The difference between four and two strokes in a lawn mower gasoline engine
The lawn mower has two strokes and four strokes. Many of them are not clear and do not know the difference between them.
What's the difference between four and two strokes for a lawn mower gasoline engine?
The difference in gas distribution, lubrication and mixture composition between the two engines
1. Differences in gas distribution mechanism
Four-stroke engine through the pass of the crankshaft to the camshaft timing chain, in the process of the camshaft rotating at the intake and exhaust CAM push rocker arm swing, and under the action of valve springs, the inlet and exhaust valves open and close regularly.
Under certain pressure, the mixture of the two-stroke engine entering the crankcase can control the opening and closing of the inlet and scavenging ports through the movement of the piston to complete the scavenging and exhaust process.
2. Differences in lubrication methods
The piston and connecting rod mechanism of four-stroke engine adopts crankshaft splash lubrication method.
Camshaft, rocker arm and valve are lubricated by pump pressure.
The two - stroke engine usually adopts mixed lubrication or separation lubrication.
As far as separation lubrication is concerned, crankcase crankshaft connecting rod assembly, cylinder, piston assembly and so on are lubricated by fog mixture of engine oil, gasoline and air.
Lubricating oil plays the role of lubrication, cooling, sealing and cleaning in the engine, which is related to the wear and service life of parts.
3. Differences in composition of combustible mixture
The four-stroke engine is a combustible mixture of gasoline and air.
A two-stroke engine is a combustible mixture of gasoline, oil and air.