This test rig is used to find the performance and combustion parameters of Variable Compression Ratio Petrol Engine. The compression ratio of the engine is variable from 2.5:1 to 10:1.A unique provision is been made to vary the spark timing of the engine. Wide range of combustion studies can be conducted with the help of this setup. Engine Combustion and performance parameters like Actual volume of Air, Volumetric Efficiency, Specific fuel consumption (SFC), Brake Thermal Efficiency, Brake power, Heat Balance chart, mechanical efficiency, Frictional Power , indicated Power, PV and P-θ diagrams, Mass Fraction Burnt Angle, Estimated End of Combustion Angle (EEOC), Gross IMEP, Maximum Heat Release Rate, Maximum Heat Release rate crank angle, Maximum pressure rise rate, Maximum pressure rise rate crank angle, Maximum pressure, Maximum pressure crank angle, Start of Combustion, Total heat release, Ignition delay, ignition duration can be studied.