engine question

[xox]

just wondering, what's the significance of the engine's hp, torque, displacement, # of cylinders, # of valves, to its power. looking at these values, how do u know if an engine is powerful? accelerates fast? etc kc i've noticed for ex. there are cars with low hp but high torgue, high hp but low displacement etc.

[empy]

hp will tell you how much power an engine makes when it reaches its optimal rpm range...it influences how fast your car can go, but not so much how much it accelerates. typically, however, hp = power

torque tells you how much 'pull' the engine has, or that jump off the line and the force that pins you back in your seat. high torque typically means good acceleration but not always. the best test of acceleration will always be tested 1/4 mile times and trap speeds

high-displacement (big) engines make more power more easily and effortlessly (think american musclecars). that can be overcome, however, by smaller, very high-revving engines (honda s2000) or forced induction (lancer evolution)

the bigger engines typically have more cylinders...more valves mean that an engine can get fuel in and out of the combustion chamber more quickly - which means more power.

[pajerokid]

The more of these, typically, the faster. Of course, primary point of comparison among engines is displacement followed by confiuration,

Originally posted by xox
just wondering, what's the significance of the engine's hp, torque, displacement, # of cylinders, # of valves, to its power.

[OTEP]

I usually look at how much power and torque it has and at what RPM they are available. A high powered engine which produces peak power at high revs is not very useful in slow off-roading and in stop-and-go traffic.

A small engine producing high power figures tends to be more stressed than a bigger engine producing a similar figure.

The vehicle performance is determined by actual track testing and not just by looking at the specs.

[Drexx]

28Jan2004 (UTC +8)

Low HP vehicles with relatively high torque are typically diesel engines. They make most of their power in the low rpm range --which is great for slugging it out in the city streets, and/or pulling heavy loads, and low rpms will make the engine last longer.

High HP cars with relatively low torque are typically the Fast-And-Furious compact cars with gasoline engines. They have a high tops-speed, and reach peak power only when revved like crazy. Of course, you can't expect its engine to last as long as the diesels.