So, you could run it on two cylinders and get over 300 hp? Or am I not understanding what he said? It does look like it might make a good aircraft engine, but those in fear of 2-strokes might have a problem.
Dave

I understand him to mean that one module is comparable to a four cylinder engine. His hand crank demo is one module having four pistons making the 325 hp. The two module would have eight pistons and 650 hp. He does not talk about torque rise in the engine so getting the power needed for direct drive aircraft engines at the appropriate rpm is unanswered, but he does say that because of the shortened stroke, the piston speed is high and the engine rpms are also high, 3800. This engine would probably require a reduction drive on a propeller aircraft.

The two stroke designs we are used to seeing have been designs whose purpose is to provide the cheapest manufacturing costs. That goal in engine design itself brings unreliability and creates dirty running engines. Advances in direct injection of fuel and improved cooling and lubrication methods along with unmatched power to weight ratios will keep bringing them back.

That is a sweet looking design! It's similar to the Junkers Jumo 205 engine that the Nazis used in WWII for high altitude bombers. Those were also two-stroke engines, but they used two crankshafts (one at each end) instead of one crank in the middle with those long connecting rods.

When you have two pistons that are opposed in one cylinder, then the intake is covered/uncovered by one of the pistons, and the exhaust is covered/uncovered by the other piston. That is much more efficient than a traditional 2-stroke design, which tends to suck a little of the intake out through the exhaust, and still leave some exhaust gases in the cylinder.

I love the guy's german accent in the video. They've got a rich heritage of making diesel engines in that country (starting with the meister himself, Rudolph Diesel), so hopefully they will succeed. Once they address the lubrication issues, I think this has the best potential for a GA engine of anything out there right now. It's a pity that the FAA red tape is such an impediment that it will likely never see any use in this market.

http://www.deltahawkengines.com/ has a 180 hp that is about to get certified. I think they are selling to experimental market now but are $30k ( I think).

Some more diesel discussion:
viewtopic.php?f=1&t=6579

The two stroke concept is what will take the shock stress out of the crankshaft and bring the weight down. The firing of the piston each time it reaches TDC will make a four cylinder diesel run as smooth as an eight. We all know that the sixes in gas are smoother than the fours. Eights would be smoother yet. The Delta Hawk is a V4 160 two stroke and should be as smooth as an eight cylinder diesel. If this engine would have been available when I needed one, I would have had it in my Tundra. The fuel savings would have more than paid for the difference in the engine price and the torque available with the throttle back would have made the constant speed prop a breeze to operate, both with a single lever. Here is an update on the outlook for diesels, which is ultimately tied to the demise of 100ll and its replacement UL100, at least in this country.


News of January 27, 2011

Perspectives for aero diesels after FAA's and EPA’s engagement on unleaded avgas, and after strategic Chinese initiatives in Piston-Engined Aircraft.

