On the other hand, maybe those of us who think that a Twin Star owner will balk at paying $180,000 to take a pair of diesel engines to 1200 hours are the delusional ones. Kubler tells us owners are "relieved" to know that parts are once again flowing. For some twisted reason, this reminds me of the old Woody Allen joke about the brother thinking he's a chicken. "Why don't you call him on that?" asks the shrink. "I would," says the straight man, "but I need the eggs."

Maybe those 1200 or so Centurion owners need the eggs, too.

[OZBUSDRIVER]

My money would be on a variant of Subaru's EE20. Just a few more cubes and it would be on the money.

[megle2]

That's running at ROP isn't it

[Old Akro]

My money would be on a variant of Subaru's EE20. Just a few more cubes and it would be on the money.

Goodluck getting a common rail injection system certified.

If this is the Piper diesel engine, there is no gearbox:

Continental Launches Diesel Program | Flying Magazine (http://www.flyingmag.com/news/continental-launches-diesel-program)

[UnderneathTheRadar]

My money (literally) is with these guys:

Testing (http://www.eps.aero/EPS_website_2013/Testing.html)

350Hp flat 6, engines certified to run at 85% all day long. Only problem is that they have orders for 1000's already in the queue (aviation - but probably not as we know it) (and yes, they will be geared but the principals in the company are primarily from gearbox backgrounds).


UTR

[onetrack]

Ozbusdriver - Good article that gets to the nitty-gritty, and exposes the deception.

I have to disagree with Wally Mk 2 - diesel cars are not the huge financial advantage they claim to be, the same as in aviation.
A diesel is vastly more expensive to purchase and diesel fuel costs around 20-25c more per litre. A diesel car has no advantage whatsoever in short-trip city operation.
Diesels perform best at moderate RPM's, and at a steady RPM. Constant speed fluctuations and high RPM's see diesels advantage evaporate rapidly.

Diesels are a much longer life engine - but it's at the expense of much higher build cost, due to expensive components such as fuel injector pump and injectors - and a need to have heavier, more robust components to withstand the much higher compression ratio, and the vastly extended period of high combustion pressures.

You're on the money with the Subaru. They have an aviation design origin for a start. A flat engine design is ideal for aircraft, the crankshaft weight is substantially reduced and counterweights are unnecessary.
However, water cooling is an unnecessary weight burden - air cooling works just fine, particularly where weight reduction is crucial.

The avgas problem isn't going to go away, we need a basically simple, new, lightweight, efficient design, GA engine in the 100-200HP range that runs on JetA1 or diesel, and doesn't have horrendous O/H or repair costs - and I'm amazed that no-one is putting some major effort into producing the answer.

I feel a combination of newer technologies (such as Mazda's SkyActiv-D low-compression diesel design, coupled with flat, air-cooled design) - combined with other new engine weight-saving technologies (composites, new alloys), is what is needed to produce the affordable, efficient, new JetA1/diesel aviation engines we urgently need.

[Old Akro]

diesel cars are not the huge financial advantage they claim to be, the same as in aviation.
A diesel is vastly more expensive to purchase and diesel fuel costs around 20-25c more per litre. A diesel car has no advantage whatsoever in short-trip city operation.

Firstly, you need to recognise that Australian diesel pricing is different than most of the rest of the world. The economics of diesels are different in Europe.

10 - 15 years ago, most automotive engine development effort went into diesel engines. Now its small capacity turbocharged / supercharged petrol engines. The current belief is that petrol engines can be made more efficient than diesel.

There is even development work going on at the moment with compression ignition petrol engines.

A lot of the initial advantage of diesel was due to emissions legislation. But now that emissions regulations have been brought in to apply to diesels a lot of that advantage has eroded.

A common feature of all the new technologies is high levels of computer control. I really struggle seeing that being accepted by aviation regulators.

Australia is not getting the best of the new automotive engines. Partly because we have no policies to promote low emissions / efficient engines (eg registration & tax incentives) and partly because we are nearly alone in the world in not having a roadmap for future fuels. So, the car companies have no certainty of direction so we tend to get "lowest common denominator"engines.

Have a look at the International Engine of the year awards if you want to see some really interesting technology.

My bet is that in 10 years we'll see less automotive diesel engines, not more.

[VH-XXX]

The diesel price is irrelevant to aircraft in Australia anyway... You use JetA1 !

I drive a BT50 3.2 litre 5 cylinder turbo diesel dual cab. I get sub 8 fuel economy on average and sub 7 on a long trip out of town, down to as low as 4.5 lp/100 coasting into the city at 80kmh down the freeway. You won't ever get that in a petrol equivalent with the power and torque of my diesel.

Diesel in Melbourne is within a few cents of petrol most of the time and was this week at 1.42.

[Andy_RR]

The whole diesel aero engine saga is a sorry tale of botched design, derailed commercial progress and a simple lack of economic payback for most solutions.

