ok, well here i was, clearing some brush with nothing on my mind when suddenly i though " why does a two stroke sound so much different from a four stroke"primarily because of the chainsaw winding out. Since then, i havent been able to get this off my mind and i cant figure it out. Any one have any explanatiion to the sound?

 

Some great info...

mufflers

2stroke works

4stroke works

more

more

 

sine the pistion fires every up motion and gives more pressure and what not i guess thats wat makes it sound better!

 

2000warrior, if thats the case, wouldnt a 4 stroke revved twice a fast as a similar sized 2 stroke sound the same? And its also been my knowledge that most 2 strokes operate at lower pressures than 4 strokes, i may be wrong though
Oh and rook, thanks, but i know how a 2 stroke works verses a 4 stroke, i am just wondering how there is such a difference in exhaust note

 

well the piston is under more pressure with a 4 stroke then a 2. but im sayint since it fires every time it goes up instead of every othere time it would create more exhaust presssure. i guess. idk really it was just a guess

 

In the reading of those articles....a 2-stroke fires every revolution, a 4-stroke every other revolution....more bang equal more noise---different exhaust properties equal different exhaust note [img]i/expressions/face-icon-small-wink.gif[/img]

 

A four stroke is louder per each power stroke. This is due to generally running higher compression ratios as compared to a 2-stroke, and being more efficient per power stroke due to using valves instead of piston port systems. But since a 2-stroke fires twice as often, it puts out more power than a 4-stroke, engine sizes being equal.
Another thing that gives a 2-stroke that distinctive "buzzing" tone is the use of an expansion chamber type exhaust system. The expansion chamber creates a reverse pulse back through the pipe in order to better fill the combustion chamber. The reverse flow tends to make the sound of each individual power stroke exhaust pulse blend together, thus creating a smoother, buzzing or whining exhaust tone, when compared to the "putt putt" of a 4-stroke.

 

novakaw, your explanation was perfect, i can now understand how the scavenging effect of the reverse pulse smooths out each power stroke, thanks.