2 SROKE ENGINES

[Opsguy1979]

Hi Guys

This may seem like a really stupid question but can someone explain how a 2 stroke engine works?? I know the principles on 4 stoke just cant work out 2.... /forums/images/graemlins/cool.gif /forums/images/graemlins/cool.gif

Cheers

Karl

 

[owen]

google 2 stroke engines- how they work or look here
http://gofree.indigo.ie/~vire7/2stroke.htm

 

[cliff]

or Here
--------------------

"Artificial intelligence is no match for natural stupidity"
sailroom <span style="color:red">The place to auction your previously loved boatie bits</span>

 

[Tisme]

I don't think much of that animation Cliff. AFAIK the fuel/air mix usually goes into the crankcase initially, then gets pumped into the cylinder.
In your animation the crankcase never seems to see any fuel.

Or have I missread it?

 

[VicS]

Neither of these replies show the basic 2 stoke cycle without the reed valve.

In its simplest form the fresh fuel air mixture is drawn directly into the crankcase as the piston reaches the top of its stroke then when the piston approaches the bottom of its stroke the transfer port is uncovered and the mixture, now slighly compressed, passes into the combustion chamber. On the upward stroke the exhaust gases are expelled and the mixture is compressed, ready to fired as the piston reaches the top of its travel, and the next charge of fuel and air is drawn into the crankcase The piston is then forced down again and the process repeats.

Thats HOW it works but WHY it works is another matter!

Sorry I dont know of an animation.

 

[Alrob]

no expert myself but the terms 2 cycle & 4 cycle puts a better slant on the principle

alan

 

[Topcat47]

Piston ported 2-strokes are fairly simple in operation but all 2-strokes are problems to explain, especially as not all of them rely on crankcase compression.

 

[cliff]

And YOUR animation shows??. Oh sorry you did not bother your ar$e posting one, choosing instead to criticise what was posted. I see..... Easy to criticise... If you don't like it then post your own so we can see what you come up with.
--------------------

"Artificial intelligence is no match for natural stupidity"
sailroom <span style="color:red">The place to auction your previously loved boatie bits</span>

 

[Tisme]

Touchy tonight. The early posting gave a perfectly good example. Little point in posting yet another.

 

[pappaecho]

All 2 stroke engines work by magic, so no point in explaining it.
Main reason why EU is banning 2 stroke outboards, because of course magic is not taxable

 

[ex-Gladys]

The stuff shown on the various links only shows simple small two strokes. The biggest engine in the world is a 2 stroke (100,000 bhp ship engine). Link

The requirement for a 2 stroke is to have externally pressurised induction. On a 4 stroke, you get the induction, compression, power and exhaust strokes - so the engine does the uinduction and exhaust scavenging for you. In a two stroke, the incoming induction charge scavenges the exhaust for you - and in small engines the crankcase does this. In diesels, you get a "supercharger" type pump that blows the charge in and the exhaust out. This explains why 2 strokes are less fuel efficient because some of the incoming charge has to go out the exhaust....