Quote:
Originally Posted by JRMichler
Nissan Motor Co. was just granted Patent 8,598,098 for "A lubricant composition ... to significantly lower a friction coefficient ... diamond nano-particle"
The patent lists some test results where adding diamond nanoparticles reduced coefficients of friction. BUT, those results only apply to boundary layer lubrication. They do not apply to engine components which have fluid film lubrication. The improved friction may apply to cam lobes, especially at low RPM. Most engine components have fluid film lubrication, where the friction losses are proportional to lubricant viscosity. Since only a small part of engine friction is caused by boundary lubrication, the end result of adding the diamond nanoparticles will be only a small reduction in total engine friction. A small reduction in engine friction is an even improvement in gas mileage.
All of which is why he did not respond to my challenge to test his additive and pay double or nothing depending on the results.
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. . . If you used a 5% gain as your target. In our testing of a 2.2L diesel and gasoline engine who's bores were coated with a nano lubricant (not diamond ) after the engines had been run and broken in, the ring drag reduction resulted in an improvement of 5% for the gasoline engine and 7% in the diesel in BSFC (brake-specific-fuel-consumption) on the average. As load increased, so did the ring pressure and so did the efficiency gains. The engines were torn down for inspection and the nano lubricant applied to the bores. This pattern of tear-down and application was done several times starting with the bores, crank bearings, connection rod bearings then cam and lifters. The roller timing chain was coated in the diesel. All to identify the most promising areas to reduce friction in an engine and improve lubrication. This was part of the effort of a former Xprize team. Our tests support your conclusion that the nano lubricants would not help the areas where a fluid film lubrication mode is used and only the ring-bore has any measurable benefit.
The Nissan patent is not surprising. Manufacturers have picked over the low hanging fruit as far as efficiency gains for their engines. Modern manufacturing technology now allows engine bore treatments to be realized as most new engines need little to no break in period. Alloy liners have been used in the past. BMW uses laser fused bores on some of their engines. If Nissan has found a way to apply nano diamonds in a production setting, it can only help their engine efficiency and longevity.