Mechanical Efficiency; Torque; Conversion - Royal Enfield Bullet Classic EFI Service Manual

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 engine
components.
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
Indicated Horse power

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
= BHP
IHP
1HP (Horse
Power Available
after explosion)
FHP (Frictional
Losses)
BHP (Horse
Power Avaiable at
Crankshaft)
02-4