AOPA says: Good news: The EPA and FAA are in sync regarding unleaded Avgas. Most of the early process has been with the EPA—responding to a petition from the environmental group, Friends of the Earth, to review the environmental effects of leaded avgas. However, in 2011 and beyond, the FAA will take on a more visible role, aiming at safety, performance, and practicality of an unleaded replacement for 100LL. Refresher: The Clean Air Act requires that EPA consult with FAA when issuing proposed emission standards for aircraft, and EPA is prohibited from issuing those regulations if that consultation reveals an adverse impact on safety or noise. On the other hand, FAA may prescribe standards for aviation fuel, but only if EPA determines that aircraft emissions from the fuel endanger public health. The FAA has invested resources to support research for unleaded alternate fuels at the William J. Hughes Technical Center in Atlantic City, N.J. The FAA's Engine and Propeller Directorate is also closely involved and in regular direct communication with the GA Avgas Coalition, individual aircraft and engine manufacturers, the petroleum industry, and new fuel producers. FAA says “Aviation fuel is certified by FAA as an operating limitation of both the aircraft and the engine. If a new fuel can be developed that falls within the existing aviation fuel operating limitations of the legacy fleet of aircraft, then FAA approval is easy. … The operating limitations must … ensure that the fuel is controlled to the extent necessary for safe operation. An alternative fuel specification is acceptable as long as it provides the necessary level of control of the fuel composition and properties.” This defines the long-term process. In the near term, and as an interim step, the FAA, at the request of the GA Avgas Coalition, is now evaluating very-low-lead fuel that could be incorporated into the existing avgas production and supply chain without the need for engine modifications or re-certification. This is seen as a short-term initiative to address the EPA's new National Ambient Air Quality Standards and not as a long-term solution. But the long-term process to assess unleaded solutions will go forward and will be accomplished with an industry consensus-based fuel specification, such as those written by ASTM International. ASTM …is an organization that develops standards and specifications for many industrial and engineering products, including aviation fuels. Within the ASTM process, the FAA has noted the particular progress of two leading unleaded fuel developers, General Aviation Modifications Inc. (GAMI) and Swift Enterprises. The FAA outlined the two companies’ progress in a backgrounder:
• GAMI has requested an ASTM specification approval for its unleaded fuel and requested a supplemental type certificate (STC) approval for use of its G100UL fuel on Teledyne Continental Motors IO-550-N engines that are modified with a turbonormalizer. “While the STC approval will be limited to the IO-550-N engine installed in the Cirrus SR22 airplane, it is expected that the ASTM specification will have broader applicability,” the FAA explained. GAMI plans to work with the FAA to develop a detailed compliance plan for the G100UL fuel.
• Swift Enterprises has also been developing an unleaded high octane aviation gasoline designed to meet or exceed the operational parameters of conventional, leaded aviation gasoline. “Through industry consensus and direction, Swift has developed a test specification for their fuel, called UL102, and has generated the necessary research and development data over these last five years to support that specification. Swift is currently in the final stages of balloting the test specification and supporting data to the ASTM International membership for final approval and issuance,” the FAA said.
In addition, the FAA is focusing significant resources on developing an alternative to this consensus-based ASTM process that would support FAA approval of an aviation fuel operating limitation using a compliance method that provides an equivalent level of safety to the ASTM process. Such a compliance concept would be predicated on compositional control of the fuel and would require a rigorous evaluation of the fuel performance, the FAA said. (Sources: AOPA, 1/25/11; DieselAir expert panel)
This report does not justify any change in DieselAir’s previous forecast on the future of Avgas: 100LL as we use it now will be phased out between 2016 at earliest and 2022 at latest. If a new, unleaded 100 Octane Avgas is indeed put on the market (call it 100UL), it will be priced, on the airfield, at least $10 per gallon in 2010 dollars. 100UL will be marketed essentially in the US and Canada, and will delay somewhat the take off of aero diesel engine in these countries. Diesel will continue its progression outside North America and will notably take off in China. Centurion Engines, who manages Thielert presently in receivership and seeks an investor, recently received the biggest Chinese order for Thielert aero diesels: eleven engines, for new planes, in early 2011 from Shandong Bin Ao Aircraft, who manufactures the Diamond DA40 for the local market.
The main question remains that any of the present aero diesel manufacturers (Thielert, SMA, Wilksch, DeltaHawk, Austro Engine…) is in bad need of massive funding in order to build up its business to the point of offering a complete range of engine powers from 100 to 500HP, to get them certified and STC’d at least for the main piston-engined airplane vendors, and to generate a positive cash flow. We are talking here of funding levels of around $100 million on top of whatever was already invested… Continental, SMA’s licensee, is now Chinese-owned. DeltaHawk got equity funding also from China. Sunward Aviation, a Chinese private venture, has plans for a diesel 2-stroke 100HP light airplane. The initiative seems to come more and more from China…
posted at 10:26 AM

today's news says that deltahawkengines.com are going to finally release certified production very soon.

http://www.avweb.com/avwebflash/exclusi ... 373-1.html

The Chinese money is really speeding things up.

I expect these will be showing up in experimentals as soon as they make it here:

http://www.boxerdiesel.com/engineering/en/index.html

Eggenfeller has converted quite a few Subaru engines. There is a Tundra nearly done in Nevada that had a 220 hp turbo Eggenfeller mounted but was pulled out and replaced with a Continental when another Eggenfeller engine quit on him in another plane. Loss of ignition system.
The EA-81 has also been a popular conversion engine for home builders but most Subaru models are heavy for the hp compared to traditional air cooled aircraft engines. I expect the diesel to come in heavier yet.

Hafast wrote:http://www.engineeringtv.com/video/Opposed-Piston-Opposed-Cylinder

I follow new engines like a second passion. Just when I thought it would take Chinese investment to make this commercial, up steps Bill Gates and Vinod Khosla to back a company called EcoMotors and attract an OEM for a market. Here's an update on the Opposed Piston engine on the commercial side. (This one might find its way into a homebuilt plane yet.) Game changing for engine makers.

WARRENVILLE, Ill., Feb. 22, 2011 /PRNewswire/ -- Navistar International Corporation (NYSE: NAV) today announced it has reached a development agreement with EcoMotors International in support of the company's opoc (Opposed-Piston, Opposed-Cylinder) engine architecture.

EcoMotors International's first product targeted for commercial application is a turbo-diesel version of the innovative opposed-piston, opposed-cylinder engine.

"We continue to be on the cutting edge of technology and our development agreement with EcoMotors once again demonstrates our commitment to develop new, innovative approaches to the commercial vehicle industry," said Dan Ustian, Navistar chairman, president and chief executive officer. "Our company has a long history of pushing the envelope to deliver state-of-the-art, customer-focused solutions and we see great promise in EcoMotors' breakthrough engine design."

