Following the FIA's decision in October 1986 to allow 3.5-litre normally aspirated engines alongside turbocharged units from the 1987 season, Cosworth developed the DFZ as a rapid stop-gap and then the DFR as a more refined successor, both derived from the legendary DFV architecture. However, Ford and Cosworth recognised early on that the DFR — still fundamentally rooted in Keith Duckworth's 1966 design — could not compete long-term with the new generation of ten- and twelve-cylinder engines being developed by Ferrari, Honda, and Renault. The decision to create an all-new engine was made in early 1988.
The first design drawings for what would become the HB were completed in May 1988, and the first test-bench runs occurred in December 1988. Chief designer Geoff Goddard and engineer John Hancock led the project. The new engine adopted a narrower 75-degree V angle between cylinder banks, compared to the 90-degree layout of the DFV family, providing aerodynamic advantages particularly in airflow toward the rear of the car.
The HB displaced 3,498 cc (approximately 96 mm bore × 60.4 mm stroke) and employed a 90-degree V8 layout with dual overhead camshafts per bank and four valves per cylinder. Early versions used gear-driven camshafts; from the HB Series VI onward, chain drive replaced the gear train. The Series VI also introduced semi-pneumatic valve control, eliminating conventional valve springs in favour of compressed air to reset the valves — a system Renault had already deployed on its V10. This innovation increased reliability at high revs but raised maintenance costs and complexity. Ignition and fuel injection electronics were typically supplied by Ford; Minardi's engines were an exception, running Magneti Marelli electronics.
Initial power in the 1989 HB I was estimated at approximately 630 bhp, some 40 bhp more than the DFR. By the final production variant — the HB VIII of 1993 — the engine was producing approximately 725 bhp at 13,700 rpm, though this remained some 70 to 100 bhp behind the contemporary Renault RS5 V10 used by Williams. The HB's advantages over more powerful rivals lay in its lighter weight and better fuel economy, characteristics inherited from the Cosworth engineering philosophy established by the DFV.
The HB progressed through eight numbered series across its production life. The HB I debuted at the 1989 French Grand Prix exclusively with Benetton. The HB II followed later that season, and Benetton driver Alessandro Nannini took the engine's first victory at the 1989 Japanese Grand Prix following Ayrton Senna's disqualification. The HB III and IV series carried Benetton through 1990, with HB IV blocks subsequently passed to Jordan Grand Prix for their debut 1991 season. The HB V, introduced for the 1991 San Marino Grand Prix, brought chain-driven camshafts and raised performance to approximately 670 bhp by mid-season; customer teams Fondmetal and Lotus received HB V units in 1992, and McLaren ran them in the early part of 1993. The HB VI introduced semi-pneumatic valve control. The HB VII, debuting in 1992, reached 710 bhp. The definitive HB VIII, first used in practice at the 1993 German Grand Prix, featured newly designed cylinder heads incorporating solutions developed during the abortive Cosworth V12 project; it produced 725 bhp and 13,700 rpm.
Benetton served as the exclusive works recipient of the HB from its 1989 debut through 1993. The arrangement mirrored Ford's earlier DFV strategy, with factory engines typically running one or more specification levels ahead of any customer supply. Benetton finished third in the Constructors' Championship in 1990, 1991, and 1992, and third again in 1993 behind Williams and McLaren.
The 1990 season saw Nelson Piquet and Roberto Moreno take a victory each in Japan and Australia respectively. In 1991, Piquet won at Canada. Michael Schumacher, who joined the team mid-1991, claimed his first Formula One victory at the 1992 Belgian Grand Prix with the HB VII — also the last Formula One win by a car using a conventional manual transmission.
In 1993, despite access to the factory HB VIII, Benetton could not match the McLaren-Senna combination which benefited from sophisticated TAG Electronics systems, nor the dominant Williams-Renault. Schumacher won once in 1993. After 1993, Benetton switched to the all-new Cosworth EC engine, badged as the Ford Zetec-R, for the 1994 season, with which Schumacher won his first Drivers' Championship.
Jordan Grand Prix was the first HB customer team in 1991, using HB IV units that were a generation behind Benetton's HB V. Despite this, Jordan achieved an impressive debut season, finishing fifth in the Constructors' Championship. Notably, Michael Schumacher made his Formula One debut in a Jordan-HB at the 1991 Belgian Grand Prix.
McLaren's 1993 season with the HB represented the most competitive use of a customer HB. Initially forced to run the older HB V — approximately 40 bhp behind Benetton's HB VII — McLaren's electronics expertise with TAG partially closed the gap. Ayrton Senna won three races with the customer HB V before receiving the HB VIII from mid-season, adding two further victories in Japan and Australia.
A Jaguar-branded version of the HB, developed by Tom Walkinshaw Racing, was fitted to the Jaguar XJR-14 for sports car racing, producing approximately 650 bhp at 11,500 rpm. The XJR-14 proved extremely successful in the 1991 World Sportscar Championship.
The HB represented Cosworth's break from the DFV bloodline — the first entirely new Formula One engine design the company had produced since the mid-1960s. Despite never matching the peak power of the Renault V10 or Honda V12 against which it competed, its combination of light weight, reliability, and fuel efficiency kept it competitive through six seasons and multiple development stages. The parallel development of the Ford Zetec-R (Cosworth EC) that replaced it in 1994 used several advanced design solutions originally explored during the unrealised HB successor V12 programme. The HB engine remains closely associated with Schumacher's early career and the Benetton team's rise as a consistent championship contender in the early 1990s.