Simanaitis Says

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THE BRITISH MOTOR TRUST had high aspirations for its BRM 15 Grand Prix car described in Part 1. The car’s engine, especially, was replete with innovation. However, as motoring journalist extraordinaire Laurence Pomeroy said, “The first instance of novel principle is invariably defeated by the developed example of established practice.” And, as we see today in Part 2, changing regulations play a role too.

The BRM 15’s Engine Technicalities. A Lucas-supplied ignition (non-transistorized, of course) had a coil with four distributors. In The Grand Prix Car, Pomeroy notes, “At maximum engine r.p.m., the formidable number of 85,000 sparks per minute has to be delivered, the firing order being 1, 10, 6, 13, 2, 16, 5, 11, 8, 15, 3, 12, 7, 9, 4, 14.”

The BRM V-16 features hairpin-type valve springs, sodium-filled exhaust valves, and pistons a mere 49,53 mm (1.95 in.) across. This and following image by L.C. Cresswell from The Grand Prix Car.

The choice of hairpin valve springs in lieu of the conventional coil type was to forestall valve float at high rpm. According to Wikipedia, “… test figures from Rolls-Royce suggested that the engine would be able to run at up to 14,000 rpm.”

The BRM V-16 was essentially two V-8s back-to-back with gear drive mounted between them. Four separate heads were part of the layout. Cylinder banks were aligned at a wide angle, 135 degrees, thus reducing the overall height of the engine.

The wide-angle engine’s layout didn’t preclude complication. This and the following image from The Grand Prix Car.

In general, centrifugal superchargers have a narrower range of efficient operation and more peaky boost than Roots-type blowers. The BRM’s displayed this to a fault. In refusing a factory ride, Mike Hawthorn, future Formula One World Champion, said, “It was no use—every time I came to a corner and went below the 8000-rpm mark, the power went right off. Then, suddenly, as you reached the 8000 mark the full power would come in and you had a job to hold the car straight…. but the steering was nothing to write home about.”

Pom’s Adage Prevails. The BRM 15 had the inevitable teething problems of a new race car, together with its peaky supercharging. In its debut at the 1950 Daily Express race at Silverstone, the car had universal-joint failure at the drop of the flag. Its engine screamed, but the car never left the grid. Later in the year, the BRM won two short sprints at Goodwood.

This was followed by troublesome runs at the more lengthy 1951 British Grand Prix, where drivers of the two cars had to wrap their legs in burn dressings (exhaust plumbing had been routed within the bodywork).

Frolián Gonzalez piloted the BRM 15 after Mike Hawthorne turned down a factory ride.

For the 1952 season, Stirling Moss joined BRM. According to Wikipedia, Moss was later to call the car “without a doubt the worst car I ever raced—it was a disgrace.”

Yet, Juan Manuel Fangio, Moss’s future Mercedes-Benz W-196 teammate, said of the BRM 15, “I consider it to be, basically, the best Formula One car ever made. All it needs is improvement in certain details.”

A Changing World. But changing regulations made BRM improvement rather a moot point. Because of Alfa Romeo’s retirement and Ferrari’s domination of Formula One, the World Championship in 1952 and 1953 was run to Formula Two regulations (2-liter normally aspirated, 750-cc supercharged). Even in improved form, the BRM 15 had only non-championship events to contest. (And a future of modern demonstrations.)

A BRM 15 in a demonstration run.

It does so with brilliant sounds. ds

© Dennis Simanaitis,, 2020

6 comments on “1952 BRM 15—AN ADAGE VERIFIED PART 2

  1. Andrew G.
    April 8, 2020

    What a great story, Dennis! The engine itself is fascinating. The disassembled parts must look like a display of jewels.

    Your historical tidbits are so revealing. Spoiled by modern technology, I thought that valve float only became a problem in a much later generation of hyper-rpm racing engines. And that any supercharger delivered linear boost, not laggy and peaky like an early Turbo Carrera.

    What if history had drifted in Fangio’s direction, and BRM fixed a few things? Holy Nigel Shiftright!

    • simanaitissays
      April 8, 2020

      Hi, Andrew,
      Agreed, the BRM 15 is fascinating. And thank you sincerely for your kind words. — Dennis

  2. patrick clement
    September 7, 2022

    Did this engine fire two cylinders simultaneously?

    • simanaitissays
      September 7, 2022

      I believe I see your thinking: two designs abutted. However I don’t know of engines having multiple firings.

      • patrick clement
        September 7, 2022

        I read somewhere in a book a long time ago that BRM v-16 fired one cylinder on each bank together, to get the torque, the small engine needed, thus firing every 90 degrees, 2 cylinders instead of firing every 45 degrees individually.

      • simanaitissays
        September 7, 2022

        Very interesting. And logical. Thanks for this.

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