‘ There are ways to get a Nord to rev, but the benefits don’ t often outweigh the sacrifices you have to make’
Piston rings
Piston
Flywheel
For race engines, drilling of the block’ s oil ways is necessary to lubricate Twin-Cam’ s crank
Thrust washer Starter ring gear
Spigot bush
Big end bearing
Little end bearing
Big end tab washer
Thrush washer
Crankshaft
Conrod bolt
Conrod nut
Crankshaft oilway plug
Conrod
Flywheel bolt lock tab
Flywheel bolt
Crankshaft pulley
Crankshaft nut Main bearings
Crankshaft tab washer
‘ There are ways to get a Nord to rev, but the benefits don’ t often outweigh the sacrifices you have to make’
Twin-spark heads weren’ t the only way Alfa’ s raced with more power in period. Four-valve and narrow-angle valve heads were produced in small numbers. In the late 60s, race teams were also thinking of forced induction. It was, after all, allowed within the regulations. BMW created the 2002Tik, a turbocharged version of its two-door saloon before making the 2002 Turbo road car. An exhaust-driven compressor wasn’ t what ended up in the 60s race Alfas, though. Instead, a small number of Nord engines were equipped with two superchargers driven with oil pumped by the engine’ s oil supply. More conventional forced induction methods would be successfully applied to the Twin-Cam, but not until later in its life.
Building race engines for historic motorsport, the sort the Paul does a lot of, doesn’ t allow for forced induction. Revs are what you need, and that’ s not the Twin-Cam’ s forte.‘ The biggest problem with these is you can’ t rev a 2-litre version very much. They’ re a very long stroke engine. Any more than 7500rpm, they start to shake themselves to bits.
‘ You can rev the 1600 to 8200rpm. But they don’ t last that long. The biggest problem with the Nord is it’ s a wet liner engine and when you start revving it above 8000rpm, what happens is the liners actually start to move side-to-side.
‘ You can tell a Nord that’ s been revved over 8000rpm continuously because the gudgeon pins won’ t come out the pistons. They flatten the piston out slightly where the gudgeon pin goes in. If a customer says,“ Oh, I’ ve not revved it above 8,000 very much” and you can’ t get the gudgeon pins out, he’ s lying. There was a monoblock liner assembly years ago, where all the liners were cast together and the block has to be machined to accept the liner assembly. That helps stop the oscillation.’
There are ways to get a Nord to rev, but the benefits don’ t often outweigh the sacrifices you have to make.‘ Some people will use a 1300 crank for the short stroke and then you can increase the capacity with oversized liners.
Fuel injection was added to later versions of the Bialbero
28 The Engine Rebuilder Issue 01