CHECK OUT WHY TYRES HAVE TREADS ON THEM !!

The tread of a tire or track refers to the rubber on its circumference that makes contact with the road or the ground. As tires are used, the tread is worn off, limiting its effectiveness in providing traction. A worn tire can often be retreaded.

The grooves in the tire are correctly called the tread pattern, or simply the pattern, but the word tread is often used casually to refer to the pattern of grooves molded into the rubber.

But why do tires have treads anyway? Why aren’t the tires on our vehicles bald with no treads like those on race cars?

The reason our tires look different from those outfitted to race cars, is because we drive for different reasons. Race car drivers require a smooth tread on their tires because it provides more grip during dry conditions. If dry conditions are not present, then they may switch to tires with treads.

Since the rest of us do not use our vehicles for racing, we frequently drive through adverse conditions, like rain, snow and mud. Since water accumulates on the road during these wet conditions, our tires need treads for better traction in these harsh conditions that we so often drive through.

The grooves that you see on your tires work to siphon water away from the tires when the roadway is wet. This can help to reduce the risk of hydroplaning when traveling at higher speeds on a wet road or highway. If the treads on the tire are not at the proper depth, it can become difficult for enough water to be carried out from beneath the tire, thus increasing the possibility that you could lose control in such conditions.

When a vehicle is traveling too fast, or the tire treads are not able to channel enough water out from beneath the tire, it can result in hydroplaning. This is where your vehicle loses contact with the road and skims across a thin layer of water instead, causing a loss of control.

That is why monitoring your tires tread depth is critical to vehicle performance and safety. 

CHECK OUT WHY IN A THREE PIN PLUG THE EARTH PIN IS THICKER AND LONGER THAN OTHER PINS!!

When we use electrical appliances with metal bodies, we require protection against possible electric shock. If there is a fault current (leakage) inside the appliance, the whole metal case becomes live. If you happen to touch it, a current will flow through you to the earth (ie. electric shock). 

Hence, to prevent electric shock, we need to ensure that the system is properly earthed (= 'grounded'). This way if you touch a faulty appliance, you don't get electrocuted!

So, why is the earth pin made bigger?

1. The earth pin on a plug is longer than the live and neutral pins. This means the earth pin is the first to connect and the last to disconnect. 

• When inserting the plug, the earth connection is made before the current carrying contacts of the plug become live.
• When withdrawing the plug, the current carrying contacts shall separate before the earth connection is broken.

Thus, the earthing connection is always maintained to improve safety.

2. Many wall sockets have safety shutters (see image) on the live and neutral lines to prevent children from inserting conducting materials which may result in electric shock. Insertion of a longer (earth) pin helps in opening the shutters, facilitating the insertion of other two pins. These are called Earth-pin operated shutters.

3. Though it is impossible to insert the plug into the socket upside down, one may try to insert the plug top in a misaligned position (for e.g. trying to insert the earth pin into the phase socket with the other two pins further down out of the socket). Hence, the earth pin is made thicker so that even by mistake it cannot be inserted into the live or neutral hole of the socket. This prevents earth pin from establishing an electrical contact with the live terminal.

As we can see, every effort is taken to protect you from electric shock.

DIFFERENCE BETWEEN FAN AND BLOWER EXPLAINED !!

The fan and blower are two different kind of machine belonging to same group. Both these machines are used to flow a gas or mostly air in a large area but the main difference between fan and blower is that the fan operates at low pressure while blower operates at high pressure.

These machines are used in many industrial machines for air conditioning or cooling purpose.

The fan consists a rotor which is equipped with some blades. This rotor rotates by an electric motor or sometimes by a mechanical machine. It is primary used to flow the air into a large space. Mostly fans are used to blow the air axially or the direction of the air flow along the axis of the rotor. Fans blow large volume of air with minor change in pressure. It has specific pressure ratio is 1.1.

                               

Blower is different from fan. It is a centrifugal unit which blows the air radially. It consists of a impeller equipped with series of blades which are designed to flow air radially. It blows the air or gas with a moderate pressure change. The change in specific pressure ratio is 1.11 to 1.2.

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OIL COOLED ENGINE EXPLAINED !!

The term oil cooler and oil cooling became very popular in India after launching the Pulsar series 200 (discontinued) and 220 F from Bajaj motors. Oil cooling as we know from the name itself is cooling of engine oil by help of a special component called an oil cooler. Generally an engine oil will loose its viscosity if temperatures are very high than its specified heat range. As a result it may not be able to lubricate the mechanical components properly as specified. To overcome this problem and to provide better cooling especially for air cooled high performance engines oil coolers are generally used.

Oil cooling is a way apart from liquid cooling mainly in the following aspects,

* It does not maintain a constant temperature like a liquid cooled engine.

* It does not have a thermostat, bypass system and cooling fan but instead uses a small radiator alone.

* Cost wise it is very economical because of simplicity and components involved.

The oil pump which is normally used in  a conventional engine pumps and circulates oil for lubrication (forced lubrication) to all parts in a particular circuit. It starts from the crankcase and ends back in the crankcase after lubrication. 

Where as in oil cooling it reaches a radiator fixed outside from a centrifugal filter, cooled and then circulated back to the engine.

CONS:

As already told it cannot maintain a steady engine temperature like liquid cooling. The oil flow to radiator is not controlled by any thermostat like a coolant controlled by a liquid cooled engine and engine oil begins to flow to the radiator as soon as the engine is fired up.  

During heavy start, stop traffic and idling where there is minimal airflow this system loses its potential but it provides better cooling when there is a steady air flow while riding and in long run. Hence a liquid cooled engine offers better engine cooling and performance than an air cooled engine. This can also improve the life of engine oil as well.

