Engine Testing (Chassis Dynamometer) (014-002)
B3.9 and B5.9 Series Engines
Section 14 - Engine Testing - Group 14
Engine Testing (Chassis
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.
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
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