The JS29 was originally to be powered by a turbocharged
Alfa-Romeo 415T 4-cylinder engine (the 415T had actually been in slow development by the
Autodelta since 1984 as a possible replacement for Alfa's heavy, thirsty and underpowered
890T V8 turbo). However, during pre-season testing lead driver
René Arnoux publicly gave his thoughts on the engine, scathingly comparing it to "used food" which gave Alfa's parent company
Fiat the excuse they had been looking for to pull the plug on the project. It was reported at the time that Fiat, who had just bought Alfa Romeo that year, did not want the then
Milan based company involved in Formula One as a competitor to
Ferrari, which at that stage they also part-owned. As a result of losing their engine supply so close to the start of the season, Ligier had to come up with an engine in order to compete. The team managed to get a supply of
Megatron Straight 4 turbo engines for the season (the Megatron engine was the old
BMW M12 engine formerly used by such teams as
Brabham. They had been acquired from
BMW by
Arrows major sponsor, American insurance company
USF&G, and were re-branded
Megatron for 1987 and ). The updated car with the Megatron engine was now designated the
JS29B. Arnoux was retained for the season and he was joined by
Italian veteran
Piercarlo Ghinzani. While
Guy Ligier was able to lease the Megatron engines from the Arrows team, Arrows boss
Jackie Oliver only supplied the French team with the bare minimum of engines while (somewhat understandably) keeping the best and majority for his own team. By the last race of the season in
Australia, Ligier only had 7 engines to work with. The JS29 should have made its debut at the
1987 Brazilian Grand Prix using the Alfa Romeo 890T
V8 turbo until the 415T was ready. However, following Arnoux's unfavourable comments, and Fiat's withdrawal, this meant that the team had no engine with which to compete until the second race in
San Marino. It was there that the JS29B with its Megatron engine would make its competition debut. The JS29B was updated following the
Detroit Grand Prix to its final JS29C specifications. While the JS29 was originally designed for the 4-cylinder Alfa engine, it wasn't simply a case of slotting in the replacement Megatron 4-cylinder in its place. Major differences in the 'plumbing' of the two engines caused the team to have to completely re-design the cars rear suspension as tests showed that the Megatron was causing bad vibrations which was causing suspension failures. As a result of the late start to the season due to their switch of engines, the Megatron powered Ligiers were never truly close to the pace of the
Arrows A10-Megatrons of
Derek Warwick and former Ligier driver
Eddie Cheever. Only at
Hockenheim in
Germany did a Ligier (Arnoux) ever qualify in front of both Arrows-Megatrons and only once (Arnoux again at
Paul Ricard in
France) did a Ligier even split the Arrows in qualifying. ==Race history==