( Our Engines )
Why is the Scuderi Split-Cycle Engine Better?
The Scuderi Split-Cycle Engine solves both the breathing and thermal efficiency problems with two unique and patented concepts.
Unique Valve Design
On the compression side of the Scuderi Engine, the breathing problem is solved by reducing the clearance between the piston and the cylinder head to less than 1 mm. This design requires the use of outwardly opening valves that enable the piston to move very close to the cylinder head without the interference of the valves. This effectively pushes almost 100 percent of the compressed air from the compression cylinder into the crossover passage, eliminating the breathing problems associated with previous split-cycle engines.
Solving the Thermal Efficiency Problem - Firing After Top Dead Center (ATDC)
Although considered bad practice in conventional engine design, firing ATDC in a split-cycle arrangement eliminates the losses created by recompressing the gas. The big issue was not how to solve the thermal efficiency problem of the split-cycle engine, but rather how to fire ATDC. In fact, determining how to fire ATDC is possibly the single most important breakthrough of the Scuderi Engine design.
High Pressure and Massive Turbulence
In the Scuderi Engine, firing ATDC is accomplished by using a combination of high-pressure air in the transfer passage and high turbulence in the power cylinder.
Because the cylinders in a Scuderi Split-Cycle Engine are independent from each other, the compression ratio in the compression cylinder is not limited by the combustion process. A compression ratio in the order of 75:1 is obtained, with pressure in the compression cylinder equal to that of a conventional engine during combustion. The pressure in the compression cylinder and the crossover passage reach more than 50 bar (725 psi) on our naturally aspirated (NA) engine and more than 130 bar (1885 psi) on our turbocharged (TC) engine.
This high-pressure air entering the power cylinder creates massive turbulence. The turbulence is further enhanced by keeping the valves open as long as possible during combustion. The result is very rapid atomization of the air/fuel mixture, creating a fast flame speed or combustion rate faster than any previously obtained. The combination of high starting pressure and fast flame speed enables combustion to start between 11 and 15 degrees ATDC and end 23 degrees after ignition. The result is a split-cycle engine with better efficiency and greater performance than a conventional engine.