When I think of drum brakes, I always see Ferrari and Maserati drivers being out-braked at Mulsanne by Jaguars. Or rather, I see the frantic driver of a red car braking like crazy, while a green car is still on the throttle, and it’s driver is grinning from one ear to the other. It has become part of the folklore of motor racing that when Dunlop and Girling came out with disc brakes, the stubborn italian marques continued for a few years with their drum brakes.

I got my 8 year classic road-worthiness approval in april, and for some reason that old assumption about the inadequacy of drum brakes popped up in my mind again. Because Steffen, my trusted mechanic at Skallebølle Auto, had issued my car with big aluminum drums at the front – and had gotten rid of the proven Girling 3-piston setup. But I needn’t have worried at all, because it sailed right through the scrutiny of Bil-syn in Assens (where they are quite used to classic cars from Skallebølle). The drum brakes were perfectly balanced left-right and front-rear, and Steffen had already sent me numerous reports after test drives that “they were actually quite convincing”!

drumbrakes_01

As I have mentioned, I bought the car from Søren Poulsen in Egå near Aarhus; he’s one of the most knowledgable guys in this country when it comes to Alfa Romeo Giuliettas from the 1950s, and he was perfectly aware of my plan to take the car racing. It had actually been his own intention, but he had abandoned the idea after having started configuring the car as a Giulia 1600 version. He had fitted Girling disc brakes and the car really just needed a carburetor change; from the two double Webers to a single twin-barrel Solex, and the parts were actually included in the package, I bought from him. But my plans went a whole other direction.

Girling disc brakes were fully refurbished – and then discarded

Alfa Romeo had never raced the 1600 cars. Mostly because the 105-series (Bertone coupe, step nose, Giulia GT – whatever people call it) was already offered for sale, and that was the car to have for the future. No, the Giulietta racers had been the Sprint Veloce (SV), Sprint Veloce Zagato (SVZ) and the Sprint Zagato (SZ), and they all ran with 1300 engines. Highly tuned, mind you, and much more appropriate for the nimble car. And they also ran with drum brakes. The model was introduced in 1954, started racing in standard form in 1955 and in 1956 the factory homologated the SV model. This was right in the middle of the afore-mentioned discs-versus-drums conflict, and some of the reluctance amongst old-school engineers was in fact because such companies as Alfa Romeo always had been able to make quite astonishing drum brake systems. I was convinced – not least by the necessity presented by the writing in FIA-121, the homologation file from 1956 on the Alfa Romeo Giulietta Sprint Veloce.

Uprights and spindles can be used for both disc and drums

The original 1954 brake setup has ordinary in it’s concept, in so far that it had twin shoes; one leading and one trailing, but the drums themselves were cast in aluminum – utilizing a new patented casting process where the fins were finished already in the casting machine – and issued with a steel insert for friction surface and strenght. But for the SV the Portello engineers came up with a delicate, yet robust and compact, setup that had three overlapping shoes; all fitted in a leading edge configuration. Powerful stuff, but not so easy to maintain and trouble-shoot (some say).

And I got a set of these famous jugs with me from Søren Poulsen! They were the actual 70×267 mm items and they just needed “some tender love and care”. But luckily Steffen is just that kind of mechanic, so during winter he made it all happen. All the parts were cleaned and checked; some were exchanged for new parts, but most were “just” refurbished. It is a robust design and the adjustment is not that difficult – if you have the tools. Steffen fabricated alignment rulers and with just proper good discipline and straight thinking, he got it all working.

You can convince yourself by watching my video: I don’t spare the merchandize! All components in my car get to live that “Sprint Veloce” life. The life that it deserves. I must admit that I am a bit scared by the thought of driving the Nürburgring Nordschleife and Spa Francorchamps saturday-sunday-monday one weekend next month, but it’s okay to take it easy on those tracks when you are in such an old car. I will go easy – to begin with.

I haven’t had to adjust the brakes yet, so there’s nothing to complain over there. Only when they are very cold, do they sometimes cause trouble; they loose balance, and brake harder on one wheel. So I have taught myself to go the first 100-200 meters with the brake pedal slightly depressed while driving out of the drive way; just to heat up the linings. And when I drive in heavy rain – especially after the car has been parked in the rain – I have to be extra careful to heat the brakes, because water in the cold drums totally ruins the braking performance. But I have learned – heart in throat.

3 Responses

  1. LarsN

    Great post!

    I love these racing inspired aluminum drum brake. Beautiful and very right for the period.

    I would expect that you would find the largest difference in performance between the disc and drums, with continuous use. The drums would properly fade earlier that the disc system.

    I am now inspired to (at I plan to) take a close look at my own aluminum drum system. I know the master cylinder could use an overhaul, so might as well go thru the entire system. And, of cause, measure the braking performance! 

    Reply
  2. Kim Jensen

    Drums are actually more efficient than discs, untill they heat up and fade.

    Reply

Leave a Reply