first, the origin of JASO motorcycle engine oil
Unfortunately, it is difficult for you to find the development history of motorcycle engine oil in the mainland forum. In order to dispel doubts and doubts, I had to turn to the website of Hong Kong and Taiwan, only then did I know that the original motorcycle engine oil was only an industry standard exclusively recognized by JASO (Japan Automobile Standards Organization). The world's three leading authorities, API(American Petroleum lnstitute) and ACEA (Association des Constructeurs Europe), Ilsac (International Lubricants Standardization and Approval Committee) doesn't have the classification of motorcycle engine oil, and there is no national standard and special classification of motorcycle engine oil in China.
JASO of Japan formulated the MA/MB standard in 1999, and the world's first motorcycle oil was born in Japan in 21.
"JASO has set up another four-stroke locomotive engine oil specification, which is based on the performance specification above API SE grade or ACEA A1, plus the limitations of sulfate ash, volatility, defoaming, shear stability and high-temperature high-shear viscosity, and is divided into high-dynamic friction according to the proportion of friction modifiers in its oil, plus the limitations of sulfate ash, volatility, defoaming, shear stability and high-temperature high-shear viscosity.
JASO's engine oil standard is divided into MA, that is, four-stroke high-friction wet clutch motorcycle special gasoline engine lubricating oil, and MB-four-stroke low-friction full range gasoline engine special lubricating oil.
There are three kinds of special lubricants for p>JASO two-stroke gasoline engine: FA, FB and FC. FC standard is adopted in China, so I won't discuss them in detail here.
In view of the fact that all motorcycles with displacement in the world used steam engine oil before 21, the so-called reasons why motorcycles can't use steam engine oil, such as higher rotating speed, higher engine temperature, higher cylinder pressure, worse working environment, air-cooled motorcycles and water-cooled automobiles, different engine structures, motorcycle crankcases and clutches together, and separate automobiles, are all ulterior motives and cheating against the facts.
the reason why JASO of Japan put forward the MA/MB standard is that after 1999, the traditional asbestos materials were banned in the friction plates of motorcycle clutches all over the world. When Japan participated in MOTO GP competition, it was found that the friction plates made of new environmental protection materials would slip and fail because of the additive molybdenum in high-grade lubricating oil (which can reduce the friction of metal parts) when using engine oil above SJ. Therefore, the special engine oil for wet clutch motorcycles with JASO MA standard additive formula is introduced. The properties of JASO MB standard engine oil are exactly the same as those of steam engine oil, and it is suitable for dry clutch motorcycles (pedal motorcycles and BMW motorcycles). In other words, if it is a dry clutch motorcycle, JASO MB admits that the traditional steam engine oil can be used as usual, and the standard of JASOMB is completely consistent with the traditional API and ACEA steam engine oil.
another reason why JASO of Japan put forward the MA/MB standard is that in order to reduce the damage to the exhaust gas conversion catalyst in the additives of modern advanced automobile oil, the phosphorus-containing formula has been abolished from the additives of automobile oil after SJ. As an additive, phosphorus plays an important role in protecting parts. It is said that JASO MA/MB has a special formula to protect engine parts, but what formula is unknown.
ii. API of gasoline engine lubricating oil (gasoline engine oil) and grade and function classification of JASO MA
API SA ~ SD: it was formulated and implemented in 195s and 196s, but it is no longer used and cannot be bought at present.
SE: implemented in 1972, it is superior to SD in high temperature resistance, wear resistance, corrosion resistance and rust prevention, and is not used at present.
SF: implemented in 198, it is superior to SE in anti-sludge, anti-fouling, acid stability and wear resistance, and adding oxidation stabilizers, such as phosphorus derivatives, phenol derivatives and sulfur-containing compounds, can increase the oxidation resistance of engine oil at high temperature and air and prolong its service life. The dosage of this additive is very small, about less than 1/1, and adding too much will be counterproductive.
SG: implemented in 1989, its wear resistance, high temperature resistance, oxidation resistance, detergency, sludge prevention and dispersity are superior to SF. Adding additives to improve oiliness and oil film strength can enhance the oiliness, oxidation resistance and rust prevention of engine oil, and reduce the power consumption when parts are worn and rubbed. In addition, it also has the functions of increasing oil film strength, preventing parts from being damaged by grinding control and avoiding bearing alloy welding. The addition amount of this additive is generally 5% ~ 1%. At the same time, clean dispersion additives are added, such as fatty acid soaps of metals such as calcium, zinc and aluminum, naphthenates of calcium, barium and cobalt, sulfonated naphthenates, etc., which can wash off the deposits in the engine and lubrication system, prevent engine parts from fouling, and especially have a good preventive effect on piston ring adhesion caused by oil film. The dosage of this additive is generally 2% ~ 3%. .
SH: it was formulated in 1992 and implemented in 1994. the content of SH specification is the same as that of SG. however, SG can make up tests for unqualified items in the future until they are all qualified, and sh must be all qualified at one time when it is sent for testing.
