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.
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 ...
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.
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 two crankshafts are connected with a special transmission that rotates the four-stroke crankshaft at twice the speed of the two stroke crankshaft. In the M4+2, the advantages of both engines being connected are obvious; the pistons of the engine working in one combustion cylinder are set opposite to each other but in different modes ...
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.
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.
Unlike a four-stroke engine, the crankcase of which is closed except for its ventilation system, a two-stroke engine uses the crankcase as part of the induction tract, so oil must be mixed with gasoline to be distributed throughout the engine for lubrication. [1] The resultant mix is referred to as premix or petroil. [2]