I've tried posting the Q at Moyer Marine Forum, but I don't seem to have the correct privileges over there.
I've started a rebuild (spare engine) using a 1977 "freshwater cooled" engine I purchased last year.
Currently at a work stoppage awaiting parts. The reassembly is going as planned, but I have a question for those that know the answer. The question concerns my initial cylinder head pressures. The engine spec range is 95-110psi, mine are spot on (all 4 cylinders) at 75psi. I'm getting these pressures using the starter to turn over the engine. The engine is freshly rebuilt; cylinder's honed to .010 overbore. The cylinders are lightly lubed and not under full oil pressure yet. I'm guessing I will see higher pressures after the oil pump kicks in at 40psi at "first startup", but this is my first engine to rebuild so I'm not familiar with what to expect.
Condition of parts/block: The engine has new valve guides, valves, valve job by a reputable machine shop in Tacoma, the block was high frequency cleaned, crank and flywheel were balanced, and the block deck was milled, new pistons, rings and bearings, new head and two gaskets. Valves were adjusted and checked twice for proper adjustment. The engine went together with no binding, turns freely. The new head is torqued to OEM spec and the head bolts are holding the torque as I've retorqued and checked several times.
Before I tore the original engine down the cylinder head pressures varied between 70-90psi, the block water jacket passed a 20psi pressure test for 20 minutes, so the block was a "good" candidate for a rebuild.
What am I missing, or am I just paranoid?
I've started a rebuild (spare engine) using a 1977 "freshwater cooled" engine I purchased last year.
Currently at a work stoppage awaiting parts. The reassembly is going as planned, but I have a question for those that know the answer. The question concerns my initial cylinder head pressures. The engine spec range is 95-110psi, mine are spot on (all 4 cylinders) at 75psi. I'm getting these pressures using the starter to turn over the engine. The engine is freshly rebuilt; cylinder's honed to .010 overbore. The cylinders are lightly lubed and not under full oil pressure yet. I'm guessing I will see higher pressures after the oil pump kicks in at 40psi at "first startup", but this is my first engine to rebuild so I'm not familiar with what to expect.
Condition of parts/block: The engine has new valve guides, valves, valve job by a reputable machine shop in Tacoma, the block was high frequency cleaned, crank and flywheel were balanced, and the block deck was milled, new pistons, rings and bearings, new head and two gaskets. Valves were adjusted and checked twice for proper adjustment. The engine went together with no binding, turns freely. The new head is torqued to OEM spec and the head bolts are holding the torque as I've retorqued and checked several times.
Before I tore the original engine down the cylinder head pressures varied between 70-90psi, the block water jacket passed a 20psi pressure test for 20 minutes, so the block was a "good" candidate for a rebuild.
What am I missing, or am I just paranoid?