AUTER301 - Automotive Engine Repairing

An overhaul engine is one that has been removed, disassembled, cleaned, inspected, repaired as necessary and tested using factory service manual approved procedures. The procedure generally involves honing, new piston rings. Bearings, gaskets and oil seals. Engine overhaul is basically giving engine new life.

Overhaul means to make necessary repairs on, restore to serviceable condition. To investigate or examine thoroughly for repair or revision

Evolution of the motor vehicle

1860 The Frenchman Lenoir constructs the first fully operational internal-combustion engine; this power plant relies on city gas as its fuel source. Thermal efficiency is in the 3% range.
1867 Otto and Langen display an improved internal combustion engine at the Paris International Exhibition. Its thermal efficiency is approximately 9%. (R.Gscheidle, 2006)

Source: Internet
Figure: Daimler motorcycle and Benz motor carriage

1876 Otto builds the first gas-powered engine to utilise the four-stroke compression cycle. At virtually the same time Clerk constructs the first gas-powered two-stroke engine in England.

1883 Daimler and Maybach develop the first high speed four-cycle petrol engine using a hot tube ignition system.
1885 The first self-propelled motorcycle from Daimler. First self-propelled three-wheeler from Benz (patented in 1886).
1886 First four-wheeled motor carriage with petrol engine from Daimler (Fig. 2).
1887 Bosch invents the magneto ignition.
1889 Dunlop in England produces the first pneumatic tyres.
1893 Maybach invents the spray-nozzle carburettor.
1893 Diesel patents his design for a heavy oil-burning powerplant employing the self-ignition concept.
1897 MAN presents the first workable diesel engine.

Source: Internet

Figure: Ford model T and VW beetle

1897 First Electro mobile from Lohner-Porsche.
1899 Fiat Automobile Factory founded in Turin.
1913 Ford introduces the production line to automotive manufacturing. Production of the Tin Lizzy (Model T). By 1925, 9,109 were leaving the production line each day.
1916 The Bavarian Motor Works are founded.
1923 First motor lorry powered by a diesel engine produced by Benz-MAN.
1936 Daimler-Benz inaugurates series-production of passenger cars propelled by diesel engines.
1938 The VW Works are founded in Wolfsburg
1949 First low-profile tyre and first steel-belted radial tyre produced by Michelin.
1950 First gas-turbine propulsion unit for automotive application makes its debut at Rover in England.
1954 NSU-Wankel constructs the rotary engine
1966 Electronic fuel injection (D-Jetronic) for standard production vehicles produced by Bosch.
1970 Seatbelts for driver and front passengers.
1978 Initial application of the ABS Antilock Braking System in passenger cars.
1984 Debut of the airbag and seatbelt tensioning system.
1985 Advent of a catalytic converter designed for operation in conjunction with closed-loop mixture control, intended for use with unleaded fuel.
1997 Electronic suspension control systems.

DESIGN OF MOTORVEHICLE

The motor vehicle consists of component assemblies and their individual components. The layout of the individual assemblies and their relative positions is not governed by invariable standards. Thus, for. Example, the engine may be designed as an independent assembly, or it may be integrated as a sub- assembly within a larger power train unit.

One of the options described in this book is to divide the vehicle into 5 main assembly groups:
Engine, drive train, chassis, vehicle body and electrical system.
The relationships between the assemblies and their constituent components are illustrated in

Source: Internet

 
ENGINE CLASSIFICATIONS
Today’s automotive engines can be classified in several ways depending on the following design features:

• Operational cycles. Most technicians will generally come in contact with only four-stroke engines. However, a few older cars have used and some cars in the future will use a twostroke engine
• Number of cylinders. Current engine designs include 3-, 4-, 5-, 6-, 8-, 10-, and 12-cylinder engines.
• Cylinder arrangement. An engine can be flat (opposed), inline, or V-type. Other more complicated designs have also been used.
  
• Valve train type. Engine valve trains can be either the overhead camshaft (OHC) type or the camshaft in-block overhead valve (OHV) type. Some engines separate camshafts for the intake and exhaust valves. These are based on the OHC design and are called double overhead camshaft (DOHC) engines. V-type DOHC engines have four camshafts—two on each side.
  
• Ignition type. There are two types of ignition systems: spark and compression. Gasoline engines use a spark ignition system. In a spark ignition system, the air-fuel mixture is ignited by an electrical spark. Diesel engines, or compression ignition engines, have no spark plugs. A diesel engine relies on the heat generated as air is compressed to ignite the air-fuel mixture for the power stroke.
• Cooling systems. There are both air-cooled and liquid-cooled engines in use. Nearly all of today’s engines have liquid-cooling systems.
  
• Fuel type. Several types of fuel currently used in automobile engines include gasoline, natural gas, methanol, diesel, and propane. The most commonly used is gasoline although new fuels are being tested. (R.Gscheidle, 2006)