COMPLETE NOTES ON NITROUS OXIDE SYSTEM (NOS)

NOS or nitrous oxide - a familiar name among drag racers and those who are crazy about speed and power. This gas also called as laughing gas, was once used as an anesthetic for minor surgeries, yet now being widely used in automobiles and other propulsion systems. Many would have seen NOS system in action while racing in  the movie- fast and furious. Due to its superb property as an oxidizer, this gas is used in boosting up the performance of bikes and cars. Along with instant acceleration it also increases the horsepower of  engines. A nitrous oxide system is one which delivers NOS with right quantity to the engine. Generally air is required to burn the fuel inside the engine.

The air contains oxygen which is the supporter of combustion to take place. More the quantity of oxygen in air, the more complete and efficient the combustion will be. Based on this the usage of NOS is employed in automobiles.

A gas molecule of nitrous oxide contains one oxygen atom and two nitrogen atoms. So when its being fed and ignited inside the combustion chamber of  an engine, it releases a great number of oxygen atoms. 

This sudden increase of oxygen level inside the chamber causes more fuel to burn effectively at an instant of time, delivering tremendous power. It's just like an additional supplement for boosting the performance.

A nitrous oxide system can be classified under two categories :

>Dry fogger type 

>Wet fogger type.

The key difference between the two systems are simple. The dry fogger type uses a nozzle or port to inject only the NOS without any injection of fuel. A wet fogger type uses two nozzles or ports. One nozzle feeds fuel and another feeds NOS. It injects the fuel along with NOS combined to a throttle body or directly inside the combustion chamber.

The wet fogger type is usually complex and generates more power when compared to dry fogger type.

In fuel injected motorcycles the nitrous oxide system can be equipped with wet fogger system. Along with a fuel injector, a nozzle for wet fogger can be used. For carburetorbased motorcycles the dry fogger system can be fixed. Likewise, the same scheme can be applied for cars too. A solenoid valve is used to operate and regulate the flow of NOS into the engine. A solenoid valve is an electronically controlled valve.

NOS damages engine and its components like pistons and valves under prolonged usage, since it produces rapid combustion which liberates high heat, power and excess stress to piston, rings and other components. So it's suited only to motor racing which uses high performance engines, and especially during drags.

BIKE MODIFICATION :PROS,CONS AND GUIDELINES

Many have an idea and will to modify their bikes in to a stylish one like super bikes and top cruisers. The idea is quite awesome but everyone should know the benefits and drawbacks behind modifications before modifying a bike. People who are not affordable to buy a top end bike generally prefer to change its look to a top class bike and also who like to make the bike their own identity. However they have to keep some ideas in mind before engaging in such tasks.

Pros & Cons in general:

• Generally bike lovers love to have bikes a full fairing appearance and they wont hesitate to fit one for getting a sporty look. Many people don't know the fact that a full fairing cowl resists the air flow to cool the engine fins which is essential for an air cooled engine.
• All the major sport bikes with full fairing are equipped with liquid cooled engines so they don't require air to cool them up. So to be wise don't use a full fairing cowl for air cooled engines.
• The extra body work and accessories can increase the weight of the bike thus reducing its performance.
• Apart from stock body, changing the body work by replacing tanks or including some other accessories like large visors, engine guards or any other unwanted spares.
• The next thing which is most common in modification of bikes is changing the exhaust muffler to get the beat similar to a race bike. Using brandedexhaust systems similar to the bike specifications generally increases the power and gives a good roar to hear.
• Daytona has launched its racing kit for Yamaha R15 & FZ 16, which includes chain & sprocket, Large diameter disc brakes with front master brake cylinder and exhaust muffler. Using genuine branded accessories are very much worthy for custom modifications.
• Duplicate mufflers which are available in various sizes when fitted increases fuel consumption and offers poor performance.
• Replacing the tyres of stock model with wider tyres offers good grip but it has to be ensured that replacement of both front and rear tyre with the same brand has to be done to get good stability. 
• The tyres of  few inches extra size from that of stock model offers good stability and oversize tyres has to be avoided. Usually wide tyres provide good grip but at the same time it affects pick up, handling and fuel efficiency. So the right kind of tyres has to be chosen prior modifications.
• The next modification many bikers prefer is to use air horns and electronic synthesizers. Make sure of using branded ones. Also use an optional switch to change over horns when needed.
•  Take care while using air horns within city limits since its illegal.Using cheap duplicates may damage wiring and battery life.
• Headlights also comes under modification for many guys. High  power halogen bulbs, projectors and LED's are options. Use a correct one according to the bike's specifications to prevent battery charge draining away.
• Philips HID conversion kit is one of the good brand to choose. Provides good illumination during night riding and in highways.
• Alloy wheels are also a part of modification, Always use a original branded ones for modifying your bike. Alloy wheels adds look of the bike and also enable easy maintenance.
•  Avoid duplicates to prevent risks in case of accidents.

