This document discusses camless engines. A camless engine uses solenoid actuators instead of a camshaft to open and close valves. It describes the basic 4-stroke cycle of a camless engine involving intake, compression, combustion, and exhaust. It also discusses two methods for actuating the valves electronically without a camshaft: using electro-mechanical rotary solenoid actuators controlled by a microcontroller or a hydraulic system with an electrically operated hydraulic valve. The main sensors used in a camless engine are the engine load sensor, exhaust gas sensor, valve position sensor, and engine speed sensor.