head was machined using it on a rebuilt motor with forged pistons etc. will be boosting this setup hard. While lapping the head i found 2 small cracks they seem to start from the edge of the exhaust valve seat and stop in the surface of the head the cracks are small and do not make it into a water jacket. I just had the head pressure tested and recleaned, and they said it was fine they obviously missed this (very small). So anyone had this happen? thoughts? im thinking i shoul not reuse this head now cracks will probly expand and spread with heat thoughts on this? ij, doward,. Pulled the head cause i was leaking combustion gas into the cooling sys.
built cracked head
- Thread starter quake
- Start date
gonna kill these guys i pressure test it first they ok it then i put shims new valve seals helicoiled all the stud holes lapped it then this i think pressure would seep past it across the head surface and make it into a coolant passage. Will try to post pics later the head is a work. Since i buy parts a cost anyone know what the cost of a new head is?jdub said:
Quake: I wouldn't use it for a performance build.....
Worst case scenario and what will probably happen is the crack spreads vertically at the valve seat and the seat falls out under power
Depending on how it falls out and gets lodged there's a very good chance of it jamming the valve open enough that the motor becomes an interference motor in a big way.
Worst case scenario and what will probably happen is the crack spreads vertically at the valve seat and the seat falls out under power
Depending on how it falls out and gets lodged there's a very good chance of it jamming the valve open enough that the motor becomes an interference motor in a big way.
yeah i was thinking of something like that ill pull the spare head i have thanksIJ. said:Quake: I wouldn't use it for a performance build.....
Worst case scenario and what will probably happen is the crack spreads vertically at the valve seat and the seat falls out under power
Depending on how it falls out and gets lodged there's a very good chance of it jamming the valve open enough that the motor becomes an interference motor in a big way.