ELECTRONIC FUEL INJECTION (EFI) EXPLAINED !!

For an engine needs to work it requires energy from fuel, whether it may be petrol, diesel or any other alternative fuels. Electronic fuel injection is a kind of fuel delivery system or feeding of fuel to the engine in a electronically controlled environment.

It is similar to a computerized delivery of fuel supply to the engine. A computer here in the sense is a small micro controller (a microprocessor and a control unit).

Microcontroller is a  hardware device which is controlled by a microprocessor. This setup is similar to a washing machine where a user sets a washing program and the entire wash cycle takes place automatically as per the predefined program.

An electronic fuel injection is similar to the washing machine but here it delivers the fuel into the engine as per the engine requirement Many may raise a question why we use an electronic fuel injection rather than using a conventional system like carburetor (petrol engines) or fuel pump with injectors (in diesel engines).

Conventional systems which we are using so far can be suitable only for ideal conditions. A carburettor or a fuel injection pump works only according to an appropriate setting for delivering fuel correctly. This setting is a fixed and it cannot adapt itself to the outside weather and environmental conditions and many other factors.

One best example is starting a bike or car in cold weather is a hard job, A carburetor fitted bike cannot start easily and manually we use choke to induce more fuel into the engine for getting started. The cars without EFI system use heater plugs to warm up the engine before getting started.

A bike equipped with fuel injection system do not get this problem. The electronic fuel injection system gathers all the details from sensors of outside world such as weather, environmental conditions which includes engine temperature, atmospheric pressure, air intake temperature etc.

The microprocessor is already programmed with some predefined set of  algorithms and all the above factors are monitored constantly. So the system predicts how much fuel and air has to be delivered into the engine for a given condition to get optimum performance and efficiency. The microprocessor takes care and controls the fuel delivery here. So when the engine gets cold or the atmospheric pressure is low (in mountains) the microprocessor senses it and delivers the fuel according to it.

During high speeds the conventional systems lacks efficiency. For example riding sane at economical speed delivers good mileage of 45-50 kmpl for Honda Unicorn and while riding at 90km/hr returns only a max of 35 kmpl.

A bike equipped with fuel injection system provides hassle free rides with a constant mileage, No starting problem, better mileage and good acceleration (pick-up) and performance remains unchanged whether you are driving in mountains or  hot plains, more power output, no tuning for most modifications, smoother running, doesn't require a manually operated "choke" and very emissions friendly. It also prevents knocking and pre ignition.

Honda patents its electronic fuel injection system as PGM-fi (programmed fuel injection).

Fuel Injection Cons:

• Requires more wiring, fuel line, and parts.
• Needs expert supervision to configure it. An ordinary mechanic cannot fix it.
• Requires a fuel pump.
• More expensive.

EVERYTHING ABOUT LUBRICANTS EXPLAINED !!

Lubricant is substance that reduces friction and wear at the interface of two materials. Or we can say that a lubricant is a substance introduced to reduce frictional force and heat generation between the surfaces in mutual contact, when the surfaces move. The lubricant at interface reduces the adhesive friction by lower the shear strength of interface. 

Based on the shear strength of lubricant or molecular state, lubricants are classified in four categories.

• Gaseous lubricants
• Liquid lubricants
• Semi-solid lubricants
• Solid lubricants

  Gaseous lubricants:-

Gas(i.e, Air, Nitrogen, and Helium) lubrication is used for ultra thin film thickness(separation) between tribo-pairs. Gas lubricated bearings have numerous advantanges over liquid and solid lubricated bearings for a wide range of applications.   A gas bearing is virtually frictionless, silent, and vibrationfree.   Gas bearings can be used for extremely large surface velocities.   A gas bearing can eliminate the risk of contaminating a process with lubricant.  A gas / air bearing can be hydrodynamic or hydrostatic.  In hydrodynamic bearings the gas is introduced into the bearing surfaces by the action of the bearing.  In hydrostatic bearing the gas is introduced under pressure from an external source.Air bearings are also widely used to allow frictionless movement of large heavy items over flat surfaces using air pads. Liquid lubricants:- There are two systems for oil classification. The SAE (Society of Automotive Engineers) viscosity grade and the API (American Petroleum Institute) classification that designates the type of engines for which the oil was designed. The SAE viscosity grade is known as the “W” number when classifying winter oils. In general, the lower the first number, the better the oil performance in extremely cold conditions. Conversely, the higher the second number the better the oil protection at higher temperatures. The API designation is typically “S” designation for gasoline engines and a “C” designation for diesel engines. Most of today’s oils carry an SH,CF or SJ,CF designation signifying that they are suitable for use in all gasoline or diesel automotive applications. Semi-solid lubricants(Grease):- In layman’s language Grease is: A black or yellow sticky mass used in the bearings for lubrication purpose. Lubricating greases consist of lubricating oils, often of quite low viscosity, which have been thickened by means of finely dispersed solids called thickeners. It consist of base oils(75 to 95%), additives(0 to 5%) and minute thickener fibers(5 to 20%). Solid lubricants:- A solid lubricant is basically any solid material which can be placed between two bearing surfaces and which will shear more easily under a given load than the bearing materials themselves. The coefficient of friction in dry lubrication is related to the shearing force and the bearing load.One way to apply solid lubricant is powder coating. We can use powder form of solid lubricant and rub against the tribo surfaces.Examples are Graphite and molybdenum disulfide (MoS2),Graphite etc. A good lubricating oil generally possess the following characteristics: Suitable Viscosity: The viscosity of oil should not change with rise in temperature. Oilness: It ensures the adherence to the bearings and spread over the surface. This property makes oil smooth and very important in boundary lubrication. Strength: The lubricant must have high strength to avoid metal contact and seizure under heavy loads. Chemical Stability: The lubricant should not react with surfaces and any deposit in the cylinder. Pour Point: It should be low to allow the flow of lubricant at low temperature to the oil pump. Flash Point and Fire Point: The lubricating oil should not burn inside the cylinder, otherwise it will leave heavy deposit and poisonous exhaust. Therefore, the flash point and fire point of the lubricating oil must be high. Neutralization: The oil should not have a tendency to form deposits by reacting with air, water, fuel or the products of combustion. Cleaning: The oil should act as cleaning agent inside the engine and should carry any deposits with it. It should also have non-foaming characteristics, low cost and be non-toxic.

