Showing posts with label lawn mower repair. Show all posts
Showing posts with label lawn mower repair. Show all posts
Friday, September 11, 2009
Gasoline - Continue
Modern unleaded gasoline is a complex substance. I have found that ongoing research is necessary to seek ways to produce fuels that offer efficient engine performance and meet air pollution standards. Back in the 70s, while I was still in high school, 10% etanol blend of gasoline, known as gasohol, was introduced. My best friends dad was in too this area big time. He bought a large piece of land outside of our town to store and develope in this area of new fuels. Today, this product is often sold as super unleaded or preminum unleaded gasoline, depending on the octane level. The main drawback to these gasoline blends is their ability to absorb moisture, which can pass through the fuel filter and into the combustion chamber. These fuels should never be stored in high humidity areas or used in engines that set idle for long periods of time. Gasoline containing alcohol can also corrode fuel tank linings, shrink carburetor floats and seals, increase carbon deposits, and pit metal parts. For maximum performance and engine life, only use the type of gasoline recommended by the engine manufacturer.
Thursday, September 10, 2009
Small Engine Construction and Principles of Operation - Part I
After reading this, you will be able to:
* Explain simple engine operation.
* Know the qualities of gasoline that make you're mower an efficient small engine.
* Know why gasoline is atomized in the small engine.
* Know the basic components of your small engine and know the function of each part.
GASOLINE ENGINES
A gosoline-fueled ingine is a mechanism desinged to transform the chemical energy of burning fuel into mechanical energy. In operation, it controls and applies this energy to mow lawns, cut trees, propel tractors, and perform many other laborsaving jobs. A gasoline engine is an internal combustion engine. Gasoline is combined with air and burned inside the engine. In its simplest form, an engine consists of a ported cyliner, piston, connecting rod, and crankshaft.
The piston is a close fit inside the cylinder, yet it is free to slide on the lubricated walls. One end of the connecting rod is attached to the poston; the other end is fastened to an offset crankpin, or jouranl, of the crankshaft. As the piston moves up and down, the connecting rod forces the journal to follow a circular path, rotating the crankshaft.
SIMPLE ENGINE IN OPERATION
When the engine is cranked, gasoline is atomized (reduced to minute particles) and mixed with air. This mixture is forced through an intake port and into the cylinder, where it is compressed by the piston on the upstroke and ignited by an electrical spark. Combuston forces the piston down to rotate crankshaft. Burning rapidly, the heated gases trapped within the cylinder (combustion chamber) expand and apply pressure to the walls of the cylinder and to the top of the piston. This pressure drives the piston downward on the power stroke, causing the crankshaft to turn. As the piston and connecting rod push the crankshaft journal to the bottom of the stroke, the pressure of the burned gases is released through an exhaust port. Meanwhile, a fresh air-fuel charge enters the cylinder and the momentum of the power stroke turns the crankshaft journal through bottom dead center (BCD) and into the upstroke on another power cycle. Tommorow: Gasoline - The Hydrocaarbon Fuel in Small Engines.
* Explain simple engine operation.
* Know the qualities of gasoline that make you're mower an efficient small engine.
* Know why gasoline is atomized in the small engine.
* Know the basic components of your small engine and know the function of each part.
GASOLINE ENGINES
A gosoline-fueled ingine is a mechanism desinged to transform the chemical energy of burning fuel into mechanical energy. In operation, it controls and applies this energy to mow lawns, cut trees, propel tractors, and perform many other laborsaving jobs. A gasoline engine is an internal combustion engine. Gasoline is combined with air and burned inside the engine. In its simplest form, an engine consists of a ported cyliner, piston, connecting rod, and crankshaft.
The piston is a close fit inside the cylinder, yet it is free to slide on the lubricated walls. One end of the connecting rod is attached to the poston; the other end is fastened to an offset crankpin, or jouranl, of the crankshaft. As the piston moves up and down, the connecting rod forces the journal to follow a circular path, rotating the crankshaft.
SIMPLE ENGINE IN OPERATION
When the engine is cranked, gasoline is atomized (reduced to minute particles) and mixed with air. This mixture is forced through an intake port and into the cylinder, where it is compressed by the piston on the upstroke and ignited by an electrical spark. Combuston forces the piston down to rotate crankshaft. Burning rapidly, the heated gases trapped within the cylinder (combustion chamber) expand and apply pressure to the walls of the cylinder and to the top of the piston. This pressure drives the piston downward on the power stroke, causing the crankshaft to turn. As the piston and connecting rod push the crankshaft journal to the bottom of the stroke, the pressure of the burned gases is released through an exhaust port. Meanwhile, a fresh air-fuel charge enters the cylinder and the momentum of the power stroke turns the crankshaft journal through bottom dead center (BCD) and into the upstroke on another power cycle. Tommorow: Gasoline - The Hydrocaarbon Fuel in Small Engines.
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