HELP!!!Bout to torch car.

[Chetly]

Heres the deal. Put motor together. Brand new block and internals and everything. Used old front cover and rods. Started it up in garage and let it run for 20 minutes. No problems except a small trickle leak around t-stat houseing. Checked oil, no water in oil. Pulled intake manifold and fixed leak. THen i had a front cover/water pump external leak. Took car around the block. Fixed external leak around front cover started it and had water in oil. Replaced head gaskets, front cover gasket, intake manifold gasket, exhuast manifold gasket and all other gaskets. Did not see any problems in teardown. Put back together, started it, and had water in oil again. Block and all is brand new. New motor probably has 300ft on it if that. My question to all is, WHAT THE HELL? Just have water in oil, no oil in water, and combustion chambers are clear. What do you think.