NMWR-9-2815-220 Overhaul Manual for M60 M88 Engine AVDS-1790-2CA, AVDS-1790-2DA, AVDS-1790-2DR Download
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NMWR 9-2815-220 FINAL ASSEMBLY AND TESTING—Continued 0047 00 FINAL PERFORMANCE CHECK – Continued e. Brake Specific Fuel Consumption. The brake specific fuel consumption is determined as follows: Brake specific fuel consumption = obs. fuel flow (lb/hr.) x CF F corrected gross brake hp. f. Brake Specific Oil Consumption. The brake specific oil consumption is determined as follows: Brake specific oil consumption = obs. oil consumption (lb/hr.) corrected gross brake hp. g. Example. The following is an example showing how the above formula information is used in determining various log sheet data. (1) Operating Parameters. For this example, the following hypothetical engine operating parameters are: engine rpm = 2400 rpm beam/torque = 255/1340 wet barometer reading = 29.64 in. Hg. dry barometer reading = 29.35 in. Hg. average air entry pressure in inches H O = 0 2 average air entry temperature = 88° F (31° C) fuel temperature = 70° F (21° C) fuel flow = 308 lbs/hr. (2) Correction Factors. The required factors are determined from the parameters listed above using Tables 2 through 5 as follows: (a) The dry entry pressure correction factor is calculated by subtracting the difference between atmospheric and actual at inlet to turbo in inches Hg from the dry barometer reading. 29.35 – 0 = 29.35 in. Hg. and this value is used to find the correction factor (1. 00670) listed in Table 3. (b) The average air entry temperature correction factor for 88° F (31° C) is 1.01540, as listed in Table 2. (c) The fuel temperature correction factor for 70° F (21° C) is 1.010, as listed in Table 4. (d) The total correction factor is then calculated as the product of the three correction factors as follows: 1.00670 x 1.01540 x 1.010 = 1.03240 0047 00-6 Change 1