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Piston and cylinder wall finishings

Do you know of any possible contact material between an engine's piston rings and cylinder wall (or piston and cylinder wall) that would eliminate the need for lube oil and still get the same (or better) operating life under the following conditions: The pistons are always square in the cylinder. Side thrust is completely eliminated. There are 1240 power strokes/min at peak power (120 hp). The peak combustion temperature at peak power is 2400 deg R = 1940 deg F.

Robert L. Giuliani
- Honolulu, HI, USA
2002

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No. the idea that oil is simply a lubricating system is too simplistic. It also acts as a coolant. In theory you could use a dry lubricant such as Molybdenum disulfide, but this does not offer the cooling properties and the engine will seize. Better coolants lack the lubricating characteristics of the oil, especially at the high temperatures. If you want to make the engine more efficient, try developing a low burn temperature engine with an all plastic construction, but then there will be a problem with the thermodynamics. You may also want to consider the pressures generated in an internal combustion engine.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2002