For the last 50 years or so, the GA industry has supported two main aero engine manufacturers delivering relatively simple products. How is it going to support a bunch of small purveyors of complex diesel engines? The honest truth is, it won't, because the (shrinking) industry isn't big enough to support even one new player. If Europe, China and India open up their skies to more GA and private operations, it may change the economics, but don't hold your breath. Put simply, diesel aero engine economics don't add up because of volume - that's all.

In my opinion, there has only been one technically promising aero diesel engine so far, which is the Wilksch Airmotive WAM-120. Unfortunately for reasons far from explainable, the commercial direction that WAM seems to have taken has pretty much destroyed the potential of the market adopting this engine or more powerful derivatives of it. It is, in my opinion, one of the best near-term, low-risk design concepts out there. The designer Mark Wilksch has published a paper (http://papers.sae.org/2011-24-0089/) demonstrating the theory that a DI version of the same engine could be pushed to 150hp and offer a substantial fuel consumption benefit to boot. All this for an engine that is weight-competitive to an O-235! That would be impressive!

[Ozgrade3]

http://bmepinc.com/AEHS%20presentation%202012%2005%2008.pdf

[Ultralights]

slightly off topic, my little diesel shopping trolly commuter..

4.7ltrs/100km on the open road, 5.1 around town, 1.6 ltr with 280Nm torque. equiv performance of a V6 medium sized car. especially on the hwy. 1800 rpm at 120kph, right at peak torque.

be a long time before petrol engines get those torque figures with that fuel burn.

as for aircraft, the Pipistrel Virus, 147kts cruise buring 15ltr per hour. sure its only 100 Hp, but maybe just some more modern technology in our current aircraft engine design might be the key? electronic ignition? How many cars have aluminium intake manifolds now? how about fuel rail direct injection as opposed to the old fashioned spider system currently in use?

Rotax has proven that magneto less electronic ignition can be reliable in an aircraft application, not to mention water cooling, dry sump setups, why not 4 valves per cylinder?

there are a lot of tried and proven efficiency upgrades that can be done to the base current design engine that i think would improve economy significantly before we need compression ignition powerplants.

[Andy_RR]

http://bmepinc.com/AEHS%20presentation%202012%2005%2008.pdf

Ah, Bill Brogdon's opinion on the subject! It's an interesting one, and a likeable guy, but it's hard to take too seriously from someone who pissed away one of the few opportunities to design a clean-sheet aero diesel, admits that it failed because of "too much weird" and then proposes yet more weird for his "solution"

What's with his screwed up cylinder barrel design? Head gaskets are doing fine for the gazillions of diesel engines out there. And through-bolting as he proposes is heavy-heavy-heavy! Four valves-per-cylinder is completely unnecessary and arguably an impediment to good combustion, cylinder head structural efficiency and cooling.

As Bill demonstrates admirably, it's easy to design a lot of unnecessary hurdles into your diesel engine...

[Andy_RR]

as for aircraft, the Pipistrel Virus, 147kts cruise buring 15ltr per hour.

Have you sat in one? Impressive numbers, but they're sized for dwarf pilots. I guess they were concentrating on keeping the CdA down...

[Ultralights]

yep i have, and thats why i dont own one. a bit to cosy for my liking..

[Rich-Fine-Green]

I would guess the major GA Countries are not the market Piper has in mind for the Archer DX.
Therefore any pros vs cons argument is a bit pointless.
Most of the planet has either little or no Avgas.
The Archer DX will be the ideal (and only) choice to most of the emerging world.

[VH-XXX]

The Dyn'aero Sportster does 150-160 on a 100hp Rotax 912. That is efficiency for you, but it's micro sized.

Diesel / JetA1 is the fossil fuel for the future or at least until the big jets stop using JetA1.

[27/09]

VH-XXX: There are lots of 2 litre diesel cars and commercial vehicles out there pumping out figures higher than that.

But they're not running at 75% power day in day out and not going to 100% power every time they start moving.

The 1.7 litre Thierlerts were unreliable at 135 HP. That's why they stated fitting 2.0 litre 135 HP variants. The 2.0 litre ones at 155 HP are approaching the same power to cc ratio as the 1.7 litre ones were at 135 HP. I'd say it's reasonable to presume reliability will suffer for the 155 HP 2.0 litre variants. So far as I know the 2.0 litre 155 HP version hasn't been used in any numbers yet.

The gear boxes are another issue. Gearboxes on engines of less than 9 cylinders producing much more than 100 HP have generally never been all that successful/reliable.

No doubt about it diesel or JetA1 is the way to be heading, but no one has yet built a successful diesel GA piston engine, much less one that is based on an automotive engine. By successful I mean one that can compare to the likes of the typical Lycoming or Continental for cost, power to weight and reliability/TBO.

[Andy_RR]

What makes you say the 1.7's were unreliable?

I'm pretty sure they changed to a 2.0L block of their own design because of supply issues with MB - always a problem when using short production lifespan auto parts.

