Pre-race
The "return to power" caused some manufacturers significant problems, as the supply of suitable large-capacity engines was restricted. Only four teams managed to provide true 3-litre cars this early in the season. Regular front runners Ferrari and Lotus were both prepared with new vehicles, as was former World Champion Jack Brabham's eponymous team, fielding Australian Repco engines. The fourth team to have a 3L car was Cooper, however, their engine was far from new. The team's first monocoque chassis, the Cooper T81 was fitted with what was in essence Maserati's 1950s engine, which had seen success in the Maserati 250F, bored out to the new capacity limit. BRM's new H16 engine was also slated to appear, but reliability problems resulted in Peter Arundell being forced to withdraw his Lotus-BRM prior to qualifying.
Read more about this topic: 1966 BRDC International Trophy