KNOW WHY UPSIDE DOWN SUSPENSION IS USED IN HIGH END MOTORBIKES !!

A lot of bikes today are getting upside down suspension setups on the front while the others are getting the regular telescopic suspension.For example,KTM is using them as a default.

Here are top reasons,what makes them so special :

1.)In case of regular telescopic suspension system,hollow tube or damping unit is laden on to the wheel. This ends up with the entire weight of the shock system on to the wheel which kind of makes the movement of the wheel and the handle a lot stiffer.Thus,with upside down suspension handling is improved.

2.)Now the reason why only the performance bikes are provided with upside down forks is for this reason. The bikes generally travel at very high speeds, and that means the steering of the bike needs to be as agile as possible.So,less weight on the wheels help in better steering.

3.)More rigid- In a conventional fork the narrower stanchion is fixed to the frame, but in a upside down suspension fork the larger diameter slider is fixed this makes the forks more rigid and improves feel.

So all in all, if you plan to run your bike(at higher speeds) on the highways most of the times which are in somewhat good shape, then yes you can opt for upside down forks, but for someone who has the running within city limits and broken roads, then please put in conventional telescopic suspension on as it will provide better protection to the bike.

CHECK OUT WHY AIR CONDITIONER IS MEASURED IN "TONS" !!

Why is air conditioner capacity measured in tons? You may have wondered this, especially since you know your 1.5-ton capacity air conditioner doesn’t actually weigh 1.5 tons. Here’s what that 1.5 ton designation really means and why air conditioner capacity is measured this way.

We know that the air conditioner’s number of tons doesn’t refer to its weight. In fact, this number refers to the amount of heat the air conditioner can remove from a house within one hour. For example, a 4-ton air conditioner is able to remove 48,000 British thermal units (or BTUs) from the house per hour. One BTU is roughly equivalent to the heat that would be produced if you lit one match and burnt it all the way. One ton of A/C capacity is equivalent to 12,000 BTU per hour.

Now we know what a ton means, but we still haven’t answered the question of why the ton is the unit of measure for air conditioner capacity. Before the invention of the air conditioner, people who could afford it used large blocks of ice to cool their homes in the summer and refrigerate food. The ice was harvested during the winter from frozen lakes and rivers.

But how did the use of ice to cool buildings lead to the term “ton”? Basically, it takes 143 BTUs to melt a one-pound block of ice at 32 degrees. Accordingly, if you have a one-ton (2000 pound) block of ice, it takes 286,000 BTUs to melt it completely. If that block of ice melts evenly over the course of the day, it absorbs heat at the rate of 11,917 BTU/hour. Rounded up, we get 12,000 BTU/hour, or one ton of AC capacity.

Today most people know that a ton is used to measure A/C capacity, but not everyone know that the term originally referred to blocks of ice!

TECHNICAL TERMS OF BOILER EXPLAINED !!

1.)AUTOMATIC FEED WATER REGULATOR – Device that regulates feedwater supply to the boiler according to load, and so does away with hand operation of valves on feed lines. It is controlled by temperature,its action depends upon expansion and contraction of some metal part.

2.)BABCOCK and WILCOX BOILER – A water tube boiler consisting in its simplest form of a horizontal drum from which is suspended a pair of headers carrying between them an inclined bank of straight tubes.

3.)BLISTER – A separation of the metal from the shell plate, caused by impurities rolled into the shell plate when formed.

4.)BLOWDOWN OF SAFETY VALVE – The difference between the pressure at which the safety valve pops and that at which it closes.

5.)FIREBOX BOILER – Boiler having the fire within a firebox, although external to the shell, is rigidly connected to it.

