Datsun 240K Skyine Coupe
Reviewed by Unique Cars and Parts
Our Rating: 2
LAUNCHED outside of Japan in 1979, the Datsun Skyline was really a technically sophisticated coupe update of the old 240Z GT fastback
, which was subsequently replaced by the 260Z
and then the 280ZX. The six-cylinder, single overhead camshaft 2.4-litre engine was fitted with a Bosch electronically controlled fuel injection
system, made under licence in Japan, and using integrated circuitry.
It also featured a breaker-less ignition system, which used a magnetic pulse to generate the firing sequence via a transistorised amplifier. Datsun claimed the system gave a five per cent increase in power over the older system, with seven per cent more torque, seven per cent quicker 0-60 mph times, and a six per cent improvement in fuel economy. These small percentage gains may not have been all that startling, but in practice, the results on the road said much for the thinking behind Datsun's Skyline's development.
The 2393 c.c. engine had a compression ratio of 8.9-to-1, and produced 127 bhp (DIN) at 5,600 rpm, which gave the Skyline brisk performance, in spite of the fact that it was far from being light, having a kerb weight of more than 25 cwt. There was a good spread of power all the way through to the 6,350 rpm red line, which was easily reached without any signs to suggest that the six-cylinder engine was running out of breath.
On the down side, the engine was nowhere as smooth as it should have been during hard acceleration. Road testers seemed to always find it to easy for find "vibration periods", which much have suggested that the crankshaft was not strong enough to take the torsional vibrations. A decade earlier this could have been forgiven, but during the 1970's most other manufacturers had sorted this problem, so it was a blemish on the 240K's copy sheet that really should not have been there.
Another complaint, which was far more noticeable, was the jerky throttle response at low speeds. Road testers were unanimous in detailing just how difficult it was to creep along at just above tickover in city traffic, because the throttle snatched almost violently on re-engagement, as if the accelerator were an on / off switch. The only solution was to slip the clutch to cushion the effects - not as easy as you would think given the six-cylinder engine was so tractable. The throttle issue made driving manual 240K around town a chore - something the Datsun engineers should have addressed.
At least the clutch was light and coped well with excessive use in town traffic, rarely displaying signs of excess slip. Having said that, one road tester did note the smell of the clutch linings on getting under way from a 1-in-3 hill start, indicating the clutch did indeed have limitations. The five-speed gearbox was a sports type, that is to say that the top speed of 110 mph was achieved in fifth, rather than 5th being an overdrive
type where top speed would come in 4th, with 5th being used for economy.
As was usual with Japanese cars, the gear change was good with little friction and a precision marred only by the occasional baulk in selecting first gear when the engine is cold - a common problem back then. Fifth gear was to the right of the conventional four-speed H pattern, alongside third. Cold starts emphasised the advantages of electronic fuel injection
with a smooth drive away on the coldest of mornings, made possible by the precise metering of the fuel/air mix. In an era when the carburettor was still king, owners of the 240K quickly discovered what a revelation it was to have the fuel system controlled by a computer which relied on several sensors for information on variable states such as water and air temperature.
Economy - Reasonable for its weight
Of course there were othere benefits from using the Bosch L Jetronic fuel injection
on the 240K. The 240K's overall fuel consumption figure was 21 .4 mpg. which, again considering the weight disadvantage of the Skyline, is better than it might at first seem. The 240K was well insulated too, it was only during high speed cruising that any noise became noticeable. The fifth gear, which was indirect, whined a little, but past owners have said this was not bothersome at all, and was quieter than the usual diff whine evident on most rear drive 1970's cars. The lack of a central pillar to give adequate alignment for the two window could induce some wind whistle - but again this was not overly bothersome.
For a car that looks big from outside or in, the Skyline handled surprisingly well and had responsiveness that matched the brisk character of the engine. Much was due to the coil spring all-independent suspension
with MacPherson struts at the front and the rear axle located by semi-trailing links. anti-roll bars
were fitted front and rear. On the firm side, the ride improved considerably with a full load on board, retaining a tautness that made the 240K an enjoyable car to drive.
The power steering
was manufactured in Japan under licence from ZF in Germany, and though rather low geared, it was one of the better designs; it featured a variable ratio. This made the steering
light enough for the needs of car park manoeuvres and yet provided reassuringly solid feel at high cruising speeds. The low gearing of 4½ turns lock to lock dictated (in common with many other Japanese cars of the time) a lot of steering
movement, but the presence of power assistance rendered this less of a problem. The only problem with low gearing was that you could over-correct when the mild understeer gave way to oversteer - rare in a 240K though, at it was shod with excellent Michelin XVS tyres
that rarely could be coaxed into losing their grip. Cross the line however, and you would find the transition to be so gradual that the driver would have to be in a deep sleep not to catch the resulting tailslide.
Forward visibility was very good, however the rear view was compromised by the wide, steeply rake pillars. The control layout was logical - stalks on the steering
column controlled lights, two-speed cum intermittent wipers, washers and indicators. The seats were covered in a velour cloth, these offering movement fore and aft, tilt, fully reclining adjustment and variable lumbar support. Raised edges on the sides which provided excellent lateral support whilst cornering. The seat belt mounts were located too far behind the front seats - you had to twist around and stretch to reach the belt. Access to the rear seats was good, though the levers which moved the front seats forward were located on the inboard side of both, and the front seat belts were in the way. Rear leg room was adequate for any but the really long-legged.
The 240K's boot capacity was acceptable for a coupe, but the high rear lip made stowing heavy suitcases far more strenuous than it needed to be. The Datsun had an interior boot release which was operated by a lever mounted on the floor by the driver's seat - not all that common back then. Electric windows were standard on the Skyline, being controlled from a central console located between the driver and front passenger seats, as were the headlamp washers and rear window washer and wiper. For the time, the 240K featured arguably the best instrumentation in the business - if not for quality but for the number and style of the arrangement.
Apart from the usual speedo
, rev counter, and water temperature gauge, there was a voltmeter and oil pressure gauge. There was also a "boost" gauge, but unfortunately this did not indicate the presence of a turbo
, rather it was merely a vacuum guage with a green segment to show the driver when they were conserving fuel. The most obvious dash feature was, however, the elaborate warning light panel which used a plan view of the car alongside a bank of lights. This, coupled with the excellent digital quartz clock, made the instrument panel look both long and attractive.
Braking - Arguably The Biggest Disappointment Of The 240K
Under most circumstances, the all-disc servo assisted brakes
provided good retardation, but were prone to fade after only a little heavy handed treatment. Road testers noted fade after 4 or more heavy braking tests, brake pressure required going up after each stop, and stopping distances increasing rapidly - not the sort of reassurance a driver is looking for. You could forgive the torsional vibration, and maybe even the jerky throttle response, but the brakes
would prevent any spirited driving. The 240K should have been a drivers car, akin to a 240Z for the family man. But the brakes
would spoil the fun. Owners would soon figure out it was not the discs themselves, but the pads that were the issue.