Important questions of 2 stroke and 4 stroke engine cycle
Quest 1. What do you mean by 2 stroke engine?
Ans. 2 Stroke means one stroke in each direction. A 2 stoke engine will have a compression stroke followed by an explosion of the compressed fuel. On the return stroke new fuel mixture is inserted into the cylinder.
Quest 2.What do you mean by 4 stroke engine?
Ans. A 4 stroke engine has 1 compression stroke and 1 exhaust stoke. Each is followed by a return stroke. The compression stroke compresses the fuel air mixture prior to the gas explosion. The exhaust stroke simply pushes the burnt gases out the exhaust.
Quest 3. What is the difference b/w 2 stroke and 4 stroke engine?
Ans. a) The two-stroke engine completes one cycle of events for every revolution of the crankshaft, compared with the two revolutions required for the four-stroke engine cycle.
b) Theoretically, the two-stroke engine should develop twice the power compared to a four-stroke engine of the same cylinder capacity.
c) In practice, the two-stroke engine’s expelling of the exhaust gases and filling of the cylinder with fresh mixture brought in through the crankcase is far less effective than having separate exhaust and induction strokes. Thus the mean effective cylinder pressures in two-stroke units are far lower than in equivalent four-stroke engines.
d) With a power stroke every revolution instead of every second revolution, the two-stroke engine will run smoother than the four-stroke power unit for the same size of flywheel.
e) Unlike the four-stroke engine, the two-stroke engine does not have the luxury of separate exhaust and induction strokes to cool both the cylinder and the piston between power strokes. There is therefore a tendency for the piston and small-end to overheat under heavy driving conditions.
Quest 4. What should be prefer 4 stroke or 2 stroke?
Ans. Depending on how you modified it. 2-stroke motorcycle indeed fast (and easily modified), but fuels will flow like rivers. 4-stroke indeed very difficult to modify (and high-end 4-stroke may be only 2/3 power of the high end 2-stroke) but you can save the environment as well as fossil fuels
Quest 5. Example where 4 stroke and 2 stroke engines are used?
Ans.
Lawn Mowers
Motorcycles
Boat Engines
Usually any small gasoline powered engine has both versions
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This article is very important for mechanical branch students and also who wants to enhance their knowledge in 2 and 4 strokes engines. This article contain important questions related to 2 and 4 strokes engines.So please go through these questions.