Types of Oil Pumps

 Gear-type oil pump

Gear-type oil pumps have
a primary gear that is driven by an external member, and which drives a companion
gear.  Oil is forced into the pump cavity, around each gear, and out the other side
into the oil passages.  The pressure is derived from the action of the meshed gear
teeth, which prevents oil from passing between the gears, forcing it around the
outside of each gear instead.  The oil pump incorporates a pressure relief valve, a
spring-loaded ball that rises when the desired pressure is reached, allowing the
excess oil to be delivered to the inlet side of the pum

 
Rotor-type oil pump

A rotor-type oil pump for sucking and discharging oil to be supplied to a variety of oil-requiring parts of an automotive engine. The oil pump comprises a generally annular outer rotor which is rotatably disposed in a pump casing. A generally annular inner rotor is disposed eccentrically inside the outer rotor and has an external gear which is partly in mesh with the internal gear of the outer rotor. The outer rotor is designed such that stress at the tooth base section of the internal gear is generally equal to stress at the tooth base section of the external gear of the inner rotor in their dynamic condition, thereby reducing the thickness of the tooth base section of the outer rotor.

Crescent type oil pump 

 

Vane Type oil pump

Lubrication System

how a engine lubrication system functions and talks about the main components for lubricating an engine (oil pump, oil filter, oil store, oil splash, etc


Functions of oil
   
Oil reduces unwanted friction. It reduces wear on moving parts, and helps cool an engine. It also absorbs shock loads and acts as a cleaning agent.

 Viscosity
   
Viscosity rating indicates flow rate of oil at a given temperature. There are many grades. Thin oils tend to be for cold conditions. Oil with improver is called multi-grade or multiple-viscosity oil.

 Oil additives
   
Different additives do different jobs. They can inhibit corrosion, foaming and oxidation, and act as dispersants.

Synthetic oils
   
Synthetic oils offer better protection against engine wear and can operate at higher temperatures. They have better low temperature viscosity, are chemically more stable and allow for closer tolerances in engine components without loss of lubrication.

Lubrication systems
   
The lubrication system
   
The lubrication system is designed to keep the components in the engine lubricated and to reduce friction.

Splash system
   
In the splash lubrication system, a dipper or slinger splashes oil through the internal parts of the engine. Oil is also splashed up to the valve mechanism.

 Pressure system
   
In force-feed lubrication, pressure forces oil around the engine. In a wet-sump system, oil is kept in the sump ready for the next use. In a dry sump system, oil falls to the bottom of the engine and a scavenge pump sends it to an oil tank.

 2-stroke engine premix fuel systems
   

Most 2-stroke gasoline engines use a set gasoline-oil mixture for lubrication. As the air, fuel and oil enter the crankcase, the fuel evaporates, leaving behind enough oil to keep parts coated and lubricated.

 2-stroke engine oil injection systems
  
An oil injection system doesn't need the oil and gasoline mixed manually. An engine-driven oil pump takes oil from a tank and pumps a measured amount directly into the engine where it mixes with the fuel and lubricates the internal engine parts.

 Rotary engine lubrication system

In addition to normal internal lubrication, the rotary engine uses oil injection. A pump injects a measured amount into the intake manifold. Oil from these nozzles goes to the engine and lubricates the rotor seals.

Corrosion/noise reduction
   
Engine oil performs many other functions apart from lubricating moving components. Two other functions are corrosion protection and noise suppression.

Lubrication system components
   
Sump
   
The sump is at the base of an engine. It can be used as a storage container in a 'wet sump system'.

 Oil collection pan
   
An oil collection pan is used in 'dry sump systems' prior to being returned to an oil tank.

 Oil tank
   
The oil tank is part of the dry sump lubrication system and is used for oil storage.

Pickup tube
   
A pickup tube is used to provide a means of collecting oil for the oil pump.

