Volkswagen Audi  TFSI V6 EA839 engine

Volkswagen AG
EA839
Production period:	since 2016
Manufacturer:	Volkswagen AG
Engine Type:	V-engine , six-cylinder
Valve control:	DOHC
displacement:	2894-2995 cm 3
Fuel supply:	direct injection
Engine charging:	Turbocharger withintercooler
Power:	243-331 kW
Previous model:	VW EA837

The VW EA839 is a gasoline engine series of Volkswagen AG , which was developed by Audi . The series comprises six cylinder - V engines and is used in various vehicles of the Volkswagen Group since 2016th The engines are produced by Audi Hungaria Zrt. in Győr .

The 3.0-liter engines (3.0 TFSI) have a turbocharger , the 2.9-liter engines (2.9 TFSI) via two turbochargers ( biturbo ). All engines have gasoline direct injection .

Technology 

The 3.0 TFSI engine is operated in parts of the engine map in the so-called Miller cycle . This means that the intake valves close well before the piston reaches its bottom dead center , thus artificially producing a smaller displacement or starting the effective compression phase later than in a conventional engine. Compared to the compression phase, the expansion phase is extended, the longer expansion of the gas increases the efficiency. 

The displacement of the 3.0-TFSI six-cylinder - V-type engine is 2995 cm³ with a bore of 84.5 mm and a stroke of 89.0 mm, at a cylinder distance of 93 mm. The geometric compression ratio is 11.2: 1. The V angle of the engine is 90 degrees. The cylinder crankcase is made by sand casting from an aluminum-silicon alloy. New is the very wear-resistant iron coating of the raceways by atmospheric plasma spraying . Overall, the engine weighs 172 kg. 

The 2.9-liter engine is derived directly from the 3.0-liter engine. The displacement reduction to 2894 cc is achieved by shortening the stroke by 3 mm to 86.0 mm. Another change concerns the crankshaft main bearings, which have a 2 mm larger diameter due to the higher load. 

The change of charge is controlled by four valves per cylinder ( four-valve technology ) and a total of four overhead camshafts driven by a timing chain . The crankshaft first drives the balance shaft via gears , which sits in the V of the cylinder banks. The roller bearing balance shaft is now connected via chains with the four camshaft gears. These are formed trioval (slightly triangular), to compensate for force peaks and to ensure a harmonious engine run.

The engines have stepless adjustment of the intake and exhaust camshafts by means of hydraulic phasers, the maximum adjustment angle is 50 degrees crank angle. In addition, the engines have the so-called Audi valvelift system (AVS) , d. H. a two-stage Hubumschaltung the inlet valves. At higher load is switched to a different cam profile, which increases the lift of the intake valves from 6 mm to 10 mm and at the same time increases the opening duration of the intake valves from 130 to 180 degrees crank angle. These measures allow for improved cylinder filling. 

Charging and exhaust

The 3.0 TFSI engine has an exhaust turbocharger (monoturbo), which operates on the twin-scroll principle. The turbocharger is located in the inner V of the cylinder banks, d. H. the exhaust side is inside and the suction side outside. As a result, a compact design of the engine allows and keeps the gas flow paths short. The maximum boost pressure of the engine is 2.5 bar (absolute). 

The 2.9-TFSI engine, on the other hand, has two turbochargers (biturbo), each of which is supplied with the exhaust gases of a cylinder bank. Also with the 2.9 TFSI the exhaust side lies in the interior V. The maximum boost pressure of the engine is also 2.5 bar (absolute). 

In both engines, the exhaust manifold is integrated into the cylinder head and is surrounded by the coolant, which allows faster heating of the engine and on the other hand, the exhaust gas temperature can be lowered. This can be reduced at full load consumption, since less must be greased. All engines have a close-coupled three-way catalytic converter .

The crankcase and the cylinder head have separate cooling circuits (split-cooling). During cold start, the coolant pump initially remains completely switched off. Only when the operating temperature of the cylinder head is reached, the coolant pump turns on the water cycle through the entire cylinder head. The cooling circuit of the crankcase is only involved when the coolant in the crankcase has reached its limit temperature.The engines have a fully variable oil pump. The high-pressure fuel pump injects the fuel at 250 bar into the combustion chambers. 

Variants 

2.9-liter six-cylinder (2.9 TFSI) 

3.0-liter six-cylinder (3.0 TFSI)