0
Having the exhaust valve still open when the intake starts to open uses the exhaust "pull" out the exhaust port to help start the intake charge entering the chamber -- before the piston has started down and has generated it's own vacuum. Also, leaving the valves open longer (duration) increased the density of the intake charge and allowed the headers to better scavenge the exhaust gasses out.
Add your answer:
Earn +20 pts
How important to change PCV valve Nissan pickup 1994?
It is very important to change PCV valve. If valve is old it will plug or seize. This will cause oil pressure to rise and may cause leaks. Most likely the valve cover gaskets will leak if PCV valve is plugged.
What is overlapping of valves?
Valve overlap occurs in a four-stroke engine at the end of the Exhaust stroke and at the beginning of the Induction stroke; and is when both the exhaust and inlet valves are open at the same time. At the end of the Exhaust stroke, the Exhaust valve is closing and the Inlet valve is starting to open in preparation for the induction of fuel and air into the cylinder. It is common knowledge that in vehicles that cannot alter the valve timing, the Inlet valve opens approx 6 degrees before top-dead-centre and the Exhaust valve closes at 9 degrees after top-dead-centre
What makes flames come out your exhaust?
Usually a product of valve overlap and exhaust. It's basically unburnt fuel coming through and igniting on the hot exhuast tip when it hits the air at the end of the exhaust pipe. In aspirated cars it's large valve overlap which helps scavenging and performance in the top end. Turbo cars, due to the large amounts of fuel at full noise. Normally happens after high RMP then throttle snapped shut.
For what reasons may an aortic valve replacement surgery be needed?
Aortic valve replacement surgery will be required if the valve in the heart is either too narrow for all of the blood to pass through or if the valve is leaking. This valve is very important as it prevents blood from rushing back into the heart after it has been pumped out.
What is the prognosis for aortic valve insufficiency?
The faulty working of the aortic valve can be caused by a birth defect; by abnormal widening of the aorta (which can be caused by very high blood pressure and a variety of other less common conditions).
Where is the EGR valve on a 1997 Hyundai Elantra?
Does not have one. The engine uses cam overlap to achieve the effect of the EGR valve.
What does the term valve overlap mean?
Valve timing overlap is the time when both exhaust and intake valves are open most engines with catalytic converters require valve overlap in order to send a small amount of raw fuel/ air mix to the converter's. An "open cam" has valve overlap a "closed" cam does not
What is valve overlap?
Valve overlap occurs in a four-stroke engine at the end of the Exhaust stroke and at the beginning of the Induction stroke; and is when both the exhaust and inlet valves are open at the same time. At the end of the Exhaust stroke, the Exhaust valve is closing and the Inlet valve is starting to open in preparation for the induction of fuel and air into the cylinder. It is common knowledge that in vehicles that cannot alter the valve timing, the Inlet valve opens approx 6 degrees before top-dead-centre and the Exhaust valve closes at 9 degrees after top-dead-centre
What is purpose of valve overlap?
It improves the efficiency of the engine by allowing better exhaust out flow and intake in flow.
When the intake and exhaust valves are both open at the same time that length of time is called?
Valve overlap.
What does a overlap valve do?
send a small amount of raw fuel/air to the catalytic convertor,which increases the efficiency of the operating engine.
What are the disadvantages to have a large valve overlap?
High end Rpm output tails sooner, engines idle is lumpy, emissions are higher, too much overlap can cause rough low rpm driving, more chance of detonation.
What is meant by the term valve overlap?
There is a short time between the exhaust and intake stroke where all the valves are slightly open at the same time. This period of time is called valve overlap. This is because the intake valves are just starting to open as the exhaust valves are just finishing closing. This is done so flow through the engine can be maintained at engine operating speeds.
How important to change PCV valve Nissan pickup 1994?
It is very important to change PCV valve. If valve is old it will plug or seize. This will cause oil pressure to rise and may cause leaks. Most likely the valve cover gaskets will leak if PCV valve is plugged.
When valve overlap happens to aircraft reciprocating engine?
High performance piston aircraft engines do have valve overlap, just like high performance engines used in land vehicles, and for the same reasons. Listen to the Continental O-470, IO-520, IO-550, even IO-360 at idle (or Lycoming IO-540) and you can hear the same exhaust note quality as a racing car engine.
How do you write overlap in the sentence?
I ama sitting overlap
In a four stroke engine the time period when both valves are slightly open is called valve?
If the valve timing is correct and there are no damaged engine parts (or weak/faulty valve springs) that should not happen, yet however if the engine is "over-revved" the valves could "float" which is not normal operation. (If the engine is an interference engine there may possibly be engine damage.) That is normal and it is called valve overlap.
