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Diesel V8 flys
In all of the discussions around various diesel alternatives, my money has always been on these guys. Up until now have very much flown 'underneaththeradar' but now have something to show for it all.
First test flight last week in a Cirrus with Dick Rutan at the controls. This one is the game changer for commercially operating big twins and remote area 206/210s. EPS | A Revolution in Flight |
Looks a very nice setup. It appears even the radiator is contained within the engine cowl, it looks like it's fitted on top of the engine.
Perhaps the new metallurgy being used is the quantum step required to make a leap forward in piston engine aircraft design. Having said that the website is a bit light on specifics, so it's hard to make a really informed assessment. Certainly looks as if it could be a viable replacement for the TSIO and IO 540 and 520/550 engines. The only concerns I have are: 1: What size market do they need for it to be a commercial success? 2: Will it fit inside existing cowls using the same mounting points on the firewall? Do they intend to make an engine for the masses, by that I mean the O 320, IO 360 market. |
Purely my guesses:
1. Yes - their main market is actually looking like drones - predominately for the US DOD. 2. It took them a few weeks to attach it to a Cirrus which seems pretty good for the first time it's been near an aircraft - if you look at the various test videos you can see it's usually mounted on aircraft-type mounts and it's been vibration tested by Hartzell - again on aircraft-type mounts. It has been specifically engineered to fit inside existing cowls (they have done this by literally measuring a variety of engine bays). Remember this has been engineered from ground up as an aircraft engine and not adapted from another application type. They are planning to manufacture about 500 year. At the moment, the first available slots in the schedule are in 2017 assuming it gets STCd next year. All slots ahead of that are gone. Whether or not its a replacement for the smaller market - I suspect not. It will be expensive (the idea being that it pays for itself in longer TBO, lower fuel consumption and/or operating at max continuous whilst not at full rich) and so probably not an option for aircraft operating less than a couple of hundred hours a year. Once proven though - it could be scaled down - the current unit is capable of 450HP (I think?) and so will be de-rated for many applications anyway. |
The website is a beautifully crafted piece of advertising. Nothing wrong with that of course, but it's in the same league as a glossy brochure for any new product. Heavy on promises, light on evidence.
TBO 3000 hours is interesting. If it actually achieves that, it could become very popular. Vibration and fatigue-related issues prevent that kind of TBO with other diesel engines - particularly Diamond's otherwise very good engine. This leads me to the question: what do they know, that Diamond don't? Perhaps something, perhaps nothing... |
No mention of weight comparison. I suspect that with an iron block and eight steel pistons, it's not going to be a pretty number.
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Andy RR: No mention of weight comparison. I suspect that with an iron block and eight steel pistons, it's not going to be a pretty number. EPS | Reliability, Safety & Durability The Graflight V-8 engine derives its name from this key component. CGI is an advanced material that offers extraordinary strength and fatigue resistance, allowing CGI blocks to be made lower weight than equivalent strength aluminum blocks. It was first patented by a German scientist in 1965, but in 2008 an American engineer, Dr. Steve Dawson, first wrote about using CGI in modern diesel engine cylinder blocks and heads. EPS CEO Michael Fuchs was among the first to employ CGI in the automotive field in America. It has since set the standard in the industry because its high tensile strength provides extraordinary durability. Aluminum aviation crankcases often crack from fatigue – a common point of failure in GA airplane engines. But the Graflight V-8 block offers incomparable durability, and will be able to serve far longer between maintenance overhauls as a result. |
I think the part that would concern a lot of operators, especially Bush Operators is the level of Electronics that is seems to employ to control it, I know a few Engineers that would bring up this point straight away. The more complex you make something the more there is that can break down and the more parts you need to keep instock to keep it flying or get it back in the air! One of the reasons so many people think of Diesel Engines as being a great introduction to their Aircraft would be because of their reputation as being reliable engines elsewhere, but I know from a few Diesel Mechanics that this is because of their simplicity.
