'MIICROFICHE REFERENCE LIBRARY - Cd3wd.com

2.04 - 2.05faster, it becomes necessary to shift both levers. First shift the transfercase to high range, then put the gearshift into the appropriate gear. Itmay also be necessary to engage the front wheel drive after shifting thetransfer case. The whole shift may take so long that aromentum will be lost,and the regular gearshift will probably have to be put into the first geareven though it is a lower ratio than top gear in lw range.2.05 Introductiontothel%gineFor those who are not familiar with the basic principles of automotiveengines, the following basic introduction may be useful.Energy to move the car is derived from the fuel, usually gasoline,which must be mixed with air to make it burn, andthenmstbe burned ina controlled way so that the energy can be used.Gasoline, stored in the fuel tank, goes thmughtubingt~ a small pump,which forces it into the carburetor. At the sametime,airis sucked inthrough the air cleaner where dust and solid particles are removed, and intothe carburetor. In the carburetor the fuel and air are mixed to a c~@.m?tiblevapor. This vapor is then suckedthroughthe intakemanifoldtothe engineitself. At the engine, the fuel vapor passes through a valve at the top,cfeach cylinder, being sucked into the Cylinder when the piston within it movesdown, creating a vacuum inside the engine.The engine operates on what is termed a four-stroke cycle. The fourstrokes are intake, campl?ession, ignition (or power) and exhaust. On theintake stroke of a piston, the cylinder is filled with fuel vapor throughtie intake valve. As the piston reaches the bottom of the cylinder theintake valve closes, and the piston starts up again. The fuel vapor is thuscompressed, cramning mre energy into a smaller space. As the piston passesthe top of its stzoke, when the space within the cylinder is smallest, thefuel mixture is ignited by a spark from the spark plug. The fuel explodesviolently, but since both valves are closed there is nowhere for the energyto go unless the piston is forced downward. This is the power stroke, andit is the energy of the explosion forcing the piston dawrrward which turnsthe engine and makes the a3r go. The fourth stroke, exhaust, serves toforce the used gases out the exhaust valve to clear the cylinder for thenext cycle.In order to keep this cycle moving, several extra parts are essential.The generator is turned by the engine, and provides electric power to keeptie battery charged for the operation of electric accessories such as headlights,windshield wipers and horn. The battery also provides power to theignition system of the car: 12 WLt PckJer from the battery travels throughthebreakerpointstothe sparkcoil. There it is built up to a very highvoltage, tiich is sent through the distributor to each spark plug at preciselythe right time to ignite the fuel mixture at the top of the compresyionstoke.The cooling system keeps the heat of the explosions inside the cylindersfrom damaging the engine. It consists of a radiator, fan, water pump,and a supply of cooling water which runs through little channels inside theengineblock. The fan blows air through the radiator to keep it cool, andwater flowing thx~ugh the radiator is therefore also cooled as it circulates