Running the chance of sounding reeaaaly stupid, what is the difference between 2 and 4 stroke, and what are the (diss-)advantages of either one?

You can see I don't belong here, usually I hang out among the electric crowd...

I'll go out on a limb here.

2 strokers:
fire every revolution
create more power for given size
rev a little higher
have more of a wine/higher sound
a little better fuel mileage
easier to tune and maintain

4 strokers:
fire every other revolution
can swing a larger prop as compared to a comparable size 2 stroke
rev a little lower, thus create less heat,,might last a little longer
have the coolest thumpy sound
a little more thirsty to a comparable size 2 stroker
a little more tougher to tune and sometimes needs to be timed,


i think i'm right,,,good luck,,,

Check this out for some detailed information on how 4-stroke motors work: http://auto.howstuffworks.com/engine.htm

And for 2-stroke: http://science.howstuffworks.com/two-stroke.htm

There are some very neatly done animated .gif files showing how most types of engine work - including some exotic and unusual ones - at http://www.keveney.com/Engines.html

Tony

Thanks for the links!

I needed the refresher. OK, so we know the difference between 2 and 4 stroke. Now how about the glow engine? The plug doesn't spark on each cycle of the cylinder, but glows all the time.

How does that work then? (You can see I'm an E-junky, but my son is a confirmed glower)

It stays hot (and glowy) because of the heat from the explosions in the engine. By the way, while I am here, I have an o.s .46 fx, is it 2-stroke? is there such a thing as one stroke?

Yes, there is a 'one-stroke' - the engine fires then the conrod snaps and it won't go again!

The two stroke is the 'lowest' because the up stroke of the piston creates lower than atmospheric pressure in the crankcase. This results in the fuel/air being sucked into the crankcase. The piston comes down, having been pushed there by the previous fuel charge detonating in the cylinder head. As the piston goes down it compresses the fue/air mixture and around the bottom of the piston movement the port in the crankcase/cylinder wall opens and transfers the charge into the cylinder head. The piston keeps moving up, compressing the charge until around top dead centre, the charge explodes and pushes the piston down again, drawing more mix into the crankcase and at the same time opening the exhaust port to spray your model with the resultant gunk of unburnt fuel/oil, then goto the top of this to start again - at around 250 times per second.

Incidentally, there is now a 6-stroke!

Tony

ok, thanx! Could you post a link to the 6 stroke?

Here it is!
http://www.sixstroke.com/pageone.htm

Tony

Oh, the element of a glowplug continues to glow because of the catalytic action of alcohol on platinum and other rare metals which are used in plugs (although the heat does contribute as well)

Is that a glow engine?????? It's a monster!!!!!!!!!

No, just a bog-standard spark ignition, 6-stroke motorbike engine.

Tony