Two-stroke oil (also referred to as two-cycle oil, 2-cycle oil, 2T oil, or 2-stroke oil) is a special type of motor oil intended for use in crankcase compression two-stroke engines, typical of small gasoline-powered engines.
Two-stroke oil (also referred to as two-cycle oil, 2-cycle oil, 2T oil, or 2-stroke oil) is a special type of motor oil intended for use in crankcase compression two-stroke engines, typical of small gasoline-powered engines.
Unlike a four-stroke engine, the crankcase of which is closed except for its ventilation system, a two-stroke engine uses the crankcase as part of the induction tract, so oil must be mixed with gasoline to be distributed throughout the engine for lubrication. [1] The resultant mix is referred to as premix or petroil. [2] The oil is ultimately burned along with the fuel as a total-loss oiling system. That results in increased exhaust emissions, sometimes with excess smoke and/or a distinctive odor.
The oil-base stock can be petroleum, castor oil, semi-synthetic or synthetic oil, and is mixed (or metered by injection) with petrol/gasoline at a volumetric fuel-to-oil ratio ranging from 16:1 to as low as 100:1. To avoid high emissions and oily deposits on spark plugs, modern two-strokes, particularly small engines powering such items as garden equipment and chainsaws, may now require a synthetic oil, and can suffer from oiling problems otherwise.
Engine original equipment manufacturers (OEMs) introduced pre-injection systems (sometimes known as "auto-lube") to engines to operate from a 32:1 to 100:1 ratio. Oils must meet or exceed the following typical specifications: TC-W3® (NMMA), API-TC, JASO FC, ISO-L-EGC.[ citation needed ]
The relevant difference between regular lubricating oil and two-stroke oil is that the latter must have a much lower ash content, to minimize deposits that tend to form if ash is present in the oil when it is burned in the engine's combustion chamber. Additionally, a non-2T-specific oil can turn to gum in a matter of days if mixed with gasoline and not immediately consumed. Another important factor is that four-stroke engines have a different requirement for "stickiness" than do two-strokes.
Since the 1980s, different types of two-stroke oil have been developed for specialized uses, such as outboard motor two-strokes, as well as the more standard auto lube (motorcycle) two-stroke oil. As a rule of thumb, it will be stated somewhere on the printed label of most containers of oil available commercially, that it is compatible with "Autolube" or injector pumps. Those oils tend to have the consistency of liquid dish soap if shaken. A more viscous oil cannot reliably be passed through an injection system, although a premix can be used on either type.
"Racing" oil or castor-based does offer excellent lubrication, at the expense of premature cooking. The average moped/scooter/trail rider will not achieve an appreciable increase in performance and will require very frequent teardowns.
Additives for two-stroke oils fall into several general categories: Detergent/Dispersants, Antiwear agents, Biodegradability components and antioxidants (Zinc compounds). [3] Some of the higher quality include a fuel stabilizer as well.
The current international standard (ISO 13738) for two-stroke gasoline engine oil evolved from JASO M345, which were grades intended to exceed API-TC. Grades include: [4]
The National Marine Manufacturers Association (NMMA) of the USA maintains its own TC-W line of standards.
A lubricant is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces. The property of reducing friction is known as lubricity.
A two-strokeengine is a type of internal combustion engine that completes a power cycle with two strokes of the piston during one power cycle, this power cycle being completed in one revolution of the crankshaft. A four-stroke engine requires four strokes of the piston to complete a power cycle during two crankshaft revolutions. In a two-stroke engine, the end of the combustion stroke and the beginning of the compression stroke happen simultaneously, with the intake and exhaust functions occurring at the same time.
Motor oil, engine oil, or engine lubricant is any one of various substances used for the lubrication of internal combustion engines. They typically consist of base oils enhanced with various additives, particularly antiwear additives, detergents, dispersants, and, for multi-grade oils, viscosity index improvers. The main function of motor oil is to reduce friction and wear on moving parts and to clean the engine from sludge and varnish (detergents). It also neutralizes acids that originate from fuel and from oxidation of the lubricant (detergents), improves the sealing of piston rings, and cools the engine by carrying heat away from moving parts.
Synthetic oil is a lubricant consisting of chemical compounds that are artificially modified or synthesised. Synthetic lubricants can be manufactured using chemically modified petroleum components rather than whole crude oil, but can also be synthesized from other raw materials. The base material, however, is still overwhelmingly crude oil that is distilled and then modified physically and chemically. The actual synthesis process and composition of additives is generally a commercial trade secret and will vary among producers.
The Monosoupape, was a rotary engine design first introduced in 1913 by Gnome Engine Company. It used a clever arrangement of internal transfer ports and a single pushrod-operated exhaust valve to replace the many moving parts found on more conventional rotary engines, and made the Monosoupape engines some of the most reliable of the era. British aircraft designer Thomas Sopwith described the Monosoupape as "one of the greatest single advances in aviation".
