Posted by dave horvath on Thursday, November 02, 2006 at 6:18PM :
Last year, I removed the head to check the condition of the 251 in m 1967 WM300. It had been rebuilt once before. When I got it the water pump housing was cracked, the engine had overheated warping the head, and rust fouled #1 exhaust valve so it was stuck open. I had the water pump housing repaired, had the head planed, and replaced the valves, guides and springs. I borrowed a valve grinding tool and did an amature job on the valve seats and hand lapped them.
Well, I just wasn't satisfied with my efforts, so I pulled the engine and took it to Harvey Bush in Greensburg, PA for a total rebuild. He is the guy who rebuilt the engine in my 1950. He is semi-retired and now has a machine shop at his home. Harvey has rebuilt hundreds of these old engines.
Anyway, Harvey let me come up to his place and guided me through the dissassembly of the engine, clutch, flywheel, etc. The pressure plate and clutch need to be rebuilt and the flywheel needs to be resurfaced. The crank had standard sized bearings, which weren't in bad shape (Harvey thinks the crank just needs a .010 grind). The cam shaft is fine also. However, every cylinder had ridges in the top, some worse than others. All of the rings were worn out and over half of the rings were broken. The expansion rings were wearing the cylinder walls oversize and out of round.
Harvey will order the needed parts, perform the machine work, and let me help reassemble the engine. I can't wait. The money I save using the original crank and cam can go towards 4.89 gears and a locking differential.
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