( Our Engines )
Prototype I
The Revolution - A Split-Cycle Engine Firing After Top Dead Center (ATDC)
The revolutionary feature of the Scuderi Engine is combining a Split-Cycle design with the combustion process of firing ATDC. This combination is what produces a truly unique thermodynamic process that enables new levels to be reached for both efficiency and power. Its design is elegantly simple, leading to further enhancements that will continue to improve the engine's performance.
The current NA prototype engine demonstrates the viability of the design. It proves that the concept of splitting the cycles and firing ATDC is real and it is just the start of many design improvements to come.
Developments, Findings and Features of the NA Prototype
Intake and Exhaust Valves Used To Control Engine Load: The intake and exhaust valves are pneumatic valves that are fully-variable in both lift and timing. The air needed to operate the valves is provided internally from the compression side of the engine. These valves are used in place of a throttling valve to control the engine during part load operation.
Crossover Valves: The valves for the inlet and outlet of the crossover passage are cam actuated and are designed to lift outwardly. Air springs are utilized to return the crossover valves with the make-up air for the air springs being supplied internally from the compression side of the engine.
Crossover Gas Passage: The crossover passage has become a major control point for the engine. It is utilized for controlling pre-detonation (knock) by providing an additional cooling point after compression has occurred. This is a feature unique to the split-cycle design that is simply not possible in a conventional engine.
In addition, the configuration of the crossover passage going into the power cylinder has a significant effect on the air/fuel mixing, and the crossover design can also play a major roll in controlling the engine at part load.
Fuel Delivery System: High Pressure fuel injectors with unique spray pattern. The Scuderi NA engine utilizes Bosch injectors configured with a unique spray pattern. These injectors are high pressure, direct injection type operating at 200 bar. The combination of spray pattern, pressures and injection timing help to ensure proper air/fuel mixing and prevent fuel from being trapped in the crossover passage.
Unique Power Piston Head Design: This engine utilizes a kidney shaped depression in the piston head to enhance the air/fuel mixing. This unique design is part of the Company's patent portfolio.
Valve and Ignition Timing: One of the major factors required to obtain a good combustion process is combining valve performance with ignition timing. The Scuderi Engine utilizes a patented valve actuation mechanism that ensures high velocity air flow into the power cylinder. Our combustion process of firing ATDC is then optimized by controlling the ignition timing of the engine.
Valve Lash Control: The combination of outwardly opening valves with low lift and rapid timing profiles requires a unique lash control device. Our team has developed a patented lash control mechanism specifically designed to accommodate the various operating conditions that the crossover valves will be under.
High Pressure and Massive Turbulence
In the Scuderi Engine, firing after top dead center 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 split-cycle configuration are independent from each other, the compression ratios in the compression cylinder are not limited by the combustion process. Compression ratios in the order of 100:1 are obtained, with pressures in the compression cylinder equal to that of a conventional engine during combustion. The pressures in the compression cylinder and the crossover passage reach over 50 bar (735 psi) on our naturally aspirated (NA) engine and over 130 bar (1900 psi) on our turbocharge (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 fuel/air mixture creating a fast flame speed or combustion rate faster than any previously obtained. The combination of high starting pressures and fast flame speeds enables the engine to fire between 11 and 15 degrees ATDC. The result is a split-cycle engine with better efficiency and greater performance than a conventional engine.