Since your reply is to Joshes comment about getting water into an engine by cranking it too long, I presume that is what your friend did.
There are two typical was for water intrusion to seize a diesel engine: Corrosion - Normally the flow of compressed vapor in the cylinders will keep water from going from the exhaust manifold to the cylinder while the engine is cranking. After the engine stops cranking, water can drain back through the exhaust valve into the cylinder and cause the piston rings to corrode to the cylinder walls and seize the engine over time. The cure, unfortunately, is to disassemble the engine, hone the cylinders (or replace the liners if they are part of the design), and replace the rings, bearings, seals, etc. Often, rebuilding with a new short block is more cost effective than a piece by piece rebuild. Hydraulic Lock - If your friend got water into the exhaust manifold by cranking, then stopped cranking, and the engine "seized" when he started cranking again, the problem is probably an hydraulic lock and not corrosion. Incompressible liquid gets into a cylinder or two and when the piston moves upwards it reaches a point where the crankshaft can no longer turn. There is a slight chance of this happening when an engine is cranked too long with the compression released. A starter is usually not strong enough to actually break any engine components, but the engine will be locked up by hydraulic pressure in the cylinders. The solution here is to pull the cylinder head (the quicker the better) remove the liquid, spray in a bit of fogging oil to lube the cylinders, reinstall the head, and retime the injection pump. Not a pretty thing to do, but less expensive than a rebuild. >From my perspective as a Yanmar, Perkins, Cummins industrial engine maintenance trainer, and a former certified Cummins diesel technician, I'd like to comment on the practice of putting liquid oil (diesel, motor, or Marvel Mystery) into the intake manifold before first startup in the spring. Don't do it. It only takes an ounce or so getting into through an intake valve into a cylinder to cause an hydraulic lock. And if you only put a tablespoon or so into the air intake, realistically, none of the oil is going to make it into the cylinders before startup. It would not be a bad practice to spray a small bit of fogging oil into the intake as you crank the engine for the first time. The atomized oil will be drawn past the intake valves to lube valve guides and upper cylinder walls, but the quantity will not be enough to cause hydraulic lock. Actually, putting in the fogging oil (a couple of cranks of the engine with fuel cutoff, while spraying oil into the intake) as a last step in the layup process makes more sense than fogging at first startup. Rick Brass Washington, NC From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Steve Thomas Sent: Friday, November 29, 2013 10:09 AM To: cnc-list@cnc-list.com Subject: Re: Stus-List Winterizing A friend of mine managed to seize the engine in an almost unused diesel generator that way. It would not budge either way immediately afterwards, in spite of big wrenches and much grunting. Don't know yet what broke. He filled it with oil and has left it sitting. Steve Thomas C&C27 MKIII -----Original Message----- From: CnC-List [mailto:cnc-list-boun...@cnc-list.com]On Behalf Of Josh Muckley Sent: Friday, November 29, 2013 4:38 AM To: cnc-list@cnc-list.com Subject: Re: Stus-List Winterizing <snip> " As advised recently one needs to be conscientious not to roll it too long or sea water can back up in the exhaust and damage the engine. " Josh Muckley S/V Sea Hawk
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