Two-stroke oils

Two-stroke oils Esters such as C36 dimer esters and polyoleates have several advantages over mineral oils as the lubricant component of two-stroke engine fuel mixtures. First, their clean-burn characteristics result in less engine fouling with considerably reduced ring sticking and lower levels of particulate deposit build-up... 

Performance Additives Two-stroke lubricants do not contain conventional antiwear chemistry such as ZDDP, the main reason being the lack of highly loaded surfaces such as cams in the engine. Instead, viscosity alone is the main antiwear component in two-stroke oils, which is driven predominantly by the choice of base oil in the formulation. For the short time that the lubricant is in the engine, it must have sufficient inherent viscosity to prevent the piston assembly from scuff-... 

How will the additive components change in the future Vegetable base oils are susceptible to oxidation by virtue of their double bond structures, although they are being used in some applications such as chain bar lubricants and two-stroke oils. It is possible to utilize vegetable oils in long use applications but the antioxidation protection needed is thus far excessive however, the future utilization of the double bond to attach performance molecules to the base oil itself must be a long-term possibility. 

Two-Stroke Oil 21 100 6 Satisfactory Huntsman PP Huntsman Specimen Virtually stressed free specimen... 

Two-Stroke Oil Urethane Coating Polyamide, Nylon MXD6 (PA MXD6) 5... 

Emission control systems for two-stroke engines depend heavily on an efficient oxidation catalyst. These may be based on Pt and/or Pd. Higher lube oil consumption characteristics of two-stroke engines may result in modification to the lube oil or require the development of oxidation catalysts more resistant to lube oil ash compounds. 

CDll Service typical of two-stroke cycle diesel engines requiring highly effective control over wear and deposits. Oils designed for this service also meet all the requirements of CD. 

Synthetic hydrocarbons Poly(a-olefms) Polyisobutenes Alkylated aromatics Engine oils, industrial (hydraulic, compressor, bearings) Two-stroke engine, electrical insulation, metal forming oils Low temperature oils (engines, gears, hydraulics)... 

Finally, PAHs (polyaromatic hydrocarbons) in exhaust emissions of a two-stroke engine are reduced by 25% when a carboxylic ester is used instead of a mineral oil [56]. PAHs are a major contributor to the carcinogenic nature of exhaust emissions. Esters can also be used to reduce the level of smoke emitted by the engine. 

Calhs, G.E., Mochizuki, A., Nakasoto, M., et al., (1993) Development of engine oils for two-stroke motor cycles in the Asian Market, SAE 931568. 

Naitoh, Y, Yashiro, Y. and Kawabe, H. (1991) Effect of base oil on two-stroke engine oil performance, SAE 911275. 

The free hydroxyl group in ricinoleic acid is able to interact with polar groups on metal surfaces, thereby giving superior lubricity. The largely mono-ene nature of castor oil gives it low-temperature fluidity without the loss of oxidative stability of polyunsaturates. Castor oil is used in specialist two-stroke applications and can be modified for use in greases. 

By their design, two-stroke engines have different lubrication requirements from four-stroke automobile engines. Two-strokes rely on lost oil lubrication where a continuous feed of lubricant into the engine is burned or lost and replenished every cycle. This lubricant may be either pre-mixed with the fuel or injected via a small metering delivery pump into the engine as a function of throttle position. Two-stroke lubricants must have a number of important attributes, mainly ... 

Solvents The primary purpose of the solvent in a two-stroke system is to assist with the miscibility of the finished oil with the fuel and also to aid pumpability in auto-lube systems. Whilst kerosene is often used, de-aromatised solvents are more commonly used with flash points of around 80°C. 

Because of the difficulty in providing a controlled lubricant supply to the rotating cylinder assembly, lubricant was supplied in the fuel feed. High centrifugal forces caused rapid lubricant loss from the piston/cylinder interface so that the technique of dissolving a mineral oil in the fuel, as in modern small two-stroke engines, would leave an inadequate oil film on the cylinder walls. Standard practice used a vegetable... 

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