On the whole its a cost effective way to improve cooling system especially for an air cooled engine.

CRUISE CONTROL AND ADAPTIVE CRUISE CONTROL EXPLAINED !!

In 1945 a blind yet prolific inventor, Mr. Ralph Teetor invented a system which is now one of the most important features of any good car globally, the Cruise Control. The system was first introduced in 1958 with Chrysler models such as Imperial, New Yorker and Windsor and by 1960 all Cadillacs were offered with Cruise Control.

Presently most of the global automobile giants like Volvo, Mercedes-Benz, BMW, Audi, Nissan, Kia, Honda, Nissan, etc. offer this feature with most of their cars.

What Is Cruise Control?

Cruise Control is a system which is capable of maintaining the speed of a car at a desired level. The conventional or I would say the basic systems are capable of taking over the throttle once the driver activates Cruise Control and sets the desired speed. In most of the cars, the cruise control buttons are mounted on the steering wheel, just like the audio control buttons, whereas in older car models a separate lever is provided similar to the ones used for windscreen wipers and headlights.

Once enabled the new ones only ask the driver to set the maximum and minimum cruising speeds after which it takes over the controls and the same gets disabled as soon as the driver presses the throttle, brake or clutch pedal.This feature is very useful for long drives where the roads are fairly good and high speed cruising is possible. The driver can set the car’s cruise control system close to the speed limit of the road and just relax with his foot off from the accelerator and brakes, the car will maintain the speed set on the cruise control system using the arrangements (car’s computers, activators etc.) which are provided in the car.

What Is Adaptive Cruise Control Systems? How Is It Different?

Adaptive Cruise Control or ACC is an advanced type of cruise control system and is the most widely used one. The system is capable of adjusting the speed of the vehicle depending on various factors influencing it. In simple language, if your car’s cruise control is set to a speed of 80 KMPH and the car in front of you is going slower than 80 KMPH, your car will slow down automatically to maintain a safe distance from car in front of you. Once the car in front goes 80 KMPH or faster or gets out of the way, the cruise control system again speeds up to initially set 80 KMPH without any manual intervention ! Isn’t it useful for a long highway journey.

Behind the grille of a vehicle, radars or lasers are installed that track the distance and speed of the vehicle ahead. This information is sent to the main ECU or the computer and together they help the car to reduce speed or re-accelerate depending on the position and speed of the car in front. This way, Adaptive cruise control is a more refined version of the cruise control system and is a very nice feature for even the city driving conditions with slow moving traffic.

MEANING OF GRADE WRITTEN ON BOLT HEAD EXPLAINED !!

A fastener is a device that mechanically joint two or more objects together. In general, fasteners are used to create non-permanent joints. That is, joints that can be removed or dismantled without damaging the joining components.

Before starting we need to clear some basic mechanical engineering concept.

Proof Load:  It is defined as the maximum tensile force that can be applied to a bolt that will not result in plastic deformation. In other words, the material must remain in its elastic region when loaded up to its proof load.

Yield Strength: Maximum load at which a material exhibits a specific permanent deformation or plastic deformation.

Tensile Strength: Tensile strength is a measurement of the force required to pull something such as rope, wire, or a structural beam to the point where it breaks. The tensile strength of a material is the maximum amount of tensile stress that it can take before failure.

In simple words “ digit written on bolt head is indicate its grade”

 Now let’s explore all thing in deeply.

What Does a Grade Mean?

The grade of your industrial fasteners not only determines how much stress they are able to stand, but also why type of tool must be used to tighten them. For a grade 8.8, you must use the part turn method of tightening with a torque wrench; this is where the fold is fit snug tight with your fingers and then advanced up to three turns, depending on length and size. Indicating washers may also be used in the part turn method, and added security of the joint can be accomplished by using other fasteners and fixings, such as spring washers, wired heads, nuts, and split pins. 

What’s the difference between 10.9 and 8.8 bolts?

The first digit relates to the ultimate strength of the material, while the second is the ratio of yield stress to ultimate strength. Thus grade 10.9 bolts have an ultimate material tensile strength of 1000N/mm2 and the yield (or proof) stress is 90% of the ultimate strength. Similarly grade 8.8 bolts have an ultimate strength of 800 N/mm2 and a ratio of yield/proof stress to ultimate strength of 80%. 

DIFFERENCE BETWEEN HOT SPARK PLUG AND COLD SPARK PLUG EXPLAINED !!

Introduction:

In order to ignite air fuel mixture we need heat.In case of diesel engines (compression ignition engines) this head is achieved by the compression of gases.But in case of spark ignition engines we need to have an external source to ignite air fuel mixture because compression is not enough to ignite the mixture.

A spark plug is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air mixture by an electric spark, while containing combustion pressure within the engine.

There are two types of spark plug :

• Hot Spark Plug
• Cold Spark Plug

“Cold” spark plugs normally have a short heat flow path. This results in a very quick rate of heat transfer. Additionally, the short insulator nose found on cold spark plugs has a small surface area, which does not allow for a massive amount of heat absorption.

On the other hand, “hot” spark plugs feature a longer insulator nose as well as a longer heat transfer path. This results in a much slower rate of heat transfer to the surrounding cylinder head.

The heat range of the spark plug must be carefully selected in order to create an optimal thermal performance. If the heat range is not correct, you can expect serious trouble. Typically, the appropriate firing end temperature is  900-1,450 degrees. Below 900 degrees, carbon fouling is possible. Above it, overheating becomes an issue.