 A cast 6-cylinder BMW engine block - For the G.I. Joe character, see List of G.I. Joe ARAH characters.
In a piston engine, the crankcase is the housing for the crankshaft. The enclosure forms the largest cavity in the engine, separated from the cylinders by the reciprocating pistons. Image File history File links Metadata Size of this preview: 800 × 600 pixelsFull resolution (2048 × 1536 pixel, file size: 663 KB, MIME type: image/jpeg) Mondial de lautomobile, Paris 2006 File historyClick on a date/time to view the file as it appeared at that time. ...
Image File history File links Metadata Size of this preview: 800 × 600 pixelsFull resolution (2048 × 1536 pixel, file size: 663 KB, MIME type: image/jpeg) Mondial de lautomobile, Paris 2006 File historyClick on a date/time to view the file as it appeared at that time. ...
// The list covers every known character in the G.I. Joe: A Real American Hero series to have received his/her own action figure. ...
For the use of the term in optics, see piston (optics). ...
The internal combustion engine is an engine in which the combustion of fuel and an oxidizer (typically air) occurs in a confined space called a combustion chamber. ...
Crankshaft (red), pistons (gray) in their cylinders (blue), and flywheel (black) Continental engine marine crankshafts, 1942 Components of a typical, four stroke cycle, DOHC piston engine. ...
Cylinder with piston in a steam engine A cylinder in the central working part of a reciprocating engine, the space in which a piston travels. ...
Besides protecting the crankshaft and connecting rods from foreign objects, the crankcase serves other functions, depending on engine type. piston (top) and connecting rod from typical automotive engine (scale is in centimetres) Components of a typical, four stroke cycle, DOHC piston engine. ...
Two-stroke engines
In two-stroke engines, the crankcase is sealed and is used as a pressurization chamber for the fuel/air mixture. As the piston rises, it pushes out exhaust fumes and provides a vacuum in the crankcase which sucks in new fuel/air. As the piston lowers, the fresh fuel/air is pushed from the crankcase and sucked into the cylinder. [1] Image File history File links No higher resolution available. ...
Image File history File links No higher resolution available. ...
The two-stroke cycle of an internal combustion engine differs from the more common four-stroke cycle by completing the same four processes (intake, compression, power, exhaust) in only two strokes of the piston rather than four. ...
Unlike four-stroke engines, the crankcase does not hold the engine oil because it holds the fuel/air mixture. Instead, oil is mixed in with the fuel, and the mixture provides lubrication for the cylinder walls, crankshaft and connecting rod bearings. piston (top) and connecting rod from typical automotive engine (scale is in centimetres) Components of a typical, four stroke cycle, DOHC piston engine. ...
It has been suggested that Bushing be merged into this article or section. ...
Four-stroke engines In a four-stroke engine, the crankcase is filled mainly with air and oil, and is largely sealed off from the fuel/air mixture by the pistons. Image File history File links No higher resolution available. ...
Image File history File links No higher resolution available. ...
Today Internal combustion engines in cars, trucks, motorcycles, construction machinery and many others, most commonly use a four-stroke cycle. ...
Oil circulation Oil circulation is kept separate from the fuel/air mixture, thereby preserving oil rather than burning it as happens in two-stroke engines. Oil moves from its reservoir, is pressurized by an oil pump, and is pumped through the oil filter to remove grit. The oil is then squirted into the crankshaft and connecting rod bearings and onto the cylinder walls, and eventually drips off into the bottom of the crankcase. [2] In a wet sump system, oil remains in a reservoir at the bottom of the crankcase, referred to as the oil pan. In a dry sump system, oil is instead pumped to an external reservoir. [3] An oil pump is a pump designed to supply pressurised oil as part of a lubrication system. ...
Spin-on oil filter beneath the engine of a Saab 9-5 (2005) Many items requiring lubrication by petroleum products need the lubricant to be especially clean. ...
A wet sump is a lubricating oil management design for four-stroke piston internal combustion engines which uses a built-in reservoir for oil, as opposed to an external or secondary reservoir used in a dry sump design. ...
A dry sump is a lubricating oil management method for four-stroke and large two-stroke piston internal combustion engines that uses a secondary reservoir for oil, as compared to a conventional wet sump system. ...
Even in a wet sump system, the crankshaft has minimal contact with the sump oil. Otherwise, the high-speed rotation of the crankshaft would cause the oil to froth, making it difficult for the oil pump to move the oil, which can starve the engine of lubrication. [4] Small amounts of oil may splash onto the crankshaft during rough driving, referred to as windage. [5] Windage is a force created on an object by friction when there is relative movement between air and the object. ...
In a wet sump system, the main dipstick and oil filler cap connect to the crankcase. This article does not cite any references or sources. ...
Air ventilation During normal operation, a small amount of unburned fuel and exhaust gases escape around the piston rings and enter the crankcase, referred to as "blow-by". [6] If these gases remained in the crankcase and condensed, the oil would become more diluted over time, decreasing its ability to lubricate. Condensed water would also cause parts of the engine to rust. [7] To counter this, a crankcase ventilation system exists to draw fresh air in from the air filter and expel the gases out the PCV valve into the intake manifold. The intake manifold is at a lower pressure than the crankcase, providing the suction to keep the ventilation system going. Spring-loaded piston rings. ...
Air filter in an Opel Astra car, top side=clean side Air filter in an Opel Astra car, bottom side=dust side Automotive air filter clogged with dust and debris. ...
The Positive Crankcase Ventilation valve, or PCV Valve, is a one-way valve that ensures continual refreshment of the air inside a gasoline internal combustion engines crankcase. ...
In automotive engineering, an intake manifold or inlet manifold is a part of an engine that supplies the fuel/air mixture to the cylinders. ...
Manifold vacuum, or engine vacuum in an internal combustion engine is the difference in air pressure between the engines intake manifold and Earths atmosphere. ...
If an engine is damaged or enters old age, gaps can form between the cylinder walls and pistons, resulting in larger amounts of blow-by than the crankcase ventilation system can handle. The gaps cause power loss, and ultimately mean that the engine needs to be rebuilt or replaced. [6] Symptoms of excessive blow-by include oil being pushed up into the air filter, out the dipstick[8], or out the PCV valve.
References - ^ The Compression Stroke in Two-stroke Engines at HowStuffWorks
- ^ How Car Engines Work at HowStuffWorks
- ^ Why do some engines use a dry sump oil system? at HowStuffWorks
- ^ October 1996 question on Car Talk
- ^ Jeff Huneycutt. Oil Pans For Power. Circle Track magazine. Retrieved on 2006-11-16.
- ^ a b September 1999 question on Car Talk
- ^ January 2001 question on Car Talk
- ^ August 2002 question on Car Talk
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