compression through radiator??? dont know what to do

i have a b16 block with a gsr head. i put the motor together but when i start it up, after about 2 min or so the radiator starts to boil up with the cap off. the steam goes pretty high up in the air so obviously the is compression coming from somewhere. there is a brand new b16 head gasket on the motor. we replaced the gsr head gasket that was on there for the b16 one and it is still doing the same thing. i dont know what to do next. if anyone has any ideas please let me know. thanks!

is the head warped?

same thing happened to my d15 the mechanic told me i had a bad headgasket or blown cylinder

sounds like the head gasket is bad (or not installed correctly) or head is warped. they sell a dye to tell if there is emmisions getting into your coolent, call up your honda dealership and or a few auto parts places, someone will have it.