Search results
Results from the WOW.Com Content Network
Congenital pulmonary airway malformation (CPAM), formerly known as congenital cystic adenomatoid malformation (CCAM), is a congenital disorder of the lung similar to bronchopulmonary sequestration. In CPAM, usually an entire lobe of lung is replaced by a non-working cystic piece of abnormal lung tissue.
In four-stroke cycle engines and some two-stroke cycle engines, the valve timing is controlled by the camshaft. It can be varied by modifying the camshaft, or it can be varied during engine operation by variable valve timing. It is also affected by the adjustment of the valve mechanism, and particularly by the tappet clearance.
A stroke is the action of a piston travelling the full length of its cylinder.In a two-stroke engine, one of the two strokes combines primarily the intake stroke and the combustion stroke, while the other stroke primarily combines the compression stroke and the exhaust stroke, though technically since both ports are exposed during both the combustion and compression strokes, some reversion ...
Two-stroke engines which use crankcase compression do not require a crankcase ventilation system, since all of the gases within the crankcase are then fed into the combustion chamber. Many small four-stroke engines such as lawn mower engines and electricity generators simply use a draught tube connected to the intake system.
Typical airflow in a four-stroke engine: In stroke #1, the pistons suck in (aspirate) air to the combustion chamber through the opened inlet valve.. A naturally aspirated engine, also known as a normally aspirated engine, and abbreviated to N/A or NA, is an internal combustion engine in which air intake depends solely on atmospheric pressure and does not have forced induction through a ...
Animation of a two-stroke engine. A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes of the piston (one up and one down movement) in one revolution of the crankshaft in contrast to a four-stroke engine which requires four strokes of the piston in two crankshaft revolutions to complete a power cycle.
The actual gas leaving the pipe during a particular cycle was created two or three cycles earlier. This is why exhaust gas sampling on two stroke engines is done with a special valve right in the exhaust port. The gas exiting the stinger has had too much resident time and mixing with gas from other cycles causing errors in analysis.
The induction stroke is the first phase in a four-stroke (e.g. Otto cycle or Diesel cycle) engine.It involves the downward movement of the piston, creating a partial vacuum that draws an air-fuel mixture (or air alone, in the case of a direct injection engine) into the combustion chamber.