Eight Companies Determined to Change Diesel Engines Forever

This Tour Engine prototype, based on two large Briggs & Stratton engines, shows the compressor cylinder at the 9 o’clock position. The crossover valve mechanical cam is at 12 o’clock (since the valve actuation opens and closes within 40 to 50 degrees, it helps to have a big one). At the 3 o’clock position is the combustion cylinder, and at 6 o’clock is the hydraulic pump used for loading the engine during testing.

This Tour Engine prototype, based on two large Briggs & Stratton engines, shows the compre

Right now, internal-combustion engines (ICE) are hot—hotter than battery-powered vehicles, hotter than hybrids, hotter than anything else on the market for that matter. Though gasoline-fueled engines represent the bulk of the internal-combustion engines on the road, new high-tech diesels are coming on strong.

Traditionally, diesel engines have been simple and robust powerplants. They’ve changed very little and only in small increments since their creation in 1893. That slow-and-steady trend appears to be changing in today’s marketplace. Engineers in Detroit are looking into new compression-ignition concepts, Navistar is investing in innovative up-starts, Cummins is working on new engine architectures, and the Japanese automakers are coming to market with small, lightweight diesels.

It turns out the idealized transition toward fleets of battery-powered electric vehicles isn’t as rapid as some media outlets would have you believe. Trust us when we say internal combustion is here to stay for a long time to come.

Eight Paths To The Future Of Diesel
The next generation of diesel engines will follow the principles of thermodynamics much closer. New control strategies and faster computer processors will allow combustion to be more precise than Rudolf Diesel could have ever dreamed. A few years ago, some of the engines we’re about to show you were only theories and CAD renderings, but today they’re starting to materialize. The following is a look into the future of what diesel engines might look like.

By separating the traditional combustion cycles, the Tour Engine design means the compressor cylinder no longer needs to be cooled to produce dense air. A single and direct crossover valve regulates the air going from the compressor to the combustor. Furthermore, the compressor cylinder’s volume is about a third smaller than the combustion cylinder. This means less work to compress the air and more room to expand the combusted gases—this allows for more work on the piston. It also means the combustion cylinder is cooled as a result of the increased expansion—just as Rudolf Diesel intended.

By separating the traditional combustion cycles, the Tour Engine design means the compress

1. Tour Engines
Dr. Oded Tour, CEO of Tour Engines, shared his engine philosophy with us this way: “We could develop a single appliance that acts as a freezer and stove at the same time, but it works much better to keep them separate.” This analogy was used to describe the current configuration of the diesel engine. Basically, we have two contradicting things (a cool compressor and a hot combustor) forced to compromise by sharing the same piston and cylinder.

Oded and his father, Lt. Colonel Hugo Tour, founded The Tour Engine company. He was a former researcher at the lab of Roger Tsien, the 2008 Nobel Prize winner in Chemistry, and his father was previously in charge of all technical aspects at the largest Israeli Air Force Base and has 20 years experience developing novel engines. Their first prototype was built from two small Honda engines sandwiched together with their pistons opposed to each other. You can see this split-cycle engine running for the first time at: http://www.youtube.com/watch?v=ExAO_JA0NgA. The Tour Engine first tried compression ignition by decreasing the phase-lag between the two pistons. This increased the compression ratio. In this setting, the engine kept running without needing a spark plug.

The Niama-Reisser NR-1 concept car holds four passengers, weighs 1,200 pounds, and is reported to get 200 mpg at 70 mph. The car’s 1.0L Centrifugal Heinz Boxer (CHB) engine represents a clean break from traditional combustion engines. The CHB engine uses a pair of opposing torus-shaped pistons (they look like a section of a doughnut) that oscillate in a rotary motion. Torque is applied to the crankshaft with a mechanism that can also vary the compression ratio (beyond 25:1).

The Niama-Reisser NR-1 concept car holds four passengers, weighs 1,200 pounds, and is repo

2. Niama-Reisser
Even as the push for battery-electric vehicles becomes stronger, Niama-Reisser wants you to resist and hold off on buying that Volt, Leaf, or Prius. Remain unplugged just a little longer, and in one year you’ll be able to get behind the wheel of a vehicle capable of obtaining 200 mpg. Based in Coshocton, Ohio, this new car company utilizes ceramic engine materials, ultra-light suspension systems (which we displayed at http://blogs.dieselpowermag.com/6762484/diesel-engines/niama-reisser-200-mpg-diesel-car/index.html), and superb aerodynamics to achieve its amazing fuel economy.

Its CHB engine is said to have a 60 percent parts count reduction compared to today’s diesel engines. It also doesn’t need oil for lubrication. Furthermore, it can be turned into a steam engine—the only modification needed is a steam valve, either controlled mechanically or hydraulically. At 1,600 psi steam pressure, the moment reaction at the crankshaft is said to peak at 2,052 lb-ft—not bad for a 1.0L engine. The engine is supposed to be able to handle 2,610 psi. Niama-Reisser just announced it is going to start production on the engine in the second quarter of 2012 and the NR-1 car the fourth quarter of 2012.

Achates Power claims its 3-cylinder will out power 8-cylinder engines we use and love today. This performance increase is due to the opposed-piston architecture that uses two pistons in one cylinder. According to Achates Power, the opposed-piston engine creates a larger cylinder displacement for a given cylinder bore diameter, leading to a reduction of the number of cylinders. Fewer cylinders reduces the surface area available for in-cylinder heat transfer—meaning more work goes into the piston. In addition, a piston replaces the cylinder head, so higher metal temperatures are possible.

Achates Power claims its 3-cylinder will out power 8-cylinder engines we use and love toda

3. Achates Power
Although opposed-piston engines (OPE) are radical to the consumer world today, they are not new. The first OPEs were in operation more than a century ago. First they were used in stationary power applications, then marine, then aircraft, and finally truck and tank applications. Opposed-piston engines use two pistons in one cylinder, and the combustion chamber is formed in the middle of the pistons.

The beautiful thing about opposed-piston engines is they will never fail because of a head gasket problem—because they don’t require them. Here is the Achates Power engine fully dressed with supercharger and turbocharger.

The beautiful thing about opposed-piston engines is they will never fail because of a head

The two-stroke, diesel-fueled, compression-ignition design of Achates Power uses ports in the cylinder wall instead of a valvetrain to control intake and exhaust flow. Achates Power started back in 2004 when John Walton, son of Sam Walton (founder of Walmart), provided funding for Dr. James U. Lemke.

The Rivian diesel-electric engine has three cylinders, common-rail injection, a single overhead camshaft, and an electric motor integrated into the front of the engine. Transmission choices will be either a manual or an automated manual gearbox.

The Rivian diesel-electric engine has three cylinders, common-rail injection, a single ove

4. Rivian
Ever notice how leaders at most car companies are old and seemingly against new ideas? That’s not the case with Rivian. Its CEO, R.J. Scaringe, is in his 20s. We’ve had a few conversations with R.J., and he is a big supporter of diesel and Diesel Power. If you follow our blogs, you already know that we’ve been getting the scoop first when it comes to Rivian’s press releases. We’ve been told to expect a radically different car from Rivian. It’ll have a diesel-electric engine and ultra-light body, which should equal outstanding fuel economy and a car that’s actually fun to drive. What’s better is it’s reported that this will all come at a price most people can afford. The icing on the cake is Rivian is an American company based in Rockledge, Florida.