Old two stroke engines.

[shadetree57]

Does anyone know why the exhaust pipe configuration on a two stroke is different than it is on a four stroke?

 

[aussiekeeper]

What do you mean by different? Because it has a different shape?

 

[turbobusa2000]

Sound waves. Much like a 4 stroke engine airbox, the two stroke exhaust pipe is deisigned to take advantage of sound waves to suck the cylinder gases out after combustion and draw in fresh fuel/air mix at the same time.

 

[ibified]

Sound waves. Much like a 4 stroke engine airbox, the two stroke exhaust pipe is deisigned to take advantage of sound waves to suck the cylinder gases out after combustion and draw in fresh fuel/air mix at the same time.

+1

Excellent (and simple) explanation.

 

[proud dad]

expansion chamber

 

[outlawbusa]

expansion chamber

And proper back pressure~!~

 

[raydog]

I remember racing gokarts as a teenager, the races were so loud with 2-stroke expansion chambers! Anyone remember Mccullough, West Bend and Clinton engines? Raydog

 

[Blanca BusaLess]

I remember my live axle gokart with a 7hp McCullough engine .
I had it when I was like 8 or so .
Grass feared me !!!!

 

[raydog]

I remember my live axle gokart with a 7hp McCullough engine .
I had it when I was like 8 or so .
Grass feared me !!!!

I remember there were mac-5's, mac-6's, mac-10's. I had a live axle too, with a disc brake (no front) remember? My brother had dual mac-10's with direct drive...you had to lift the whole thing up into the air when pushing it....then slam it down on the tarmac, oh, memories!

 

[tclause]

I remember racing gokarts as a teenager, the races were so loud with 2-stroke expansion chambers! Anyone remember Mccullough, West Bend and Clinton engines? Raydog

I have a scat cat mini bike with a 4hp clinton that still runs good

 

[shadetree57]

The expansion chanbers do use sound waves but it actually pushes unburned fuel mixture back into the cylinder. Kinda acts as a turbo charger. The waves travel to the rear of the chamber and bounce off the small end. They travel back up to the cylinder head and push the gasses back into the cylinder bore. I read this the other day and thought it was kinda neat. Back in the day when I had a two stroke Kawi, I had a chamber on it but never knew how they worked.

 

[turbobusa2000]

The expansion chanbers do use sound waves but it actually pushes unburned fuel mixture back into the cylinder. Kinda acts as a turbo charger. The waves travel to the rear of the chamber and bounce off the small end. They travel back up to the cylinder head and push the gasses back into the cylinder bore. I read this the other day and thought it was kinda neat. Back in the day when I had a two stroke Kawi, I had a chamber on it but never knew how they worked.

Didn't you start this thread?

 

[shadetree57]

Didn't you start this thread?

Yep.

 

[Spkrdctr]

yup. Its a mechanically fixed super charger. It is what allows 2 strokes to make such high power per cc. They are RPM dependant and if it is not muffled, is VERY loud. I mean LOUD!!
I love 2 strokes......

 

[Spkrdctr]

Did I say I love 2 strokes? I do!

 

[StromBusa]

No but I like em!!! Pipe made a big difference on CR125, big fat expansion chamber with a long thin stinger - earsplitting power.