‘ I don’ t see why they can’ t make them last now when they could in the‘ 60s’
The punchy Twin-Cam powered Alfa’ s 105 Spider, coupé and saloon
But working on them means that Paul can appreciate the twin-cams charms from within. There’ s some really solid engineering and there’ s one thing that Paul sees as being ahead of its time.‘ The chain design. It’ s a double chain and I’ m fairly sure there’ s probably still Alfas running on the original chain now.
‘ The chain setup, the sprockets, it’ s all fairly durable. They’ re from the 1960s and all we do is just clean them up with the bead blaster and there’ s hardly any wear on the teeth. It’ s a well-designed cam gear setup. I don’ t see why they can’ t make them last now when they could in the 60s.’
The entire valve train continues to impress, too.‘ The cam operates a bucket follower, and you’ ve got a shim under the bucket that sits atop the valve. In terms of the shimming purposes, it’ s a time-consuming process, but actually, it’ s a pretty solid design. Fairly simple to set up. It’ s not complicated.’
Not everything about the Nord is as well designed.‘ If you look at a Nord block, you’ ve only got about a centimetre of block mating surface for the head, around the edges. They’ re not most forgiving if you overheat them. Quite often you see, after quite a few years, it might be weeping a bit of oil between the head and the block. And if you don’ t get proper clamping, you’ ll get water in your oil.’
That’ s a small issue compared to, possibly, the Twin- Cam’ s biggest flaw.‘ The oil is only pressure-fed to the crank in the main bearing one, three and five. Two and four are not pressure-fed, it’ s fed through the crank.
‘ In the race engines, every race engine builder doing these will cross-drill the block. So they’ ll drill down the main bearing journal to the oil way and then drill across to meet in the middle of the block so you can then pressure feed oil to the second and fourth main bearing.’
‘ As a road engine, or even a fast-road spec engine, it’ s fine. But when you’ re constantly on throttle and you’ re using a lot of heat in the engine, they suffer. That’ s one thing they didn’ t do from the factory, which I don’ t know why they didn’ t.’
Instead of addressing the crank, factory updates saw further increases to the Nord’ s capacity. In 1968, the 1750 GTV and 1750 Berlina came with a 1779cc 122hp version.
‘ I don’ t see why they can’ t make them last now when they could in the‘ 60s’
Twin Weber or Dellorto carbs help give the Nord its memorable character
Weber carburettor fuel inlet
Weber carburettor fuel inlet elbow
Weber throttle balance linkage
Weber carburettor
Weber carburettor jet cover
Brake servo valve
24 The Engine Rebuilder
Weber jet cover gasket Issue 01