The Perkins is designed to be rebuildable, as you note, it is a linered engine, you theoretically could run one forever. We have one that we resurrected, had been given up for scrap, as it was flooded in hurricane Isabel, sitting in the PO's garage. Full of water for 8 years, and we took the engine with the boat, as it had usable parts on it. I tasted the water in the crankcase when we drained it out, and it was essentially fresh, not salty (rain water floats on stormsurge water). Anyway, to make a long story short, all it took was a polish job on the crank journals, new bearings, a gasket set, and she runs. Liners and rings didn't have water or damage, head was perfect, the engine was rebuilt before it was flooded. They're not hard to work on, but the parts are pricey and sometimes almost impossible to get. Both the rebuilt engine and the one in the boat are counter rotaters, and try finding a new water pump for one. Some of the higher hp ones have a so-called Mani-cooler that is out of sight expensive. What we have are 160 hp, turboed and aftercooled, not too exotic. Plan to change the rebuilt one into the boat this winter, the engine in the boat is extremely leaky, probably could fix it, but want to clean and paint the bilge so it needs to come out, even though it runs just fine. Nice reliable engines, not speed demons, but relatively quiet, run a long time, don't use much fuel, we like 'em.
