With early induction
Some systems disable alternator field (rotor) power during wide open throttle conditions. Disabling the field reduces alternator pulley mechanical loading to nearly zero, maximizing crankshaft power. In this case the battery supplies all primary electrical power.
Gasoline engines take in a mixture of air and gasoline and compress it by the movement of the piston from bottom dead center to top dead center when the fuel is at maximum compression. The reduction in the size of the swept area of the cylinder and taking into account the volume of the combustion chamber is described by a ratio. Early engines had compression ratios of 6 to 1. As compression ratios were increased the efficiency of the engine increased as well.
With early induction and ignition systems the compression ratios had to be kept low. With advances in fuel technology and combustion management high performance engines can run reliably at 12:1 ratio. With low octane fuel a problem would occur as the compression ratio increased as the fuel was igniting due to the rise in temperature that resulted. Charles Kettering developed a lead additive which allowed higher compression ratios.
The fuel mixture is ignited at difference progressions of the piston in the cylinder. At low rpm the spark is timed to occur close to the piston achieving top dead center. In order to produce more power, as rpm rises the spark is advanced sooner during piston movement. The spark occurs while the fuel is still being compressed progressively more as rpm rises.18
Power or working stroke
Intake, induction or suction: The intake valves are open as a result of the cam lobe pressing down on the valve stem. The piston moves downward increasing the volume of the combustion chamber and allowing air to enter in the case of a CI engine or an air fuel mix in the case of SI engines that do not use direct injection. The air or air-fuel mixture is called the charge in any case.
Compression: In this stroke, both valves are closed and the piston moves upward reducing the combustion chamber volume which reaches its minimum when the piston is at TDC. The piston performs work on the charge as it is being compressed; as a result its pressure, temperature and density increase; an approximation to this behavior is provided by the ideal gas law. Just before the piston reaches TDC, ignition begins. In the case of a SI engine, the spark plug receives a high voltage pulse that generates the spark which gives it its name and ignites the charge. In the case of a CI engine the fuel injector quickly injects fuel into the combustion chamber as a spray; the fuel ignites due to the high temperature.
Power or working stroke: The pressure of the combustion gases pushes the piston downward, generating more work than it required to compress the charge. Complementary to the compression stroke, the combustion gases expand and as a result their temperature, pressure and density decreases. When the piston is near to BDC the exhaust valve opens. The combustion gases expand irreversibly due to the leftover pressure?in excess of back pressure, the gauge pressure on the exhaust port?; this is called the blowdown.
Exhaust: The exhaust valve remains open while the piston moves upward expelling the combustion gases. For naturally aspirated engines a small part of the combustion gases may remain in the cylinder during normal operation because the piston does not close the combustion chamber completely; these gases dissolve in the next charge. At the end of this stroke, the exhaust valve closes, the intake valve opens, and the sequence repeats in the next cycle. The intake valve may open before the exhaust valve closes to allow better scavenging.
Car - etymology
The word "car" is believed to originate from the Latin word carrus or carrum ("wheeled vehicle"), or the Middle English word carre (meaning cart, from Old North French). In turn, these originated from the Gaulish word karros (a Gallic chariot). The Gaulish language was a branch of the Brythoic language which also used the word Karr; the Brythonig language evolved into Welsh (and Gaelic) where 'Car llusg' (a drag cart or sledge) and 'car rhyfel' (war chariot) still survive.1112 It originally referred to any wheeled horse-drawn vehicle, such as a cart, carriage, or wagon.1314 "Motor car" is attested from 1895, and is the usual formal name for cars in British English.3 "Autocar" is a variant that is also attested from 1895, but that is now considered archaic. It literally means "self-propelled car".15 The term "horseless carriage" was used by some to refer to the first cars at the time that they were being built, and is attested from 1895.16
The word "automobile" is a classical compound derived from the Ancient Greek word autós (?????), meaning "self", and the Latin word mobilis, meaning "movable". It entered the English language from French, and was first adopted by the Automobile Club of Great Britain in 1897.17 Over time, the word "automobile" fell out of favour in Britain, and was replaced by "motor car". It remains a chiefly North American usage.18 An abbreviated form, "auto", was formerly a common way to refer to cars in English, but is now considered old-fashioned. The word is still used in some compound formations in American English, like "auto industry" and "auto mechanic".