Car Life Road Test - 1965 Thunderbird
Published in the November 1964 issue
ONE THING ABOUT a stable car design: There's not much point in putting one of the models through road test procedures every year or so. A case in point is the Thunderbird, which Car Life editors last reported on in the July 1962 issue. That test car, a convertible with the then-available fiberglass tonneau cover and wire wheels, has been superseded by the newly-dressed 'Bird which displayed its angular lines for the first time last fall. For 1965, Ford Motor Co. has satisfied itself with only a slight re-arrangement of decorative bright work to serve as the visual indicator of the new model year. Save for the brakes, there have been no significant mechanical changes between '64 and '65, either—or for that matter since the '62. The latter weighed 10 lb. less and had exactly the same engine /transmission / rear axle equipment, although it was mounted on 8.00-14 wheels. Regular readers will recall it returned an 18.7 sec. quarter-mile time, attaining 72 mph at the quarter marker.
That the new 'Bird improves on such performance is most likely because of the different tire size (8:15-15 low profiles) and apparent attention on the part of the engineering staff to reduction of operating friction. Aerodynamics hardly play a part in this car's e.t. and terminal speed but it would be interesting to determine the relative difference between the new body and the old. Frontal area of the latter was 22.1, com-pared to the present car's 22.5 sq. ft.
Nonetheless, the data panel illustrates the present 'Bird's level of performance. The real interest insofar as the new model is concerned lies in the caliper-disc braking system and its effect on the woefully neglected area of stopping performance. Results of the usual braking test, i.e., two all-on stops from 80 mph, with a similar '64 model, are quite enlightening and elevate the newly-braked car into proper perspective.
The "crash stops" are made at the end of acceleration runs in each direction, a matter of only a minute or so apart and hardly space enough to allow the drums to cool down. While perhaps a bit unfair in view of the rarity of such treatment in normal service, the procedure has teen used by CL as a criterion by which to rate ultimate stop-ping power. In the first stop with the '64. serious fade was evident before the car had slowed to 65 mph: all pedal feel was lost and by the time velocity had dropped to 25 mph, the right rear shoes were grabbing and locking, forcing the car to skid sideways. Maximum reading on the CL decelerometer: 17 ft. /sec. /sec., quite substandard in our view and below the average of all recent domestic cars tested. The second stop recorded a maximum deceleration of 18 ft. sec. 'sec. (actually less than 0.5 G but there was quick lock-up of the rear wheels upon slowing past 70 mph: it was necessary to release pedal pressure momentarily to bring the car under control.
The '64s had 11.1-in. diameter drums, 3.0 in. wide in front and 2.5 in. wide behind, providing 381 sq. in. swept area (only Imperial and Continental had more). But the power assistance was so sensitive and the servo-action so extreme that a great deal of familiarity was necessary to avoid lock-up even during easy, about-town driving. The naive may whistle in wonder at the "great brakes" as they're pitched forward by the sudden deceleration, but the knowledgeable cringe in horror at the same phenomenon. In comparison, the '65 test car was put through the normal 2-stop treatment and then through another eight. This car produced the following results:
As can be seen in the table, the new 'Bird's disc/drum braking system gets stronger and firmer as it is used—and the harder it gets used the quicker it stops the car. The deceleration rates and stopping distances are nothing short of phenomenal for a 5000-1b. car. Some rear-wheel locking and skidding occurred in the earlier stops, but as the linings and drums heated up they seemed to stabilize. Ford engineers have noted similar characteristics in controlled-rate stopping tests and say that this point is reached at approximately 1200 psi brake line pressure.
In the Thunderbird (and Lincoln Continental) front-wheels-only application, Ford uses a fixed caliper with dual opposed cylinders mounted to the steering spindle above and behind the wheel axis. Cylinder bores are I.937-in. in diameter, each containing a piston with attached molded rubber dust boot and a rubber piston seal (which also provides automatic brake adjustment) set in a groove around the bore. This unit saddle-mounts over the rotor, or disc. assembly which is ventilated by 40 integrally cast fins between faces and measures 11.87 in. overall diameter. This cast-iron unit is 1.25 in. thick and rotates with the wheel hub, protected from splash and mud by a stamped-steel shield on the inside.
The pads, which the pistons press against the rotor to generate the friction for stopping the wheel, are bonded to flat metal shoes (replaced as a unit) which slide in caliper channels. The organic pad linings are 1.9 in. by 5.36 in. (10.05 sq. in. per segment) and are 0.436 in. thick. Pads are good for 30,000 miles (by the book) or down to 0.030 in. from surface to shoe, with re-placement requiring only the removal of a stamped protection plate (two screws) and sliding the worn units out. Pads ride with microscopic clearance (0.005 in.) over the rotor surface, effectively wiping it clear of any moisture or dust which might accumulate on the face.
It is evident in theory, at least, the harder disc brakes are used the better they work. Heat build-up, which expands normal brake drums away from internal shoes, also expands the discs—but toward the pads. Instead of in-creasing clearance (and reducing effectiveness). disc brakes decrease clearance and thereby enhance effectiveness. Pad lining materials, because of somewhat limited durability, have been one of the serious problems which delayed disc brakes for heavier American cars. Ford uses Johns-Manville Type 1398 for the 'Bird's binders and claims longevity equal to the normal lining life.
