Ive seen a thread on here how to find out what it is,but cant find itI need to work out my comp ratio as i think its to high,problems with det and blowing head gaskets NOT due to fuel or timing.How can i work it out with the head off without any technical machines etc if possible? ive been told about deck hight at tdc to measure how far out the block the piston protrudes but what to do from there i havnt a clue can anyone shed any light on the subject for me please?