2 litres in 1 golf.... it goes

[Harooshum]

I thought putting 2L bottom ends in mk2's was a very common mod I thought the bottom end was exactly the same fitting whether 8v or 16v head is put on.  So if i wanted to do this conversion to my valver then I would need to find a bottom end from a 2L 16v VW???

[mk1]

Pistons in 16v engines are different to 8v due to valve clearance "pockets", so a 2000cc 16 valve engine would be the easy and cheapest option, A9 engine is almoast a direct swap.

[Gambit]

for a 16v you want the 9A from a passat or corrado

or the 6E (i think) from an Audi

you just need the block, use your own 16v head & fuel injection & all ancilliaries

with the 9A its a straight swap - like for like

with the Audi block you need to use your oil lift & sump also as the Audi block is transverly mounted.

[modulater]

I thought the bottom end was exactly the same fitting whether 8v or 16v head is put on

Well no , look at pictures of an 8 and 16V and you'll see that the 16V has a breather on the front of the block and the 8V doesnt as it uses the cam cover as its breather.

on an 8V I would get the engine bored and stroked to 2 litres and do a polished and ported head and better camshaft.

For a 16V it would have to be the 9A head and block as the 9A head has more meat on it so its better to polish and port when required. Fit the KR inlet cam and the inlet manifold and swap the throttle body and sensors over.