Why does a two-stroke engine make a high-pitch whine sound while a four-stroke engine makes a low-pitch sound?

Question

One of my neighbors owns a leaf blower that has a two-stroke engine. Therefore, when he uses the blower, it makes this high-pitch whine sound. I was told that four-stroke engines do not make high-pitch sounds that two-stroke engines make. I was wondering what process in a two-stroke engine causes the engine to make the high-pitch sound.

Answer 1

It is in the way the engines work. A four stroke engine uses valves for intake and exhaust. A two stroke engine has a port where the exhaust and the intake of air both accrue. The output(exhaust) from a four stroke engine can be muffled easier and completely whereas a two stroke engine needs a sufficiently sized area at the port to draw air in at the same place the exhaust comes out.

Answer 2

The RPM is usually a lot faster at full throttle. It fires twice as much as a 4 cycle. The faster an engine turns the more of a whining sound. 2 cycle are lighter in weight, so they are more often found in pieces of equipment that are carried around. Example, Leaf Blowers, Chain Saws, and some lawn mowers.

Mix the oil into the gas, eliminates the need for a crank case.
Since it turn so much faster it wears faster, so it generally will be a much shorter life machine.

Answer 3

There is a difference in revolutions per minute (RPM) between the two motors, with the two stroke churning faster. Also, with the leaf blower, you are also hearing the whine of the blower.

Answer 4

4 strokes are air purifier burning. 2 strokes have extra hollow shot and function. The oil isn't probable an determination in case you examine out it this type, The 4 stroke takes oil it is barely contained in the crank case. the two stroke the two takes it contained in the gasoline (cautioned) or it is injected with the gasoline from a reservior. gasoline efficency on a 2007 form 2 stroke is in basic terms almost as good as a 4 stroke. you will no longer the hollow shot out of a 4 stroke which you will a 2 stroke so it actually relies upon on what your utilising the boat for.

Answer 5

Two stroke engines run harder and faster then four stroke
engines and generally have different types of exhaust. This is
why there are two different motor oils as well.

Answer 6

a two -stroke engine exhaust burned gases every revolution,a four-stroke every other revolution,so you are hearing twice as much "noise".This makes it sound like the two-stroke is turning faster,and because of design they pass more unburned fuel,that "after-burns"