Bigger Power with Two Strokes!

Written by Thomas Yoon


What is a 2-stroke diesel engine?

Asrepparttar name suggests, these engines work on reciprocating actions of pistons. One stroke means one linear motion ofrepparttar 102782 piston in one direction. Whenrepparttar 102783 piston moves inrepparttar 102784 opposite direction, that is counted as another stroke.

For a 2-stroke engine,repparttar 102785 piston has to move up, and then down to complete one cycle ofrepparttar 102786 engine. In those 2 strokes ofrepparttar 102787 piston,repparttar 102788 crankshaft will have turned 1 revolution.

The 2 strokes ofrepparttar 102789 piston is to complete 4 stages ofrepparttar 102790 combustion cycle - air intake, compression, combustion and exhaust. As you might have known, in order for a fire (or explosion) to occur to powerrepparttar 102791 engine, we need a fuel, a heat source, and oxygen coming together atrepparttar 102792 same time.

Remember howrepparttar 102793 crankshaft andrepparttar 102794 piston moves in a cylinder? The reciprocating movement ofrepparttar 102795 piston is converted to rotary motion by means of a crankshaft. The piston reciprocates between Top Dead Center and Bottom Dead Center insiderepparttar 102796 cylinder liner.

One ofrepparttar 102797 most prominent feature of a 2-stroke engine isrepparttar 102798 presence of air intake ports onrepparttar 102799 cylinder liner that will enable fresh air to be led in for combustion.

These air inlet ports are cut intorepparttar 102800 cylinder liner somewhere atrepparttar 102801 lower end ofrepparttar 102802 latter. In a typical design,repparttar 102803 air inlet port are located about 35 degrees fromrepparttar 102804 Bottom Dead Center (BDC).

In many designs,repparttar 102805 fresh air that is introduced intorepparttar 102806 cylinder is also used to drive outrepparttar 102807 spent exhaust gases inside it. Many designs make use of scavenging air fans like electric blowers or turbochargers to slightly pressurizerepparttar 102808 intake air beforerepparttar 102809 latter is introduced intorepparttar 102810 cylinder.

In order to allowrepparttar 102811 exhaust gases to be expelled fromrepparttar 102812 cylinder, exhaust ports are often cut intorepparttar 102813 cylinder just likerepparttar 102814 air intake ports. A typical design will haverepparttar 102815 exhaust port located about 50 degrees from Bottom Dead Center.

What Do You Mean by Four Stroke?

Written by Thomas Yoon


What is a 4-stroke diesel engine?

Asrepparttar name suggests, these engines work on reciprocating actions of pistons. One stroke means one linear motion ofrepparttar 102781 piston in one direction. Whenrepparttar 102782 piston moves inrepparttar 102783 opposite direction, that is counted as another stroke.

For a 4-stroke engine,repparttar 102784 piston has to move up, then down, then up again, and then down again to complete one cycle ofrepparttar 102785 engine. In that 4 stroke ofrepparttar 102786 piston,repparttar 102787 crankshaft will have turned 2 revolutions.

The 4 strokes ofrepparttar 102788 piston is to complete 4 stages ofrepparttar 102789 combustion cycle. As you might have known, in order for a fire (or explosion) to occur to powerrepparttar 102790 engine, we need a fuel, a heat source, and oxygen coming together atrepparttar 102791 same time.

Atrepparttar 102792 start ofrepparttar 102793 cycle, air must be introduced intorepparttar 102794 combustion space insiderepparttar 102795 cylinder. Inrepparttar 102796 4-stroke (also called 4-cycle) engine, this isrepparttar 102797 air intake stroke. The piston moving down will suck fresh air intorepparttar 102798 cylinder through repparttar 102799 air inlet valve(s) that is opened.

The next stroke isrepparttar 102800 compression stroke. With allrepparttar 102801 valves atrepparttar 102802 cylinder head closed,repparttar 102803 piston moves up again. The air becomes compressed to a very high degree. So high thatrepparttar 102804 temperature ofrepparttar 102805 air becomes sufficiently hot to ignite a finely sprayed fuel mist on contact.

That is precisely what happens. Beforerepparttar 102806 piston reachesrepparttar 102807 top-dead center (the maximum heightrepparttar 102808 piston can reach before coming down again),repparttar 102809 fuel is injected as a very fine mist into combustion space atrepparttar 102810 piston top. In order for this fuel to be injected intorepparttar 102811 highly compressed air insiderepparttar 102812 cylinder repparttar 102813 fuel itself must be at a higher pressure. This is achieved by a fuel pump.

There is a reason for injectingrepparttar 102814 fuel slightly beforerepparttar 102815 piston reaches top dead center. The fuel takes some time to reach repparttar 102816 temperature that it can burn. Sorepparttar 102817 timing ofrepparttar 102818 injection ofrepparttar 102819 fuel is adjusted so that byrepparttar 102820 timerepparttar 102821 piston reaches slightly beyondrepparttar 102822 top dead center,repparttar 102823 fuel has acquiredrepparttar 102824 temperature high enough for ignition.

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