I'm feeling like a broken record here. That AREA document is wrong. I asked my machine shop guy yesterday when I called about my VR6 head. He's been working on VW/Audi engines for 20 years, he said he has never had to re-balance a VAG crank.Lord_Verminaard said:All VAG engines are internally balanced. That's why you can zero balance everything and it's fine.
I just swapped the flywheel on my 20v for a spare used flywheel that I had turned. Didn't balance anything. Put on a new Southbend Clutch too. Didn't balance that either. Hey guess what? The engine doesn't vibrate. How amazing is that. If it actually were an external balance engine, I'd be screwed because I didn't balance the clutch/flywheel to the crank.
That's the beauty of internal balance. You can swap pistons and rods, and as long as the weight match between all of them is pretty good, the engine will not experience an out-of balance situation.