As far as the gearbox reliability issues go, I have heard from an ex-Thielert engineer that the 300hr, now 600hr inspection was a bit of a con and amounted to not much more than a poke around with a borescope through an inspection hole before sealing back up and shipping back to the customer. They also mentioned that the military/UAV derivatives were much more advanced than the GA version because the re-certification issues were a financial burden the product couldn't bear, despite the leaps and bounds made in the military applications of essentially the same engine.

[27/09]

AndyRR What makes you say the 1.7's were unreliable?

I understand an operator here had more than a few issues with the 1.7 litre engines and has re-engined with the 2.0 litre engine. Admittedly second had info but I think it's correct.

Also I seem to remember reading the reason for the bigger engine was to improve reliability.

[skkm]

What makes you say the 1.7's were unreliable?

I understand an operator here had more than a few issues with the 1.7 litre engines and has re-engined with the 2.0 litre engine.

At least one large DA42 operator in Australia re-engined their fleet with (L)IO360s after quite a number of IFSDs.

[Two_dogs]

VH-XXX

It won't be a constant 155 hp, there would be a time-based limit. No engine as far as I know is approved to operate continuously at its' maximum horsepower.Just for the record ...
Narrow deck Lycoming IO-540

POWER PLANT

1. ENGINE
a) Manufacturer Lycoming
b) Model IO-540-E1B5
c) Fuel 100/130 Octane (Minimum grade)
d) Oil grade Per Mil-L-22851. See Lycoming Service Instructions
e) Engine Operation Limitations
CONDITION --- --- BHP--- RPM--- TIME
Takeoff -------------290 ---2575---- No Limit
Max cont at SL -----290--- 2575---- No Limit

[VH-XXX]

They must have plenty of margin built in there if they certify to run flat chat 24x7.

[27/09]

VH-XXX They must have plenty of margin built in there if they certify to run flat chat 24x7.

The O -320 is also good for FT 2700 max continuous. So it's not unusual in the aircraft world to have unlimited full power operation.

[skkm]

Some IO360 aircraft I've flown have no time limit on full throttle/2700rpm.

[Wally Mk2]

As I mentioned in a previous post there being no time limit as far as I am aware regarding basic piston engine power plants & I would imagine that this is because the manufacturers would have no way of controlling any said limits once it left the factory anyway. I mean there would be a lot of pilots out there whom just run the engine anywhere within it's operating range inc full power all day everyday with minimal care.
These power plants would have been tested well beyond their normal operating regime to gain certification anyway.
Bit like the SWL of a crane, it would have been tested to destruction to find it's max limits them probably reduced by half.


Wmk2

[Andy_RR]

At least one large DA42 operator in Australia re-engined their fleet with (L)IO360s after quite a number of IFSDs.

I don't think in-flight shut-downs or reliability issues had anything to do with that it was only 1.7L. Most of the rumours I heard were to do with the electrical/FADEC system

[edsbar]

Cessna took on the Thielert as a production engine 172TD in 2008, a dozen went to the Iraq Airforce. In the mean time Thielert went broke and the program was abandoned.

http://web.archive.org/web/20080308232728/http://se.cessna.com/skyhawktd_brochure.pdf

As Cessna now have the 182JT-A and have not re released the 172TD it makes you wonder.

Having flown a 172R with the Centurion I can tell you it's a dog.

STC's to fit the 135 hp Centurion engine in the Warrior have been around since around 2005, Thielert would not offer the 155 hp version into the retrofit market trying to keep it up there sleeve to induce the OEMs with more HP.

Gearbox, clutch and fuel pump require frequent replacement. The 2,400 TBO has been promised since around 2005. This was to be paid pro-rata on the 1,000 hour engines but as Thielert went tits up many owners were left high and dry.

Yes common Rail diesels are very reliable and efficient however to get the power to weight small diesels had to be used and pumped up. The base Thielert in its previous Benz spec is only about 60 kW and will do millions of Kms, nearly double the output and boost and the reliability goes out of the window. In the car it cruises at probably less than 30 kW. Diesel has excellent lubricity so the HP fuel pump survives in the automotive world on Jet A1 the pumps just don't last, these things run nearly 20,000 psi of fuel pressure between the HP pump and the rail and the by product is heat, having flown the Simpson with the fuel temp in the red I can tell you this is also a major concern.

[skkm]

I don't think in-flight shut-downs or reliability issues had anything to do with that it was only 1.7L. Most of the rumours I heard were to do with the electrical/FADEC system

You're right – and the diesel 42s had 2.0s. Still relevant to the discussion of overall reliability.

[edsbar]

http://web.archive.org/web/20080308232728/http://se.cessna.com/skyhawktd_brochure.pdf

[edsbar]

FTAs 6 x DA42's had 1.7 Thielerts, they were removed after lack of confidence due to 13 un-commanded power losses as well as replacements due to head gasket problems. The aircraft sat for 18 months until the Lycoming retrofit was carried out.

Ask anyone that has had one if they would buy another .....