In the mid-1970s, the geopolitical map of sports car racing was often drawn in broad, nationalistic strokes. The Germans had Porsche and BMW; the Italians had Ferrari and Abarth; the British had Lola and Chevron. But in the workshops of Annemasse, France, a unique cross-border alliance was being forged that would disrupt this order with startling effectiveness. This was the domain of Fred Stalder and his Racing Organisation Course (ROC). Stalder, a visionary tuner with a fierce patriotic streak, sought to conquer the 2.0-litre class using French horsepower, but he lacked a domestic chassis capable of harnessing it. His solution was to look across the Channel to Derek Bennett in Bolton. The result was the 1976 Chevron B36 ROC Chrysler-Simca, a machine that combined the ultimate evolution of the British aluminium monocoque with a high-revving Gallic heart, creating a package that would achieve one of the most remarkable giant-killing feats in the history of the 24 Hours of Le Mans.

The B36 chassis was the perfect vessel for Stalder’s ambitions. By 1976, Bennett had refined the B31 concept into the B36, sharpening the aerodynamics with a flatter, more aggressive nose and optimized rear wing struts. It was a stiff, lightweight, and incredibly compliant platform, widely regarded as the best handling customer car in the world. Into this British masterpiece, Stalder installed his own masterpiece: the ROC-Simca engine. Based on the humble cast-iron block of the Chrysler-Simca 180 saloon, Stalder engineered a bespoke 16-valve aluminium cylinder head that transformed the pedestrian commuter engine into a fire-breathing racer. Displacing 1,996cc and fed by Kugelfischer fuel injection, it produced a screaming 290 to 300 bhp at over 9,000 rpm.

Technically, the B36 ROC was a study in integration. The ROC engine was physically larger and heavier than the Cosworth BDG, requiring specific engine mounts and a revised rear subframe layout within the B36’s engine bay. The weight distribution was shifted slightly rearward compared to the Ford-powered cars, but the B36’s suspension geometry—double wishbones at the front and a multi-link rear—was versatile enough to be tuned around this. The ROC engine delivered its power in a frenetic rush at the top of the rev range, lacking the mid-range torque of a BMW M12 but matching it for peak horsepower. To keep this high-strung engine cool over 24 hours, the ROC cars often featured modified cooling ducts and distinctive engine covers that set them apart visually from their Cosworth-powered brethren.

The impact of the B36 ROC was defined by its exploits at the Circuit de la Sarthe. While the car was a dominant force in the French Sportscar Championship, winning titles and beating the lingering Alpine A441s, its global legend was forged at Le Mans. The 1977 24 Hours of Le Mans serves as the car’s defining moment. In a race of relentless attrition that saw factory Porsches and Renault-Alpines crumble, the #26 Chevron B36 ROC, driven by the French trio of Michel Pignard, Albert Dufréne, and Jacques Henry, ran with clockwork precision. They didn’t just survive; they thrived. As the big prototypes failed, the little French-British hybrid climbed the leaderboard. By Sunday afternoon, it crossed the line in an astounding 6th place overall and 1st in the 2.0-litre class. To put this in perspective, a privateer 2.0-litre car had beaten every Porsche 935 and 934 in the field, finishing behind only the factory Martini Porsche 936s and a pair of 935s. It was a performance of David vs. Goliath proportions that vindicated Stalder’s belief in the Simca block and Bennett’s chassis design.

The B36 ROC proved that a “hybrid” privateer effort could defeat factory engineering through a combination of chassis compliance and engine durability. While the ROC engine was notoriously difficult to build and maintain—requiring the touch of Stalder’s own mechanics—when it held together, it offered a power-to-efficiency ratio that was perfectly suited to endurance racing. The B36 ROC continued to be a threat in 1978 and 1979, often the fastest 2.0-litre car in a straight line thanks to the engine’s willingness to rev and the B36’s slippery shape.

The legacy of the Chevron B36 ROC Chrysler-Simca is that of the ultimate Entente Cordiale. It represents a moment when the best of British chassis engineering met the best of French engine tuning to create a world-beater. It remains the high-water mark for ROC as a constructor and stands as one of the most successful iterations of the B36 platform. In the pantheon of motorsport, it is remembered not just as a class winner, but as the little yellow-and-blue car that embarrassed the turbo monsters of Group 5, earning its place as a true legend of Le Mans.