Two-stroke? Forced induction? Compression-ignition-capable? That is many unexpected engine technologies combined into a single engine.

The two-stroke gasoline engine was once a marvel of engineering, offering up huge doses of power in small and lightweight ...

Two power strokes and two compression strokes per cycle. Generally, the biggest difference between a typical 4-stroke engine and the 6-stroke design is in the cam and valve timing.

"This two-stroke engine could solve these practical difficulties and simultaneously permits a much larger range of compression ratio adjustment," added the official.

Once thought too polluting, the two-stroke engine makes a comeback in advance of stricter fuel efficiency standards.

As it turns out, you can indeed build a two-stroke engine from scratch, using little more than some metal piping and other parts from the hardware store.

Now, here’s the thing: this motor isn’t a one-stroke engine. It has a compression stroke and exhaust stroke, making it a two-stroke cycle.

Is this high-revving, two-stroke, flex-fuel, 106-pound, 173-horsepower, parallel-twin engine really all it’s cut out to be?

This New Two-Stroke Engine Design Could Help Keep Internal Combustion Around Longer Engines using "entry ignition" could be up to 14 percent more efficient than a traditional internal combustion ...

We found that patients with RVLM vascular compression had a greater variability in blood pressure during the acute ischemic stroke phase, which may be related to poorer prognosis.