How Does A 4 Stroke Engine Work?
HTML-код
- Опубликовано: 24 апр 2018
- In this video, Cycle World Technical Editor Kevin Cameron explains how 4 stroke engines work, how it delivers power and propels your motorcycle. Kevin also breaks down how rapid combustion is critical to engine performance.
If combustion were much slower than it is, engines such as this single-cylinder example wouldn’t be able to operate at peak rpm. But thanks to turbulence, which spreads the flame rapidly in the combustion chamber, they can. There’s a lot of science to the shaping of ports and valves to allow maximum intake and exhaust flow to create this turbulence.
In this case, air flows down the intake pipe into the cylinder head. When the valve lifts that air flows around the valve and into the combustion chamber to follow the retreating piston. Intake air with fuel mixed into it by the carburetor comes out from under the valve at several hundred feet per second. This is essential for rapid combustion.
By itself, a mixture of evaporated gasoline and air burns quite slowly-a matter of a foot or so per second. But the fact that mixture comes out from under the intake valve at such great velocity puts a lot of energy into the air accumulating as the piston continues to complete its intake stroke.
When the piston comes back up and compresses that gas all the turbulent motion is confined to an ever-smaller space causing it to whirl faster. The spark plug produces a tiny flame kernel and the vigorous motion tears that kernel apart, shreds it, and distributes it around the combustion chamber, causing rapid combustion.
The velocity of the combustion process is of the order of 50 feet per second but it can be as high as 200 feet per second. Normally in an engine like this ignition spark occurs at about 36 degrees before top dead center. The combustion initiated by the spark continues for roughly 30 degrees after TDC.
The value of fast combustion is real because the longer you have flame in this chamber the more heat is being driven into the cylinder head and into the crown of the piston from which it is lost-it’s not there anymore to push the crankshaft around. So designers take care to make the combustion process pretty much as fast as they can.
Read the full article here: www.cycleworld.com/how-does-f...
Subscribe to Cycle World RUclips: ruclips.net/user/cycleworld?s...
Read more from Cycle World: www.cycleworld.com/
Buy Cycle World Merch: teespring.com/stores/cycleworld 
Развлечения
Great as always. Thanks Mr. Cameron. Thanks Cycle World.👍👍
They keep this genius looked in the basement! Reading cycle world mag for almost 25 years never noticed this gentalmen til now. Very happy you guy let him out.
I love this series. I learn so much from Mr. Cameron. This is the only other place you will hear in this kind of detail is a college engineering course, and it won't be about motorcycles.
Excellent video, thank you
ALWAYS BETTER THAN WORTH THE TIME! Thanks!
Great video, thanks a lot. Gus
Thank you, as always top notch.
Very helpful!
Now with the lowered back music is much better! Thanks!
I wanted to understand, what forces the air into the cylinder after turning on the key..can anyone help,
And how does the valve initially open..I'll watch again...thank you..
That's quite a valve angle ya got goin there.
What about multiple spark plugs per cylinder? Some Indian manufacturers claim they gain a bit extra out of that... does it make much sense?
0:15 "Two stroke nonsense".
What!?!?!
You must be mistaken.
It's Mr. Cameron being humble about his previous presentations :) I'm sure no offense towards two-strokes implied.