No compression-ratio calculation is worth spit if the numbers used to calculate it are wrong. In the old days, a lot of the chamber volumes published for stock heads were NHRA minimum-legal blueprint ...

A remote starter switch and a top-quality, screw-in-type compression gaugeâ such as these models from Sears, Roebuck & Companyâ can be used to measure the pumping efficiency of an engine, as well as ...

You've heard the term compression ratio before, but have you ever wondered exactly what it means? Well, it's time to explain exactly what compression ratio is, and why every carmaker is now obsessed ...

A gasoline piston engine that can dynamically change its compression ratio —that is, the amount by which the piston squeezes the fuel-air mixture in the cylinder—has long been a holy grail of engine ...