Quote:
Originally Posted by oil pan 4
I was mowing the rental house and the push mower ran out of gas. I thought it was full, I guess not. So I filled it up with my 40:1 weed eater gas. The push mower really seems to like that 2 stroke gas. Think I might have to start using mostly weed eater gas then I can just carry the one gas can for both machines.
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For those that don't know;
Why 2-stroke oil makes sense in single cylinder engines:
These single cylinder engines have a one way valve in the crankcase because a single piston would be pulling in and immediately pushing out a huge amount of air without one, robbing a lot of power from the engine.
So, viewed from inside the crankcase;
The engine pulls a large vacuum every time the piston moves up.
That's going to turn the exhaust and compression strokes into strokes that suck any oil that is gathered between and around the rings out, via the ring gaps etc.
That makes cylinder lubrication oil starved vs a 4 cylinder etc engine.
If you really want to mod a single cylinder engine:
Intake into sump via reed valve.
Exhaust that air to a intake manifold attached to the std intake valve, via another reed valve.
Now you get a supercharging effect as (ideally) 2 cylinders worth of intake are forced into the cylinder on every 4th (intake) stroke.
Challenges:
- The manifold needs to be a eg; cyclone separator to get most all the oil caught in the intake air, out and back into the sump via a one way valve.
- Fuel injection is a must.
I got a provisional patent on this idea back in my miss-spent, foolish youth.
This seems to have come of it:
There's also a bit of research on this, but I wont bore you all with links to that!
It seems few here believe peer reviewed published research to be worth a damn anyway..?