 Oil pump
   
Oil pumps deliver oil under pressure to the internal engine parts. In a rotor-type oil pump, an inner rotor drives an outer one. Pressure differences force the oil to move. Geared oil pumps use a similar principle.

 Oil pressure relief valve
   

The pressure relief valve is used to prevent damage to an engine due to too much oil pressure.
 
Oil filters
   
The oil filter helps to clean the oil in the system. If the filter clogs, a valve opens and directs unfiltered oil to the engine. Most oil-filters on diesel engines are larger than those on similar gasoline engines.

Spurt holes & galleries
   
Spurt holes and galleries are used to deliver oil from the oil pump to various components and bearings in the engine.

Oil indicators
   
Oil indicators are used to check when there are safe oil levels in an engine.

Oil cooler
   
An oil cooler cools oil prior to its reuse in the engine.

Lubrication procedures
   
Checking engine oil

The objective of this procedure is to show you how to check and adjust engine oil level and condition. Make sure the vehicle is on a level surface and the engine is off before taking a reading. If you don't, you'll get inaccurate readings.

 Draining engine oil

Oil loses its clean, fresh look very quickly and yet may still be serviceable. The best guide to changing oil is knowing the vehicle's mileage and period of time since the last oil change. The objective of this procedure is to show you how to safely drain engine oil.

Replacing an oil filter

The objective of this procedure is to show you how to replace an oil filter to the manufacturer's specifications. Before removing an oil filter, first refer to the Service Manual for the vehicle and identify the type of filter required.

Refilling engine oil
   
The objective of this procedure is to show you how to safely refill engine oil. The service manual or the owner's manual will also tell you the correct grade of oil for the vehicle, and the quantity you will need to fill the engine.

cav rotary pump (epic)

Careful section of a CAV rotary pump for training purposes, showing all its operating parts. The transfer pump, the speed governor, the automatic advance regulator, the hydraulic sensor device, the fuel circuit and the pumping small piston are clearly shown. It is operated by hand through a hand wheel.

It is supplied complete with an indirect injector and mounted on an elegant laminated plastic base.

New vehicle air condition system

air condition system
 Vehicles are found to have primarily three different types of air conditioning systems. While each of the three types differ, the concept and design are very similar to one another. The most common components which make up these automotive systems are the following: COMPRESSOR, CONDENSER,EVAPORATOR, ORIFICE TUBE, THERMAL EXPANSION VALVE , RECEIVER-DRIER,ACCUMULATOR.
 Note: if your car has an Orifice tube, it will not have a Thermal Expansion Valve as these two devices serve the same purpose. Also, you will either have a Receiver-Dryer or an Accumulator, but not both.
 COMPRESSOR
 Commonly referred to as the heart of the system, the compressor is a belt driven pump that is fastened to the engine. It is responsible for compressing and transferring refrigerant gas. The A/C system is split into two sides, a high pressure side and a low pressure side; defined as discharge and suction. Since the compressor is basically a pump, it must have an intake side and a discharge side. The intake, or suction side, draws in refrigerant gas from the outlet of the evaporator. In some cases it does this via the accumulator. Once the refrigerant is drawn into the suction side, it is compressed and sent to the condenser, where it can then transfer the heat that is absorbed from the inside of the vehicle.
 CONDENSER
 This is the area in which heat dissipation occurs. The condenser, in many cases, will have much the same appearance as the radiator in you car as the two have very similar functions. The condenser is designed to radiate heat. Its location is usually in front of the radiator, but in some cases, due to aerodynamic improvements to the body of a vehicle, its location may differ. Condensers must have good air flow anytime the system is in operation. On rear wheel drive vehicles, this is usually accomplished by taking advantage of your existing engine's cooling fan. On front wheel drive vehicles, condenser air flow is supplemented with one or more electric cooling fan(s). As hot compressed gasses are introduced into the top of the condenser, they are cooled off. As the gas cools, it condenses and exits the bottom of the condenser as a high pressure liquid. . EVAPORATOR
 Located inside the vehicle, the evaporator serves as the heat absorption component. The evaporator provides several functions. Its primary duty is to remove heat from the inside of your vehicle. A secondary benefit is dehumidification. As warmer air travels through the aluminum fins of the cooler evaporator coil, the moisture contained in the air condenses on its surface. Dust and pollen passing through stick to its wet surfaces and drain off to the outside. On humid days you may have seen this as water dripping from the bottom of your vehicle. Rest assured this is perfectly normal. The ideal temperature of the evaporator is 32 Fahrenheit or 0 Celsius. Refrigerant enters the bottom of the evaporator as a low pressure liquid. The warm air passing through the evaporator fins causes the refrigerant to boil (refrigerants have very low boiling points). As the refrigerant begins to boil, it can absorb large amounts of heat. This heat is then carried off with the refrigerant to the outside of the vehicle. Several other components work in conjunction with the evaporator. As mentioned above, the ideal temperature for an evaporator coil is 32 F. Temperature and pressure regulating devices must be used to control its temperature. While there are many variations of devices used, their main functions are the same; keeping pressure in the evaporator low and keeping the evaporator from freezing; A frozen evaporator coil will not absorb as much heat.

