Things weren't going to be easy for them, not only did they have to worry about the privately entered Porsches that won the last race, but Prince had their R380 prototype ready to race with it's Brabham chassis and 200hp engine. And now those up-starts over at Toyota were about to race their new 2 litre twin-cam six cylinder Toyota 2000GT. Nissan decided that it was going to build a racing prototype themselves, and the car was given the designation A680X. The A680X used a Fairlady chassis as a basis, and then had a fibreglass coupe body added to it, which had more than a hint of the future Z car to it.
For an engine Nissan decided to emulate what Prince had done with their car and use a twin cam six cylinder engine. Yamaha was called in to design an engine that was designated the B680X, which was a 1998cc double overhead cam, four valve per cylinder engine with three 42DCOE Weber carburettors, two spark plugs per cylinder and two distributors. The engine produced an impressive 190hp at 6400rpm, though was still short of the 200hp the Prince R380 had. In the meantime Nissan had just mergeged with the Prince Motor Company, and rather than having a company with two seperate racing prototypes in development they decided to axe the A680X program and continue with the more promising Prince R380, which would soon be re-badged as a Nissan. Details about the Nissan A680X and the B680X engine can be found on the Nissan A680X page of this website.
Meanwhile Nissan had just released the Fairlady 1600, with it's 96hp 1600cc push-rod R series engine. For the Japanese Grand Prix the 1600s were to be fitted with twin Mikuni Solex carburetors, similar to those that would later be used on the production 2000s. These race spec 1600s were developing around 140hp, but they were still worried that this would not be enough. At about this point Nissan realised that they had a rather trick 190hp engine sitting in a Fairlady chassis thanks to the cancelled A680X project, they knew it would fit in the Fairlady chassis, all they had to do was to make it work in a Fairlady body as well and they would have quite a car. They took and each way bet and continued to work on the Mikuni-fitted 1600 Fairlady, and at the same time went to work on the 6 cylinder car that would be known as the Fairlady S. At this time the designation of the engine changed from the B680X, as it was in the A680X prototype, to the Nissan UY engine.
The Fairlady S was based on a 1965 Datsun Fairlady SP311. The rules at the time stated that all convertibles must run with a hardtop fitted, which was fine because it also helped with aerodynamics. To help the aerodynamics even more Nissan played around with an extended nose section as well. The aero nose worked well, but in the end it was a case of the marketing department winning out over the race department. There was no use winning the race in a car no one recognised, so the nose was discarded. There were several other features that made the Fairlady S stand out from the regular production version though. Track testing of the car showed that brake and engine cooling was going to be a major issue, so the Fairlady S had five cooling slots that are cut out of both the front and back guards. The car also had wheel openings at the back that left the wheels completely exposed. This wasn't a great look, but it was necessary to give the extra room for the wheel and tyre package the room it needed as the wheelarch could not be moved inboard thanks to the proximity of the chassis rails at the back.
On race day the Fairlady S, driven by a Mr. Kitano, comfortably qualified in 1st place, Nissan were fully expecting a glorious victory. The 60 lap race began and the Fairlady S stayed at the pointy end of the pack during the rain affected race, until lap 36.
Simple mathematics state that if you double the number of valves, cam shafts, distributors and spark plugs, you also double the chances of something going wrong, and sure enough, on lap 36 something went wrong and the Fairlady S retired with ignition problems.
But all was not lost for Nissan, behind the Fairlady S was car #20 and car #21. In a triumph of reliability over technology the push-rod Fairlady 1600s continued on to take 1st and 2nd place in their class at the 1966 Japanese Grand Prix, ahead of a Porsche 911 in 3rd. Nissan got their glorious victory after all.
Only one Fairlady S was ever built, and after the 1966 Japanese Grand Prix it never raced again. For 1967 Nissan had a new weapon in it's arsenal, in the form of the new U20 engine. When the new Fairlady SR311 appeared in 1967 it marked the start of four years of total dominance of the event by Nissan. In the 1967 Grand Prix the Fairlady 2000s took 1st, 2nd and 3rd places in the race. From then on things got even better, in 1968, 1969 and 1970 the 2000s took 1st, 2nd, 3rd, 4th and 5th places in each race. Sometimes it's better to keep things simple.
