Variable compression ratio is becoming increasingly desirable as oil prices increase and car buyers have an increased interest in fuel economy. The cylinder head can be altered by using a hydraulic system which is connected to the crank shaft and responds according to the load and acceleration required. Increasingly stringent emissions and fuel economy standards have long remained a source of challenges for research in automobile engine technology development towards the more thermally efficient and less polluting engine. Spark ignition (SI) engines have lower part-load efficiency when...