 PRESSURE REGULATING DEVICES
 Controlling the evaporator temperature can be accomplished by controlling refrigerant pressure and flow into the evaporator. Listed below, are the most commonly found. ORIFICE TUBE The orifice tube, probably the most commonly used, can be found in most GM and Ford models. It is located in the inlet tube of the evaporator, or in the liquid line, somewhere between the outlet of the condenser and the inlet of the evaporator. This point can be found in a properly functioning system by locating the area between the outlet of the condenser and the inlet of the evaporator that suddenly makes the change from hot to cold. You should then see small dimples placed in the line that keep the orifice tube from moving. Most of the orifice tubes in use today measure approximately three inches in length and consist of a small brass tube, surrounded by plastic, and covered with a filter screen at each end. It is not uncommon for these tubes to become clogged with small debris. While inexpensive, usually between three to five dollars, the labor to replace one involves recovering the refrigerant, opening the system up, replacing the orifice tube, evacuating and then recharging. With this in mind, it might make sense to install a larger pre filter in front of the orifice tube to minimize the risk of of this problem reoccurring. Some Ford models have a permanently affixed orifice tube in the liquid line. These can be cut out and replaced with a combination filter/orifice assembly.
 THERMAL EXPANSION VALVE
 Another common refrigerant regulator is the thermal expansion valve, or TXV. Commonly used on import and aftermarket systems. This type of valve can sense both temperature and pressure, and is very efficient at regulating refrigerant flow to the evaporator. Several variations of this valve are commonly found. Another example of a thermal expansion valve is Chrysler's "H block" type. This type of valve is usually located at the firewall, between the evaporator inlet and outlet tubes and the liquid and suction lines. These types of valves, although efficient, have some disadvantages over orifice tube systems. Like orifice tubes these valves can become clogged with debris, but also have small moving parts that may stick and malfunction due to corrosion.