Gasoline direct injection (GDI), also known as petrol direct injection (PDI), is a mixture formation system for internal combustion engines that run on gasoline (petrol), where fuel is injected into the combustion chamber. This is distinct from manifold injection systems, which inject fuel into the intake manifold.
In a piston engine, the crankcase is the housing that surrounds the crankshaft. In most modern engines, the crankcase is integrated into the engine block.
Within piston engines, a wet sump is part of a lubrication system whereby the crankcase sump is used as an integral oil reservoir. An alternative system is the dry sump, whereby oil is pumped from a shallow sump into an external reservoir.
JASO M345 is a quality classification standard for two stroke engine oils for engines of Japanese origin. It was introduced by the Japanese Automotive Standards Organization (JASO) in 1994 as JASO M345-93 with the quality levels JASO FA, JASO FB and JASO FC – with FC setting the highest standard. It was revised in 2004 as JASO M345:2004 which discontinued the FA level, and introduced the new JASO FD level – the FD level supersedes JASO FC as the highest rating. ISO 13738 is a similar, but stricter, specification.
API TC is a certification for two-stroke oils, awarded by the American Petroleum Institute. It is given after the product passes through stringent tests that determine the level of detergent performance, dispersion, and anti-oxidation. It is the only remaining, not revoked classification of the API Two-Cycle motor oil specifications. Being a very old standard itself, most currently produced 2T lubricants meet its specifications, even the lowest quality ones; current high-quality oils exceed them.
A crankcase ventilation system (CVS) removes unwanted gases from the crankcase of an internal combustion engine. The system usually consists of a tube, a one-way valve and a vacuum source.
The Japanese Automotive Standards Organization is an organization that sets automotive standards in Japan, analogous to the Society of Automotive Engineers (SAE) in the United States. JASO also sets standards for grades of oil; the highest grade for two-stroke engines being JASO FD, and JASO MA for four-stroke engines (motorcycles).
The hot-bulb engine, also known as a semi-diesel, is a type of internal combustion engine in which fuel ignites by coming in contact with a red-hot metal surface inside a bulb, followed by the introduction of air (oxygen) compressed into the hot-bulb chamber by the rising piston. There is some ignition when the fuel is introduced, but it quickly uses up the available oxygen in the bulb. Vigorous ignition takes place only when sufficient oxygen is supplied to the hot-bulb chamber on the compression stroke of the engine.
A model engine is a small internal combustion engine typically used to power a radio-controlled aircraft, radio-controlled car, radio-controlled boat, free flight, control line aircraft, or ground-running tether car model.
Shell Rotella is a line of heavy-duty engine lubrication products produced by Shell plc. The line includes engine oils, gear oils and coolants. The oil carries both the American Petroleum Institute (API) diesel "C" rating as well as the API gasoline engine "S" rating. Ratings differ based on the oil. Rotella oils, like the T3 15W-40, meet both the API CJ-4 and SM specifications, and may be used in both gasoline and diesel engines. However, it is formulated specifically for vehicles without catalytic converters, containing phosphorus levels beyond the 600–800 ppm range. Therefore, Rotella is not recommended for gasoline vehicles with catalytic converters due to the higher risk of damaging these emission controls. Newer formulations of Rotella T6 however are API SM rated as safe for pre-2011 gasoline vehicles.
Oil additives are chemical compounds that improve the lubricant performance of base oil. The manufacturer of many different oils can utilize the same base stock for each formulation and can choose different additives for each specific application. Additives comprise up to 5% by weight of some oils.
Crankcase dilution is a phenomenon of internal combustion engines in which unburned diesel or gasoline accumulates in the crankcase. Excessively rich fuel mixture or incomplete combustion allows a certain amount of fuel to pass down between the pistons and cylinder walls and dilute the engine oil. It is more common in situations where fuel is injected at a very high pressure, such as in a direct-injected diesel engine.
An internal combustion engine is a heat engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine, the expansion of the high-temperature and high-pressure gases produced by combustion applies direct force to some component of the engine. The force is typically applied to pistons, turbine blades, a rotor, or a nozzle. This force moves the component over a distance, transforming chemical energy into kinetic energy which is used to propel, move or power whatever the engine is attached to.
The 4 VD 14,5/12-1 SRW is an inline four-cylinder diesel engine produced by the VEB IFA Motorenwerke Nordhausen from 1967 to 1990. The engine was one of the standard modular engines for agricultural and industrial use in the Comecon-countries. Approximately one million units were made.
The Suzuki A100 is a Japanese motorcycle from the Suzuki Motor Corporation with production starting in 1966.Similar models were produced by Yamaha and Kawasaki with the YB100 & KH100 models, also with a single-cylinder two-stroke engine and rotary valve being examples.