Khosla Ventures' Vinod Khosla, EcoMotors' primary investor along with Bill Gates, sees the Navistar-EcoMotors alliance as a reflection of the disruptive nature of the opoc technology.

"We are delighted that Navistar, a global leader in the commercial vehicle industry, has recognized the game-changing promise of opoc," said Khosla. "The only truly disruptive technologies are those that can provide not only rapid payback but also economic and carbon benefits to large segments of the world's population without the need for subsidies or massive infrastructure investments. Among next-generation propulsion systems, the opoc engine is broadly applicable and can provide lower carbon emissions than almost any other technology."

Opposed-Piston, Opposed-Cylinder Engine with Modular Displacement Capability

EcoMotors' patented engine design creates a ground-breaking internal combustion engine family architecture that will operate on a number of different fuels, including gasoline, diesel, natural gas and ethanol. The opoc's new opposed piston-opposed cylinder direct gas exchange operation provides the well known emissions benefits of 4-cycle engines, the simplicity benefits of 2-cycle engines, the power density of the less well known opposed piston engine, and the extraordinary developments in electronics and combustion technology all tied together in a new and proprietary engine architecture.

"EcoMotors is proud to partner with Navistar to commercialize the revolutionary opoc engine," said Don Runkle, CEO, EcoMotors International. "For customers such as Navistar, this remarkable engine technology represents a competitive advantage that enables not only enhanced environmental sustainability, but also greater profitability. Our engineers are working to effectively rejuvenate the internal combustion engine for the 21st century."

The opoc engine comprises two opposing cylinders per module, with a crankshaft between them -- each cylinder has two pistons moving in opposite directions. This innovative design configuration eliminates the cylinder-head and valve-train components of conventional engines, offering an efficient, compact and simple core engine structure. The result is an engine family that is lighter, more efficient and economical, with lower exhaust emissions.

EcoMotors' opoc engine has a number of distinct advantages over traditional internal combustion engines. The opoc engine has very high power density of nearly one horsepower per pound resulting in an unprecedented lightweight and compact engine. The opoc engine is perfectly balanced enabling stackable power modules. This unique modular displacement capability is one of the long standing, but elusive goals of engine engineers' quest for high efficiency. In addition, it also results in much less NVH than a conventional engine of comparable power. Its elegantly simple design allows for low cost, efficient manufacturing and increased operating durability:

50 percent fewer parts than a conventional engine
Straightforward assembly
No cylinder heads or valve-train
Uses conventional components, materials and processes

Hafast wrote:http://www.engineeringtv.com/video/Opposed-Piston-Opposed-Cylinder

There's a 3 cylinder inline turbocharged Diesel powered RV here at Boulder City airport . 3 blade composite prop ,120 hp. 3-4 gallons a hour at 120 knots. Comes from England -he's waiting on the 160 hp coming out soon . Sounds like a sewing machine when it's flying .

182 STOL driver wrote:

Hafast wrote:http://www.engineeringtv.com/video/Opposed-Piston-Opposed-Cylinder

There's a 3 cylinder inline turbocharged Diesel powered RV here at Boulder City airport . 3 blade composite prop ,120 hp. 3-4 gallons a hour at 120 knots. Comes from England -he's waiting on the 160 hp coming out soon . Sounds like a sewing machine when it's flying .

Bill, I think this is the inline 3 cylinder 120hp. It is two stroke so the three cylinders firing each time over tdc is as smooth as a six. 15 liters/hr equals 3.96 gallons/hr. (This is an inline conventional piston two stroke but not the opposed piston/cylinder OPOC engine)

Wilksch Airmotive, a British company is developing/producing a 120 hp (89 kW) three-cylinder (WAM-120) two-stroke diesel and are working on a four-cylinder 160 hp (120 kW) design (WAM-160). In 2007 Wilksch claimed that they had completed multiple tests on the WAM-100 LSA in accordance with ASTM F 2538 - the WAM-100 LSA is a derated WAM-120. Wilksch originally showed a two-cylinder prototype alongside the three- and four-cylinder models. By mid-2009, approximately 40 WAM-120 units had been sold, with around half currently flying. The British owner of a RANS RV-9A fitted with a WAM-120 reports getting 125 knots (232 km/h) TAS at 6,000 ft (1,800 m) on 15 litre/hr of jet A1 fuel. A Rutan LongEz canard-pusher (G-LEZE) has also flown with the WAM120 engine with test flights showing a TAS of 160 kn (300 km/h) at 11,000 ft (3,400 m) and 22ltrs per hour. At economy cruise of 125 knots (232 km/h) at 2,000 ft (610 m) the fuel consumption is 12 ltrs/hr giving a range of 1,890 nautical miles (3,500 km); see [1]