 RECEIVER-DRIER
 The receiver-drier is used on the high side of systems that use a thermal expansion valve. This type of metering valve requires liquid refrigerant. To ensure that the valve gets liquid refrigerant, a receiver is used. The primary function of the receiver-drier is to separate gas and liquid. The secondary purpose is to remove moisture and filter out dirt. The receiver-drier usually has a sight glass in the top. This sight glass is often used to charge the system. Under normal operating conditions, vapor bubbles should not be visible in the sight glass. The use of the sight glass to charge the system is not recommended in R-134a systems as cloudiness and oil that has separated from the refrigerant can be mistaken for bubbles. This type of mistake can lead to a dangerous overcharged condition. There are variations of receiver-driers and several different desiccant materials are in use. Some of the moisture removing desiccants found within are not compatible with R-134a. The desiccant type is usually identified on a sticker that is affixed to the receiver-drier. Newer receiver-driers use desiccant type XH-7 and are compatible with both R-12 and R-134a refrigerants.
 ACCUMULATOR
 Accumulators are used on systems that accommodate an orifice tube to meter refrigerants into the evaporator. It is connected directly to the evaporator outlet and stores excess liquid refrigerant. Introduction of liquid refrigerant into a compressor can do serious damage. Compressors are designed to compress gas not liquid. The chief role of the accumulator is to isolate the compressor from any damaging liquid refrigerant. Accumulators, like receiver-driers, also remove debris and moisture from a system. It is a good idea to replace the accumulator each time the system is opened up for major repair and anytime moisture and/or debris is of concern. Moisture is enemy number one for your A/C system. Moisture in a system mixes with refrigerant and forms a corrosive acid. When in doubt, it may be to your advantage to change the Accumulator or receiver in your system. While this may be a temporary discomfort for your wallet, it is of long term benefit to your air conditioning system

Diesel Electronic Unit Injector

The unit injector combines a high-pressure pump and nozzle with a solenoid valve to form compact assembly. As a result, high-pressure lines are no longer necessary and injection can be controlled by the integrated and extremely precise solenoid valve at pressures of up to 2000 bar. Each cylinder has a unit injector fitted between the valves in the cylinder head. The unit injector is used in both passenger cars and commercial vehicles. The Bosch Unit Injector system was first used in the VW Passat TDI in 1998, after which it rapidly found favour within the VW range. With the V10 TDI, VW recently presented what is currently the most powerful diesel engine for use in a car.

Diesel injection pump

Robert Bosch has contributed to Diesel In-Line Fuel-Injection Pumps: Bosch Technical Instruction as an author. Robert Bosch GmbH is ranked among the world's major equipment suppliers. The Bosch experts that make up the editorial team come from the relevant divisions of Bosch and are at the forefront of technical developments in their field. Bosch demonstrates its leading competence in automotive technology through the sheer number of its applications for patents and patented designs. inline pump

The diesel fuel pump is a fairly complex and sturdy mechanism. In fact, it is the most complex diesel engine part. Additionally, a diesel fuel pump must be durable enough that it can withstand the pressure of the compressed air, and the heat of the injection process. The fine mist of fuel needed for the proper ignition must be maintained by the diesel fuel pump under these extreme conditions. Diesel fuel pumps may be located just about anywhere on the engine, depending on the manufacturers design. Much experimentation has been done over the years regarding the most effective placement of the diesel fuel pump. So far it seems that so long as the pump is mounted on the engine, it will effectively deliver fuel to the cylinders. A gasoline fuel pump, on the other hand, may be mounted anywhere in the engine compartment or along the fuel distribution system. Depending on the location and design of the diesel fuel injector pump, pre-combustion chambers, customized induction valves, and other systems are often used in the injection process. These injection enhancers often aid in circulating, or swirling the air inside the cylinder for more efficient combustion. Just as with any engine fuel injection system, diesel fuel pumps are constantly being improved to be more efficient and less costly.

Common Rail System

The common rail system accumulates high-pressure fuel in the common rail and injects the fuel into the engine cylinder at timing controlled by the engine ECU, allowing high-pressure injection independent from the engine speed. As a result, the common rail system can reduce harmful materials such as nitrogen oxides (NOx) and particulate matter (PM) in emissions and generates more engine power. DENSO leads the industry in increasing fuel pressure and maximizing the precision of injection timing and quantity, achieving cleaner emissions and more powerful engines. DENSO’s common rail systems are supplied to a variety of vehicles including passenger cars and commercial vehicles. DENSO Technology – Leading the World In 1995, DENSO launched the world’s first common rail system for trucks. In 2002, DENSO launched a 1,800-bar common rail system that achieved the industry’s highest injection pressure, and five-time multiple injections at a high accuracy. This system comfortably cleared EURO4 emission regulations without a diesel particulate filter. Benefits and Features DENSO’s common rail system can inject fuel at up to 1,800 bar, significantly reducing the concentration of PM in emissions. DENSO’s new injectors can perform five injections during each combustion stroke. The five times multiple injections, including pilot injection with a predetermined small fuel quantity, reduce PM and NOx in emissions, and achieve quietness at idling equivalent to gasoline-powered engines. The high fuel injection pressure is generated by the supply pump, which is the lightest in the world for passenger car common rail systems.

