Rebuilding the delicate twin-cam: Part one
It was built in four displacements, 1300, 1600, 1750, and 2000. It produced from a modest 62 BHP all the way up to a mad 240 BHP when it was in the hands of the mentalists at Autodelta, as a 2 litre Supercharged unit. It enjoyed great success in motorsport with a twin-ignition cylinder head in the GTA and 1300GTA Junior. It was even used in Formula 3 cars for a while.
However, in my car it does none of these things, as my one is absolutely ruined.
The original 1600 engine out of my car had, at some point, been in the care of a moron. It had over heated and destroyed all the piston rings and blown the head gasket. This is most likely because it had the wrong thermostat, which had come loose and jammed shut in the top radiator hose. It also had a BMW fan, which is not as good as an Alfa fan. Obviously.
Originally the liners in these engines were simply sealed with a rubber O-ring, between the liner base and the block. But as they aged it became common practice to add a little high heat silicone as a “belt and bracers” solution. Very wise.
However, a previous owner decided to forgo the O-rings and high heat silicone and seal the liners with the sort of glue you would use to install a headlamp cover. Brilliant.
And this is the result…
Just awful, awful corrosion. Water had been in the oil for years by the time I pulled this engine apart. It might as well have been stored at the bottom of the sea, for all the damage it did.
There was plenty of corrosion in the water jacket, which occurs when plain water is run as a coolant, in place of a proper corrosion inhibiting solution. The crankshaft was also so rusty that I had to simply throw it away, along with the camshafts.
Next? What can be done to get this engine swinging again?