The Second Version

18/06/07

Piston Engine

It seems all the rage today to revile piston engines and desperately seek some other device to turn chemical energy into kinetic energy.

But the piston engine is, in fact, a great engineering achievement. It left steam engines in the dust as a matter of energy efficiency and performance (turbine/jet engines are external combustion, and they are marvellous too). In its story slightly longer than a century, it has successfully powered the most disparate vehicles and fixed installations all over the world- land, sea, air; from the scorching heat of deserts to the freezing cold of Antarctica.

Piston engines come in a huge variety of sizes and shapes: from the tiny but fast & furious 2-stroke nitro engines employed in RC vehicles, to the gigantic diesels that move ocean ships around*. This V10 4-stroke petrol engine instead propelled the Ferrari F1 car to its victory in the 2003 championship; it produces some 900 hp at 19 000 rpm and has to last a few hundred kilometers at least. Top Fuel dragsters have supercharged engines that generate over 7000 hp, burning a mixture of nitromethane and methanol as fuel. The downside is, such a monster has to be rebuilt every run even if it doesn't blow up - a not so uncommon occurrence. This aircraft engine made a good deal of difference during WWII.

Small petrol engines, 1 to 2 liters displacement, are the most common power plants for small cars in Europe, Japan and increasingly the USA: they provide good performance, great fuel economy and a durability of 200 000 km; but for maximum durability I suggest an oilfield mechanical rig power engine - slow, but steady and sure.

Piston engines can run on a variety of fuels: hydrogen, methane, natural gas, gasoline, diesel, biodiesel, kerosene (word is that Jet-A makes a passable substitute for diesel) methanol, ethanol, nitromethane... and the low-quality fuels available in backward areas. Also the success of liquid hydrocarbon fuels is easy to understand: they are cheap, do not require advanced technology (at least the basic versions); are easy to handle and store; they are not too dangerous nor toxic - and pack a considerable amount of energy per volume unit.

And let me tell you, against the odds the piston engine will remain with us for quite some more time.

*The article says the engine is built by a Japanese company, but the writing on the signs in the factory is clearly Korean.

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