Many found it hard to believe that less than 200 extra c.c. could be the sole reason for the engine's improved performance. Claimed figures showed an increase of 11 b.h.p. SAE to 162 b.h.p. at 5,600 r.p.m. and 152 lb. ft. torque instead of 146 lb. ft. torque at the same 4,400 r.p.m. and that while running on a lower compression ratio of 8.3 to 1 instead of 9.0 to 1 to suit low-lead three-star fuel.
No
emission equipment was fitted, but the two SU-type Hitachi carburetters and ignition had been recalibrated to meet more stringent anti-pollution requirements. Yet the 260Z feelt much more flexible and much quicker than the old 240, suggesting that beneficial modifications to the
cylinder head and/or camshaft were also made. The engine seemed more willing to pull the higher final drive ratio (3.70 to 1) than the 240 engine did its 3.90 to 1 ratio. Overall gearing in 5th gave 22.3 m.p.h. per 1,000 r.p.m. as against 21.6 m.p.h. for the 240Z.
The whole of the drive train was beefed up and at the same time the gearbox ratios were revised to make more efficient use of the torque and eliminate the 240's gap between 1st and 2nd gears. The 1st gear ratio was revised to 2.91 to 1 instead of 3.32 and 2nd gear was 1.90 to 1 instead of 2.08. The five-speed gear-box was one of the best then available, although it was somewhat ironic that the engine in the 260Z was so flexible as to need less gearchanging - the gearbox was so good that it would literally encourage cog-swapping for the fun of it.
A comfortable leather knob surmounted the hefty gearlever in place of the earlier nasty plastic-wood device and this selected the lower four gears in a conventional H pattern with 5th up to the right opposite reverse. There was very little spring-loading to overcome across the gate, the gearlever nonetheless being self-centring in the 3rd/4th plane, and the change was thus rapid, light and accurate although with fairly long moveements.
First gear
synchromesh occasionally baulked when selecting this gear from rest. The 8.87 in. diameter clutch was positive and its hydraulic operation not unduly heavy. Uprated coil springs had been incorporated in the 260Z's otherwise unchanged four-corner McPherson strut independent suspennsion, allegedly to compensate for the extra weight of the new engine and improved interior, although this was fairly negligible and the truth was probably because Datsun wanted to improve the handling, which indeed the combination of these sti ffer springs and wider
tyres had achieved.
Stability on fast bends was very impressive, having less roll, less pitch and virtually none of the wallow which the 240Z's outside front corner would engage in when confronted by a bump in the middle of a fast corner. Near the limit on fast corners there was a predictable and gentle transition to oversteer, but the Bridgestone radials showed no sign of letting go completely; even in the wet their roadholding was excellent.
Traction too was excellent, the McPherson strut rear suspension with lower wishbones using the greater acreage of rubber to advantage. In spite of the long bonnet the 260Z remained a comparatively easy car to place through the lanes, the
steering was fairly heavy at low speeds but this became more manageable with speed.
A new 14 in. wheel with a commfortable, leather-like padded rim and heavily padded boss was an improvement, enabling you to feel just how precise and responsive the front suspension/steering was, although it inherited the same annoying bump steer evident on the 240Z.
Datsun also failed to improve the Girling-Sumitomo servo-assisted, twin-circuit braking system (10.67 in. front discs and 9 in. finned drums at the rear). These proved perfectly fine if moderate demands were made of them, however to drive a Z very fast was to experience almost certain brake fade, first announced by a heavy pedal and then by an embarrassing unwillingness to stop.
The single o.h.c. straight-six gained 172 c.c. and 11 b.h.p. Datsun claimed a 127 m.p.h. maximum for the 260Z, which would reach 60 m.p.h. in less than 8 sec., average 22 m.p.g. driven extremely hard, and driven less arduously would offer over a 350-mile range from its 13.2 gallon tank.
While the 240Z engine was unwilling below 4,000 r.p.m., the 260 engine offered progressive power most of the way up the range and excellent flexibility, 5th being usable down to about 20 m.p.h. The 8,000 r.p.m. rev. counter wais yellow-lined at 6,500 r.p.m. and red-lined at 7,000, but very fast progress could be made without exxceeding 6,000 r.p.m. Speeds available in the lower three gears were 46, 71 and 102 m.p.h., 70 m.p.h. was achieved at a quiet, effortless 3,150 r.p.m. in 5th and the 127 m.p.h maximum speed required a mere 5,700 r.p.m., all the while the beautifully smooth, mechanically silent engine emitting an exciting, but reasonably muted, deep-throated roar.
Interior appointments were excellent, if you could stand the abundance of nasty plastic. An excellent three-speed heater and four-outlet ventilation system was controlled by a triple-lever illuminated panel, instrumentation was clear and comprehensive, two-speed plus intermittent wipers, electric screenwashers, lights and flashers were controlled by two
steering column stalks.
The high-back seats unforgivably lacked a reclining mechanism and the big throttle pedal, well-placed for heel-and-toeing, was too light and sensitive for low-speed town driving. But many would contest these were small issues, and the 260Z remained a true sports car that was fast, handled well, required skill to drive very quickly and, perhaps most importantly, was tremendous fun while doing so.
Also see:
Datsun 240Z Review |
Datsun 260Z Review