diesel engine

internal combus­tion engines designed to convert the chemical energy available in fuel into mechanical energy. This mechanical energy moves pistons up and down inside cylinders. The pistons are connected to a crankshaft, and the up-and-down motion of the pistons, known as linear motion, creates the rotary motion needed to turn the wheels of a car forward. Both diesel engines and gasoline engines covert fuel into energy through a series of small explosions or combustions. The major difference between diesel and gasoline is the way these explosions happen. In a gasoline engine, fuel is mixed with air, compressed by pistons and ignited by sparks from spark plugs. In a diesel engine, however, the air is compressed first, and then the fuel is injected. Because air heats up when it's compressed, the fuel ignites. The diesel engine uses a four-stroke combustion cycle just like a gasoline engine. The four strokes are: Intake stroke -- The intake valve opens up, letting in air and moving the piston down. ­ Compression stroke -- The piston moves back up and compresses the air. Combustion stroke -- As the piston reaches the top, fuel is injected at just the right moment and ignited, forcing the piston back down. Exhaust stroke -- The piston moves back to the top, pushing out the exhaust created from the combustion out of the exhaust valve. Remember that the diesel engine has no spark plug, that it intakes air and compresses it, and that it then injects the fuel directly into the combustion chamber (direct injection). It is the heat of the compressed air that lights the fuel in a diesel engine. In the next section, we'll examine the diesel injection process.

