Tag Info

New answers tagged

0

The idle speed is determined by fuel flow and air mixture based on either computer or carb/tbi - Flywheel does not determine the idle speed by only influences how easily the engine maintains its current rpm and how quickly it can increase or decrease (the answer above is slightly inaccurate to say the least) Idle speed differs by make and model and ...


0

There is nothing saying that 540 RPM is the minimum theoretical speed for engines. The idle speed is usually controlled by carburetor settings or engine computer in case of fuel-injected engines. The speed below which the engine cannot sustain itself is highly-dependent on its design and application. Usually the manufacturer will leave a little bit of ...


3

Idle speed is limited by the weight of the flywheel. A heavier flywheel allows for lower RPM idling and vice versa. If the flywheel is too light, it doesn't have enough inertia to keep the engine turning when you're not using the accelerator pedal. But if the flywheel is too heavy, the car won't accelerate fast enough. At 540 to 1000RPM idle speeds, you can ...


2

Your engine was designed in such a way that it is most efficient between 3500RPM and 5000RPM. That means that the valve timing and camshaft profiles were made in such a way that your engine "breathes" best between those speeds. That's why you have the most torque in that region. Another thing is that as the RPM increases, it gets harder and harder to get the ...


0

The engine starts to consume more power in order to keep the piston and crank at high rpm due to higher friction associated with higher rpm.


2

There are various reasons as to why an engine is not efficient beyond its tuned range. Laws of thermodynamics, I do not want to get into scientific details but it simply means that you cannot transfer heat and convert it into energy efficiently beyond a certain point where the ambient temperature and cylinder pressure start to make more impact. Geometry of ...


0

Well every car has a maximum power output. After a certain point, the engine doesn't produce any more power. The RPM power range of your engine is dictated by how powerful it is, whether it is naturally aspirated or super/turbo charged, etc... Also past the 5500 RPM point on your car is most likely hitting the "red" section of your rev counter. The extra ...


2

I'm betting your Jag is Drive-By-Wire (DBW), meaning, there isn't a direct connection between you and the throttle. If so, the gas pedal rheostat is probably telling the computer you are pressing it, causing the throttle to go up. You could possibly test the gas pedal by unplugging it and checking for even/smooth operation by putting an ohmmeter on the ...


0

I've thought about this a bit and don't see how lugging a motor could blow a head gasket. I do see, however, how lugging can do damage to other areas of an engine. That being said, lugging a motor does not give it good volumetric efficiency due to the low RPM's. Look at this way. An intake track at high RPM's creates an effect where the mass of the ...


4

Engines are designed to withstand a certain amount of stress. When you exceed that threshold, longevity will start to deteriorate. I stated something to that effect in this answer. The engine has a redline where you shouldn't take its speed past. This redline is not the maximum speed which the engine car run, but more correctly the threshold which you ...



Top 50 recent answers are included