Absolute pain in the arse job and massively not worth the effort!

Even a 1.6 - 2.0 litre conversion isn't worth it for the effort.

EVERYTHING has to come out of the 1.6 to fit the larger engine and all the required parts - seeing as they are fitted the opposite way to each other!

Woolford - You're talking about Silvertop engines, completely different to Blacktops from the Focus.

G T M - 1.8 to 2.0 litre isn't 'that' difficult to do depending on how much you want to change. The blocks are different (obviously) and the cylinder heads are only different due to the larger combustion area in the 2.0 litre head. The camshafts are exactly the same in both engine, the mounting points for both engines are the same and the 2.0 litre engine can be made to run with the 1.8's IB5 gearbox and shafts if you use the 1.8 flywheels and clutch. As for the ECU - I'm not sure if it will have enough tolerance in its running parameters to 'self-learn' to cope with the larger engine and air/fuel delivery but I'm planning on finding out later this year. Don't just swap the ECU's over - the PATS system and PCM/GEM systems are built into them so not only will you need new keys and transponders for the immobiliser you will also over-fuel the engine as the 2.0 litre ECU will be expecting to use 2.0 injectors which are either bigger or will be kept open for longer (can't remember right now if they are the same as 1.8 ones or not - either way it won't work).