help no compression in cylinder 4

[antiguan gti-r]

hi guys,

just rebuilt ma engine, now testing it got no compression in cylinder 4, what could pin point the issue.

 

[red reading]

poor some oil down the bore if you have some compression after its a ring or piston problem (you did oil the bore's as you built the engine?)

also take the rocker cover off and check you don't have a stuck valve, if they don't work you'll have to take the head off and go from there.