Single-piston designs[ edit ] These designs use a single piston per cylinder, like a conventional two- or four-stroke engine. A secondary, non-detonating fluid is injected into the chamber, and the leftover heat from combustion causes it to expand for a second power stroke followed by a second exhaust stroke. Griffin six-stroke engine[ edit ] The Kerr engine at the Anson Engine Museum Inthe Bath -based engineer Samuel Griffin was an established maker of steam and gas engines. He wished to produce an internal combustion engine, but without paying the licensing costs of the Otto patents.
Exhaust The maximum amount of power generated by an engine is determined by the maximum amount of air ingested. The amount of power generated by a piston engine is related to its size cylinder volumewhether it is a two-stroke engine or four-stroke design, volumetric efficiencylosses, air-to-fuel ratio, the calorific value of the fuel, oxygen content of the air and speed RPM.
The speed is ultimately limited by material strength and lubrication. Valves, pistons and connecting rods suffer severe acceleration forces. At high engine speed, physical breakage and piston ring flutter can occur, resulting in power loss or even engine destruction.
Piston ring flutter occurs when the rings oscillate vertically within the piston grooves they reside in. Ring flutter compromises the seal between the ring and the cylinder wall, which causes a loss of cylinder pressure and power. If an engine spins too quickly, valve springs cannot act quickly enough to close the valves.
At high speeds the lubrication of piston cylinder wall interface tends to break down. This process is called portingand it can be done by hand or with a CNC machine. A large part of the waste energy is in the form of heat that is released to the environment through coolant, fins etc.
Many methods have been devised in order to extract waste heat out of an engine exhaust and use it further to extract some useful work, decreasing the exhaust pollutants at the same time.
Use of Rankine Cycle, Turbocharging and Thermo electric Generation can be very useful as a waste heat recovery system. Though waste heat recovery systems are being used frequently among all the devices but still some issues like their low efficiency at lower heat supply rates and high pumping losses remain a cause of concern for the researchers.
Supercharging[ edit ] One way to increase engine power is to force more air into the cylinder so that more power can be produced from each power stroke. This can be done using some type of air compression device known as a superchargerwhich can be powered by the engine crankshaft.
Supercharging increases the power output limits of an internal combustion engine relative to its displacement. Most commonly, the supercharger is always running, but there have been designs that allow it to be cut out or run at varying speeds relative to engine speed.
Mechanically driven supercharging has the disadvantage that some of the output power is used to drive the supercharger, while power is wasted in the high pressure exhaust, as the air has been compressed twice and then gains more potential volume in the combustion but it is only expanded in one stage.
It consists of a two piece, high-speed turbine assembly with one side that compresses the intake air, and the other side that is powered by the exhaust gas outflow.
When idling, and at low-to-moderate speeds, the turbine produces little power from the small exhaust volume, the turbocharger has little effect and the engine operates nearly in a naturally aspirated manner. Turbocharging allows for more efficient engine operation because it is driven by exhaust pressure that would otherwise be mostly wasted, but there is a design limitation known as turbo lag.
The increased engine power is not immediately available due to the need to sharply increase engine RPM, to build up pressure and to spin up the turbo, before the turbo starts to do any useful air compression. The increased intake volume causes increased exhaust and spins the turbo faster, and so forth until steady high power operation is reached.
Another difficulty is that the higher exhaust pressure causes the exhaust gas to transfer more of its heat to the mechanical parts of the engine. Rod and piston-to-stroke ratio[ edit ] The rod-to-stroke ratio is the ratio of the length of the connecting rod to the length of the piston stroke.
A longer rod reduces sidewise pressure of the piston on the cylinder wall and the stress forces, increasing engine life.
It also increases the cost and engine height and weight. A "square engine" is an engine with a bore diameter equal to its stroke length.
An engine where the bore diameter is larger than its stroke length is an oversquare engine, conversely, an engine with a bore diameter that is smaller than its stroke length is an undersquare engine.
Valve train[ edit ] The valves are typically operated by a camshaft rotating at half the speed of the crankshaft. It has a series of cams along its length, each designed to open a valve during the appropriate part of an intake or exhaust stroke.
A tappet between valve and cam is a contact surface on which the cam slides to open the valve. In other engine designs the camshaft is in the crankcasein which case each cam usually contacts a push rodwhich contacts a rocker arm that opens a valve, or in case of a flathead engine a push rod is not necessary.Buy Challenge 55cm 4 Stroke Petrol Hedge Trimmer - 26cc at Argos.
Thousands of products for same day delivery £, or fast store collection. Difference Between 2 Stroke and 4 Stroke Engines The main difference between two and four stroke engine is that in 2 stroke engine the crankshaft revolve two times to complete its working cycle where as in 4 stroke, the crankshaft does 2 revolution to complete its working cycle.
Two Stroke Engine. Four Stroke Engine. Difference . Jan 18, · Re: the proper way to mix gasoline/oil 2 stroke engine. The motion of the boat surely mixed the oil fine by the time you got her launched. ozs per initiativeblog.com oil . Actually the efficiency of petrol engines will be around %..
Six stroke engine is considered more efficient than the present 2&4 stroke engine. It is simiar to 4 stroke but in last two stroke,water is injected which turns into steam and adds to power stroke and the last stroke is again exhaust of steam.
So in a 6 stroke engine we can. A two-stroke (or two-cycle) engine is a type of internal combustion engine which completes a power cycle with two strokes (up and down movements) of the piston during only one crankshaft revolution.
This is in contrast to a "four-stroke engine", which requires four strokes of the piston to complete a power cycle during two crankshaft initiativeblog.com a two-stroke engine, the end of the.
Mar 15, · Explanation of how 4 stroke engines work, Intake, compression,Combustion and Exhaust. Entirely developed using Blender a. Do not forget to like it if you do:) All Actions and Baked Particles.