The barrels have alloy cooling fins and shrunk-in “Hirai” (a special cast iron) liners. The bore and stroke, at 3.15 x 2.60 inches (80 x 66mm) are fashionably oversquare, with a ratio of .825 (vs. .895 for the pushrod engines and .804 for the 2-liter four-cam engine). The pistons are sharply domed with healthy valve recesses.
The axial fan is fiberglass, surrounds the alternator, and is driven from the crank by a V-belt. Single ignition is used in conjunction with 12-volt electrics, replacing the old 6-volt system. Porsche has indicated its confidence in the new engine by extending the warranty from six months/6000 miles to a full year and/or 10,000 miles.
Transmission and Clutch
As mentioned, the 5-speed, all-synchro gearbox is the 911’s best single feature. Actually, the torque and flexibility of this engine are such that a 3-speed would suffice, but it was Porsche’s aim to be much more than merely sufficient. There is, in effect, a gear for every occasion: one for starting, one for cruising, and three for passing. It is to Porsche’s everlasting credit that they didn’t make first gear superfluous by having second an alternative starting gear—you must start in first, and it’s a pretty long gear at that. In fact, 6800 rpm through the gears gives 44, 65, 93, 118 and 138 mph. All the gears are indirect, with the famous—and flawless—Porsche servo-ring synchromesh. Fourth and fifth gear are actually overdrives, but pulling power is not lost as the upper three ratios are close in an already close-ratio gearbox.
Operating the shift lever is confusing at first. First gear is to the left and back, with the other four gears in the normal H-pattern. Reverse is to the left and forward, but to go from first to second, you just push forward—toward reverse—not forward and right. You half expect it to go into reverse, but it won’t . . . scout’s honor. Everything else is a piece of cake (the linkage is not as “remote” as other Porsche’s), including changing down to first gear for those mountain-pass hairpins.
Clutch diameter is up to 8.5 inches and the mechanism should prove more robust than older Porsche clutches.
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Steering, Suspension, and Brakes
Porsche is also trying rack-and-pinion steering in a production car for the first time on the 911. It’s fast, precise, incredibly direct and—like the carburetion—a little late in being perfected. The prototype we drove was subject to “torque steer”, i.e., changing the throttle position would change the car’s direction. This had been eliminated on the production car, but a new bug had cropped up: the steering felt too direct, like a racing Ferrari—you could feel every ripple in the road. Revised front end parts are coming through on the latest cars, but it’s almost impossible to make a rack-and-pinion system completely free of kick-back. Doubtless, Porsche will work out an honorable compromise between damping action and road feel that will satisfy most of their customers. Incidentally, the steering column contains two U-joints, not to clear any obstacle (the steering box is on the car’s centerline), but so that it will collapse toward the dash in case-of a crash, a good safety measure.
The 911’s suspension is a departure for Porsche. A MacPherson strut system is used at front with longitudinal torsion bars. This layout takes much less trunk space than the transverse bars of the 356. It also improves control and reduces roll (by raising the front roll center), and has the odd effect of banking the wheels into a trun, like a motorcycle rider. To avoid oversteer a link-type rear suspension with semi-trailing arms (and transverse torsion bars) was adopted. There is very little camber change on jounce and rebound, so the cornering power is not as variable on an undulating surface as the 356. Koni telescopic shocks are fitted all around, but no “camber compensator” is used as the new suspension makes it unnecessary. Body roll is moderate, pitch and harshness seem well under control, and the ride is surprisingly soft. In all, it’s a great improvement over the 356 suspension.
The 911 uses 15-inch wheels. A 14-inch wheel would be more aesthetically pleasing (and add to the available interior room), but would have restricted brake size, so we’re not complaining. We will complain about the wheel width, however. The rims are only 4.5 inches wide—what’s happened to all that racing experience? Porsche does have 5.0 x 15 and 5.5 x 15 wheels (from the 904) that will fit; substituting these wheels would yield greater cornering power (and less tire wear) at the penalty of a slightly stiffer ride. We recommend them, and also the ZF-made, U.S.-design limited-slip differential—if you can get them.
The brakes are virtually the same as the four-wheel discs of the 356C. In the 1965 Car and Driver Yearbook we said: “There’s nothing like four-wheel discs . . . that halfway business with discs at the front and drums at the rear doesn’t even come close. In an emergency, good brakes are probably the single most important factor in avoiding an accident.” The Porsche’s brakes are without peer; smooth, positive, unaffected by water, and absolutely fade-free.
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Performance
The performance figures on the specifications page speak for themselves, but while we’re on the subject of quotes, David Phipps, our European Editor, had this to say about the 911’s handling: “Both directional stability and cornering are far better than they have any right to be in a car which has the engine in the extreme rear. In corners, you can forget all the things you have been told about the sudden, vicious oversteer of rear-engine cars. The 911’s handling characteristics are basically neutral, progressing to a slight understeer. It takes a ham-fisted clot to upset the back end in the dry, and even in the wet you will only get the tail out by using lots of revs in the lower gears.”
The 911 performs better than any previous street Porsche, including the two-liter Carrera. It’s kind of a pocket battleship: what it can’t out-accelerate it can out-handle and what it can’t out-handle it can out-accelerate. In absolutely showroom condition, there probably aren’t five comparable sports/touring cars in the whole spectrum that could lap a road course faster than the 911. And—back to the pocket battleship analogy—those that could would probably fall by the wayside long before the Porsche expired.
Summary and Conclusions
The best gas mileage we could record flat-out on the Autobahn was 24 mpg, but oil consumption was minimal. The oil change interval is up to 3000 miles and the number of grease fittings has been reduced to zero. There are no other surprises in the 911 for any driver familiar with Porsches. The fan noise and growl of an air-cooled engine are typically Porsche. Getting in and out—despite the wider doors—still requires a supple spine, and so on.
What Porsche has wrought in the 911 is a worthy replacement for all the models that preceded it. Race breeding and engineering refinement ooze from the 911’s every pore. The whole package, especially the power train, is designed to be more reliable and less difficult to service, thus all the better suited to the factory’s concept of the Porsche as a sealed machine for ground transportation. Although the 911 costs a lot less than the Carrera—and a lot more than the current C and SC—it’s worth the price of all the old Porsches put together. Most importantly, the 911’s appeal should be considerably wider than the earlier models—which, in truth, you had to be something of a nut to own. Withall, anybody who ever felt a flicker of desire for a Porsche before will be passionately stirred about the 911.
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