Volkswagen V8 diesel engine EA898 

Volkswagen AG
EA898
Production period:	since 2016
Manufacturer:	Volkswagen AG
How it works:	diesel
Engine Type:	V-engine
Valve control:	DOHC
displacement:	3956 cm 3
Fuel supply:	Common rail
Engine charging:	Turbocharger withintercooler
Power:	310-320 kW

The VW EA898 is a diesel engine series of Volkswagen AG with eight cylinders. The engine generation with common-rail injection has been used in various vehicles of the Volkswagen Group since 2016 and is the successor to the V8-4.2 TDI. Also fitted to the Porsche Panamera II and Bentley Bentayga.

Technology 

The displacement of the eight-cylinder - V-type engine is 3956 cm³ with a bore of 83 mm and a stroke of 91.4 mm, at a cylinder distance of 90 mm. The compression is 16.0. The V-angle is 90 °. The crankcase of the engine is designed as cast iron (GJV450). 

The control of the charge cycle takes place via four valves per cylinder ( four-valve technology ) and four overhead by a timing chain driven camshaft .

In the 320 kW variant, the engine weighs 266.5 kg according to DIN standards. 

The engine has two water-cooled exhaust gas turbochargers from Honeywell (GTD 2056) with variable turbine geometry . The adjustment of the guide vanes takes over an electric motor. The charging group is designed as a sequential biturbo . Up to an engine speed of 2200 min ^-1 , the engine is in monoturbous operation, that is, the first turbocharger is permanently subjected to the exhaust gas mass flow of the first exhaust valve of all cylinders, the second turbocharger is not active. Thus, the charge is changed over only two intake and one exhaust valve per cylinder, the second exhaust valve is via the so-called Audi Valvelift systemdisabled. At higher engine speeds further exhaust valves are gradually opened and the second turbocharger is charged with the exhaust gas of the second exhaust valves. From 2700 min ^-1 of the charge cycle takes place entirely over all four valves per cylinder and the engine is in operation Biturbo. The two turbochargers are located in the hot inside V of the engine. The maximum exhaust gas temperature is 860 ° C. 

The compressed fresh air is cooled by two intercoolers , one on the left and one on the right side of the vehicle.

An engine variant also has an electrically driven compressor (EAV) from the automotive supplier Valeo . The EAV is used in the lower speed range to provide faster boost pressure and torque build-up. For this purpose, the EAV after the intercooler on the left side of the vehicle is integrated close to the engine in the air system and can be integrated depending on the operating point via a pneumatic bypass flap. The power consumption of the EAV is up to 7 kW, which is why the EAV draws its energy from a 48-volt electrical system . The maximum speed of the EAV is 70,000 min ^-1at a maximum ramp-up time of 250 ms. The water-cooled EAV consists of a housing for the compressor and the electric motor as well as a separate housing for the electronics. 

The entire exhaust aftertreatment takes place close to the engine in the inside V of the engine. Directly after the turbocharger turbines, a NOC (NOx oxidation catalyst) with a volume of 2.37 l is arranged, followed by the addition of a water-cooled SCR dosing module to add the urea solution AdBlue required to purify the nitrogen oxides. After a short mixing section, an SCR- coated diesel particulate filter (sDPF) with an integrated barrier catalyst (volume 5.0 l) follows . Further, the motor has a cooled low pressure exhaust gas recirculation (EGR), The exhaust gas of the low-pressure EGR is removed behind the particle filter, cooled and re-introduced before the compressor.The common-rail injection works with a fuel pressure of up to 2500 bar. The high-pressure pump used is a CP4 stamping pump made by Bosch . 

Versions