25 Mar 2014, 11:18 pm
#14
(25 Mar 2014, 9:57 pm)Andreos Constantopolous 240 bhp is quite frankly shocking.
There are some cars with even more bhp than the bus engine!
I realise that your comment was accompanied by a smiley and therefore not confrontational, however for those who didn't notice, the 240 bhp engine in the bus will be operating at half the revolutions per minute that the 240 bhp car engine will need to achieve that figure - so the bus engine
torque will be twice that of the car engine.
Think of
pushing the bus - the effort (torque) available from the bus engine will be twice that available from the car engine and assisted by the torque converter ratio ( 1.968:1 ) it will be four times that of the car engine.
Power (bhp) indicates the
rate at which the effort can be applied - it is defined as the amount of energy consumed per unit time - power is the rate at which this work is performed.
The same amount of work is done when carrying a load up a flight of stairs whether the person carrying it walks or runs, but more power is expended during the running because the work is done in a shorter amount of time.
Agreed that the bus is much heavier than the car, but the gearing compensates for that - though the bus will
not accelerate as quickly as the car of course!
It's not that long ago when truck and bus engines of 240 bhp would have been considered 'top of the range', and 140 bhp considered 'adequate' for 24 tons (6 bhp per ton was the maxim)
(OK, maybe that was 40 years ago . . . )
