In Two Stroke Spark Ignition engines the thermal efficiency increases with increase in compression ratio. Also, with higher compression ratios the lean burning limit increases because of the reduction ...

Because this has become so critical, knowing how to accurately determine the true compression ratio of an engine is essential. That's what this Back To Basics segment is about.

Read the tech article on an Engine Compression Guide, brought to you by the experts at Chevy High Performance Magazine.

Variable Compression Ratio Engines have been some sort of a Holy Grail, and now Porsche proposes a viable solution for this ...

In an effort to both increase engine efficiency and generate new, consistent, and reliable data useful for the development of engine concepts, a modern single-cylinder 4-valve spark-ignition research ...

An engine's compression ratio is actually a theoretical number. This ratio compares the cylinder volume of the piston at bottom dead center (BDC) versus top dead center (TDC).

That's because Infiniti is planning to roll out the variable compression ratio engine for its next generation of cars.

But too high a ratio causes knocking—premature detonation of fuel-air mixture during the engine's compression stroke caused by high cylinder temperatures.