• Go for split seats. It would offer an all new look for your bike you wouldn’t have even thought, It offers a sporty look. Anyone in a seat repairing and lining shop can help you with this idea.
• Use quality seat materials. A brand called Royal Touch introduced Joyride seat covers which claims to prevent UV rays and keeps the seat temperature15 - 20 degrees cooler.
• To increase the horsepower many bikers use K&N air filters. These air filters substantially increase the HP. Ensure that correct jetting and tuning of carburetor has to be done after fitting a K&N air filter to get optimum performance.
• Improper carb setting leads to poor mileage and engine damage. Also clean these filters at mentioned time period to prevent major damage to filter as well as the engine. For electronic fuel injected bikes it won't be an issue since the ECU adjusts the air flow setting automatically.
• Whatever the modifications it never renders the bike's performance. Mostly the modifications on body work should not be done and changing the paint is strictly illegal and offence. Major mods depends on how much budget you have starting from 20k to 100k.
• Remember the last point. When you make your bike undergo any massive mods, see to it that you consult the concerned people in the RTO (Regional Transport Office), ask them in advance what is to be done regarding re-registration of your bike after all these modifications are done. After these are performed, make your documents of your bike legally faultless in all aspects.
• A good mechanic and authentic spares will do a great job. Modifications without affecting the bike's performance and originality yet increasing the style and performance is always appreciated.

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.

NITROX SHOCK ABSORBERS NICELY EXPLAINED

The rear shock absorbers on current Bajaj Pulsar series bikes are also popularly known as NITROX shock absorbers. These types of shock absorbers are actually called as ‘Gas Filled Shock Absorbers’. The visual differentiation between a conventional shock absorber and a gas filled shock absorber is a small canister (box) which is attached on one side of it. This canister holds a small amount of Nitrogen gas in it. Hence these hydraulic shock absorbers or dampers are called as gas filled shock absorbers. So what is the reason to use a gas filled hydraulic dampers instead of using a conventional one? we'll find out the answer here.

The 'Royal Enfield - Bullet Electra' was the first bike in India to have this feature. 

A typical shock absorber or an hydraulic damper contains oil with two tubes sliding inside one another and also has a piston inside. It also has a valves inside. The oil inside the damper moves along the valves as the piston moves up and down to absorb the shocks. These dampers have a tendency for the oil to form foam (form bubbles) under heavy use and riding conditions. The foaming is usually caused by air bubbles inside oil during suspension action. This is similar to shaking a can of oil. After shaking the oil inside the can gets foamed. Similarly the same case happens to a hydraulic damper also. This  foaming temporarily reduces the damping ability of the unit.

In order to solve this, a secondary cylinder is connected to the shock absorber which acts as a reservoir for the oil and pressurized gas (nitrogen). The pressurized nitrogen gas inside the canister prevents foaming of hydraulic oil inside the damper due to heavy usage or damping action. Due to this, the performance of the suspension remains constant.

This nitrogen gas also helps in absorbing the road undulations and provides a smooth ride for both the rider and the pillion. The new Bajaj Pulsar 200NS uses a Nitrox piggy-back type canister gas filled suspension.