6.)FIRE CRACKS – Cracks caused by radiant heat, usually around circumferential riveted seams of thick plates.

7.)FOULING – A condition of the flue gas passages in a boiler or furnace that adversely affects the transfer of heat, usually in the form of soot or scale.

8.)GAUGE COCK – A device for determining the water level in the boiler.

9.)GOOSE NECK – A short length of pipe having one complete turn to which the steam gauge is attached.

10.)JAW STAY – A round bar having jaws forged at one end and a flat plate at the other inclined at the proper angle for riveting to the boiler shell.

DIFFERENCE BETWEEN FIRST ANGLE AND THIRD ANGLE PROJECTION EXPLAINED !!

Orthographic projection  is a means of representing a three-dimensional object in two dimensions. It is a form of parallel projection, where all the projection lines are orthogonal to the projection plane, resulting in every plane of the scene appearing in affine transformation on the viewing surface. A lens providing an orthographic projection is known as an (object space) telecentric lens.

There are two types of drawing in orthographic , First Angle and Third Angle. They differ only in the position of the plan, front and side views.

First Angle Projection :

1.)In first angle projection, that object is assumed to be in the first quadrant. Hence, the top view is projected below, i.e. to the x-z plane - which lies below the object.

2.)The object is assumed to be positioned in between the projection planes and the observer.

3.)The views are obtained by projecting the images on the respective planes.

4.)First Angle Projection is commonly used in all countries other than United States. The Indian Standard Institution (ISI) recommend the use of First Angle Projection method now in all the institutions.

5.)In first angle projection right view come in left of front view and top view come at the bottom of front view.

Fig : First Angle Projection

Third Angle Projection:

1.)In the third angle projection method, the object is assumed to be in the third quadrant. i.e. vertical Plane is in front of the object and the Horizontal Plane is above the object.

2.)For the third angle projection plane of projection is placed between the object and observer.

3.)Third Angle Projection is commonly used in United States of America.

4.)In third angle projection right view come on right side of front view and top view comes at the top of front view.

Fig:Third Angle Projection

Major differences between first angle and third angle projection:

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KNOW HOW TO READ BEARING SPECIFICATION !!

A bearing is a machine element that constrains relative motion to only the desired motion, and reduces friction between moving parts.

Each bearing has a specified number which tells about the type and size of bearing.

Let's take an example below :

• (1) Prefix :
  
• (2) Basic Number:
  
• (3) Suffix
• • 
    
  • 
    
  • 
    

  • Prefix

    K	Cage with roller elements
    L	Removable bearing ring
    R	Ring with roller set
    S	Roll body of stainless steel
    W	Stainless steel deep groove ball bearing

    *Note: Each bearing company may create their own prefixes. e.g. E2. = SKF Energy Efficient bearings

    Suffix

    2 RS	Bearing with rubber seal on both sides. RS provides a better seal but more rolling friction than 2Z.
    RS	Bearing with rubber seal on one side, one side open.
    2 Z / ZZ	Bearing with a metal seal on both sides.
    Z	Bearing with a metal seal on one side, one side open.
    E	Reinforced Design
    P2	Highest precision
    K	Bearing with taper bore

    Bearing Numbers

    The example at the header shows a 6001 2RS bearing. So what does the 6001 actually mean?
    (6)001
    This first number relates to the bearing type, as shown in the table below type 6 is a deep grooved roller bearing.
  • 
    
  • Lets attempt to break it down.
  • 
    
  • 
    

  • 1	Self-Aligning Ball Bearing This kind of ball bearing has a spherical outer race, allowing the axis of the bearing to "wander around". This is important because misalignment is one of the big causes of bearing failure.
    2	Barrel and Spherical Roller Bearings
    3	Tapered Roller Bearing Designed to take large axial loads as well as radial loads.
    4	Deep Groove Double-Row Ball Bearing Designed for heavy radial loads.
    5	Axial Deep Groove Ball Bearing Intended for exclusively axial loads.
    6	Deep Groove Ball Bearing (Single row) Typical ball bearing. Handles light axial loads as well as radial loads.
    7	Single-Row Angular Contact Bearing Specific geometry of angular contact bearing raceways and shoulders creates ball contact angles that support higher axial loads
    8	Axial Cylindrical Roller Bearings Axial cylindrical roller bearings comprise axial cylindrical roller and cage assemblies and shaft and housing locating washers. The bearings have particularly small axial section height, have high load carrying capacity and high rigidity and can support axial forces in one direction.

6(0)01

This second number relates the bearing series, which reflects the robustness of the bearing. As you go up the scale below from 9 to 4 the inner and outer race thickness will usually increase along with the ball size, this will be to help cope with extra load.

9 Very thin section
0 Extra light
1 Extra light thrust
2 Light
3 Medium
4 Heavy

60(01)

The 3rd and 4th digits of the bearing number relate to the bore size of the bearing, numbers 00 to 03 have a designated bore size depending on the number.

00 10mm
01 12mm
02 15mm
03 17mm

While numbers over 03 simply have a bore size which is 5 times that of the 3rd and 4th digit.