Twincam. Sounds so sexy. Even the acronym DOHC – for double overhead camshafts – is surrounded by a degree of magic. Just recently a was discussing legendary 4-cylinder twincams with a car friend of mine – more specifically comparing Alfa Romeo’s Nord engine with the Lotus-Ford engine.
My dear friend didn’t hesitate long to point out that the Alfa Romeo engine was the superior of the two. But then, as an Alfa Romeo enthusiast, he is perhaps somewhat biased. These two twincams are actually surprisingly comparable, and deciding which is the better will no doubt depend on personal preferences.
The Lotus Cortina was launched in 1963 and its engine the year prior to that, when it debuted in Lotus’s own and brand new Elan. With its double camshafts installed in an aluminium head, it was an excellent machine which Lotus constructed on the cast iron block from the Ford Consul. Granted, it may not sound particularly “thoroughbred” to base such a fine engine on a simple cast iron block out of a mundane saloon, but then again, why not? The Consul block was strong and well-constructed, so why try to reinvent the wheel – even more so, when Lotus were of course always short on cash?
It certainly did the job, and the 1558cc Lotus-Ford twincam managed to produce 105 horsepower breathing through its two single carburettors. Which is just a tad less than the comparable Alfa Romeo twincam. There are multiple variations of Alfa Romeo’s iconic Nord engine, but when comparing it with the Lotus-Ford engine, it would make sense to look at the 1570cc version from the 1963 Giulia TI Super which pushed out all of 110 horsepower using two big sidedraught Weber carburettors.
So does that make the Alfa Romeo engine superior and more interesting? Well, there’s probably an argument for calling it more of a thoroughbred, seeing as it was Alfa Romeo’s own engine construction right from the base, and it was furthermore only ever utilised in Alfa Romeo’s own cars too. It also has a significantly longer history as it was first introduced in the Giulietta back in 1954. In that light, I will agree with my dear Alfa Romeo obsessed friend so far as to say that the Nord engine probably has a little more prominence than does the Lotus-Ford engine. From a more practical perspective it also has the advantage of being easier accessible through its higher production numbers, and thereby also being both easier and cheaper to acquire spare parts for. Through these spare parts, many owners nowadays choose to modify and tune their engines further and often with really good results too – it really doesn’t take all that much to extract more power from the Alfa Romeo twincam.
But then the Lotus-Ford twincam is highly receptive to tuning and modifications too. It did after all leave the factory in a relatively conservative state of tune. But which of the two engines is then the best when stretched to its very limits? It’s difficult to judge for a road engine, as it depends so much on how the engine is driven and used? There are so many variables. But if we merely look at maximum power – which is of course often the case within motorsport – it’s actually the Lotus-Ford engine which comes out victorious. In full racetrim but still within FIA regulations, they can manage in excess of 180 horsepower, where I believe the Alfa Romeo engines have to make due with approximately 170 horsepower.
As it is, both of these numbers are significantly higher than what they developed in period. And of course, they can be made higher still if you’re not concerned about your FIA homologation. Back in the sixties though, the race spec Lotus-Ford engine would push out approximately 150 horsepower, while I’ve been unable to find reputable specifications on the race Nord engine – but rest assured that it was a lot less than current days 170 horsepower. The reason is of course found in development and evolution. Time doesn’t stand still. Today we know better how to extract more power from an engine, and we can also manufacture better and stronger parts with smaller tolerances. These last fifty plus years of development – rather than just one race season – have led to more horsepower for both engines. But more so for the Lotus-Ford engine as the head is simply a fundamentally better design than Alfa Romeo’s.
But should the ultimate race specifications of an engine be the deciding factor as to which is the better? No. Quite frankly, it shouldn’t. That wouldn’t make much sense, but I still choose to do so in this case, simply to point out that the Lotus-Ford engine most definitely isn’t bad either!
The Alfa Romeo engine has hemispherical combustion chambers, while the Lotus-Ford engine makes do with what one might call semi-hemi. While the hemispherical combustion is ideal for achieving a greater fuel and air mixture to burn, it often suffers a little when it comes to actually burning that mixture in an effective manner. Alfa Romeo tried to compensate for this in 1965 when they introduced a twin spark head with two spark plugs per combustion chamber for their Nord twincam engine.
But regardless of whether you’re in the Alfa Romeo camp or the Lotus-Ford camp, you can rest assured that they are highly comparable and both are among the very best of what the 1600-class had to offer in the sixties. Off the top of my head, I can really only think of three outsiders which are comparable to any extent.
There’s of course Fiat’s delicious Lampredi twincam, but bear in mind that when it was first introduced in 1966, it was only available in the small 1438cc version developing a very respectable 90 horsepower. But the point being, it wasn’t until the seventies – more precisely 1971 – that the Lampredi engine entered the 1600-class when it grew to 1608cc. Still, it’s of course a fabulous example of a characterful Italian small displacement twincam engine, and it also outlasted the others as it remained in production until the year 2000 by which time it had grown further to a 2-litre twincam, and had powered such iconic models as the Fiat 131 Abarth, the Lancia Beta 037 and of course all those rally conquering Lancia Delta Integrales…
I think it’s fair to say, that while the other two I have in mind are both 1600cc twincams and they even predate the Lotus-Ford engine, they really are outsiders in this context. In 1958 MG added a twincam engine to their MGA range by fitting an aluminium twincam head to their trusty old B-series engine. A bold move for the small Abingdon based sports car maker. Initially it produced 108 horsepower, but there were both detonation problems and excessive oil consumption to deal with, costing MG a painstaking amount of warranty work. The project was doomed, and only a mere two years later the twincam was discontinued after only selling little more than 2,000 cars.
Impressively, Facel Vega failed even more spectacularly when they decided to ape Alfa Romeo and introduced their new and smaller Facellia in 1960. The French developed twincam was only given two supporting bearings for each camshaft which led to excessive flexing, timing issues and more often than not complete failures. It very quickly put the French luxury car maker into deep financial issues. The twincam engine was discontinued and the Facellia was attempted relaunched with the Volvo B18 engine out front. Nowhere near as sexy, but at least the Swedish lump was associated with reliability.
But which of these sexy 1600cc twincams is your personal favourite. Are you an Alfisti like my good friend? Or do your prefer the racebred Lotus-Ford twincam? Or are you going to go against the stream and choose one of the outsiders?