COOL FACTS ABOUT BAGGER 288 - WORLD'S LARGEST LAND VEHICLE

The German mining machine, Bagger 288 is a bucket-wheel excavator built by the Krupp company for the energy and mining firm Rheinbraun. The Bagger stands higher than the Statue of Liberty and even heavier than the Eiffel Tower, with a weight of 13,500 tons.

The mobile strip mining machine was completed in 1978 superseding the Big Muskie as the heaviest machine in the world. The design and manufacturing of the machine took five years, with an additional five years for the assembly. The total cost of the machine neared $100 million. The bagger uses a revolving wheel of buckets to shovel out the dirt in open-pit mines. It can dig out 8.5 million cubic feet of land per day, and when it reaches the depth, it can extract 265,000 tons of fuel every day. The monster only requires three to four people for its operation.

The buckets on the revolving wheel deliver the soil or fuel to 4 conveyor belts, each having a width of 10.5 feet. The belts carry the material at a speed of over 11 mph. The 13,000 tons of Bagger’s weight is carried by 8,600 square feet of tread moving it with a steady speed of 0.4 miles an hour. Electric cables as thick as a man’s arm, spanning over 5,600 feet deliver electric power to the excavator. The power this behemoth uses can power a city of 20,000 people. 88,000 pounds of paint cover the entire structure. The two pylons of the structure stand at the height of 148 feet held by 7,218 feet of steel suspension cables.

The bucket wheel alone stands as high as a seven-story building at 71 feet. Each of the 18 buckets around the wheel weighs 7,700 pounds when empty. One bucket can dig out 230 cubic feet of soil alone which can easily fill a cargo van.

THERMIT WELDING

Thermit welding is a fusion welding process that makes use of the intense heat produced when a mixture containing iron oxide and powdered aluminium is ignited. The reaction is based on the high affinity of aluminium is ignited.It reduces iron oxide to thermit steel and slag, like this

8Al + 3Fe3O4 – -> 9Fe + 4Al2O3 (Slag) + Heat

The superheated molten metal is poured at the desired place which on solidification forms the welded joint. The process is thus essentially a combination of casting and welding processes. The Thermit mixture consists primarily of finely divided aluminium and iron oxide in the ratio of about 1: 3 by weight. Other metal oxides that can be used in place of iron oxide include oxides of Copper, Nickel, Chromium or Manganese but Iron oxide Thermit is the most commonly used. The mixture is filled in a specially designed refractory crucible and the reaction is started by igniting the mixture with a highly inflammable powder consisting of Barium Peroxide.

When the mixture is ignited, an ignition temperature of 1150 deg Celsius is attained which initiates the main thermit reaction. The reaction is self sustaining and very rapid as it is exothermic. A temperature of the order of 3000 deg Celsius is produced resulting in super heated thermit steel. Slag being very light floats over the thermit steel thereby protecting the metal from atmospheric gases. Apart from the basic ingredients of the thermit mixture other materials may be added to produce a desired thermit melt for any specific application.

Working Operation:

In making a thermit weld a mould is built around the sections to be welded and is preheated before use. This is done by first cutting the ends of the pieces to be welded to provide a gap with parallel faces. The gap is filled with wax which serves as a pattern for the weld. The ends of the work pieces are enclosed in a suitable flask and moulding sand rammed around the joint taking care to provide openings for the runner, riser and a heating gate.

Heat is applied through the melting gate to melt out the wax and to preheat the ends of the pieces to be welded. The heating gate is then plugged with an iron plug or sand core to prevent flow of thermit metal. Thermit reaction is started in the thermit crucible and the resulting superheated steel is let in, from the bottom of the crucible. The slag being lighter floats over the molten metal in the crucible. It flows last and remains at the top of the mould where it solidifies. Clean metal enters the mould around the sections to be welded.

The temperature of the molten steel entering the mould is around 2500 degree Celsius. The heat of the superheated metal fuses and amalgamates the sections together forming joint on solidification. After the joint has solidified the mould is broken open and discarded.

