Search results
Results from the WOW.Com Content Network
With traditional fixed valve timing, an engine will have a period of "valve overlap" at the end of the exhaust stroke, when both the intake and exhaust valves are open. The intake valve is opened before the exhaust gases have completely left the cylinder, and their considerable velocity assists in drawing in the fresh charge.
A pair of poppet valves bent by collision with a piston after timing belt failure. The engine was running at 4500 RPM. In interference engine designs, replacing a timing belt in regular intervals (manufacturers recommend intervals ranging from 60,000 to 104,000 miles) or repairing chain issues as soon as they are discovered is essential, as incorrect timing may result in the pistons and valves ...
For this inline-4 engine, 1-3-4-2 could be a valid firing order.. The firing order of an internal combustion engine is the sequence of ignition for the cylinders.. In a spark ignition (e.g. gasoline/petrol) engine, the firing order corresponds to the order in which the spark plugs are operated.
The first engines deliberately designed to encourage scavenging were gas engines built by Crossley Brothers Ltd in the United Kingdom in the early 1890s. These Crossley Otto Scavenging Engines were made possible by the recent change from slide valves to poppet valves, which allowed more flexible control over valve timing events. [1]
Four-stroke cycle used in gasoline/petrol engines: intake (1), compression (2), power (3), and exhaust (4). The right blue side is the intake port and the left brown side is the exhaust port.
Desmodromic poppet valve in a Ducati engine. A desmodromic valve is a reciprocating engine poppet valve that is positively closed by a cam and leverage system, rather than by a more conventional spring. The valves in a typical four-stroke engine allow the air/fuel mixture into the cylinder at the beginning of the cycle and exhaust spent gases ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
There are many systems for VVT, which involve changing either the relative timing, duration or opening of the engine's inlet and exhaust valves. One of the first practical VVT systems used a variator to change the phase [note 1] of the camshaft and valves. This simple system cannot change the duration of the valve opening, or their lift.