On Thu, 30 Sep 2004 04:19:57 -0400, "Paul" wrote:

I did the pressure test today. Filled the engine with water, closed the
cooling system and eliminated manifolds from the loop. Then applied 20 psi
pressure to the cooling system (water jacket). It held easily for 20 min. no
change (twice). The pressure dropped sligthly when I was cranking the engine
with plugs out while keeping cooling sys. pressurized.. Spoke with a local
rebuilder that suggested the above while canking the engine and watching for
water appearing in cylinders (coming out of plug sockets), crankcase or
elsewhere. Drained the oil and watched for water dripping from underneath.
Nada. Filled both manifolds (with raisers) with water to look for leaks.
None. I guess that I got to check them under pressure.
In summary, no obvious leaks. There may be some (tiny) there that might show
if the engine is warm. That would be my next step I guess. As advised here I
built a tool for pressure testing using a piece of plastic 3/4 inch pipe,
plastic screw-on cap and a tire valve that I installed in a cap. Worked
great. Used a small compressor (tire type) to apply pressure and since its
gauge was constanlty showing pressure changes I knew exactly what's
happening. Despite that there's no pregress locating the leak. Any ideas?

Gasket maybe? I don't think a head gasket, but maybe a water pump?

That's a head scratcher, I agree.

Later,

Tom