Combustion Chamber Layout for Modern Otto Engines

When trying to comply with the great number of increasingly severe requirements to be fulfilled by a passenger car engine, special importance has to be attributed to the design of the combustion chamber.

The most efficient way to improve the fuel economy in the part-load range being to increase the compression ratio, emphasis will be laid on combustion chambers allowing high compression ratios combined with low octane requirements. According to Porsche experience, many demands can be complied with in the simplest manner by locating the combustion chamber in the piston crown. This configuration offers various advantages over its counterpart installed in the cylinder head.