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The World's Most Powerful Diesel Engine
trex279 writes "The Wartsila-Sulzer RTA96-C turbocharged two-stroke diesel engine is the world's most powerful diesel engine built to date. Each cylinder displaces a whopping 111,143 cubic inches (1,820 liters, equivalent to a cube 4 feet on a side) and produces 7,780 horsepower. The engine is about the size of a small building." The engine is intended for use in container ships.
Not even close to as bad as gas. Gas 2 cycles have nasty problems due to the lube oil being in the gas (doesn't burn well, otherwise it wouldn't lubricate) and the intake/exhaust ports being open at the same time (and hence you get unburned crap blowing right through). All of this is for simplicity, and it does work. A 2 cycle gas engine is an exceedingly simple contraption, and will almost run in spite of anything you do to it.
2 cycle engines are very common once you start moving up into the larger diesels. They're very different creatures, though they operate on similar principles. Diesel 2 cycles have separate lube oil in the crankcase, similar to 4-cyc gas engines. Thus, no continuous cloud of semi-burned lube oil coming out. Also, they're all (at least all that I've ever seen) direct injected, meaning fuel is delivered directly to the cylinder once the intake/exhaust ports are closed, thus no unburned fuel flows through.
Since diesel cylinder always get a full air charge, 2 cycle makes since - it's simple, and since you're only flowing air, you don't have the wasted fuel as in a gas 2cyc. As a by-product, you also get twice as much power from the same space as the equivalent 4 cycle at equal rpms. They do have more particulate problems, but these have been resolved well enough in the last few years to meet the new EPA Tier II diesel exhaust requirements.
vary the power output based on amount