Would the savings in fuel that it produces outweigh the extra costs of maintaining the more sophisticated electronics it employs? I always felt simplicity was why so many of the engines used over the last 50 years are still the ones we use today. |
Ixixly: I think the part that would concern a lot of operators, especially Bush Operators is the level of Electronics that is seems to employ to control it, I know a few Engineers that would bring up this point straight away. The more complex you make something the more there is that can break down and the more parts you need to keep instock to keep it flying or get it back in the air! One of the reasons so many people think of Diesel Engines as being a great introduction to their Aircraft would be because of their reputation as being reliable engines elsewhere, but I know from a few Diesel Mechanics that this is because of their simplicity. Would the savings in fuel that it produces outweigh the extra costs of maintaining the more sophisticated electronics it employs? I always felt simplicity was why so many of the engines used over the last 50 years are still the ones we use today. Will this engine would run into the same problem as the Thielerts where a loss of electrical power means an engine failure. Remember the double engine failure in Germany of the DA42 when the gear was retracted after a jump start. I wouldn't want to fly a Thielert engine any further from a suitable landing area than the battery endurance. |
Originally Posted by 27/09
(Post 8475500)
Apparently the iron block isn't heavier according to their blurb.
The cynic in me reckons if the weight was good news, they'd be shouting about it from the treetops. They're not, so I'm expecting the bad news to be concealed as long as possible. |
Quick peak at the graphs and a BSFC of 0.30 is pretty darn good, if it is for real.
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'Ixixly' that's the exact reason why more so called modern engine types/designs aren't flourishing in the outback, too complex, nothing like simplicity when yr out there in the bush with just bush parts & bush Mech's about. Any savings on fuel would be instantly lost if one of these things stuck you up in tim-buck-too!
These sorts of power-plants have their uses for sure as DOD etc but doubt very much it will be in the front of an old crusty 206 anytime soon. Wmk2 |
Despite the smooth presentation and the big talk-up - I won't be holding my breath about the takeover of aviation power by this "radical" new engine.
1. Lots of "new" and "huge step forward" designs have been produced over the decades and only a couple have actually been placed into production - and there's been no major breakthrough as regards a widely-acclaimed and widely-used "new engine". 2. The specific "advances" mentioned in the technological features of this engine are not really advances at all. CG iron in blocks and steel pistons offers minimal advances in technological improvement. 3. A V8 engine design is not a radical advance in design, either. I'll get excited when I see some truly radical advances in metals, technology and engine principles. |
1. Electronics are more reliable than magnetos provided they are designed and constructed properly with sufficiently derated components. I would have thought Bosch has mastered this. As far as I know an integrated circuit doesnt wear out.
2. Quick google of CG iron shows that it may be just the "breakthrough technology" necessary for diesel aircraft engines.: (a) five times better fatigue life than aluminiun. (b) Solves engine design problems: All V-engines share a common design weakness, as there is a lot of flexing in the V-area between the cylinders when it is under power. CGI strengthens this physical area considerably. Audi is an early user of CGI material in its power production. All Audi 2.7L, 3.0 V6 and 4.0 V8 diesel engine blocks are now being made of CGI. The V8 main bearing caps are also cast in place, laser etched and then fractured for an absolutely perfect fit after bearing sizing. The BMW Series 7 V8 engine was also cast in CGI. Hyundai, currently the number seven automobile company in the world, and rising, has V6 CGI blocks scheduled for full series production during 2006. Its World Rally Championship car (1997-99) also had a CGI engine block. The new 2005 Jaguar 2.7L Ford/PSA V6 diesel is made of CGI. At 445 pounds fully assembled, it is lighter than a comparable aluminum diesel. Even the new James Bond will soon be driving a diesel powered Jaguar R-D6. Other CGI Users [back to top] Nearly all NASCAR teams are running CGI engine blocks, or blocks with CGI liners. These liners are usually plated with a hard-surface coating. It has been reported that some NASCAR teams are able to run a whole season without having to re-bore the blocks. The Toyota Racing Development (TRD) campaign has the #12 Craftsman pick-up truck. This 5.8L V8 CGI engine block weighs 89 kg (195 pounds), has a 3 mm (0.118 inch) cylinder wall thickness and produces 650 hp (83.5 kW/liter). For comparison purposes, standard CGI diesel engines will soon be producing 66kW/liter. General Motors’ Opel subsidiary has used CGI for the engine block of its 2.5-liter V6 DTM racing engine. Theoretically, a CGI engine block can be fabricated lighter than an aluminum block for equal power densities. A recent 500cc Suzuki Grand Prix motorcycle engine had a crankcase fabricated from CGI. Nothing is put on these racing machines that would pose any kind of a weight penalty, and this is an extreme example showing the real potential of CGI applications. |
I had a Continental in my last aircraft with Fadec. I can't say it was the best thing since sliced bread having those electronics. If anything was wrong like a plug or something similar, a warning light comes on and you have no idea what's wrong until the LAME drops in. It was getting rather frustrating in the end.
