Modern Camshaft-less Engines

Modern camshaft-less engines are termed intelligent engines because they are electronically controlled with the help of a central control unit. This unit governs the opening and closing of inlet and exhaust valves, fuel injection timing, and all other engine operating conditions.

• Each unit is equipped with a PCB-based control system.
• A sensor fitted on the flywheel detects the crank angle and, based on this input, the system controls the operation of the fuel injectors, exhaust valves, and starting air valves.
• Since there is no camshaft, the associated chain or gear drive is eliminated, along with the mechanical problems arising from it.
• The control unit also meters the fuel supply according to load demand and varying operating conditions.

The only manual input is the load/lever setting given from the control room. Using this signal, the control unit, software, and solenoid-operated valves regulate all the following functions automatically:

• Start of fuel injection
• End of fuel injection
• Exhaust valve opening
• Exhaust valve closing
• Engine starting sequence
• Automatic adjustments according to fuel quality
• Automatic slow-down or shutdown in case of faults

Since all operations are governed by software and electronic logic, these are referred to as intelligent engines.

Advantages over Conventional Engines

• Elimination of camshaft
• Elimination of chain/gear drive
• Elimination of individual fuel pumps and VIT (Variable Injection Timing) systems
• Elimination of air distributor
• Reduced overall weight of the engine
• Automatic and precise control of fuel injection and valve timing

Reliability

• The overall reliability of such engines depends on the PCB and control software.
• In case of PCB failure, replacing it restores normal operation within a short period.
• However, if a spare PCB is not available, it may become difficult to operate the affected unit, and the engine would need to be run with that unit cut out.