4. Glossary

Bowl: combustion chamber machined into the piston on direct-injection diesel engines. When the piston is near top dead center, the centrally-placed injector sends several jets of fuel radially into this bowl.

Upstream spark plug (Ricardo-type diesel engines with pre-chamber): spark plug pin positioned upstream of the injector, in relation to the direction of air flow when the pre-chamber is filled. Also known as a "horizontal spark plug".

Downstream spark plug (Ricardo-type diesel engines with pre-chamber): spark plug pin located downstream of the injector, in relation to the direction of air flow when the pre-chamber is filled. Also known as a "vertical spark plug".

Cross-flow: this refers to a cylinder head with intake on one side and exhaust on the opposite. This arrangement is more favorable both for the thermomechanical...