If they can have a good reliable EMS included with it that accurately reports what is wrong, rather than just a warning, then great, it will be a good thing. |
Ford Territory V6 diesel is also CGI. A common engine used by a number of manufacturers, Jaguar, Landrover, Peugeot. Citroen.
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Does it have a gearbox?..... or is the prop spun directly?
From the website picture, it looks to be directly driven. If so, a major drama with previous diesel aero engine design will be averted. Wow A V8!! I bet it will sound great on take-off! I still have lasting memories of the Queen Air with the excalibur conversion, and the Vickers Vimmy replica setting off from here. And then there is the claimed 40% reduction in fuel burn! That will nearly compare with running LOP :E |
All the talk is of fuel savings, extended TBO, maintenance savings etc, nothing about performance comparisons? That thing would have to be fairly light I imagine and I didn't think it was ever going to get off the ground!
Maybe initial test flying means you just baby it along? Thats probably the reason. Still, they must have some idea of performance against standard engines. |
That will nearly compare with running LOP I have several years' experience with running Diamond's product. Granted, we had LAMEs on site. But they couldn't repair anything electronic; all they could do was replace bits. It was the mechanical side of things that let down the Diamond product in the early years, not the electronics, which were very reliable. Will this engine would run into the same problem as the Thielerts where a loss of electrical power means an engine failure. Remember the double engine failure in Germany of the DA42 when the gear was retracted after a jump start. I wouldn't want to fly a Thielert engine any further from a suitable landing area than the battery endurance. Basically, an electric engine requires a digitally valid voltage (e.g. more than 5V, actual voltage I don't know) supply at all times to the FADEC. Now when you retract the undercarriage in a light aircraft, the hydraulic drive motor will briefly take 100% of both alternators' output. "Briefly", in this context, might mean as little as a tenth of a second. If you have chosen to take off with a known duff battery, the battery can't maintain system voltage over this short period. The FADEC will see a loss of voltage, and will sense that as a "shut down" signal. Game over, if you're at 100' after take-off. The cure, for Diamond at least, was to state in the Limitations section that the engine (second engine for twins) had to be started on battery power. If you couldn't do that, the battery was not fit for flight. Of course, pilots ignored that warning, so now there are, in Diamonds at least, a couple of camcorder batteries (I kid you not!) hardwired to each ECU. To maintain voltage in the event of above-mentioned pilot's actions. |
My FADEC managed Continental had a second battery fitted and if you lost an alternator you were only going to last as long as the battery did for which the timeframe was clearly documented in the POH. Not much different really to the diesels. The FADEC battery was about a third of the physical size of a small car battery or perhaps about the same as an Odyssey 300, so not big.
