The story of the Orbital two-stroke engine is a tale of innovation and missed opportunities. In the early 1990s, as the automotive industry was grappling with the future of combustion engines, Ford took a chance on the two-stroke engine. At the time, two-stroke engines had a poor reputation due to their fragility, peaky power delivery, and high emissions. However, the Australian firm Orbital Engine Company believed it had found a solution.
Orbital modified its powerplant design, incorporating a central ‘piston’ that orbited the center of the combustion chamber, rather than rotating around its edge. This new design showed promise, and Ford saw the potential. In 1986, Ford signed a license agreement with Orbital and began developing a fleet of Fiestas fitted with the two-stroke engine.
The results were impressive. The Orbital two-stroke engine was smaller, cheaper to produce, and more powerful than its four-stroke counterparts. Test drivers praised its flexibility and duality of character, noting its smoothness and briskness in low gears, as well as its ability to perform when pushed hard. Moreover, the engine had made significant strides in reducing emissions, with no telltale smoke.
Ford’s enthusiasm for the two-stroke engine led to plans for its implementation in a sports car, with Pininfarina’s Ethos concept serving as a prime candidate. The Ethos impressed with its precise steering, low roll center, and satisfying balance between slip and grip. A slight engine tune boosted power to 94bhp, making it both “brawny” and “zesty.”
However, despite the initial success and licensing agreements with other major manufacturers like Fiat, General Motors, and Volkswagen, the two-stroke engine’s future began to dim. The dominoes fell one by one, with VW canceling its deal and Ford ultimately abandoning the project. Insiders suggest that the engine’s lack of durability was a significant factor in Ford’s decision.
Fiat also considered using the two-stroke engine in its rival Cinquecento but ultimately chose a four-stroke engine for its superior fuel consumption and emissions. Orbital attempted to revive interest in the powerplant with a modified Ford Festiva, but it was met with failure.
Since then, the Orbital Engine Company, now known as the Orbital Corporation, has shifted its focus to building propulsion systems for unmanned aerial vehicles. The two-stroke engine disappeared from the automotive industry, seemingly forever.
However, with the current re-evaluation of combustion engines, there may be a chance for the Orbital two-stroke to make a comeback. In March 2024, Japanese firm Mitsui E&S successfully ran a two-stroke marine engine on hydrogen gas, signaling a potential future for two-stroke engines in a cleaner form.
While the history of the Orbital two-stroke engine may be filled with missed opportunities, the story is a reminder of the constant innovation and evolution within the automotive industry. As manufacturers explore alternative power sources, the future of combustion engines remains uncertain. The Orbital two-stroke engine may have had its moment in the 1990s, but who knows what the future holds for this unique technology. Only time will tell if it will rise again.
