Views: 0 Author: Site Editor Publish Time: 2024-01-25 Origin: Site
Small four-stroke gasoline engines serve as the heart of compact agricultural equipment such as rice transplanters, micro-tillers, and water pumps.
Engines contain numerous metal surfaces that rub against each other during operation. These components move at high speeds under harsh conditions, with operating temperatures reaching 400–600 degrees Celsius. Under such demanding conditions, only qualified lubricants can reduce wear on engine parts and extend their service life. A good lubricant must meet the following requirements:
A sufficiently thick oil film separates the surfaces of relatively sliding components, thereby reducing wear.
Engine oil dissipates excess heat from the engine block surface through the cooling cycle.
High-quality oil removes carbon deposits, sludge, and worn metal particles from engine components via circulation, flushing contaminants from working surfaces.
Engine oil forms effective seals between piston rings and pistons, as well as between rotating components and oil seals, minimizing gas leakage and preventing external contaminants from entering.
Lubricating oil adsorbs onto component surfaces, preventing contact with water, air, acidic substances, and harmful gases.
Proper lubrication effectively reduces direct contact and meshing between engine components, ensuring smooth operation and lowering noise levels.
There are numerous types of motor oil available, and selecting the right one for your engine isn't as simple as picking any random option. So, how do you choose the appropriate motor oil from the vast array of products?
On motor oil packaging, you'll frequently see the designations SAE and API. SAE stands for the Society of Automotive Engineers, while API represents the American Petroleum Institute. The number following SAE indicates the oil's viscosity grade, such as SAE 30, 10W-30, or 10W-40. This viscosity grade determines the temperature range for which the oil is suitable. SAE 30 indicates this oil is only suitable for spring and summer use, operating above 5°C. The 10W-30 viscosity rating signifies it's a multigrade oil: “W” denotes winter use, while the number preceding “W” represents low-temperature flow properties—lower values indicate better cold-start performance. The number following the “W” indicates the oil's stability at high temperatures (i.e., its tendency to thin). A higher number signifies better high-temperature stability.
The API designation following ‘API’ indicates the oil's quality grade. API engine oils are divided into two categories: the “S” series denotes oils for gasoline engines, with specifications including: API SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN.
When selecting oil, consult the equipment manual to purchase the appropriate viscosity and grade as specified. Generally, for small four-stroke gasoline engines in agricultural machinery, choose a reputable brand of all-season oil (10W-30 or 10W-40) with a grade of SE or higher. (as temperatures in most regions of China range from -20°C to 40°C year-round). A crucial reminder: When purchasing, carefully distinguish between two-stroke and four-stroke oils, as well as gasoline engine oil and diesel engine oil.
Poor cooling efficiency leads to engine overheating, causing engine detonation, piston seizure, and damage to the crankshaft and connecting rod bearings.
Poor sealing allows engine oil from the crankcase to leak into the combustion chamber, where it burns, producing excessive carbon deposits. This causes severe spark plug fouling, preventing normal operation and necessitating frequent spark plug replacement, increasing operating costs.
The oil deteriorates easily, forming carbon deposits in cylinder head cavities that can seize valves, rendering the engine inoperable.
It fails to provide effective lubrication for moving parts, accelerating component wear, shortening service life, or causing mechanical damage.
Abnormal oil consumption, blue smoke from the exhaust, reduced engine power, and excessive wear on piston rings.
