Hi Guys,

What are the main facts that messure the performence of engine ? is it horesepower ?
Can any one explain me clearly
"as my knowledge more horsepower mean more powerfull engine" are there any other factors like rpm, kw etc ? can somebody correct me

Thanks
Regards
Sumith

sheez where do u start in answering that,
hp= rpm x torque... 4hp =3kw approx.

J-mac?

Hi 1000Coupe

OK , so simply more hp means more power , will there is a change in performence changing the Torque and rpm ratio like below

10 T(Torque) X 4000 RPM
8T X 5000 RPM

Is there any change in those 2 performence ?

Thanks
Regards
Sumith

horsepower and kilowatts are a measure of power....like a kilometer is a measure of distance

there are many things that will change how an engine will perform, simly knowing the peak power and peak torque doesnt really tell you much about how it will perform

This article will tell you a bit more I think Sumith.

http://www.allpar.com/eek/hp-vs-torque.html

It gives a good real life example of torque and power - and their relationship (roughly) to acceleration.

HP is derived from torque and engine speed.

Torque is mesured in foot pounds.
Eg. imagine you had a leaver arm 1 foot long mounted from the centre of the flywheel and the engine could lift 1 pound of weight attached to the end of this arm. In this case your engine is making 1ft lb.

Or just like the reading on a torque wrench in foot pounds.

HP is the speed that the tourque is being produced.

The formula is: (ft lb x rpm) divided by 5252

So if your engine is producing 100ft lb at 5000rpm it it making 95.2 hp at that speed.

100ft lb at 10,000rpm is 190.4 hp at that rpm.

None of that is "performance" -- just power measurement.

Typical Performance measurements are:
* 0-60 mph time (or 0-100 kph time)
* 1/4 mile trap speed or elapsed time
* Fuel economy rating
Look for B210 to do a 1/4 mile in 20 secs.
Quick cars are in the 15 sec. range. Fast cars in 14 sec. range. Few cars in 13 sec range.

Not that's performance.

Quote:

thats correct, the 2 examples will amount to the same hp. now in the real world first example will feel better to drive with the more usable power for the road.

where u list torque as "T" , the proper measure is ft/lb (foot/pounds) imperial measurement or Nm (newton metres) metric.

but u get the basic idea, a more extreme example would be to compare a small diesel ute or van and motorbike engine of similar cc's the motorbike might make 100hp @ 12000rpm and only 80Nm@10000rpm torque

and the diesel might make 100hp and 300Nm torque at around 1500rpm.

obviously u cant use the motorbike engine to power the loaded ute or van because it just wont get going through the low revs where there is no torque,

and u cant use the diesel engine to make the motorbike do 300kmh because it just wont rev high enough.

so dealing with the engine alone, not taking into account weight, gearing, aerodynamics, friction loss, air temp, and all the other black arts variables.