This engine architecture separates the intake and compression stages from the combustion and exhaust stages by using different cylinders for each task. Compressed air and fuel are transferred from the compression cylinder into a separate combustion cylinder where ignition occurs. This design aims to achieve the efficiency of an extended Brayton cycle while delivering a power stroke on every revolution, similar to a traditional two-stroke block.
The engineering team is evaluating an entry ignition engine prototype to see if the thermal efficiency gains outweigh the pumping losses between cylinders.
Because the combustion cylinder never handles cold intake air, it runs significantly hotter than a conventional engine block, requiring specialized cooling and metallurgy.
Related terms
Compression ratio
The mathematical ratio of cylinder volume at the bottom of the piston stroke compared to the top.
Cylinder head
This cast metal component bolts to the top of the engine block to seal the combustion chambers.
Petrol engine
An internal combustion engine that generates power by igniting a mixture of gasoline and air with a spark.