Search results
Results from the WOW.Com Content Network
Four-stroke outboards have been sold since the late 1920s, such as the Roness and Sharland. In 1962 Homelite introduced a four-stroke outboard a 55-horsepower (41 kW) motor, based on the four-cylinder Crosley automobile engine. This outboard was called the Bearcat and was later purchased by Fischer-Pierce, the makers of Boston Whaler, for use ...
In four-stroke cycle engines and some two-stroke cycle engines, the valve timing is controlled by the camshaft. It can be varied by modifying the camshaft, or it can be varied during engine operation by variable valve timing. It is also affected by the adjustment of the valve mechanism, and particularly by the tappet clearance.
[3] [4] On 31 December 1879, German inventor Karl Benz produced a two-stroke gas engine, for which he received a patent in 1880 in Germany. The first truly practical two-stroke engine is attributed to Yorkshireman Alfred Angas Scott, who started producing twin-cylinder water-cooled motorcycles in 1908. [5]
A stroke is the action of a piston travelling the full length of its cylinder.In a two-stroke engine, one of the two strokes combines primarily the intake stroke and the combustion stroke, while the other stroke primarily combines the compression stroke and the exhaust stroke, though technically since both ports are exposed during both the combustion and compression strokes, some reversion ...
Scavenging is the process of replacing the exhaust gas in a cylinder of an internal combustion engine with the fresh air–fuel mixture (or fresh air, in the case of direct-injection engines) for the next cycle. If scavenging is incomplete, the remaining exhaust gases can cause improper combustion for the next cycle, leading to reduced power ...
The shaft of the four-stroke piston rotates twice as fast as the shaft of the two-stroke piston, and the two-stroke part always runs at half speed. This ensures that both parts work optimally regarding fuel consumption at all times. The same principles apply to having two distinct engines, but the design of the M4+2 is much simpler.
Snowmobiles Usually have one to four cylinders and can be both 2-stroke or 4-stroke, normally in the in-line configuration; however, there are again some novelties that exist with V-4 engines; Small portable appliances such as chainsaws, generators, and domestic lawn mowers most commonly have one cylinder, but two-cylinder chainsaws exist.
In crankcase scavenged 2-stroke engines, exhaust and intake are performed mostly simultaneously and with the combustion chamber at its maximum volume. The main advantage of 2-stroke engines of this type is mechanical simplicity and a higher power-to-weight ratio than their 4-stroke counterparts. Despite having twice as many power strokes per ...