ENGINE POSITION

ENGINE POSITION

                      

1.Front engine

* The large mass of an engine at the front of the car gives the driver protection in the 

   event of a head on collision.

* Engine cooling is simpler to arrange

* In addition the cornering ability of a vehicle is normally better if the weight is 

   concentrated at the front.

                                           

2.Rear engine

* It increases the load on the rear driving wheels, giving them better grip of the road. 

   Most rear-engine layouts have been confined to comparatively small cars, because 

   the heavy engine at the rear has an adverse effect on the ‘handling’ of the car by 

   making it ‘tail-heavy’.

* Also it takes up good deal of space that would be used on a front-engine car for 

   carrying luggage. Most of the space vacated by the engine at the front end can be 

   used for luggage, but this space is usually less than that available at the rear.

3.Central and mid-engine

* These engine situations generally apply to sports cars because the engine sitting 

   gives a load distribution that achieves both good handling and maximum traction  

   from the driving wheels.

These advantages, whilst of great importance for special cars, are outweighed in the case of everyday cars by the fact that the engine takes up space that would normally  be occupied by passengers. The mid-engine layout shown combines the engine and transmission components in one unit. The term mid-engine is used because the    engine is mounted in front of rear axle line.

 

~Front engine and rear-wheel drive

Advantages:- *Better axle load distribution *Better road grip *Comfort riding *Better cooling *Less noise (long exhaust pipe) *Use a long engine Disadvantages:- *Heavy (more weight) *The passenger compartment has the propeller shaft tunnel.

  

~Front engine and front-wheel drive

Advantages:- * More space in passenger compartment. * Easy to place the fuel tank (bigger) * More safe in the event of head on     collision. (engine mass) * Shorter car length and better passenger     compartment * Better cooling * No problem in steering the car in a     slippery road. Disadvantages:- * The need to a power steering * More tire wear in the front axle * Less brake efficiency, 75% front and     25% rear. * Less climbing ability * Less accessibility for engine parts    (maintenance)

~Rear engine and rear wheel drive

Advantages:- * Good brake distribution on the axles * Better climbing ability and acceleration * Less steering effort Disadvantages:- * More rear wheel tire wear. * Bad cooling * Less space for luggage * Sensitive to the wind. * Less safety (front fuel tank)

~Four-wheel drive

Advantages:- * Better traction * Less risk of wheel spin * Minimizes the possibility     of wheel lock-up when     braking the car. * More gradient ability Disadvantages:- * Heavier * Increase the fuel     consumption * Tires wear if driven on a     paved road.

INTRODUTION TO ENGINE

INTRODUCTION TO ENGINE
  
  An engine or motor is a machine designed to convert energy into useful mechanical motion. Heat engines, including internal combustion engines and external combustion engines (such as steam engines) burn a fuel to create heat, which then creates motion. Electric motors convert electrical energy into mechanical motion, pneumatic motors use compressed air and others such as clockwork motors in wind-up toys(use elastic energy). In biological systems, molecular motors, like myosins in muscles, use chemical energy to create motion.

  "Engine" was originally a term for any mechanical device that converts force into motion. Hence, pre-industrial weapons such as catapults, trebuchets and battering rams were called "siege engines".The word "gin," as in "cotton gin", is short for "engine." The word derives from Old French engin, from the Latin ingenium, which is also the root of the word ingenious. Most mechanical devices invented during the industrial revolution were described as engines(the steam engine being a notable example).

  In modern usage, the term engine typically describes devices, like steam engines and internal combustion engines, that burn or otherwise consume fuel to perform mechanical work by exerting a torque or linear force to drive machinery that generates electricity, pumps water, or compresses gas. In the context of propulsion systems, an air-breathing engine is one that uses atmospheric air to oxidise the fuel rather than supplying an independent oxidizer, as in a rocket.

  When the internal combustion engine was invented, the term "motor" was initially used to distinguish it from the steam engine which was in wide use at the time, powering locomotives and other vehicles such as steam rollers."Motor" and "engine" later came to be used interchangeably in casual discourse. However, technically, the two words have different meanings. An engine is a device that burns or otherwise consumes fuel, changing its chemical composition, whereas a motor is a device driven by electricity, which does not change the chemical composition of its energy source.
  
  A heat engine may also serve as a prime mover(a component that transforms the flow or changes in pressure of a fluid into mechanical energy).An automobile powered by an internal combustion engine may make use of various motors and pumps, but ultimately all such devices derive their power from the engine. Another way of looking at it is that a motor receives power from an external source, and then converts it into mechanical energy, while an engine creates power from pressure (derived directly from the explosive force of combustion or other chemical reaction, or secondarily from the action of some such force on other substances such as air, water, or steam). Devices converting heat energy into motion are commonly referred to simply as engines.