[SIZE=1]This may sound stupid but I want to know what causes a head to get a crackin it .
Any condition which causes the cas oron or aluminum to exceed its stress
limits will cause the head to crack or warp.
Improper bolt tightening procedures, severe overheating the car engine, inadequate coolant flow to one part of the head. Very rarely a manufacturing defect such as a porous casting or a crack formed during the casting /cooling process may happen but the manufacturer's QA programs limit this problem
thanks for your help