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Sunfish,
Electronics while being very reliable, do fail, they may not "wear out" as such but components fail, resistors can burn out electrolytic capacitors dry out, dry joints occur. Sadly more and more these days they are not field repairable, unlike the humble magneto. Oktas8 Yes, I was aware that the DA42 had been operated outside the manufacturers recommended procedures. I used that incident to prove that lose of electrical power no matter how it might be caused can result in an engine failure. Unlike the old tech Lycoming or Continental engines. Andy RR You may well be right about the weight. They do talk about weight savings, however it appears they are talking about the weight gains due to the reduced fuel burn and the need to carry less fuel for a given mission. |
27/09
Yes, you're right about a loss of power. I'm thinking that statistics are on the side of electrics though. Ignoring all the failure modes common to both engine types (cylinders, crankshafts, carburettor/fuel rail etc), which is more likely to fail: a pair of magnetos with associated drive shafts, wiring and plugs, or a pair of FADECs with associated electrical supply and wiring loom? I guess the aero-diesels are still too recent an invention to answer that question here. But long term, my money is on solid state electronics over mechanical parts, any day. For the Diamond in particular to have a power failure these days, post-power-loss-incident, you'd have to lose the alternator(s), lose the main battery, then lose the dedicated FADEC backup battery. That's a lot of failures! I would imagine that other manufacturers will probably learn from failures of the past, and have similar levels of redundancy. But as I said, it's not the electrics that tend to fail on these things. It's the mechanical parts, including the cylinder head gasket (very high cylinder peak pressures). I watch this new CGI thing with interest! |
Back in 1963, I had a BSA motorcycle, equipped with an Alternator, courtesy of Lucas, AKA "the Prince of Darkness" (Though their official slogan was "King of the Road")
The rotor contained permanent-magnets, therefore self-exciting, Rectification bt Selenium, superseded rapidly by Cilicon semiconductors. Aswitching arrangement Changed stator-coils from parallel to series configuration, according to switched load....an emergency position allowed kick-starting with a totally flat battery. as the battery voltage increased, it opposed the alty output and caused misfiring...a crude and effective system.....I must add,this was 6-volt. the later 12-Volt systems had a Zener Diode to dumpsurplusoutput. A very simple, robust and cheap item to incorporate into an aircraft engineand the whole caboodle canbe internal! Battery-system could still be used , via blocking diodes...with a built-in alty and twin FADECs, such an engine should be far more reliable than the magneto-fed Lycosaurus breed. The cost of electronic components, at these power-levels, is buttons. As a previous poster stated, components could be derated for longevity and Ireckon youcould probably double the power-handling capability for less than $5 AUD per circuit-board. For the cost and weight-penalty,there's no reason I can think of, why every engine should not have a spare, ready-mounted FADEC unit...in case of a failure "out bush" simply swap the plugs to the spare unit.......If a magneto goes sick, even an experienced fitter will struggle if, say,the points-spring has cracked or the condenser gone U/s. Time to move into the 21st.Century! |
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Continental Motors is pursuing the CI (diesel if you must) route.
TD300 is TCd in FAA land, and they have bought the Thielert engine rights. |
Unlike a Turbocharged avgas burner, you will not get flying behind one, and I do not imagine many folk would be keen either when they fly over high country like the west of the USA.
Anyone know why? |
Jabawocky - Yes, because there's a risk of a diesel engine with a set fuel injection ratio overheating at very high altitudes.
The turbocharger speeds up substantially (and therefore heats up more) with the thin air at high altitudes, and there's less exhaust back pressure because of the thin air. If an aftercooler is fitted, the charge air reaches a higher temperature because of the reduced effectiveness of the aftercooler. Diesel-powered ground equipment such as trucks and earthmovers are de-rated with adjustments to the fuel injection pumps, when operating at extremely high altitudes, such as in the Rockies or the Andes. This is done to prevent engine damage caused by overheating in the thin air. If an automatic electronic fuel injection control was fitted to this aviation diesel V8, it would compensate for the thin air at high altitudes. I seem to recall the Junkers Jumo ran to 41,000', but I'm not sure how the thin air problem was compensated for, in the Jumos. |
One track. Electronic injection for diesels compensates and enhances the cycle. Cannot say for the trucks I am driving but my common rail family hack is firing up to four times per power stroke. You are correct with the rack settings for traditional injector systems. Caterpillar placard their machines for work above a certain altitude...methinks 15000ft, if I remember correctly, bit of a giggle in this country...soooo, going by the monitoring circuits built in current common rail systems...I reckon the Bosch system will compensate for altitude.
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Turbines with fadec run what we call PMA permanent magnetic alternator's they provide power to the FADEC system alone in emergency use when normal power is lost. And as such the engine will continue to run A classic example was the A380 all power lost to #1 engine but ran till they got enough foam into it to put the flame out.