The thermit welding process is useful for welding heavy sections. Though initially used primarily for joining of rails the process can be used for repair work of heavy parts like tracks, spokes of large wheels, broken motor casings, and connecting rods.

Advantages:

1. The heat necessary for welding is obtained from a chemical reaction and thus no costly power – supply is required. Therefore broken parts (rails etc.) can be welded on the site itself.

Limitations:

1. Thermit welding is applicable only to ferrous metal parts of heavy sections, i.e., mill housing and heavy rails sections.

2. The process is uneconomical If used to weld cheap metals or light parts.

CHECK OUT THE FUNCTION OF METALLIC BAND AROUND THE WHEELS OF HEAVY EARTHMOVERS

They are called crawlers or chain(in simple words). Made from steel or rubber (in case of small machine or vehicle). Actually it is used in heavy duty machine ( Crane). This crawlers is required for better traction while moving (as it is heavyweight) and larger base area (contact pitch) while working. It take place of big wheels (tyre).

Generally it is hydraulic drive but In case of small crawlers like snow mobiles it is mechanically driven.

This type of crowlers are used in verities of Automobile, From small snow mobiles to large crains. This type of vehicle are called SPV ( special purpose vehicle)

Incase of snow mobiles main purpose of crowlers is weight distribution on snow same is in the case of tank (for better off-roading).

CHECK OUT THE REASON FOR LARGER DISC BRAKE AT FRONT AND SMALLER AT REAR

As the car brakes, the center of gravity causes a torque (like a big wrench turning the car toward its nose) to force the car to its front tires.

The center of gravity of the car wants to keep going forward. The only thing slowing it down is the transfer of force between the road, and the contact patch of the tire on the road.

That force, which the tire makes with the road, is very simplistic...  That force is composed of only two things. The weight pushing down on the tire, and some number that makes up for the stickiness of the tire, and the terrain it is on.  A sticky tire on good pavement, a high number; a normal tire on ice, a low number. 

Since that force on the tire is highly dependant on the weight on that tire, the amount of braking that the tire can do is directly related to the weight imparted on the tire.

As you can see from the above picture, the front tires can see a bit more weight than the rear under hard braking.

the highest braking capabilities are much higher on the front than on the rear, therefore, we must ensure that those brakes are up to the task.

How do we do that?

Well, it all comes back to torque. Torque is just some force that acts over some distance. It is for this reason that you might use a longer bar on a wrench that you are trying to get a stuck bolt out with.

Let's say you are trying to stop a big heavy tractor tire from spinning. Imagine that you put a little brake pad from the front of a bike a few millimeters from the center of the wheel.  It wouldn't do much would it? Then imagine that you put that same brake, with the same pressure, as far from the center as you could.  Imagine that you could actually put it a few meters farther than the tire. In fact, let's go all the way and say that you could put that little brake pad a few skyscrapers away.  That same little brake pad could do a LOT more to stop that tire.  It would be no problem.

This same principle helps us exert the extra force that we now know front wheels can receive. So bigger diameter brakes up front help even-out the pressure required to stop the car. Those higher forces require additional thickness  to transfer those forces through the disk, and into the hub.

CBS IN HONDA BIKES EXPLAINED

The Honda Combi Brake system was introduced in India with the Honda Activa in 2009. However, this system has been in use since more than 30 years internationally. The Honda Combi Brake system is a first-in-industry technology.

What is the Honda Combi Brake System?

The most efficient way of braking is to apply the front and rear brakes simultaneously. But it is a practice, most two-wheeler riders have not mastered.Combi brake means that the brake will act on front and rear wheel together every time you apply the brakes. This means a lot of improved safety.

How does the Honda Combi Brake System Enhance Safety?

In two wheelers (scooters and bikes), there are two separate brake controls for front and rear wheels.Most of two-wheeler riders apply only rear wheel brake, or use only rear brake in most of the cases. However for most effective braking and stopping in small distance safely without loosing control, both front and rear brakes should be used together. Most people fear using front brakes too much because if you press them too hard, the scooter/bike may skid and the rider will fall badly.

