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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. |
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