Big CC 20v based on older EA827 engine already demonstrated by val and his link. So we know the bits are there to make a hybrid at some expense. Full proper builds ABF forced induction or 2.0 20vT where the squish is maintained between piston and head will always incur a cost penalty as pistons and usually rods will have to be purchased + the rest. The issue with the ABF turbo from a low cost option is the custom intake and exhaust manifolds. A 20v Turbo regardless of size does not have this issue. Any version 2.0 20vT engine will have a cost penalty with pistons and I would advise rods. For any bore over 81mm you will need an overrbore which will add cost for these if using a 1.8 06A block. Danster already gave a good suggestions on 92.8 mm 06A crank doners. The 20v head does flow more air compared to a 16v head and as the engine was developed for cleaner emissions most likely the burn was better too. Costwise an low cost ABF huffed engine, if built properly will slot between a fairly modded 1.8 20vT and a much expensive but more powerful 2.0 20vT all things being equal of course. The character would be different between 16vT and 20vT engines.
Here is a thought. Why not just fit the 20v head onto a 2.0 8v APK block? This 06X block has the correct headgasket style for the 20v head already. The pistons would need the cut out for the middle inlet valve and no doubt tweaked for compression ratio optimisation. You would then just swap the crank timing belt pulley, water pump and idlers for the 20v parts. Obviously rods and pistons will need upgrading if pushing the limits, but for moderate use they should be ok.
Ahh, well there you go. Smart lad that Issam. Brilliant minds and all that. Even if he is prone to using to many valves.
Simply yes, I've got 2ltr tfsi crank with slight overview an pistons to match, with std k04 I'm running 272bhp an 345lbft...
Ok so far its all been focussed around fi, but what about increased capacity nasp 20v engines. Something along the lines of 1z tdi crank in an agg/abf or apk block, pistons? 20v head. Could make a tasty track motor, what was the name of the guy who ran a nasp 20v in his blue mk1 with great results, from the devon area around 10 yrs ago.
Thats the one, Graham Vanstone, saw it in the flesh many moons ago at a devon cgti meet, search function doesn`t bring up much on the car itself or the build of the 2.0L 20v motor.