History – The Integration of External Combustion and Heat Engine Designs

An internal combustion engine (ICE) burns fuel inside the power cylinders. An external combustion engine (ECE) burns fuel outside the power cylinders. The most rudimentary ECE is a steam powered car. One of the most advanced ECE powers a nuclear submarine.

  • Invention of the first automobile is widely credited to Flemish Jesuit missionary Ferdinand Verbiest in 1678, who built it for the Chinese Emperor. The vehicle was powered by an ECE, which dominated motor vehicle power into the 1920s. Early manufacturers included Bollee, Cederholm, DeDion, Toledo, Locomobile, White, Stanley, Doble, Alena, Davis, Endurance, Decline and others.
  • In 1816 Robert Stirling invents the external combustion Stirling heat engine, the highest efficiency practical engine.
  • In 1823 Nicholas Leonard Carnot conceives the theoretically highest efficiency engine design, the Carnot-cycle heat engine.
  • The first motorcycle was an ECE powered design called the Michaux-Perreaux Velocipede in 1867.
  • The world’s first fully tracked vehicle was the ECE powered Hornsby “chain tractor” in 1905. The patent portfolio was sold to American Holt Tractor co., which later became Caterpillar.caterpiller
  • The ECE was powerful, but comparatively expensive to build. In 1906 a Stanley set the world land speed record at 127mph while a Model T could only achieve 40mph. In 1907 Stanley driver Fred Marriott drove the same car to 190mph before hitting rough track and crashing. However, where a new 1924 Ford Model T could be purchased for $380, the Stanley was $3,950 when the average wage was 5 cents an hour. In WWII, German Minister Goebels used a Stanley parade car which coincided with their research on ECE powered armored vehicles including tanks. Original Stanley owners included Howard Hughes. Current owners include Jay Leno.
  • In 1949, the Soviet Union produced an ECE powered heavy truck based on the British Sentinel S.4.  The vehicle was designed to burn literally “any” fuel in the common definition of fuel such as diesel and kerosene, but also coal, wood, or any other combustible item.image005
  • In 1954, McCulloch Motors developed the ECE powered Paxton Phoenix car.
  • In 1969, General Motors built the ECE powered Chevrolet Chevelle SE124 and the Pontiac Grand Prix SE101 in the search for a low emissions, high efficiency replacement for the ICE.  This research was terminated at the same time as their research on Rotary engines and turbine power to concentrate on short term improvement of old ICE technology due to the first oil embargo, as opposed researching  long term solutions.history-003
  • In 1973, SAAB developed the ECE engine code-named ULF which was the size of a car battery yet produced 160hp. Continued research was curtailed by tight corporate finances, and the oil embargo.
  • In 1974, the ECE powered Pelland was contracted with the Australian government, and produced in England in 1977. The 1.9 liter engine produced 1,100ft/lbs of torque, which has been unmatched by any ICE to date.  The vehicle was built as a kit car based on the VW Beetle.image011
  • In 1992 a core group of former Ford and Honda factory technical experts and enthusiasts support the inventor of the ZED (Zero Emissions Design) engine concept with the intent of setting an emissions-free land speed record.
  • In 1996, Volkswagen group Enginion AG developed the ZEE (Zero Emissions Engine) for the Skoda car. The 1 liter engine produced 220hp and 369 ft/lbs of torque with emissions far below SULEV standard. SULEV is the US government “super ultra-low emission vehicle” classification of vehicles which produce 90% less emissions than an ICE vehicle, and had prior to this point only included electric power.
  • In 2007, the Chinese government initiated a program to develop ECE engines as a means to reduce dangerous levels of urban pollution caused by ICE powered vehicles.
  • In 2008 the ZED engineering team has a technical breakthrough by integrating external combustion engine design with heat engine design, to harness the “bottom-cycle” heat of combustion after fuel ignition in order to increase efficiency.
  • In 2009, the British Steam Car Challenge set a world land speed record. The challenge was sponsored by a conglomerate of automobile industry manufacturers, government and academic institutions interested in the promotion of low emissions, high performance ECE powertrains.image013
  • In 2010, the bottom-cycle Russian designed Kalina-cycle engine is produced by Siemens Germany and licensed to the Chinese for electricity production with 50% efficiency gains. It is believed that the US agency DARPA is working with the military on a Kalina-cycle type jet engine turbine for fighter jets.
  • In 2011, BMW refined the VW Steamcell concept which increased vehicle fuel efficiency 10%. Heat from the exhaust of an ICE heated water to drive a turbine and generate electrical power.Image27
  • In 2011 the ZED group engages the National Research Center for prototyping of the ZED “bottom-cycle” piston engine, a break-through design in engine efficiency.
  • In 2013 the first patent is issued to protect ZED engine technology.


While the power and high efficiency of external combustion engines (“ECE”) is known, its market dominance ended when the cost of internal combustion engine (“ICE”) manufacturing dropped much lower. Cheap petroleum was plentiful, and the effects of air pollution were not understood.

However, as fuel prices increased, and the inherent low combustion efficiency of the internal engine has been linked to environmental damage, people are now globally calling for its replacement.

In the search for a replacement, the cost of fuel cells has proven insurmountable. As well, electrics have limited power, and are expensive. Batteries simply cannot compete with the energy density of fuel. In contrast, the use of ECE in motor vehicles is well proven, and adaptation is a comparatively “simple” engineering exercise.

Within the ECE engine category, the ZED engine is uniquely distinguished with “bottom-cycle” heat scavenging. This feature utilizes normally wasted heat energy to improve operating efficiency. Worth noting, the internal combustion engine inherently cannot scavenge heat as that would cause its failure. ZED technology “supercharges” ECE engine performance by using both the pressure and heat that fuel creates when combusted, in a way that no other engine can.

In the history of engines, ZED is the first piston version to combine both the attributes of external combustion and heat engines, maximizing the power of both heat and pressure when fuel is burned.