Service manual

02-5
IHP :
IHP stands for Indicated Horse Power. Indicated
Horse Power is the power actually developed inside
the engine cylinder by combustion process. It is
utilised to drive the piston.
FHP :
FHP stands for Frictionl Horse Power.
It is the amount of horse power used or lost to
overcome the friction between various moving
components of the engine.
BHP :
BHP stands for Brake Horse Power
Brake Horse Power is the amount of Power
actually available at the crankshaft or output
shaft. It is calculated by using dynamometer.
BHP = IHP - FHP
Mechanical Efficiency :
Mechanical Efficiency is the ratio between Brake horsepower and Indicated horse power.
Brake horsepower
=
BHP
Indicated Horse power IHP
TORQUE :
Torque is a twisting or turning force or effort. It is the product of a distance and force in
circular motion.
In the picture shown the torque-applied is the
product of distance (distance between the center
of the bolt and point where force is acting) and
the amount of force applied.
With the same force, if the distance is increased,
the torque will also increase and if distance is
reduced, torque applied will also be reduced.
CONVERSION :
1kg-m = 7.23 lb.ft = 9.81 N-m.
1lb.ft = 0.138 Kg-m = 1.356 N-m.
1 N-m = 0.102 Kg-m = 0.737 lb.ft
1HP (Horse
Power Available
after explosion)
FHP (Frictional
Losses)
BHP (Horse
Power Avaiable at
Crankshaft)
Basic Terminology of IC Engines