engine block
An aluminum casting from the manufacturer that contains the crankshaft, connecting rods and pistons.

engine control unit (ECU)
The engine control unit in a Champ Car is a more sophisticated version of the computer in a street car, controlling functions such as ignition timing and fuel metering. In a Champ Car, the functions include traction control and driver-controlled fuel adjustment., and can be set up so that the engine will run at different maximum RPM limits or traction control settings depending on which gear the car is in or even location on a race track. An ECU can be easily reprogrammed by connecting a laptop computer to a plug on the side of the car.