New Turbocharger Ball Bearing Technology

September 4, 2009 --The Comp Turbo CT3B turbocharger is relatively new on the scene, is dynamite in a small package and has a bearing system that utilizes the latest in ball bearing technology. Racing applications need turbochargers that accelerate at the fastest possible rate and the CT3B bearing system allows it to do just that. The acceleration rate of a turbocharger is a function of the rotor inertia and the friction losses in the bearing system. Conventional bearing systems have floating sleeve bearings that have an inner and outer oil film fed by lube oil under pressure from the engine lubricating system. They also must employ a stationary thrust bearing that is also fed by lube oil under pressure from the engine. The friction loss attributed to a stationary thrust bearing is proportional to the fourth power of the radius and can amount to several horsepower at the high speed at which turbochargers operate. The oil films in conventional sleeve bearing systems have significant viscosity that produces appreciable friction losses due to oil film shear when the turbocharger rotor accelerated and running at high speed. The friction losses in the sleeve bearings and in the thrust bearing result in mechanical efficiencies in the middle 90% range in conventional turbochargers. There is little or no oil film shear in ball bearings which operate with rolling friction only so that the CT3B accelerates much faster than turbochargers using sleeve bearings systems. The CT3B bearing system is a proprietary design that is unique in the industry. It utilizes full compliment, angular contact ball bearings with ceramic balls. Compared with steel balls, ceramic balls in ball bearings have a number of advantages. Bearing service life is two to five times longer. They run at lower operating temperatures and allow running speeds to be as much as 50% higher. The surface finish of ceramic balls is almost smooth, producing lower friction losses and lower vibration levels. There is less heat buildup during high speed operation, they exhibit reduced ball skidding and have a longer fatigue life. All these characteristics make ceramic ball bearings ideal for use in turbochargers where they must operate at very high speeds and survive in a high temperature environment. The Full compliment bearings do now use a cage to position the balls and this additional feature, combined with the ceramic material provides a combination that has minimal friction losses. The mechanical efficiency of the CT3B turbo can approach 99%, and this contributes to rotor acceleration rates that have been shown to be faster than competition. The angular contact bearings are mounted in an elongated steel cylinder that is free to rotate in the bearing housing. The outside diameter of the cylinder is fed with lube oil and this outer oil film provides a cushion against shock and vibration. Two angular contact bearings are mounted in tandem on the compressor end of the cylinder in an arrangement that carries rotor thrust in both axial directions. A single angular contact bearing is slid ably mounted under pre- load on the turbine end of the cylinder and is free to move axially with shaft elongation when heat is conducted down the shaft from the hot turbine wheel. The elongated steel cylinder containing the angular contact bearings represents complete bearing system and can be inserted and/or removed as an assembly making the CT3B turbocharger fully upgradeable, serviceable and re-buildable. Racing Applications require a turbocharger that builds boost as rapidly as possible, thus allowing the engine develop high torque at low engine speeds and with boost capability that can produce very high maximum power output .The CT3B turbocharger does exactly that. For example when mounted on one dragster, the CT3B produced 1.7 bar boost in two tenths of a second and developed 650 HP ready for takeoff. Now that’s phenomenal response and very impressive. In street applications, the acceleration rate of a vehicle equipped with a CT3B turbocharger is enhanced and moves the engine out of inefficient operating regimes more rapidly. An improvement in number of gallons of fuel used is the usual result when a vehicle is accelerated faster. Under steady-state operation, the lower HP losses in the CT3B ball bearing system means power is available to the turbocharger compressor which results in higher intake manifold pressure. In most cases, higher boost can make an additional contribution to improving engine fuel consumption. Comp Turbo can supply the CT3B turbocharger with various compressors and turbine wheel trims to tailor its performance so that it matches specific engine application requirements; whether they be racing, street or stationary. In addition, the CT3B will be followed in the near future by other model sized now under development at Comp Turbo. These new models will utilize the proprietary technology that has been designed into the successful CT3B to complete a line of high performance turbochargers utilizing the many advantages of ceramic ball bearings. They will also accelerate like greased lightning to produce the ultimate in engine and vehicle response

2 stroke engine

Stroke: Either the up or down movement of the piston from the top to the bottom or bottom to top of the cylinder (So the piston going from the bottom of the cylinder to the top would be 1 stroke, from the top back to the bottom would be another stroke) Induction: As the piston travels down the cylinder head, it 'sucks' the fuel/air mixture into the cylinder. This is known as 'Induction'. Compression: As the piston travels up to the top of the cylinder head, it 'compresses' the fuel/air mixture from the carburetor in the top of the cylinder head, making the fuel/air mix ready for igniting by the spark plug. This is known as 'Compression'. Ignition: When the spark plug ignites the compressed fuel/air mixture, sometimes referred to as the power stroke. Exhaust: As the piston returns back to the top of the cylinder head after the fuel/air mix has been ignited, the piston pushes the burnt 'exhaust' gases out of the cylinder & through the exhaust system. Transfer Port: The port (or passageway) in a 2 stroke engine that transfers the fuel/air mixture from the bottom of the engine to the top of the cylinder

