VR Engine displacement 3

[SomptingGuy]

Does anyone know what figure is quoted for the stroke (and therefore displacement) of a VR engine (e.g. a VW 2.8l VR6)? Is the stroke quoted as twice the crank throw or is it the measured stroke, taking into account the massive offset between the cylinder axis and crank centre-line.

- Steve

 

[vagman2]

Yeah,
I,ve been there. VW actually build a lot of diesel engines in that factory too. There is dedicated room for Bugatti engines. As I was told production target of Bugatti engines is 3 per week. They didn't let me inside the room, just watched eng. assembling through the glass.
These pics are from Cologne Auto Show last year though.

 

[vagman2]

As I remember due to the VR shape the crank has to be assymetrical (not like R6's one) or sort of to obtain equal firing intervals. Guess have to find and read it again.

 

[TDIMeister]

A little update, Audi will introduce a new A8L with a 6.3L W12 engine to replace the outgoing 6.0L unit. It will be basically 2 3.2L VR6 units siamesed together. The 3.2L has a 10.6° minor bank angle instead of 15°. Bore and stroke are 86.0/90.9 mm, respectively, for a displacement of 3168cc. Cylinder offset is +/- 22mm (!!!) compared to 12.5mm of the predecessor.

What's crazy about this engine is that different pistons are required on the one minor bank side than the other, since all the direct gasoline injectors are on the same side of the head and the bowl-in-piston must have the same relationship to the injector position and in-cylinder charge motion.

 

[TrackRat]

Sounds like VW/Audi are getting way complicated on this W engine design. I must say that I am VERY surprised at Audi accepting this engine as VW and Audi compete like Ford and Chevy in my experience. I'll bet there are some very unhappy folks at Audi.

 

[Axewielder]

@ track rat, vw & Audi part of the VAG group and both use mostly the same parts across the range.
Ford, part of Ford Motor group, Chevy part of GM, two competing corps., im not quite seeing the comparison?
BTW big VAG fan and hoping to develop a twin charged 2.9 VR

 

[TrackRat]

Trust me... If you could see how VW and Audi engineering in Germany operate, they compete like Ford and Chevy. While competition can be good there is no love loss between these two auto devisions of VAG - in many cases... <LOL>

Audi redesigned their V-8 engine front end drive to shorten the engine so they would not be forced to use the VW W8 in an Audi. You will note that only the VW VR6 engine is used in any Audi models. The 4 cyl. and other engines are Audi designs, not VW and Audi is quick to tell you so.

I hope VW brings their twin-charger engine series to the U.S. The issue appears to be engine cost.

 

[TDIMeister]

Audi redesigned their V8 for more compact dimensions (mostly by moving the cam drive from a belt on the free-end to a chain on the flywheel-end) because the entire length of the engine hangs over the front axle in their drivetrain design. Every mm of length saved aids in overhang, weight distribution, polar moment and pedestrian collision safety of the car. Audi's V8 also long preceded the W8, dating back to the late 80s Audi V8 model. I owned a car with a variant of that engine while in Germany, a 1994 S4 Avant 4.2 V8.

The Hybrid version of the VW Touareg/Audi Q7/Porsche Cayenne will all use use the 3.6 VR6 and not the any 90-degree V6 variant from Audi.

Yes, there's intense competition and even some conflict within the VW Group, like any inter-division rivalry within a large conglomerate, but it's not like GM/Ford. But having just typed this, I must qualify that statement: I have personally worked in a project in a Tier-1 supplier where Ford and GM collaborated on a 6-speed transverse automatic transmission. In development they were known by GM and Ford as X22F and 6F, respectively. In production the X22F followed the more familiar convention and became the Hydra-Matic 6T70. It was a pretty good collaboration. I was in many a conference call with engineers and managers from both companies simultaneously.

 

[TrackRat]

My point was that the engineers at VW/Audi do not like to use the other division's engine designs. Audi engineers consider themselves "THE" auto engineers of Germany much to the chuckles of Porsche, BMW and M-B engineers. IMO they all have great engineers, but there is a definite mentality and some large egos involved at times. Some of the people just check their ego at the door and work harmoniously with their colleagues form all divisions without any issues.

When the dictate from Dr. Winterkorn or similar says you will use the 3.6L VR6 in the Q7 or the W8 in an Audi it is met with a lot of resistance.

Engineering groups at the same division are also very competitive. As an example the engine designers and development engineers at Ford U.S. 4-6-8 cyl. engines would not share ECU software strategies. They all insisted on their own unique ECU SW for personal more than professional reasons...

Anyway I'm sure there are unhappy campers at Audi when they are forced to use a VW engine design even though these engines tend to be good, reliable engines for the most part.