i've not done a proper compression test, i might stick a camera in whilst the head is on and see if i can see any cracks, certainly no sign of it with the head off (unless i've just done it)
in response to some of the questions, the block isn't sleeved (that I can tell, i presume it would be obvious). When i did first fill teh car with coolant a lot got into the sump, cylinder three was completely filled with water so i drained the collant, did an oil change and took the head off and the opened anywhere i thought water might collect (chest cover) in an attempt to get it out. When I sealed it all up again there was certainly no dramatic leak but I will check after a few days to see if there is a slight one. if there is a slight leak is my only option to have the head off and try again at sealing it all?
in response to some of the questions, the block isn't sleeved (that I can tell, i presume it would be obvious). When i did first fill teh car with coolant a lot got into the sump, cylinder three was completely filled with water so i drained the collant, did an oil change and took the head off and the opened anywhere i thought water might collect (chest cover) in an attempt to get it out. When I sealed it all up again there was certainly no dramatic leak but I will check after a few days to see if there is a slight one. if there is a slight leak is my only option to have the head off and try again at sealing it all?