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Why the valve lift of intake valve is gretter than exhaust valve?
Wiki User
∙ 14y ago
For the same reason the intake valve is larger:
- The intake charge is driven into the cylinder by 15 psi (1 bar) approximate atmospheric air pressure.
- The exhaust is driven out of the engine by several hundred to a couple thousand psi of burnt exhaust pressure.
Wiki User
∙ 14y ago
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The vertical travel distance of a intake or exhaust valve is called the?
The vertical travel distance of a intake or exhaust valve is called the lift. Valve timing and lift is critical for a properly running engine.
The vertical travel distance of an intake or exhaust valve is called the?
Lift
The vertical travel distance of an intake or exhaust valve is called?
lift
Which is bigger valve compare with inlet valve and exhaust valve?
Because much smaller than the exhaust air flow velocity, in order to reduce intake resistance and improve gas flow, to increase engine power! Some of the engine intake lift not only large, more than the intake valve (eg, five-valve, into the 3 row 2), valve diameter, but also large!
What does EGR valve lift insufficient mean?
The exhaust gas recirculation system (EGR) is an emissions control system that recirculates some of the exhaust gas back into the intake in order to re-burn any excess fuel vapor that leaves the engine. It is basically operated by a valve to control circulation. "Valve lift insufficient" means that the valve is not opening enough to circulate exhaust gas as much as the engines computer deems necessary. The vehicle will not pass an emissions test in this condition.
Do you need more or less valve duration for low to mid power?
more period. although variable valve timing changes both intake exhaust independently, so for a cam grind that is to be one lift,duration more is better.
The vertical distance of an intake or exhaust valve is called?
The question is a little vague. So i hope i give the answer you were looking for. The vertical portion of the small diameter of the valve is called the stem. The vertical opening distance is called valve lift. The entire length of the valve would be the overall length. Hope this may help?
What should intake and exhaust valv clearances be set to on a 350 with aftermarket camshaft?
If it is a solid lift cam, Then the valve specs will be written on the cam card that came with the cam. If it is a hydraulic lifter cam shaft then you adjust the valves like any other camshaft.
What is the valve clearance for 1983 Yamaha virago 500?
The valve clearance for the 1983 Yamaha Virago 500 is 7.2 mm. The exhaust valve lift is 7.7 mm. The vehicle gets on average 51 miles per gallon.Ê
What is special in BMW cars when compared to others?
The amount of technology, advanced features. -They are the only manufacturer to have a constantly variable runner length intake manifold. -First drive by wire car -First electric parking brake -Vanos, the first constantly variable valve timing for intake and exhaust -Valvetronic, the first continuously variable valve lift system - First Dual metal engine block -first production ready hydrogen vehicle
Is a 2000 Dodge Dakota 3.9 liter an interference engine?
Yes, they are an interference motor. the intake valve will hit the piston at full lift and tdc.
How does a racing cam work?
The purpose of a racing cam (sometimes called off-road cam because they frequently do not meet emission standards) is generally to get more air into the combustion chamber. More air equals more fuel which means more power. Contrary to popular belief, air is not "sucked" into an engine but it is "pushed" in by the air pressure in the intake manifold. If the engine is naturally aspirated, then that air pressure is the atmospheric pressure around the engine which is less than 15 pounds of force per square inch. The primary goal of a racing cam is to minimize obstructions to the air that is pushed through the engine. To do this, cam designers generally look at three areas: Lift, duration, and overlap.Lift determines how high off the seat the valve is lifted by the cam lobe. Very generally, higher valve lift means more air flow into the engine. It is very much like a window in your house; the higher you open it, the more air can flow through the window. But there are issues with high valve lift. The valve has mass and is moving. That means the valve must accelerate and decelerate. Higher valve lift means that the valve must accelerate more quickly to move the greater distance in the same amount of time. This acceleration can become so large that the valve's momentum (inertia) keeps it moving even when it has reached its designed height. This is called valve float and very bad things can happen when valves float - if they strike the piston mechanical failure is almost certain. To prevent valve float, more powerful springs must be used. These stronger springs exert greater pressure on the valve train and can cause premature wear. The greater speed of the valve and the greater height of the valve can also cause the springs to fail prematurely. So the cam with the biggest lift is not always the best choice.Valve lift for intake and exhaust valves are frequently different. Becuase the exhaust gases are being pushed out by the piston and the rapidly expanding flame front, exhaust valve lifts are generally not as high as intake valve lifts.Duration determines how long the valve is open. The longer the valve is open, the more time that is available for the air (or exhaust gases) to be pushed into or out of the cylinder. More time generally equals more air. But just as with lift, bigger is not always better. To open a valve longer means that it has to open sooner or close later, or both. But opening an intake valve too soon may allow combustion gasses to escape into the intake, robbing power and disturbing the incoming charge. Closing an exhaust valve to late can also rob power by allowing unburned fuel to escape the engine. And in general, the longer the duration the lower the effective compression ratio at most RPMs. So, like lift, the longest duration is not always the best.Overlap is the amount of time that both valves are open at the same time. There are many good reasons to have both valves open at the same time. As mentioned, this can allow the incoming air/fuel charge fuel to escape the cylinder unburned. But consider the overall movement of the air/fuel charge through the engine. The greater the velocity that it moves, the greater the momentum it has (the air and the fuel have mass, thus they exhibit the tendency to stay in motion). If the movement into the cylinder through the open intake valve can be accelerated by allowing some of the charge to escape through the open exhaust valve, the higher air flow velocity may actually fill the cylinder with more air/fuel than if the exhaust valve closed sooner. This is somewhat like a "ram air" effect. Also, the exiting unburned air/fuel may also have a cooling effect on the exhaust valve, preventing the valve from overheating and burning. So the loss of unburned fuel may actually help make more power at certain RPMs.The higher the overlap of the intake and exhaust valves, the more unstable the engine operation is at low RPM speeds. This accounts for the "lopey" sound of a racing engine. This results in pushing up the RPM where peak power is produced. In general, the greater the overlap, the higher the RPM where peak torque is produced. So like the other two, the cam with the greatest overlap is not always best.
