Evaluation of Future Fuels in a High Pressure Common Rail System. Part 3. John Deere 4.5L Powertech Plus

Abstract : A series of fuels were tested on a bench stand designed and constructed for the John Deere 4.5L Powertech Plus High Pressure Common Rail Fuel System manufactured by DENSO Corporation. Included were ULSD, an additized Jet A to represent JP-8, an FT SPK, and blend of the Jet A and SPK fuels. Testing occurred at 60, 82.8 and 93.3?C over a 400-hour NATO cycle. Fuel viscosity ranged from 0.57 to 1.90 cSt while lubricity wear-scar diameters were from 0.54 to 0.68 mm (ASTM D5001) and 0.47 to 0.84 mm (ASTM D6079). At the conclusion of each test, components were evaluated for wear and overall system performance with the ULSD test as a baseline for comparison. Results showed the system to be sensitive to fuel viscosity. The three evaluations which had a fuel viscosity at test temperature of 0.61 cSt or lower failed between four and five hours of test time. All other evaluations completed the full 400 hour cycle. The eccentric lobe on the fuel pump cam shaft was identified as the critical area for fuel compatibility. No issues were found within the fuel injectors regardless of viscosity or lubricity levels.