Why do 16 valve 4 cylinder engines have to be revved so high to get that extra power?

Question

The difference in the power felt after 3000 rpm is pretty dramatic. I'm trying to figure out why it can't be that powerful all the time.

Answer 1

Their is a constant of 5000 something that is used to determine horsepower. When this number is divided into the rpm's it give you horsepower. So the more the rpm's the more horsepower. This is why turbines create so much horsepower. Typical rpm's for a Turbine is about 15000.

Answer 2

There are several factors. For example, an engine usually produces more torque at higher RPM's, so more RPM's traditionally means more torque. Torque is the force that actually moves your vehicle. Also, 4-cylinder engines are traditionally smaller in size, or displacement, and increasing displacement (as in the case of big block engines like the 454 Chevy and 6.0L diesel engines Ford uses in trucks) is an easy way to increase the amount of torque an engine produces. There are other factors of course, but torque and horsepower in relation to RPM's can most accurately explain why you need a lead foot to get a Honda Civic DX up to highway speeds without getting run off the road.

Answer 3

Ok there i s a thing called a power band. when you rev the engine it develops power but not until you hit this power band. Once you reach this power band even if you rev higher it will not develop more power. So this power band is between 3000-6000 rpm's That is also why cars have a red line. this line tells you are over riving the engine and not making any more power.

Answer 4

the simple answer is the more fuel in and the more exhaust out,the more power,this is done by getting the engine to rev-up,,all race cars use very high rpm,s to produce the power they need to go fast. the four valves per cylinder are there to get the fuel in and out of the chamber......faster thats all

Answer 5

The extra valves make it possible for more air to flow into the engine. However, to take advantage of this, you need to spin the engine to a high RPM so that there is a large amount of air flowing into the engine.