Should I skim the pistons? Ive already the thickest mls gasket for my engine but would would be more confident in it with another little drop.
I would think cutting the pistons or larger precups. This begs the question as to why? These engines are known to handle 30+psi boost with lots of fuel already. Low RPM boost is the only thing I have heard they really have problems with. Please let us know what you are up to
Prechamber is the way if you must do it. But itīs not necessary to lower it from stock.
Sorry if Ive decieved anyone, its not a vw engine but very, very similar to aaz the 'xud' 1.9 peugeot, the other makes section doesnt get as much traffic so thought Id post here

. Its just ideas for new engine, Ive the big pump, big turbo and cant keep engines together so decided arp studs, lower cr and full balance, this is not the way to go? I'm on my 3rd engine in 2 years and just last month a hg cylinder head

and tbh this is the last throw of the dice then I get an om606 mercedes. My car goes very well atm though and would like a year out of it without breaking lol
The precups are out of the question as I dont much about the shapes etc

but the cloverleaf sounds do-able for me if it just needs more depth?
MJF any of these tuned in finland?
pull the head and drill holes through the pistons, the bigger the holes the lower the compression.... i know i'm brilliant
pull the head and drill holes through the pistons, the bigger the holes the lower the compression.... i know i'm brilliant

In a similar vein................
Why pay a fortune for a porting job? Simply remove the air filter run the engine at maximum revs, and pour sharp sand into the intake, this will grind away all those nasty bumps and lumps in the intake.
PSA made some fantastic diesels. My missus's Peugeot 106 diesel does 65mpg imperial, with ME driving it! Didn't the XUD come in larger sizes for vans and things? You might be able to swap for a different head (the same idea on VW's would be using the 1.9 AAZ head on a heavily tuned 1.6 SB). Time for a mooch at the scrappy's.
http://en.wikipedia.org/wiki/PSA_XUDThat 2.1 litre 3 valve head sounds interesting.
But just rereading your thread, looks like I know less than you on these machines, I am still looking for a good Pug diesel forum.
Just stick your 1.9 into an AX. You'll need an aerofoil to keep it on the ground...A bit like the Renault 5 turbo era....
FIAT forums are junk too!
Just stick to VW/Audi, Merc and possibly Landrover... Cummins, and Marine folk are on the ball too...
cash in all the scrap xuds you have and with the cash buy a aaz

have you tryed the 2.1 12valve, i took all the elcy crap of one and fited a bosch pump with the injector pipes for a guy last week it come out of a 406 , runs a treat now
Just stick your 1.9 into an AX.
I just love Q cars.

Previous favorite was a 1958 Landrover with a Ford V6 stuffed into it. Terrifying in the wet, an absolute Ditchfinder General. It was still trying to kill people in the South Hams when I last saw it.
http://www.frenchcarforum.co.uk/forum/viewtopic.php?t=31644
Actually really sorry I didnt search before asking this

Some really excellent threads already deep down in the forum
Just stick your 1.9 into an AX.
I just love Q cars. 
Previous favorite was a 1958 Landrover with a Ford V6 stuffed into it. Terrifying in the wet, an absolute Ditchfinder General. It was still trying to kill people in the South Hams when I last saw it. 
http://www.frenchcarforum.co.uk/forum/viewtopic.php?t=31644
I always wanted to put a1.9dt into the phase 2 106 1.5d.
A light car and a heavily fettled dt lump would be fun!