SJ: It was formulated in 1996 and implemented in 1997. Semi-synthetic or fully synthetic base oil VHVI is adopted, and its low-temperature fluidity, volatility, filterability, anti-foaming property and high-temperature oxidation stability are higher than SH. Phosphorus in additives is abolished to protect waste conversion catalysts, which is suitable for all gasoline engines.
sl: it was formulated in 21. It uses synthetic base oil PAO and comprehensive additives, which can improve many properties of engine oil. Liquid molybdenum and organic boron are added to replace zinc and aluminum. Because liquid molybdenum is a substance with almost zero friction, the lubrication effect is greatly improved. It is worth mentioning that the oil drain driving proposed by a manufacturer is carried out after adding liquid molybdenum. Experiments show that after adding liquid molybdenum, "the highest effective fuel saving can reach 15.33%;" The horsepower increased by 9.46%; The average exhaust gas decreased by 36.39. " Therefore, SL engine oil is defined as energy saving, high efficiency and environmental protection engine oil.
sm: formulated in the fourth quarter of 24, it is the highest standard gasoline engine oil for oxidation resistance, carbon deposition reduction, excellent low temperature and oil consumption reduction.
at present, the highest standard of JASOMA/MB is equivalent to API SJ.
Fourth, the base oils that make up engine oil: mineral oil, semi-synthetic and fully synthetic. I didn't expect lard and vegetable oil to be the best base oils.
Lubricating oil is composed of base oils and additives, among which base oils account for more than 95%.
The types of base oils are divided into the following five categories:
The first category is traditional solvent refined mineral oil;
the second category, hydrocracking mineral oil;
The above two types are both called mineral oil. The base oil of mineral oil is the residual bottom oil (asphalt) after fractionating useful light substances (such as aviation oil, gasoline, diesel oil, etc.) in the process of crude oil refining. In essence, it uses poor components in crude oil, which contains thousands of different mixture molecules. Even if the refining technology is refined, it can't remove all the bad products and impurities.
the third category, highly hydrocracked or hydroisomerized wax;
the raw materials of this kind of base oil are the same as the first two kinds, which is the most deceptive in the market now. A typical example is that Castrol began to use VHVI(very high viscosity index), a class III base oil, in 1999 to replace PAO with the label of "Synthetic"-synthetic oil, and now many domestic brands also copy it. With the improvement of processing technology, there are now patents on VHVI: 1DW (Hydrocracking-Isodewaxing) Chevron Company; MSDW (hydrotreating-hydroisomerization and hydrocracking-selective dewaxing) patented by ExxonMobil; XHVI (hydroisomerization to produce ultra-high viscosity index) is a patent of Shell Company, which is now called synthetic base oil. Among them, ExxonMobil semi-synthetic oil basically uses MSDW technology, which is called synthetic technology.
the fourth category, polyalphaolefin (pao);
poly (α-olefin) (PAO) is a patented technology of ExxonMobil, which is derived from ethylene and propylene dispersed by gas or natural gas in crude oil, and then refined into a basic liquid composed of macromolecules through complicated chemical reactions such as polymerization and catalysis. In essence, it uses better components in crude oil, and achieves the expected molecular morphology through chemical reaction and artificial control. Its molecules are arranged neatly and its ability to resist external variables is naturally strong. Therefore, the synthetic oil has a good physique, and its ability to resist thermal stability, antioxidant reaction and viscosity change is naturally much stronger than that of mineral oil.
the fifth category, other synthetic oils (generally referred to as lipid synthetic oils)
refers to diesters, polyol esters, polyethers, silicone oils, phosphate esters, etc. chemically synthesized by refining animal and plant (biological) fatty acids and alcohols. Esters are originally oily, and other base oils (including PAO) need additives to achieve this property. Moreover, the original polarity of esters can make oil film molecules adhere to the metal surface, so esters are the best in terms of lubrication performance.
so to sum up, the lubricity: esters >; PAO> Three kinds of base oils, such as < P > ester oils, are the earliest synthetic lubricating oils with good comprehensive properties. At present, almost all the jet engine lubricating oils in the world are ester oils. The molecule of ester oil contains ester functional group -COOR'. According to the number and position of ester groups in the molecule, ester oils can be divided into diester, polyol ester and multiple ester.
1. Good viscosity-temperature characteristics. Ester oils have good viscosity-temperature characteristics and high viscosity index. Lengthening the main chain of ester molecules increases viscosity and viscosity index. When the length of the main chain is the same, the viscosity of the side chain is higher and the viscosity index is lower; With aryl side chains, the viscosity index is lower. The viscosity indexes of sebacate and azelaic acid ester commonly used in diesters are all above 15.
2. Good low temperature performance. The diester with branched alcohol usually has a lower freezing point, and the freezing points of sebacate and azelaide are both below-6 C. The low temperature viscosity of the same type of ester increases with the increase of molecular weight. Incomplete esterification and the existence of some hydroxyl groups will obviously increase the low-temperature viscosity of the ester.
3, good high temperature performance. The flash point and evaporation degree of lubrication affect the fuel consumption, service life and safety of oil products in use, which are related to their molecular composition. With the increase of relative molecular weight, the flash point of the same type of ester increases and the evaporation degree decreases.
4, good oxidation stability. One of the advantages of ester oil is its strong antioxidant capacity, but it also varies with its structure. The oxidation stability of neopentyl polyol ester is better than that of diester. Anti-oxidation and anti-corrosion additives still need to be added in actual use.
5, good lubricity. Because of the polarity of ester groups in ester molecules, ester molecules are easy to adsorb on the friction surface to form interfacial oil film, so the lubricity of ester oil is generally better than that of mineral oil with the same viscosity.