Search results
Results from the WOW.Com Content Network
A higher mechanical compression ratio, or dynamic compression ratio with forced induction, can be used to improve thermodynamic efficiency. Because fuel is not injected into the combustion chamber until just before the combustion is required to begin, there is little risk of pre-ignition or engine knock.
For example, if the static compression ratio is 10:1, and the dynamic compression ratio is 7.5:1, a useful value for cylinder pressure would be 7.5 1.3 × atmospheric pressure, or 13.7 bar (relative to atmospheric pressure). The two corrections for dynamic compression ratio affect cylinder pressure in opposite directions, but not in equal strength.
The octane rating of gasoline is measured in a test engine and is defined by comparison with the mixture of 2,2,4-trimethylpentane (iso-octane) and normal heptane that would have the same anti-knocking capability as the fuel under test. The percentage, by volume, of 2,2,4-trimethylpentane in that mixture is the octane number of the fuel.
The Toyota GR engine family is a gasoline, open-deck, piston V6 engine series. The GR series has a 60° die-cast aluminium block and aluminium DOHC cylinder heads.This engine series also features 4 valves per cylinder, forged steel connecting rods and crankshaft, one-piece cast camshafts, a timing chain, [1] and a cast aluminium lower intake manifold.
The combination of increasingly stringent emission controlss, lowered octane, rising gasoline prices, and insurance company crackdown on high-performance vehicles saw the relatively expensive 340 detuned in 1972 with the introduction of low compression (8.5:1) small valve heads, and by mid-year a cast nodular iron crankshaft and a variety of ...
Bore and stroke is 79.7 mm × 90.1 mm (3.14 in × 3.55 in). It produces 165–221 kW; 222–296 hp (225–300 PS) at 6000 rpm and 300–420 N⋅m (221–310 lb⋅ft) at 3600 rpm, and has a compression ratio of 9.0:1. It is used in the Renault and Alpine vehicles since 2015, where it is named M5Pt. Applications:
mapped direct ignition with centrally mounted longlife spark plugs and eight individual direct-acting single spark coils; Bosch Motronic MED 9.1.1 electronic engine control unit (ECU) (two MED 9.1 ECUs in the RS 4 and R8, working on the 'master and slave' concept due to the high revving nature of the engine), four knock sensors, EU4 emissions ...
In naturally aspirated engines powered by octane, maximum power is frequently reached at AFRs ranging from 12.5 to 13.3:1 or λ of 0.850 to 0.901. [citation needed] The air-fuel ratio of 12:1 is considered as the maximum output ratio, whereas the air-fuel ratio of 16:1 is considered as the maximum fuel economy ratio. [citation needed]