THE 850BHP 4CYL TWIN TURBO THAT WAS NEVER RACED...

After the huge popularity of the feature I did on the awesome but barely heard of Ferrari twin turbo V6 HERE, I decided to do one about an even more obscure F1 Turbo engine...
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​Alfa Romeo are famous for making oddball stuff, and this engine is no exception, having a turbo setup I've honestly never seen on any other engine before or since, but this engine was never raced, info and pics are scarcer than any other...

Alfa already had a F1 Turbo engine in the 80s, a twin turbo 1.5ltr V8 that's very fucking cool and I'll probably do a feature on in the future, but allegedly due to the plans to change the capacity rules down to 1.2ltr in 1988, they designed a new four cylinder engine, which was to be used by Legier (in current spec 1.5ltr form) for the 1987 season.

As the pics show, while the engine was a normal inline 4, twin cam, 16 valve engine, using two fuel injectors per cylinder, it was also twin turbo, but in a VERY unique way, which to be fair, I'm still struggling to understand the reasoning for.

Twin scroll single turbo setups on 4cyl are very common and VERY effective (25psi+ typically by 3500rpm on a 2ltr with a 600bhp capable turbo), which split the exhaust gas flow from cyls 1+4 in to one scroll of the turbine housing, and 2+3 in to the other.
Using twin turbos in a similar way, using cyls 1+4 to one turbo, 2+3 to the other, works in the same way, though rarer as there's little/no real advantage over a single.
Look at the piping on this one though, it's not twin scroll or twin turbo as we know it, in fact I'm not 100% what it is to be honest.

There's 8 exhaust ports, one per valve, which is rare, but not unheard of even on some production engines (Pug 405 Mi16 for example), but if you look, the ones from cyl 1+4 don't go to one turbo, and the ones from cyl 2+3 don't go to the other, in fact it looks like the front exhaust port runner from each cylinder goes to the front turbo, and the rear exhaust port runner from each cylinder goes to the rear turbo!
Exactly what good that would do I can't figure out, in my mind it would do no good at all, as it'd be no different to a single scroll single turbo setup.

The engine produced 850bhp at 4bar boost in early testing/development, but was massively slated by the test driver for terrible drivability and reliability, and was canned before ever being raced, so maybe this bizarre turbo setup really was as cool looking but pointless as it seems. Here's a few more pics, about the only ones out there, showing how the intercooler and external wastegate pipework was laid out...

There's rumours initial testing used a single turbo and 4 exhaust ports, then twin turbo but still 4 exhaust ports rather than the final version which had eight, but I've never seen proof of this via pics or anything else; it's really about the least documented engine there is, which is a shame, as I'd love to know more...

To finish this off, here's a couple of pics of the test car running the engine, showing the fucking enormous Behr intercoolers these badass F1 Turbo engines of the 80s ran...