The compression ratio isn’t just a number: it’s one of the greatest determining factors in engine building. Compression ratio determines the type of fuel, how much boost, and has a significant ...

Strictly defined, compression ratio is the total volume above the piston at bottom dead center (BDC), divided by the total volume above the piston at top dead center (TDC). First, let's look at the ...

Assuming a properly tuned engine, there are three factors that contribute to poor streetability: long cam duration, high compression ratios, and excessive cruise rpm. Since cam selection is largely ...

The theory is simple: Improve efficiency by adjusting the effective size of the engine to produce the power needed at any given moment. In practice, the hardware to do it is more complicated. Only a ...

Jonathan loves just about anything with a motor and a steering wheel. As a kid, Jonathan collected any kind of toy car he could lay his hands on, and begged his parents to take him to the monster ...

You'd think that the pistons listed for a 10.5:1 compression ratio would actually give you 10.5:1. But it's usually not that simple. Perhaps that's why so many four-wheelers have a foggy or incomplete ...

Infiniti introduced the world's first variable compression-ratio engine, a technology it claims to have been working on for two decades, at the 2017 Los Angeles Auto Show. A variable compression-ratio ...