The friction mean effective pressure (fmep) contribution of piston assemblies running under motored engine conditions in cylinders with plateau or laser honed bores has been investigated. Results have been obtained for engine speeds in the range 400-2000 r/min and temperatures from -20 to around 60℃. The fmep of the piston assembly is observed to depend most directly on oil viscosity evaluated at the temperature of the cylinder wall at mid-stroke position. The variation of fmep with viscosity provides a basis for comparing the effects of surface finish or piston design modifications. Using liners with fine honed bores reduced piston assembly friction by between 3 and 20 per cent relative to results for pistons running in plateau honed bores. Piston assembly friction was reduced by between 5 and 38 per cent through design changes to the pistons.
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机译：已经研究了在具有平坦或激光珩磨孔的气缸中在机动发动机条件下运行的活塞组件的摩擦平均有效压力（fmep）贡献。在400-2000 r / min的转速和-20至60℃的温度范围内，已经获得了结果。观察到活塞组件的fmep最直接取决于在冲程中部位置在气缸壁温度下评估的机油粘度。 fmep随粘度的变化为比较表面光洁度或活塞设计修改的影响提供了基础。相对于在平坦的珩磨孔中运行的活塞的结果，使用带有细珩磨孔的衬套可将活塞组件的摩擦力降低3％至20％。通过对活塞的设计更改，活塞组件的摩擦力降低了5％至38％。
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