1974 Datsun 260Z Tested: Improving on a Winner

From the April 1974 subject of Automotive and Driver.

Apparently nothing is sacred at Datsun, not even enjoying to a capability crowd for 4 years with the identical profitable sports activities/GT automotive. Who is aware of, possibly these lengthy strains of consumers actually would not have lasted perpetually. Rumor has it you possibly can ac­tually get the colour of your alternative now. And in some cities, the worth has reportedly plummeted to what the sticker says. Not what you’d name a crash available in the market, however Datsun is taking these indicators critically. In consequence the 1974 Z-car has a brand new first title: 260. That greater quantity means the manufacturing unit is strive­ing to place extra into the automotive than the U.S. security and emis­sions requirements are draining out. Be forewarned: It is an obvi­ous ploy to elongate the ready strains once more.

The brand new nameplate stands for a much bigger engine: the identical fundamental 240Z single overhead cam six with piston displacement upped by 171 cc (10.4 cubic inches) because of a 0.2-inch improve in stroke. Additionally, the exhaust valves are bigger for guess­ter respiration, and a magnetic pulse generator has changed breaker factors within the distributor. Datsun engineers declare the brand new digital ignition improves beginning and stops misfir­ing with the 260Z’s emissions package deal (lean mixtures, an air pump, and heavy doses of recirculated exhaust gasoline). And since underhood temperatures have surged within the battle in opposition to air air pollution, gas strains at the moment are closely insulated for defense in opposition to vapor lock. The gas system additionally advantages from a rear-mounted electrical pump working in tandem with the engine-driven mechanical pump.

On the dyno, the brand new motor delivers 139 horsepower (internet) at 5600 rpm, a rise of six hp over final 12 months’s 2394-cc model. Torque is up by 12 pound-feet to 137 (internet) at 4400 rpm. Unfortu­nately, the dynamometer solely tells a part of the story; the remainder is unveiled on the take a look at observe. Our take a look at automotive accelerated by the quarter-mile in 17.8 seconds with a entice velocity of 81 mph. On account of that take a look at, we should sadly report that the massive motor Z-car is slower than final 12 months’s version. The 1973 Z-car we examined went down the quarter-mile in 17.0 seconds at 81 mph. A part of that distinction in acceleration could be attributed to additional weight: Our ’74 take a look at automotive was heavier by 80 kilos with manufacturing unit air-con (non-compulsory), with one other 80-pound handi­cap added by the 5-mph entrance and rear bumpers. However weight on this incidence shouldn’t be the first explanation for the 260Z’s carry out­ance fall off. Our take a look at automotive additionally had a severe drivability prob­lem that put a limp in its gait down the dragstrip. Midway by the rev vary in first gear, the engine merely ran out of gas. It died like a fish out of water, with energy coming again in gulps. Datsun engineers acknowledge the existence of the issue and are diligently looking for an answer. Their checks present that top underhood temperatures are boiling gas within the carburetors, inflicting the momentary hunger throughout sus­tained flat-out acceleration. The previous Hitachi-SU sidedraft carburetors could have come to the tip of their rope. We would sug­gest digital gas injection as a logical alternative.

That will not occur this 12 months, however nonetheless, you shouldn’t count on the 260Z to battle by the model 12 months slower than the 1973 automotive. Datsun does a large quantity of growth work on this nation—oftentimes after the vehicles go on sale. One complete shipload of early ’73s needed to have carburetors changed on the dock because of a design defect. And later within the model 12 months, a service restore equipment was issued to sellers to right extreme sizzling begin issues. The equipment included the insulated gas strains and electrical gas pump now customary tools for 1974. Sadly, the fundamental drawback remains to be not solved. Emissions {hardware} has positioned such a heavy burden on the engine, that it is not able to make clear air and stay as much as its energy potential on the identical time. So at this level, the massive motor is much less a bonus and extra a cease hole measure to fulfill the legislation. Any actual efficiency features over 1973 will de­pend on how profitable the U.S.-based growth professional­gram is.

The Datsun engineers might stand to try gas financial system as properly since that has additionally slipped for 1974. Our checks present that mileage is down about two mpg from an aver­age of 20 mpg (for a 1973 automotive) to 18 mpg for the 260Z. Environ­psychological Safety Company checks, nonetheless, have revealed no sacrifice with the larger engine; in its strictly metropolis driving checks, each ’73 and ’74 fashions turned in a mean of 16 mpg.

Apart from the gas penalty and one severe flaw in drivability, the brand new engine is simple to get together with. With the brand new digital ignition, it begins eagerly when chilly in the event you use quite a lot of choke and pulls like a freight practice at low speeds. That makes the Z-car extra versatile in site visitors as a result of you possibly can transfer out neatly forward of the move with out resorting to the highest half of the rev vary. It is simply as properly as a result of the tachometer opti­mistically advertises a thousand revs that are not helpful. The 260Z is de facto no completely different from its predecessor on this respect. The Z-car’s redline has stood at a lofty 7000 rpm from the start, and whereas the engine will wind that tight with out bursting, solely the noise degree remains to be rising. Energy noses down­ward after 5600 rpm and the helpful rev vary ends at 6000.

