starting rebuild engine

Hey you all,
Wondering what would be the way to go...
A friend got an OLD pre 1980 4.2L mercruiser he bought for his boat. I am helping him to install it.
the previous owner had it rebuilt and put it away to use later. However the guy never continued his poject. To be sure the engine would not suffer from any rust/moist, he completely filled it up with engine oil up to the cylinder head
what now?
just open the oil fill and unscrew the oil drain and let it drain during a few days?
do some manual spinning on the engine?
fill with new oil and fire up the engine?
or take off cyl head and check some internals of the engine.
all advice apreciated

 

Pull the spark plugs first or you could damage the valves

 

Water sinks. There may well be an inch of water in the bottom of the pan by now. And that water got there by passing over everything in between. And the oil is how old now??? Pull the pan off and have a good look around. I'm not saying what he did was wrong, just that it doesn't guarantee anything after a few years of sitting depending on where it sat. The cylinders might all have tide rings/pitting on them where the piston sat as well. You'll find out after a couple hours of running it if it's ruined or not.

 

I'd pump the oil from each cylinder top with a marine oil change pump. Same with crankcase.

Put some new oil in; leave the plugs out; get a bunch of rags and turn it over and clean up the mess.

Check the oil for any rust color and change again or try to run and change again quickly on any color.

No reason to use the old fuel system. It'll need going thru before running.

 

Guessing it's a bare block, no manifolds or fuel delivery?

That's an old school engine pickle. Haven't seen that in a while. Usually you drain the pan and then pop the plugs and bar it over on an engine stand. Works best if the engine Stand can rotate.

All the remote canneries up here back in the day would do that to their engines in the fall when they would shut down. On all manner of different engines from power generation to forklift engines. In the late 90s A lot of them went out of business over the winter and they stayed pickled in time. I remember in around 2010 one of my friends dad's got approval from one of the canneries to go Harvest a few of the historical engines that had still been running when the Cannery shut down in the late 90s. We removed them and brought them back to town to fire up, all were "full pickle" just like you described.

Most we drained and hand spun slowly to drain cylinders. Then his dad would come by and let them fly with a starter and make an Un holy mess.