The biggest problem with a diesel engine it has extremely bad hamomonics due to its power stoke is based on compression. A long time ago as I recall the French put one in a TB10 or 20. After the test flight and taxing back the tail fell of. This isn't the first time that has happen if they get it all wrong in the design stage has happened to normal type engines as well. From what I recall you have to run a special prop with a rubber drive and increase the size of the engine mounts as well. Ever look a a late model car engine mounts now some are even computer controlled for better NVH especially when they drop out cylinder's for better fuel economy. John dere made a rotary engine it was around 500hp from memory they could not get it to work Lcy brought it they ended up with a 500hp engine and a gear box of 2500hp rating to keep it all together then they gave up on the project. The biggest problem is its extremely hard to go past what we have now as the norm that's because believe it or not they got it very close to perfect from the start. With modern machinery better alloys they made big increases in reliability but the basic confrig is still the same. Auto engines don't work in aviation its that simple, name one that dose. Only the VW engine works but that's not in commercial use. For there investment I wish them well but it is going to be a hard road ahead for them. It dose look like a quality product I will give them that. Will it work only time will tell or will it end up like a lot that have gone before them lets see. Cheers |
Onetrack it is not px that drives the turbo it velocity that drives it.It only changes to px across the turbine . Velocity is the in the exhaust system is what is required that's why it has a convergent scoll onto the turbine.
Cheers |
yr right, pressure is velocity when it comes to gasses - heard of dynamic pressure?
At a molecular level, all pressure is is the velocity/kinetic energy of the particles regarding diesels at altitude, you can drive your common-rail diesel-powered car/truck/what-have-you to more than 10000' AMSL in many parts of the world and not have it stop/break-down/overheat/fail to start. What's the difference if it's air in the tyres or air under the wings that's keeping the crankcase off the ground...? |
yr right - Well perhaps I should have made it clearer that the turbocharger on a diesel spins at much faster speeds in thin air, because the engine is running hotter.
The speed of a diesel engine turbocharger is directly governed by the EGT. The higher the temperature of the exhaust gases, the greater the turbine speed. This is a self-compensating system for high altitude in one respect - that's the reason why many diesel drivers on the ground don't notice much power drop-off in the top of the Alps, the Rockies or the Andes. However, the engine operating temperature of a diesel is the critical factor to watch at high altitudes. |
Sorry px is not velocity at all.
Px increase velocity decreases temp increases Or Px decrease velocity increases temp decreases All at subsonic flows If what you say is true there would no need ford the convergent scroll. Cheers |
From the website - their old website had videos of the engine running at altitude:
EPS has been testing the Proof-of-Concept Engine on its mobile test stand since November 2011. In a program known in the automotive world as “accelerated durability testing,” the team has run the engine through extremes that will never be experienced in the course of normal aircraft operations, including calibrations, low inertia props, cold tests, multiple rapid acceleration and deceleration cycles, and a battery of other insults to put the engine through its paces. In the summer of 2013, EPS drove the engine to the top of Mount Evans in Colorado to conduct high altitude performance tests at 10,000 and 15,000 MSL. The engine achieved full 350 horsepower operation at 15,000 feet density altitude and achieved 420 horsepower at low altitude. The engine’s liquid cooling system has been tested in extreme weather conditions, demonstrating starts in temperatures from – 25 degrees F to more than 100 degrees F. Based on hundreds of hours of testing as of April 2014, EPS can report significant technical breakthroughs, including |
Originally Posted by yr right
(Post 8477173)
Sorry px is not velocity at all.
Px increase velocity decreases temp increases Or Px decrease velocity increases temp decreases All at subsonic flows If what you say is true there would no need ford the convergent scroll. Cheers |
The scroll is a convergent duct. It goes from a large to small. There fore it must increase it's velocity and decrease it's px due gas laws. Once it passes over the turbine it changes as in any gas turbine Engine
Cheers |
Originally Posted by yr right
(Post 8477219)
The scroll is a convergent duct. It goes from a large to small.
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The turbocharged diesel cycle engine I used to fly, was certificated up to 20,000'.
So I guess the turbocharger was designed correctly to run in less dense air, without overheating. I'm also going to guess that the manufacturer of this new V8 engine might have also designed it to run safely at altitude. Only a guess mind you... :} But you'd want to be sure of mechanical reliability before you flew it over the Rockies, for sure. Or even our humble high country! |
A Cirrus SR22 powered by an Engineered Propulsion Systems (EPS) Graflight V-8 Diesel engine made its first test flight May 2nd in Mojave, CA with Dick Rutan at the controls of the airplane.
A Successful Test Flight For EPS Engine | Aero-News Network |
Anyone know what happens to a TC or TN avgas burner when an intake tube coupling leaks or as they do lets go? Yeah you get a NA engine. :D A mixture sweep sorts that but you can have power to divert safely.
What happens on these turbo diesels? ;) |
not a fan then jabba?
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