Though the massive motor is a combined blessing, different adjustments for this 12 months are strict enhancements. Datsun has chosen 1974 to unload a repair for nearly each criticism house owners have lodged over time. That is to not say the 240Z has been riddled with shortcomings. The very fact is it has been one of the vital common vehicles in existence—at any worth. Automotive and Driver readers chosen it because the General Greatest Automotive for 1973, and Datsun is intent on preserving that stellar picture.

Dealing with is on the high of the 1974’s enchancment checklist. Previously, directional stability at freeway speeds had been the Dat­solar’s weak swimsuit: Pre-’74 Z-cars wandered down a windy free­method as in the event that they have been piloted by inebriates. The issue cen­tered round an advanced interplay of aerodynamics, steering geometry, and rubber bushings finding the steering rack. For the answer, Datsun has taken no small pains. To begin with, the physique’s angle of assault into the wind is altered by elevating the rear of the automotive barely. That diminishes front-end elevate at velocity and on the identical time reduces weight reduction from the entrance tires. With a tighter grip on the street, the entrance of the automotive shouldn’t be so simply swayed from its path by aspect winds. The steering gear mounting system has additionally been revised with particular consideration to eradicate lateral compliance. Aspect masses that may come from cornering or crosswinds can not deflect the steering rack or flip the entrance wheels. So now solely the steering wheel guides the automotive, because it ought to. The street really feel to the motive force is way too damped for our liking, however the 260Z does observe down the street with a strong respect for the straight and slender.

Spring charges are larger at each ends of the automotive largely to accommodate the additional weight of fortified bumpers and facto­ry air-con. Since that weight has favored the entrance finish, there’s a built-in tendency towards understeer. However Dat­solar engineers have properly side-stepped that mattress of fast­sand by including a rear anti-roll bar as customary tools. It shifts roll stiffness to the rear of the automotive to counteract the adverse dealing with affect of a heavier entrance finish. On the entire, the brand new suspension calibration works in a really commendable method. The 260Z sweeps by turns with a brand new degree of willpower: Physique roll is at a decent minimal and you may really feel each ends of the automotive working proper as much as the restrict. Within the entrance, there’s a gradual lack of response to the steering wheel, however the tires by no means yield to extreme understeer. It is the rear tires that really sign the restrict as they lose their aspect grip and start to audibly scratch on the pavement. You are feeling the tail slowly creeping out, however the drift angle stabilizes at a superbly manageable restrict as a result of the entrance finish additionally begins to slip. And all of it occurs with no feeling of impending doom. In actual fact, the Datsun is so secure that standard interruptions—extra throttle, much less throttle, braking, and even moist surfaces—do not shake its composure. It is sufficient to make you bypass the freeway each time seeking a twisty again passage.

It doesn’t matter what route you’re taking, the Datsun’s inside will ship you in wonderful fashion. Not one of the robust attributes have been tampered with—glorious instrumentation, wraparound seat backs, and a station wagon’s cargo maintain below the hatch­again. However a lot of the shortcomings have been mounted. The hair-trigger gasoline pedal is gone. And all of the rubbery vagueness is out of the shift lever with a brand new linkage this 12 months. Even the previous bamboo-colored steering wheel has been upgraded with padding and a leather-based cowl. It isn’t actual hand-sewn cow pores and skin, however a artifical facsimile correct proper all the way down to the wrinkles, stitches, and pores, real looking sufficient to idiot a glove producer. Fortunately, the cheap-looking heat-stamped plastic coverings for the transmission and rear suspension towers are gone, changed by vinyl with a richer texture and a finer sample.

Manufacturing facility air-con can also be a serious improve this 12 months. The {hardware} is a marvel of expertise—light-weight alumi­num supplies for the evaporator and condenser, and a compact swashplate compressor just like the GM/Frigidaire design. The compressor is vibration free in operation, and there’s no underhood muddle with the brand new system. Contained in the automotive, the {hardware} is shrewdly interfaced with the instrument panel. The heater/AC management module is without doubt one of the easiest and most informative layouts we have seen. Three fastidiously marked levers reg­ulate the inside local weather: one four-speed blower swap, one temperature selector, and one operate knob. Because the latter is graphically coded with pink and blue arrows, if the air has been heated or cooled and precisely the place it is going. Eventually cryptic labels like “Bi-Lev­el” tackle a strong that means.

The air-con system is the one comfort Datsun does not embody with the bottom worth. For $5125, you get tinted glass, intermittent wipers (new this 12 months), a useless pedal on your left foot, and even an AM/FM radio full with an electrical antenna.

True, it is not the cut price it was in 1970 at $3526, however a severe competitor to the Z-car nonetheless hasn’t materialized. The opposition is slimmer by two vehicles this 12 months with the demise of the Opel GT and Triumph’s GT6. The remaining subject, the Alfa GTV, the Jensen-Healey, and the Porsche 914, could delight purists, however the technical fascination does not appear to sway the plenty looking for a sports activities automotive at Datsun. Face worth is the important thing: The 260Z presents a much bigger engine at a cheaper price. To not point out the com­fort of becoming a member of a crowd—a mass stronger by 54,000 glad clients in 1973.

We do not count on a downturn in popu­larity even with the drivability issues wrought by emission controls. The up­grade program has been too thorough for that to occur. And if the carburetor engineers can get their act collectively, they will wipe out the 260Z’s most menacing competitor—final 12 months’s 240Z.