As above 1.8 ZVH MFI Turbo. What should it be?

 

it should be whatever the manufacturer of piston states.
what pistons is it using?

 

Its standard cast pistons but with adding a turbo i'm sure it will need more clearance?

 

why do you think it will need more clearance?
IMO i don't think they will, no reason for it at all.

 

Just the extra heat that the turbo is adding to what was a N/A bottom end

 

Yeh, you will need more clearance as you said the pistons run hotter in turbo engine, so require more space to expand. But again the clearance required is dependant on power output required. More power = more heat = more expansion.

If you dont have enuth clearance then the pistons will score the bore, piston crown and skirts

Simon.