Valery Borovskikh, an engineer from Moscow, has developed an internal combustion engine design capable of running on multiple fuel types. The engine can operate on gasoline, diesel, gas, and other liquid fuels, using hot gases from its own previous working cycle for ignition.
To achieve this, the designer added a separate chamber with a volume of only 5–10% of the combustion chamber's volume. Hot gases enter this chamber after the power stroke. During the next cycle, they are retained until the end of compression, after which they are injected back into the cylinder through a controlled valve.
The valve opens approximately 15–20° before top dead center and closes 30–40° after it. It is actuated by two electromagnets, and the opening and closing times are determined by an electronic unit.
For diesel, the designer proposes injecting fuel at a temperature below the autoignition threshold, and then initiating combustion with hot gas. The document accompanying the design states that the cycle temperature with this approach can remain below 2000 °C, which should reduce the formation of nitrogen oxides and soot.
For cold starts, the gasoline mode can use conventional spark ignition. After warming up, the engine can switch to other fuels.
From the editors of "Pervy Tekhnichesky": Borovskikh attempted to solve the problem of ignition timing control for different fuels but created a scheme with heat losses and low reliability.
The idea of retaining a "spark" of hot gases in a tiny chamber will inevitably clash with the laws of thermodynamics. During the compression stroke, heat will simply dissipate into the cylinder walls, leaving the engine with a cooled, ineffective mixture before TDC.
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