About the only way you could have cooling water in you engine oil is from
the raw water pump seals.

The cylinders are seperate from the crank case and the oil goes to the from
the oil gallery in the crank/came up two seperate passes to the rocker arms
on each head.. There is only a very remote possibility of water getting into
this oil system this way since the oil pressure is always higher than the
water pressure.

If there were to be any leakage over into the oil passage, it would have to
be from a bad head gasket. IMHO, not likely..

Back to my theory of a water pump seal leak.. There is two seals in this
pump and a weep hole between them. Sometimes someone may plug the weep hole
when they see water dripping.. That means the second seal will have water
pressure on it. Since the inter seal is to prevent oil leakage from the
crankcase, the lip is turned inward and has no resistance the water
pressure.

Is there a possibility that someone put water pressure from a garden hose on
the pump during the rebuild/test process?? This can blow the pump seal!!
Best way to bench test or test on the hard is to let the pump take suction
from a bucket and use the hose to keep the bucket full.


--
My opinion and experience. FWIW

Steve
s/v Good Intentions