[alcodiesel]

Tom came down yesterday and we experimented with regards to lowering the pressure.
We tried:
With and without the thermostat (MMI), with and without the bypass valve (MMI), larger (5/8) thermostat housing to manifold hose and fittings, circumvent the manifold all together.

Lowered the psi a pound or two at best.

So far conclusions: the main restriction is T inlet (which also has a hole directed between #2 and 3 cyl.), all the fittings and hoses add up. The 14psi appears to be on the injector T not anywhere else.

Results thus far: There is good flow and we did 2 full power runs (1600rpm) for half an hr each 165 to 170 was highest temp. The thermostat hardly opened but when it did the delta P was - 1/2 psi. Yes the box was open. Yes the prop is barnacled up and yes tied to the dock(good load), and yes the bay water is cooler than in the summer.

BTW: purging that air from this is very easy. The pump shuts down temporarily when it cavitates. Adding water to the HX while it does that, it takes about 30 seconds to a minute before all the air is out. I think having the HX 3 feet+ above the pump and no dips or valleys in the hose runs helps.

This is a new head and while I replaced it I cleaned all passages and the side cooling plenum (or whatever it is called). All new hoses.

I hope I answered all questions in my write up and faithfully described our attempts to discover where the high pressure is coming from.

Now the great news: the rigger said he'd most likely install the new mast (and all new rigging) Friday. Still a hope I'll be sailing again by New Years.