the two dangers of sucking water into an engine are compression and rust. if the piston makes a compression stroke with water in the chamber, something has to give. water does not compress and with enough RPM and water volume, something will break. if the engine was rotating slowly enough and the water was minimal, the water would cause the entire rotating assembly to come to an abrupt halt. thats the stall. that abrupt halt puts one hell of a load on the rods and rod bearings. the water also creates rust on the cam lobes very very quicky, causing contamination. the oil becomes foamy as it gets sloshed around and its protective capacities are severly diminished. it also leaves a nasty chocolate milkshake looking sludge in the oil pan that can slow the pump and gum the works if it gets cycled thru the pickup. this sludge dosent really drain out, it just sits and contaminates the new oil.
I think when you sucked up water, it did some damage that took a while to present.
