Complete combustion is when fuel in the combustion chamber has enough oxygen to burn fully, forming carbon dioxide (CO2) and water.

In conditions where there is not enough oxygen, some of the fuel will burn to form carbon monoxide (CO) or carbon (soot).

A cam lobe is an eccentric shape which is part of a camshaft. There is usually one cam lobe for each valve.

The shape of the cam lobe determines how the valves open and close. This is known as the cam profile.

A cam follower is a general name for the component which transfers motion from the cam lobe to the valve stem. If the camshaft is position directly above the valve stems, the cam follower will probably be a bucket tappet, which provides a working surface for the cam lobe to act on, but does not alter the motion. If the cam is located to one side of the valves, the cam follower may be a rocking lever called a finger follower.

The cam profile is the shape of the lobes on the camshaft, which controls how the valves open.

The shape of the cam lobes controls:

  • timing of valve opening and closing
  • rate at which the valves open and close
  • overlap between intake and exhaust valves
  • maximum lift of the valves

Controlled Auto Ignition (CAI) is a combustion system which uses carefully controlled temperature and pressure conditions inside the combustino chamber to ignite a fuel/air mixture without a spark.

CAI is also known as Homogeneous Charge Compression Ignition (HCCI).