However, the aging TC motor having only 8-valves and the potential of up to bhp were soon thought insufficient to stay ahead of the competition on the circuits and rally stages, so alternative power units such as the 2. To withstand the long distances and high altitudes of the Andes during the London to Mexico Rally, a rugged but simple push-rod motor of cc capacity was developed for the works Mexico Escort entries which went on to dominate the leader board of the South American Marathon. These Cosworth 4-cylinder engines with belt-driven double overhead-camshafts and valves powered the production Escort RS between and During this period BDAs in works cars went from being cc and larger with a steel block to having a Brian Hart developed alloy-block of cc capacity by mid, whilst progressive modifications saw the power output increasing to bhp. Coordinating the five competition cars and four support vehicles would be a Cessna , which was to spend 46 hours in the air during the event, the first time that a rally team had been controlled from the air. The well over miles route, which started and finished at Easter in the Tanzanian capital Dar Es Salaam, took 83 of the best prepared rally cars in the world inland over the back roads to Nairobi in Kenya, then via the Ugandan capital Kampala to Mombasa on the coast in Kenya on a rock-strewn epic through the East African outback.
Mikkola's rally career spanned 31 years, starting with a Volvo PV in , but his most successful period was during the s and s. The s saw Mikkola a frontrunner in many international events, usually in a Ford Escort. Mikkola was joined by Swedish co-driver Arne Hertz in and the pair were very quickly a force to be reckoned with, winning the British Rally Championship in in an Escort. He was partnered by Johnny Johansson for the season.