Glossary: Engine Blocks and Cylinder Heads

A block design with sides that extend exactly to the centerline of the crankshaft bearings and a separate, additional section that attaches to the crankcase and the oil pan and incorporates the main bearing caps into a one-piece component.

An engine operating strategy that varies intake valve closing to adjust the air charge pressure and temperature. Miller cycle engines use it.

Lines at the injectors that collect fuel and return it to the fuel tank.

A catalyst mechanism that selects and destroys only NOx emissions without the use of DEF; it is also referred to as a hydrogen-selective catalytic reduction (SCR-H) catalyst and as an NAC .

A combustion system that uses excess air so that it is air rich and fuel lean. Air-fuel ratios are above stoichiometric ratio.

An engine that turns counterclockwise when viewed from the flywheel.

The position where the pumping plunger just begins to cover the fill and spill ports.

The minimum temperature required by a catalytic converter to begin breaking down a noxious emission.

The smooth appearance left by the cylinder wall wear caused by hard abrasive carbon.

A condition of accelerated cylinder wall wear caused by carbon contact on the piston with the cylinder liner; also called bore polishing .