With a little care and cleverness -- and elbow grease -- you may be able to salvage it yourself. And if you're not successful, THEN you take the head to a machine shop.

I bought an '81 245 with a seized cam expecting to install a rebuilt head. I ended up fixing it for the price of a new timing belt and two days work.

First, I removed the cam. I found that bearing journals #2 and #3 were galled. Aluminum base metal from the bearing and cap journal surfaces was galled into the steel of the cam bearing surfaces.

Next, I wrapped the cam in a rag and carefully clamped it in a vise. This way I could very carefully file the bearing surfaces to removed the aluminum. Aluminum and steel are different colors -- it was easy to see (and feel in the file) when the metal that the file was cutting had shifted from the soft aluminum to the much harder steel. I used a new, clean, fine-toothed flat file for this, and followed with very fine paper (400 grit) to polish the bearing surface.

Next, I wrapped coarse sandpaper around a socket that barely fit into the bearing (with the cap on) and spun the socket (with paper) as I slowly tightened down the cap, finger tight. (Keep in mind that the cam has five bearing surfaces and doesn't really carry a substantial load.)

When I was satisfied that I had removed the galled metal and restored the surfaces, I cleaned, cleaned, cleaned up all the grit in the head, lubed the cam, and installed it and the bearing caps.

In addition to a bad belt, I found that the pin between the sprocket and cam had sheared.

Finally, I checked the headbolt hole that delivers oil and found it spotless. On this car, the problem was the oil pipe from oil pump to block. It apparently had been mis-installed at the factory and delivering about 1/2 the oil for the life of the car. A new o-ring and careful installation solved that. (On a 240, dropping the pan and oil pump is no small challenge.)

I bought and repaired this car around '90 or '91, put about 50k miles on this repair, and old it in '96 to a friend. He still drives it today and is still my friend.

Overall, my $20 cam repair has now about 100k miles on it and is still going strong.
--
Don Foster (near Cape Cod, MA)