Honda Combi Brake system applies the front-brakes in the correct amount whenever rear brakes are applied. This applies both brakes when you apply only rear one. This means that the scooter rider need not worry about using front brakes, they will be used in correct amount automatically when the rear brakes are used. See the image above, the highlighted green area shows how they have put an extra-cable to brake lever control of Honda-Activa 2009 to make combi-brakes work.

Advantages :-

Honda Combi Brake with Equaliser, ensures distribution of Force between the Front and Rear Wheel at the same time, giving perfect balance to the rider.

It ensures that rider with low expertise is also confident while braking.

Simultaneous application of Front and Rear Brake leads to the most effective braking.

CHECK OUT THE DIFFERENCE 20BHP @ 4000 RPM Vs 20BHP @ 8000 RPM

What is the difference between 20bhp @ 4000 RPM vs 20bhp @ 8000 RPM?

BHP is brake horse power i.e. the power generated at the crankshaft of the engine. Now in these both cases there is 20bhp. So we are assuming that these are two different engines with different configurations.

So in first case, engine generates 20bhp net power while running at 4000 RPM. On the other hand, in second case, engine generates 20bhp net power while running at 8000 RPM.

In engines, we study a power-torque curve to check performance of engine. Now from this P-T curve, you will find that power of any engine increases with increasing in RPM for some range of RPM. There comes a point of RPM where this power produced by an engines gets maximum and after this point the power generation decreases with increase in RPM.

So in these cases the power that has mentioned is the pick power an engine can produce during that particular RPM. When we look at any car's or vehicle's brochure, you will find this explanation in power category. But remember the power that the company has mentioned is max power, which you will hardly get at those high RPM. Vehicles don't run at those high RPM constantly.

Now in these cases, for engine 1 the value of RPM is low(4000 RPM) and still generating 20bhp, so that means you will get more value of torque compared to engine 2 which has 8000 RPM. As we all know torque is inversely proportional to RPM, more RPM than less torque and vice versa.

DIFFERENCE BETWEEN SHAPER AND PLANER MACHINE EXPLAINED

In Shaper machine, tool is having reciprocating motion and w/p is clamped on table which is stationary. It is mostly suitable for light duty operation.In Shaping large cutting force is transferred to tool.

In Planer machine, tool is having stationary and w/p is clamped on table which is reciprocating motion. It is mostly suitable for Heavy duty operation.In planner large cutting force is transferred to table

AIR COOLING SYSTEM

Air Cooled System:

>Air cooled system is generally used in small engines say up to 15-20 kW and in aero plane engines. 

>In this system fins or extended surfaces are provided on the cylinder walls,  cylinder  head,etc. 

>Heat generated due to combustion in the engine cylinder will be conducted to the fins and when    the air flows over the fins, heat will be dissipated to air.

>The amount of heat dissipated to air depends upon:

(a) Amount of air flowing through the fins 

(b) Fin surface area

(c) Thermal conductivity of metal used for fins

>For efficient cooling the length of the fins and the spacing between them is quite important.

>Larger inter spacing between the fins offers larger area for cooling air but the heating of the 

  air is less, so more cooling air is required.

>Smaller  interspacing between the fins results in smaller  flow area of cooling  air and hence 

  input cooling air is less.

>Usually fin height varies from 15 to 25 mm.

Air cooled engines have the following advantages:

1. Its design of air-cooled engine is simple.

2.  It  is  lighter  in  weight  than  water-cooled  engines  due  to  the  absence  of  water  jackets, 

     radiator, circulating pump and the weight of the cooling water.

3. It is cheaper to manufacture.

4. It needs less care and maintenance.

5.  This  system  of  cooling  is  particularly  advantageous  where  there  are  extreme  climatic 

conditions in the arctic or where there is scarcity of water as in deserts.

6. No risk of damage from frost, such as cracking of cylinder jackets or radiator water tubes.

Disadvantages of air cooled engines

1. Cooling fins under certain conditions may vibrate and amplify the noise level.

2. Cooling is not uniform.

3.Engines are subjected to high working temperature.