OTM Inc started the week with another famous all-day bunch. We had artists and hippies and software geeks and rafts of boat trash, all swigging screwdrivers and champagne, eating eggs and bacon and all the hashbrowns they could tolerate.
It was great, but whew – we might need a few days to recover. It’s a good thing we don’t have to do that again…until next time.
Get it right!
This week we striped down the number 4 cylinder head on the Arthur Foss‘s Washington Iron Works Diesel to replace the head gasket – again.
During the last Diesel Engine Theory class at the Northwest Seaport, we overhauled cylinder four and reassembled it using a solid copper head gasket.
It turns out that the solid copper types don’t squish enough for a diesel the size of Arthur‘s. Heavy-duty engines with cylinder liners have a very wide sealing surface between the head and the cylinder, so the gasket must be very soft. Some folks use compressed graphite to get a good seal, but originally they were all made with a sandwich of copper and asbestos.
When I was getting ready for the class last May, I made the mistake of thinking the sandwich gaskets would be too expensive and that our head and liner would be clean enough and flat enough to seal with a solid copper gasket. Of course we annealed it to make the copper as soft as possible, but it still leaked compression out the seams when we test-ran it. We may have been able to make a difference just by drawing up the head nuts tighter, but I can’t say that for sure.
Instead, I got ready this week to replace the solid copper replacement gasket with a new copper-and-asbestos sandwich gasket. I’ll let you know how it goes when I get it done.
