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In support of the Department of Defense goal to streamline procurements, the Army recently decided to discontinue use of VV-F-800D as the purchase specification for diesel fuel being supplied to continental United States military installations. The Army will instead issue a commercial item description for direct fuel deliveries under the Post-Camp-Station (PCS) contract bulletin program. In parallel, the Defense Fuel Supply Center and the U.S. Army Mobility Technology Center-Belvoir (at Ft. Belvoir, VA) initiated a fuel survey with the primary objective to assess the general quality and lubricity characteristics of low sulfur diesel fuels being supplied to military installations under the PCS system. Under this project, diesel fuel delivery samples were obtained from selected military installations and analyzed according to a predetermined protocol.

This paper is the second of two that describe the effects of low-lubricity fuels on diesel injection pump performance. The first paper describes the primary failure mechanisms and wear processes in a number of failed pumps removed from both military and civilian vehicles that had been operated on Jet A-1 and diesel fuels. However, the multitude of unregulated parameters in practical operation renders quantitative comparison between different fuels and pump combinations impractical. This paper describes the degradation in pump performance and the wear processes associated with fuels of varying lubricity in the well-defined environment of a pump test stand. The test methodology concentrates on those areas previously demonstrated to be most susceptible to wear. The results indicate that pump durability is reduced by highly refined low-viscosity fuels, but may be successfully counteracted by either improved metallurgy or lubricity additives.

The U.S. Department of Defense has adopted a concept in which a single fuel will be used on the battlefield; diesel fuel will be replaced by JP-8/JP-5/Jet A-1 in compression ignition engines, thereby decreasing the fuel logistics burden. JP-8 fuel has successfully undergone extensive testing in both the laboratory and in field trials. However, increased failure rates for fuel-lubricated rotary injection pump components operating on Jet A-1 aviation turbine fuel were reported during Operation Desert Shield. This paper is the first of two and describes the disassembly and failure analysis of twelve rotary fuel injection pumps that operated on Jet A-1. Also disassembled as a baseline for comparison were three additional pumps from civilian vehicles that had operated on commercial diesel. Each of the pumps had a unique service history, making quantitative comparison difficult.

A technology demonstration program was conducted by the U.S. Army to verify the feasibility of using aviation turbine fuel JP-8 in all military diesel fuel-consuming ground vehicles and equipment (V/E). Over 2,800 pieces of military equipment participated in a two and one-half year program accumulating over 2,621,000 total miles (4,219,810 km) using JP-8 in combat/tracked, tactical/wheeled, and transportation motor pool vehicles. Over 71,000 hours of operation were accumulated in diesel/turbine engine-driven generator sets using JP-8 fuel. Comparisons of various performance areas with baseline diesel fuel (DF-2) operation were made.

A technology demonstration program using modified administrative-type vehicles was conducted by the Army to determine the feasibility of using methanol as an alternative fuel. Over 1,026,000 miles (1,651,190 km) were accumulated using 64 sedan and pickup vehicles. Approximately 750,000 of these miles (1,207,010 km) were accumulated using M85 methanol fuel. Using M85 increases the fuel cost by a factor of approximately 3.0. No catastrophic engine failure occurred with the use of the M85 fuel. Even though wear rates, indicated from used oil samples analyses, obtained when using M85 fuel appear to be 2 to 4 times those obtained using unleaded gasoline, actual wear, from inspections and measurements, does not appear to be as severe. M85 refueling stations were set up at four fleet test sites, and no significant operational or safety problem was encountered during the program.

A high-output Army two-cycle diesel engine was subjected to proving-ground related laboratory-dynamometer endurance test cycles using four different qualified MIL-L-2104C SAE grade 30 lubricants. Three diesel fuels differing mainly in sulfur level and end point temperature were an important part of the test matrix. Two lubricants (low- and mid-ash level) produced acceptable performance and a third (of high-ash level) was considered borderline acceptable--all during operation with reference No. 2 diesel fuel (0.42% wt sulfur). A fourth oil (low-ash level) was judged to be incompatible due to its proneness to severe piston and liner scuffing. The engine was judged incompatible with a high sulfur/high end-point [1.2%S/396°C (744°F) EP] fuel intended to meet MIL-F-16884F (Marine Diesel Fuel) using two different MIL-L-2104C lubricants. This engine was also judged to be incompatible with a special blend of NATO F-54 diesel fuel (0.64% sulfur) during operation with the same two lubricants.