Posted by David Sherman on Monday, July 19, 2004 at 11:30PM :
In Reply to: Hey Guys, I need some advice posted by Big E on Monday, July 19, 2004 at 10:03PM :
I got an old 5kW genset a few years ago with a cute little water-cooled 4-cyl 65 cu in herc flathead in it and was eager to make it go even though it had sat out for a long time and was very rusty. It had good oil in it and I put water in the radiator and fired it up. It ran like a champ for about a minute and then started knocking a bit. Like a fool, I let it keep going thinking it would somehow improve itself with time. By the time I finally gave in and shut it down it sounded like the #1 piston was about to jump out of the block. Pulled the pan off and found nice smooth curly shavings of bearing metal that looked like they'd come off a lathe. The rod bearing was worn clear through and the crank was shot. The cylinders had no ridge or scuffing at all. It was basically a new engine, but with all those years of sitting, some blob of crud got stuck in the oil passage to #1 and the shavings were the result. I ended up tearing the whole thing apart, cleaning out all the oil passages, and putting in a new crank from Jerry Biro. Now I don't assume anything about old engines that have sat for decades.
I'd say pull the pan and look for shavings or lots of sludge. While it's off wiggle the rods. Put new oil in it. Crank it without spark or fuel for a good while to get oil all over everything. Squirt some oil in the spark plug holes. Check the compression while you have the plugs out. If all seems good, fire it up and let it idle till it's nice and warm. Stay nearby and listen carefully for anything that's not right. Bearings might be loose. Pistons might slap. Valves might be sticking. Water might be leaking into the cylinders or into the oil. Cylinder pressure might be blowing into the water. Make sure the oil pressure is good and water is circulating through the radiator. At that point it's ready for a short test drive. Sometimes I've ignored these steps and gotten lucky, but there are also two overhauls that resulted from ignoring them.