I found it impossible to make any decision about the future of my ‘Bird without knowing exactly what was wrong. So, last weekend I took a few hours and tore into the motor.
On Saturday, I did the light work, removing accessories, draining the radiator and digging as far down as the rocker shafts. Sunday, my son came down the help with the heavy work: hood, intake manifold and the head itself.
Getting the hood off is a coordinated effort involving two people, each using both hands and a shoulder to hold things up while the bolts come off. Once it was safely stored away, we removed the bolts from the intake and chained it to a hoist. It was sealed on pretty well and took a significant amount of force (and just a little prying) before it popped off.
We left the exhaust manifold bolted to the head, disconnecting it from the collector pipe instead. The head bolts were all tight. Once they were off, it only took a little persuasion from the hoist to break it free. Up to this point, we hadn’t found any issues, though the oil in the driver’s side valve cover and (to a lesser extent) in the valley was fouled with coolant. There were no obvious cracks in the block and the head gasket was still intact.
The piston in the bad cylinder was at the top of its stroke, so we had to turn the motor over by hand to move it to the bottom. Once we did, we found an obvious crack about 2 inches long in the cylinder wall. The crack was deep enough to get a fingernail in.
This engine will never run again.
In order to get this car back on the road, it’ll need a new motor. A used motor seems like too much of a risk, especially after this experience. Fixing the motor I have–eight new sleeves, clean, magnaflux and install a new rotating assembly–adds up to about $4,000. Buying a pre-built motor (essentially the same thing, but with a different block) is about the same price.