TM 5-2420-230-24-2
Engine Testing (Chassis Dynamometer) (014-002)
B3.9 and B5.9 Series Engines
Page 14-4
Section 14 - Engine Testing - Group 14
Engine Testing (Chassis
Dynamometer) (014-002)
Setup (014-002-011)
The performance of an engine installed in on-highway ve-
hicles can be tested on a chassis dynamometer.
NOTE: Due to driveline efficiency and engine-driven ac-
cessories, the engine horsepower when measured at the
rear wheels will be reduced by approximately:
20 percent for single-axle vehicles
25 percent for tandem-axle vehicles
NOTE: These percentages are used for engine run-in only
and are not to be used as absolute figures.
WARNING
Follow all the vehicle manufacturer's safety precau-
tions before installing or operating a vehicle on a chas-
sis dynamometer. Failure to do so can result in personal
injury.
CAUTION
Low-profile radial tires are more sensitive to heat than
bias-ply tires. Excessive operating time at full load can
damage tires due to overheating. Check the tire manu-
facturer's recommendations for the maximum allow-
able chassis dynamometer operating time.
Follow the general safety precautions listed below while
operating the chassis dynamometer:
Use tires that have more than 160 kilometers [100
miles] on them. Do not use new tires.
Do not use recapped tires or tires of different sizes
or designs.
L-1302
