The engines, built primarily by Aioi Works of Japan's Diesel United, Ltd, are available in 6 through 14 cylinder versions, all inline engines.

The cylinder bore is just under 38" and the stroke is just over 98". Each cylinder displaces 111,143 cubic inches (1820 liters) and produces 7780 horsepower. Total displacement comes out to 1,556,002 cubic inches (25,480 liters) for the fourteen cylinder version.

That means the 89 foot long 14 cylinder version produces 108,920 HP and 5,608,312 lb/ft of torque at 102 rpm. Not bad. It also weight 2300 tons with the crankshaft alone weighing 300 tons. Our only question — does it fit in a Fiero?

[bath.co.uk via TTAC]

Unlike its conventional counterpart, the free-piston engine doesn't have a mechanical connect between the piston and a crankshaft. Instead, magnets at the center of the piston's rod move past metal coils to create an electrical current. The engine's configuration allows it to combust fuel quicker, improving efficiency, emissions and easily optimized for different fuels.

The bad news: they're hard to control (variations in combustion cycles can cause poor performance) and they're incredibly loud (the quick explosions need to be muffled somehow). But automakers such as GM and Volvo are already investigating putting the engines in future vehicles. Lets hope their forays into this don't take as long as their exploration of fuel cell options. [Technology Review via Treehugger]