spherical combustion chamber
Cars & Driving
- noun the combustion chamber of an internal combustion engine equipped with reciprocating pistons is ideally very compact in design, i.e. without gaps, grooves, edges, etc.; the most favourable design would thus be a sphere but the valves of a four-stroke engine make this impossible. The combustion chamber in diesel engines, however, is located in the piston crown, where it is in fact spherical.