Hi, looking at swapping the cams out on my 1.8..

my question is, how do i know how to time them up again afterwards?

all the cam locking tools seem to just stop them spinning?? which is fine. but what about when your removing the cam. or am i missing something.

If you use a dial test guage to find TDC on cylinder 1 inlet side say (where the guage is at it's highest point) then that's when the valves are fully open for the inlet side and so you know where the lobes of the cam should be when fitted. If you set intlet at TDC then make sure exhaust is set to BDC (dial test guage at lowest point). At least I think this will work