Spica vs. carbs

Spica web

I’ve mentioned Spica injection (or Inezione, as the Italians would, much more poetically, say it) vs. carbs. Here’s what I’m talking about.

In the late 60s, the US was already looking at ways to curb emissions (as well as beginning to consider mandating larger, uglier bumpers that achieved little except making foreign cars less attractive – but that’s another story 🙂 ). You’ll note that I have (of late) been leaning toward the Alfas – part of this is because I have been impressed by what I’ve read of them. I always thought that “being ahead of the curve” was a purely German trait, but these cars were very advanced for their time – already, in the early 60s they were sporting aluminium dual overhead cams and hemi heads, and these were for their sedans. The spiders had four wheel discs when many sports cars were using drums or a mix of drums and discs. In short, these cars were engineered to a higher standard than one might expect.

So, what’s Spica? Well, when the Americans began to look at emissions, Alfa went down the hall to their competition arm and consulted them. The result was the inclusion of the Spica injection system in their Spiders. Spica stands for Società Pompe Iniezione Cassani & Affini, and it is a mechanical injection system that ensured just the right amount of petrol was being delivered to each cylinder. In short, Spica allowed the Alfas to achieve the same performance figures in America with their more stringent requirements as they did in Europe, using carbs.  I have read that the Spica is as close as you will get to a “mechanical computer” or a “mechanical logic unit”, and that fascinates me. If the system is set up well, it rarely needs to be touched.

Spica systems are on the rare side now, though, as many North American mechanics couldn’t, or wouldn’t make heads or tails of them, and when they had failed to fettle them properly, or worse, seriously botched the job, made the suggestion that a move to standard carbs would be an excellent idea (usually dual Webers, from what I’ve seen). There are of course varying camps. There is a Porsche camp that suggests that the Bosch electronic injection system is far superior to Spica, and that the Italians should concentrate their attention on discovering ever nicer “reds” for their cars. There is the Carb camp that says (with experience) that the Spica system is impossible to service and the carbs work just as well.

I lean toward the Spicas because they were original equipment (in the US and Canada, anyway), because of their racing heritage and because, apparently, most people who service these cars know what they’re about now, and can service the Spicas without rendering them useless.

I can’t really comment as to the efficacy of one over the other, as my driving experience with these is limited… but at this point, I find the Spicas attractive, and an important consideration in my checklist for purchase.


4 thoughts on “Spica vs. carbs”

  1. There is an ~ ’76 Alfa Spider I saw at Legendary Motor Car in Milton on the weekend. It’s white…and it’s sold, but it might give you an idea of what those cars go for in excellent condition (it looked great…albeit from 30 feet away). I was looking out for you man!


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