Downsized Car Engines

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Downsized car engines | The Incredible shrinking machine; Internal-combustion engines are getting smaller, more economical and cleaner—all without a loss of power. Economist, Dec 12, 2015.
http://www.economist.com/news/sc ... ical-and-cleanerall

Note:
(a) "FOR years, [in] the motor industry * * * The number of litres that a car’s pistons displaced within its engine’s cylinders was a matter of pride for its owner. This was because displacement equalled power"

There is no need to read the rest of (i) to (iii), where the most important is to get a grip of concepts.
(i) engine displacement
https://en.wikipedia.org/wiki/Engine_displacement
("Engine displacement is determined from the bore and stroke of an engine's cylinders. The bore is the diameter [NOT radius] of the circular chambers)
(ii) reciprocating engine
https://en.wikipedia.org/wiki/Reciprocating_engine
(used extensively in motor vehicles; section 3 Engine capacity)

(b) "The quickest way to squeeze more out of an engine is to use a turbocharger * * * A turbocharger employs a turbine, spun by hot gases from the exhaust, to drive a compressor that squeezes extra air into the cylinders and increases combustion. Turbochargers * * * could be unreliable"
(i) turbocharger
https://en.wikipedia.org/wiki/Turbocharger
(Turbochargers were first used in production aircraft engines)

Quotation: "A turbocharger, or turbo (colloquialism) * * * from Latin 'turbo' ('spinning top 陀螺') is a turbine-driven forced induction [qv for definition] device that increases an internal combustion engine's efficiency and power output by forcing extra air into the combustion chamber * * * a turbocharger is powered by a turbine driven by the engine's exhaust gas"

You do not have to understand this quotation. After you visit (iii), return to this quotation.
(ii) turbine
https://en.wikipedia.org/wiki/Turbine
(The word "turbine" was coined in 1822 by the French mining engineer Claude Burdin from the Latin turbo)
(iii) turbojet
https://en.wikipedia.org/wiki/Turbojet
(read the top graphic to know the location of compressor--> combustion chamber--> turbine; section 3 Design and its anime)

People often ask which part moves first: compressor or turbine?  Their confusion is understandable, because combustion chamber drives the turbine, which in turn drive the compressor (both are connected with a rod), but at the outset, combustion chamber needs compressed air flowing unidirectionally (pushed by a compressor). The beginning phase in an airplane is achieved by something similar to a spark plug in a motorbike or an automobile.

choi

(c) Fiat “has a 900cc two-cylinder design which develops 105PS (the metric measure of horsepower). This can accelerate one of the carmaker’s popular Cinquecentos from zero to 100kph (62mph) in ten seconds, and propel it to 188kph if the driver keeps his foot down.”
(i) For PS, see horsepower
https://en.wikipedia.org/wiki/Horsepower
(adopted in the late 18th century by Scottish engineer James Watt; The definition of the unit varied between geographical regions; section 1 Definitions of term)
(ii) German English dictionary:
* Pferdestärke (noun feminine; from Pferde +‎ Stärke): “horsepower”
  ^ Pferd (noun feminine; plural Pferde): "horse"
https://en.wiktionary.org/wiki/Pferd   
  ^ Stärke (noun feminine): "Strength"
https://en.wiktionary.org/wiki/Stärke

(d) "Turbochargers alone, though, do not make for a good downsized engine. A number of other technologies help as well. One is direct fuel injection (ie, injection directly into the cylinder [ie, combustion chamber]), which offers several advantages over the older method of injecting petrol into an intake chamber, to mix with the air there, before the whole lot was then passed into the cylinder proper. (Carburettors, which performed this mixing job before fuel injection was invented, have long-since gone to the great scrapheap in the sky.) Injecting fuel directly into the cylinder at high pressure permits more accurate control of the amount used. The injector also dissipates the fuel more evenly in the cylinder, so that when it is ignited by the spark plug it burns more completely and so produces less pollution."
(i) Google (scrapheap in the sky) and you will understand what it means.
(ii) "Direct fuel injection costs more than indirect injection systems: the injectors are exposed to more heat and pressure, so more costly materials and higher-precision electronic management systems are required."  en.wikipedia.org

(e) "Another useful trick is variable valve timing. The opening and closing of the valves that let air into the cylinder and exhaust gases out used to be regulated by a mechanical device operated by the engine’s camshaft. These days, the process is controlled by the engine’s management system [software]. * * * 'We could not do what we are doing now just with the hardware,' says Andrew Fraser, a senior engineer at Ford’s Dunton Technical Centre, in Britain."
(i) camshaft
https://en.wikipedia.org/wiki/Camshaft

, where "camshaft" is the shaft (horizontal, one in number), and the two cams are shaped like two-dimensional pears.
(ii) Dunton Technical Centre
https://en.wikipedia.org/wiki/Dunton_Technical_Centre
(located in Dunton Wayletts [a village; qv for section 1 Name], Laindon, Essex)

(f) "The shift from four-cylinder to three-cylinder engines also needs a change in engine design. Three-cylinder engines have a tendency to rock backwards and forwards around the middle cylinder. Carmakers have come up with a number of ways to absorb the vibrations and make sure such engines don’t shake, rattle and roll. Ford’s answer is to have the flywheel on the back of the engine and the crankshaft pulley mounted on the front, each slightly offset to counteract the rocking movement."
(i) flywheel
https://en.wikipedia.org/wiki/Flywheel
(ii) crankshaft
https://en.wikipedia.org/wiki/Crankshaft
(iii) Turbo Lag?  Hyundai Veloster Forums, June 2013
http://www.veloster.org/forum/58 ... 2939-turbo-lag.html
("Never owned a Turbo but I find when I first start out in the morning she bucks like a bronco for a few minutes till it's warmed up (auto trans). I live in Florida so cold temps aren't an issue. Any comments appreciated. Gene")