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 ...

Every engine has a specific compression ratio. The air-fuel mixture is compressed in the cylinder to create an ignition, the force of which depends on the compression ratio: the volume of the cylinder ...

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 ...

In a conventional piston engine, the compression ratio defines the relationship between the largest and smallest volume of a cylinder - when its piston is at bottom dead centre and top dead centre ...

It seems like every major automaker these days is using tricks like variable-valve timing – often in conjunction with forced induction – to eke better efficiency out of their engines while still ...

“Too little compression will usually result in unmet performance expectations. On the high side [too much compression] carries greater risk in tuning and potential component failure if appropriately ...

IRVINE, Calif.—Despite rumors to the contrary, the internal combustion engine is far from dead. Recently we've seen several technological advances that will significantly boost the efficiency of ...

With every passing day the Mule provides opportunities beyond our original expectations. Since the 467ci engine belongs to HPP editor Tom DeMauro, it is at our beck and call. This affords HPP the ...

Does “the world’s first production-ready variable compression ratio engine” mean anything to you? For general automotive consumers, perhaps not a thing – at least, not yet. But that’s the big selling ...

Mazda‘s upcoming SkyActiv-G engines will get a 14:1 compression ratio, the highest in the world for a gasoline engine, according to a report in Autoweek. Most cars run compression ratios of 8.5:1, ...

Turbocharging has mostly not lived up to its billing of being the savior of internal-combustion engine technology. Earlier this decade, facing increasing fuel economy requirements, automakers rushed ...