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Diesel Component Wear Test DDA 6V-53T Engine
Performed by AC Delco Division of General Motors (GM) Five critical component areas tested:
Upper & Lower rod bearings.
Slipper bushings.
Compression & oil piston rings.
Piston rings.
The main bearings.
Conclusion: Control of particles in the 3-10 micron range had the greatest affect in reducing engine wear.
Diesel Engine Wear and Fuel Economy:
A study of twenty-two (22) 6-cylinder diesel engines performed by Fodor & Ling (affiliated with the Research Institute of Automotive Industry-Budapest and the Rensselaer Polytechnic Institute).
It was found reducing contamination from 0.016% by weight (standard oil filter) to 0.0025% with an extended filter, reduced engine wear by a factor of 14. Most significantly, friction was reduced by 2.9% when operating with clean oil. This fraction was equated to an increase in fuel economy of up to 5%. As a comparison, this significantly exceeds the 0.6 - 0.9% fuel economy gained experienced when converting from SAE 40 to multi-grade lube oil.
Survey of Diesel Engine Oil Contamination Levels
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Conclusions:
Samples of 138 engines operating with standard paper filter were compared to 117 engines operating with up-graded 10-micron filters
Based on the relationship between dynamic oil film and size of wear generating particles, the most important particle size range is 0-10 microns.
Diesel engine lube oil contamination causes wear of engine components. Wear of these components leads to loss of performance, increased maintenance and overhaul cost, lower fuel efficiency, and shorter lube oil service life.
There is a fundamental relationship between the size of contaminate particles and the thickness of the dynamic oil films developed between moving surfaces of active components. Particles the size of, or larger than, the oil film thickness cause wear of components. By making simultaneous contact with both surfaces, these particles focus the load onto a small region of the surface, resulting in surface pitting, plowing, and cutting.
The average oil film thickness associated with the majority of diesel engine components is in the 10-micron size domain. This is the size range of the most damaging contaminant particles. In addition, mechanical stress is accentuated during the high-load/thinner oil film phase of the engine cycle. In order to minimize engine wear, emphasis must, therefore, be placed on controlling particles in the 10-micron size domain.
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