Mission: The Economist in 1986 wrote about our work in terms of the lean-burn engine, the Holy Grail of car engineers. “By using more air to burn less fuel, it promises more miles per gallon and less pollution”. In 2000, we succeeded in developing an efficient lean burn engine, using a low-cost, 2-valve engine. It has the diesel’s 30% higher efficiency and power, and a lean burn capability of 30 to 1 air-fuel ratio (AFR), given the high energy of its ignition, i.e. the CEI Ignition. The ignition is backed by work performed over ten years and by patents issued between 1996 and 2007. The ignition coil was perfected in 2008-2009, and was shown to deliver 5 times the energy for an unheard of energy-density of 1.25mj/gm.
In 2009, a major breakthrough was made in perfecting the lean burn engine, called the 2-Stroke Inverted Cross-Scavenged. In January, 2009, a U.S. patent was filed, representing the completion of the engine. The engine was given the name Holy Grail Lean Burn Engine. It represents breakthroughs in lean burn engine design and 2-stroke engines. It is the only two-stroke engine with two overhead valves, no ports in the engine block and without any oil problems. It avoids the oil-leak problem that the 4-stroke engine has at very high AFR, and it has an electric supercharger at the intake. It uses two halo-disc plugs with high energy coils, a combustion chamber similar to Michael May’s, and an electronic fuel injector first used by the Ford PROCO.
It has not been appreciated before that the two-stroke can operate as a true Miller Cycle under all conditions, and that with the proper scavenging and compression/expansion it can use a full air-charge to the cylinder despite the late intake closing. The engine uses an expansion ratio (ER) of 18 to 1 and a compression ratio (CR) of 10.5 to 1. By displacing the exhaust gases with fresh intake air, the process takes place at normal temperature and pressure, i.e. at NTP. Note that since the ER is high, there is no need to consider the complexity and expense of variable ER/CR. The engine can be viewed as a high efficiency engine one step advanced from the Big Bore Four, i.e. a high efficiency Big Bore Two.
The engine power can be controlled by a Speed-Density map, Density being MAP in a standard engine, and in the present case is proportional to the degree of Stratification, given that MAP ≈ 1. The engine has only three operating conditions: cold-start, lean burn operation, and WOT (14.7 AFR with a 3-way catalyst).
The Holy Grail Lean Burn Engine has high power despite its small size, i.e. 200 HP in a two-cylinder, 1 Liter, mildly super-charged engine and the highest efficiency >55%. It can do away with the supposed advantages of EVs. It brings truth to the statement that it is better to burn fuel in an efficient engine to directly move the car instead of burning it in a large power-plant and have to the deal with coal ash, and with the problems of having to convert its output to electricity and convert it back again to use in a hybrid and EV. In addition, the EVs have an outrageous price: $43,000 for the GM Volt and $89,000 for Al Gore’s EV, and have driving range problems, battery problems and require cancer causing rare-earth-metals which currently come mainly from China. The light-weight, highly efficient, 2-cylinder, 2-Stroke ICS can be built with a suitable chassis for a mere $10,000 in the US, and less in other parts of the world.
Smart people should be able to go through simple algebraic equations to understand the basic principals of operation of the “perfect” engine, the Holy Grail Lean Burn Engine. They should also be able to ascertain why global warming can initially produce temperatures extremes, remembering that the heat of fusion of ice is 80 calories/gm, and that global warming can initially produce large amounts of free ice, i.e. icebergs.
Michael Archimedes Ward, Ph.D., Applied Physics, Harvard University
32 Prentiss Rd, Arlington, MA 02476
e-mail: Michael_A.V._Ward@post.harvard.edu