4 stroke engine

Four Stroke Engine The four stroke engine was first demonstrated by Nikolaus Otto in 1876 hence it is also known as the Otto cycle. The technically correct term is actually four stroke cycle. The four stroke engine is probably the most common engine type nowadays. It powers almost all cars and trucks. The four strokes of the cycle are intake, compression, power, and exhaust. Each corresponds to one full stroke of the piston; therefore, the complete cycle requires two revolutions of the crankshaft to complete. Intake During the intake stroke, the piston moves downward, drawing a fresh charge of vaporized fuel/air mixture. The illustrated engine features a poppet intake valve which is drawn open by the vacuum produced by the intake stroke. Some early engines worked this way; however, most modern engines incorporate an extra cam/lifter arrangement as seen on the exhaust valve. The exhaust valve is held shut by a spring (not illustrated here). Otto compression stroke Compression As the piston rises, the poppet valve is forced shut by the increased cylinder pressure. Flywheel momentum drives the piston upward, compressing the fuel/air mixture. Otto power stroke Power At the top of the compression stroke, the spark plug fires, igniting the compressed fuel. As the fuel burns it expands, driving the piston downward. Otto exhaust stroke Exhaust At the bottom of the power stroke, the exhaust valve is opened by the cam/lifter mechanism. The upward stroke of the piston drives the exhausted fuel out of the cylinder. Ignition System This animation also illustrates a simple ignition system using breaker points, coil, condenser, and battery. A number of visitors have written to point out a problem with the breaker points in my illustration. In this style ignition circuit, the spark plug will fire just as the breaker points open. The illustration appears to have this backwards. In fact, the illustration is correct; it just moves so fast it's difficult to see! Here's a close-up of the frames just at the point the plug fires:

5 stroke engine

Ilmor Engineering, the firm made famous for its work with Indy Cars and Formula One, as well as Triumph Motorcycles and Harley Davidson plus GM, Honda and Mercedes have built an engine that will make you think for a bit, it's a 700cc, 3 cylinder, 130 horsepower turbocharged 5 stroke. Did they say 5 stroke? The 2 outboard cylinders are the high pressure (HP) fired cylinders while the center low pressure (LP) cylinder makes extra use of the exhaust gases. The point of this design is to enable the expansion and compression strokes to be decoupled. The effective expansion ratio is 14.5:1, almost diesel territory, converting the maximum thermal energy into work. The compression ratio can be reduced, delaying knock, without a decrease in performance. The extra expansion stroke of the LP cylinder is, effectively, the 5th stroke. Fuel consumption and emissions levels are similar to that of current diesel engines, without the serious problem of particulate and NOx emissions which plague diesels. Fuel consumption is decreased by 10% over conventional 4 stroke operation. The entire engine is built using conventional technology, no new manufacturing technology or processes are needed. This is more than a computer model, the running prototype is being dyno tested with a second development engine planned for in-vehicle testing. Just when you think the internal combustion engine has pretty well emptied the bag of tricks, a little creative thinking comes along and gets higher fuel efficiency and lower weight than equivalent engines by adding another stroke to the process. So now we have 2, 4, 5 and even 6 strokes. Very impressive engineering, I like it.

Chassis

A chassis is an underlying supporting structure – such as a skeleton in an animal, or the metal frame in a television on which the circuit boards and other components are mounted. In a motor vehicle, a traditional chassis gave the vehicle structural strength as well as a platform on which to mount the engine, the wheels, the transmission, and all the other mechanical components. Also bolted onto this frame was the body, or coachwork. Originally made of wood, the vehicle chassis soon became an open steel ladder-frame structure. A separate chassis is still the preferred structural basis for commercial vehicles, which are often sold without a body at all but with the running gear mounted to a chassis only, or in a 'cowl-and-chassis' or 'cab-and-chassis' configuration so that specialized bodies can be fitted to them for different purposes. Body-on-frame used to be the preferred way of building passenger vehicles too, because it allowed new models of vehicles with different body styles to be released without having to retool most of the mechanical and structural components. In the 1960s, most manufacturers switched to vehicle designs which either partially or wholly integrated the bodywork into a single unit with the chassis so that the body became part of the structure of the vehicle rather than just an external skin. The idea of a single shell – or 'monocoque' – design was first used in aircraft, then spread to automobiles, and became popular with manufacturers because with less of a chassis component it was both quicker to manufacture and lighter in weight, therefore costing less in both material and labor. The spot-welded unit body process, known as 'Unibody', is the predominant vehicle construction technology today. High performance racing cars today have no chassis at all, their structural strength coming from their light, stiff, and stable body shells molded from newer lightweight materials such as carbon fiber reinforced plastics.