Audi R8 and R10 crankshaft configuration.

[chernaudi]

Does the Audi R8/Bentley Speed 8 3.6-4.0 V8 FSI and the Audi R10 5.5 V12 TDI engines use a flat plane or crossplane crank? Hard to tell from exhaust note, but from the onboard, the R8 and R10 sound kinda like crossplane engines. Any input would be appreciated.

[AU N EGL]

From Audi's web site:

"The heart of the Audi R10 TDI is a completely new V12 TDI engine with a cubic capacity of 5.5 litres – the maximum permitted at Le Mans. Audi ventures into previously unexplored diesel-engine terrain with power exceeding 650 hp and torque of more than 1100 Newton metres from the V12 power plant.

“This engine is the specifically most powerful diesel there is in the world and, up until now, the biggest challenge that Audi Sport has ever faced in its long history,” explains Ulrich Baretzky, Head of Engine Technology at Audi Sport. “There has never been anything remotely comparable. We started development with a clean sheet of paper.”

The V12 TDI used in the R10 TDI is the first Audi diesel engine with an aluminium crank case. The cylinder-bank angle is 90 degrees. The V12 TDI has, like Audi production car engines, four valves per cylinder and twin overhead camshafts. The fuel induction is carried out by a modern “Common Rail System”. The injection pressure easily exceeds the 1600 bar achieved in production cars. The ignition pressures also reach values never previously seen in an Audi engine.

The engine’s power and the high torque are available to the driver practically from idling speed onwards – a speciality of diesel technology, something to which Audi drivers must now become accustomed. The usable power band lies between 3000 and 5000 revs per minute."


Watch this: http://mfile.akamai.com/10940/wmv/au...o_high_cbr.asx

http://www.audi.com/audi/com/en2/exp...TDI_Motor.html

ACO/ FIA rules required a reduction to 520 bhp

[chernaudi]

I already know about that press release, and sadly it doesn't mention the crankshaft arragement. I also saw that video, but it doesn't give much of a clue to this other that it looks kinda like a crossplane, but I'm not sure( it actually looks like a flat and crossplane hybird to me, as most of the crank pins are 90 deg to eachother, but not consecutively). And is the R8 a crossplane( Baretzky himself said that the bottom end of the engine is based heavily on the R8's).

[vorsprung]

From that one R10 video it looks like it has normal V12 crank, with 120 degrees between the crank throws.

Speaking of Audi cranks, back in 92 the DTM V8 Audi had a flat crank, which was ruled illegal mid-season and after that Audi withdraw from the series. Of course the production V8 had a crossplane.

[chernaudi]

I've heard about the DTM stuff, but what about the Audi R8's crank. It's a V8 with a 90 degree cylinder block, so it's either flat of crossplane.

[geeteeone]

The Audi R8 twin turbo V8 is a flat-plane crank engine.

Cross or flat-plane cranks only apply to V8s - the R10 has a V12 so the crank is of a completely different design altogether.

[knighty]

I have seen some 3D CAD pictures of the R8 V8 engine in technical journals and I can also confirm its a 180degree flat plane jobbie...........the V12 crank is quite conventional too - but I cant remember if its spaced at 120 or 60 degree intervals........like someone said above - you can clearly see it of the Audi press release video of the engine internals.........both will be machined from a billet of EN40B steel then gas nitrided for maximum fatigue strength.

[chernaudi]

Where did you see these drawings-I've never seen any!

[chernaudi]

And also, as I've already forgotten to ask this in my previous post, the R8 didn't sound much like a flat plane engine( especally on board). Why is that? The exhaust system, or the fact that the engine usually redlined at between 6250-7000rpms?

[knighty]

Originally Posted by chernaudi

Where did you see these drawings-I've never seen any!

They were printed in a copy of "Auto technology" a few months ago, it was a feature about the conversion from conventional port fuel injection to FSI - whereby they mounted the fuel injector in the cylinder head, and mounted tumble inducing horizontal flaps in the intake ports to promote better in-cylinder tumble, and better combustion - this allowed greater fuel economy and another lap at le-mans.......it was a 3D cad picture of a cut-away R8 race engine, I remember it very well, as like you I had seen nothing like it before........deffo a flat plane crank if I see it again I will scan it and put it on this thread........from the R8 engine photos on mulsanne corners website, my general opinion of the R8 engine is its a brick out-house of an engine, heavy and robust - thats why it NEVER failed!.......just gos to show that light flimsy engines are not the way to success in sports car racing.

I was involved with the BMW Ascari 4.0 LMP900 twin turbo engine in my Mountune design days, and we initially ran that with a cross plane crank and it sounded like a rumbly V8........we went over to a flat plane crank and it just sounded like a 4 cylinder engine - as expected......just like the R8's sound like

[geeteeone]

Originally Posted by chernaudi

And also, as I've already forgotten to ask this in my previous post, the R8 didn't sound much like a flat plane engine( especally on board). Why is that? The exhaust system, or the fact that the engine usually redlined at between 6250-7000rpms?

The onboard sound of a GT or sportscar is largely a product of how much a combination of the induction system and exhausts can be heard from the cockpit microphone. The Audi R8 air intakes are quite close to the cockpit, and the exhaust is very quiet, so this may influence the onboard sound heard. To me it sounds almost completely like induction noise.

[chernaudi]

I found the pic. Do you know where I can find more, or am I asking too much?

[chernaudi]

I know that I've asked this before, but what are the R8 engine's external demensions-it looks to me that the engine block is as long and maybe as wide as a 302 Ford small block.

[Hammerdown]

Just seen a pic of a disassembled R10 V12 in RaceTech monthly. Looks like the crank is a tri-lobe 120° design.

There's a long article about the engine.

http://www.racetechmag.com/racetech/...sue.asp?menu=1