Automotive Engines

Engine types/configuration:

- Inline engine

It is a reciprocating engine with banks of cylinders, one behind another, rather than rows of cylinders, with each bank having any number of cylinders, but rarely more than six. Inline or Straight are engines with a single bank of cylinders which can be arranged at any angle but typically upright or inverted.

- V engine

Engines with two banks of cylinders with less than 180° between them driving a common crankshaft, typically arranged upright or inverted.

- Horizontally-opposed engine

Engines with two banks of cylinders arranged at 180° to each other driving a common crankshaft.

-W engine

Engines with three banks driving a common crankshaft, arranged so that first and last banks are 180°or less apart.

- Wankel engine

The Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into rotating motion. Over the commonly used reciprocating piston designs, the Wankel engine delivers advantages of: simplicity, smoothness, compactness, high revolutions per minute, and a high power-to-weight ratio. The engine is commonly referred to as a rotary engine, although this name applies also to other completely different designs.

Engine orientation:

- Transverse engine

It is an engine mounted in a vehicle so that the engine's crankshaft axis is perpendicular to the long axis of the vehicle. Many modern front wheel drive vehicles use this engine mounting configuration. Some rear-mid engine vehicles, which use a transverse engine and transaxle mounted in the rear instead of the front.

Transverse front engine transaxle, FWD	Transverse rear engine transaxle, RWD

 - Longitudinal engine

It is an internal combustion engine in which the crankshaft is oriented along the long axis of the vehicle, front to back. Most rear wheel drive vehicles use a longitudinal engine configuration.

Longitudinal front engine, RWD	Longitudinal front engine, FWD	Longitudinal transaxle, RWD	Longitudinal rear engine transaxle, RWD

Engine position placement:

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.

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.

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.

Drive arrangements:

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.