A proportioning valve is incorporated in the hydraulic line to the rear drum brakes, cutting down line pressure at 450 psi to avoid lock-up of the lighter-loaded rear wheels when heavy pedal pressures are applied. This reduces rear line pressure up to 43.5% once the cut-in point is reached. (Continentals, in addition, have a delay valve which with-holds hydraulic pressure from the front wheel calipers until 125 psi line pressure is achieved, forcing the rear brakes to do the stopping in gentle, low speed situations.) The cut-in point occurs with approximately IS lb. pedal pressure in a 10 ft. ;sec./sec. stop. And, of course, braking action is assisted via the common vacuum booster cam integral master cylinder device.
Aside from the brakes, Thunderbird continues mechanical components such as the tried and true 390-cu. in. engine which generates 300 bhp at 4600 rpm and 427 lb.-ft. of torque at 2800. With hydraulic lifters, 10.1:1 compression and a single 4-barrel carburetor, this engine provides more than adequate motive force with a notable lack of fussiness. It is the only engine available with the car and no other would really seem to be necessary.
All buttoned up and cruising through a 1000-mile round trip between Los Angeles and Sacramento. the 'Bird aptly demonstrated its forte. All power accessories, including air conditioner, were operating and yet it still required constant attention to keep within speed limit maximums. So quiet and effortless was the running that the red ribbon-type speedometer too often crept well past the 80 mph mark. Even up the long and notorious "Grapevine" grade the 'Bird would pick up speed with only the slight flutter of the temperature gauge needle to indicate that the thermostat was getting a workout in preventing an overheated engine.
This is precisely the type of service for which the Thunderbird was designed —covering vast distances between two points in the shortest legal time with the least extraneous intrusions upon the passengers' serenity. It does it extremely well. There was a bit of harshness which developed at 85 mph from what probably was a slightly unbalanced wheel, but it was only noticeable be-cause of the absence of all such things at lesser speeds. Thunderbird engineers have done a commendable job in eliminating road noise and shock transmission to the cockpit, despite the tendency of unit-body construction to magnify these things.
An aid to the continual ease of riding is the 'Bird's thin-shell bucket seats, particularly the reclinable passenger's seat with pull-up head rest. While an extra-cost option, it is well worth the price when the owner contemplates more than around-town service for his car. The seats provide a fine compromise between wrap-around support and lounge chair squirm room. Once tried, the 'Bird's accommodations actually invite long (and normally dreary) drives rather than discouraging them.
The same observation cannot be made about the rear seat, however. The unique curved-back "cove" seating is both interesting and potentially comfortable. But the problem is in that Thunderbird trademark, the full-length console. This appliance, almost a foot wide down the driveshaft tunnel, corners the passenger's feet into one area. And even the thin-shell front seats are thick enough to intrude on legroom for the rear passengers, a price which must be paid with such a close-coupled body design. A single passenger in the rear can straddle the console for a short time, but this seats him atop the drive-shaft tunnel, an area without adequate padding and one which soon gets unbearably hot and hard. Experimentation proved the only long-term comfort available in the rear seat was by assuming a lounging position across the seat, impossible of course if more than one passenger is riding there.
Psychologically, the console presents something of an inhibition to front seat passengers, but is no actual encroachment. It is interesting to note, however, that the console is an integral part of the 'Bird design and styling. The space-age instrument panel (minor gauges arrayed beneath the ribbon speedometer look like a quartet of gyroscope gimbals) cuts sharply downward to become the forward panel of the console where the heater /air conditioner controls and outlets and the radio live. The dashboard before the passenger is swept deeper forward and is solid under the padded upper lip, devoid of the customary glove compartment. The latter's function is relegated entirely to a stowage locker rising above the console to serve as a between-seat armrest. The ash tray and cigarette lighter are hidden under a pivot-down leading edge which juts forward over the electric window control buttons in a somewhat unhandy fashion.
Driving the Thunderbird for the first time might remind its driver of the main drag of Las Vegas, if all the lights are blinking in front of him. There are center-mounted blinkers warning of low fuel level, door ajar, or emergency flashers operating. A red bar on the console stays lit until the seat belts are fastened (but had to be manually extinguished last year).
The turn signals have their indicator lights outside, at the bottom forward edge of the fender trim strip. From behind, incidentally, the signal for turning is a series of lights across the broad Thunderbird lens, from the inside to the outer edge, much like those flashing arrows used by roadside restaurants.
Thunderbird engineers must be given credit for the great amount of work which went into the heating, ventilating and air conditioning system for the cockpit. The rear deck ventilator, mounted under the rear window and re-placing a package shelf behind the seat, is important enough to warrant imitation by other makers. This is opened or closed by vacuum through a console-mounted lever and, when coupled with operation of the front cowl vents. causes rapid exhausting of stale air from the closed car. By juggling the operation of the rear vent and the air conditioner. choosing either fresh or recirculated air. a substantial range of chill-down rates becomes available to the cross-country traveler.
One other feature of the Thunderbird, the swing-aside steering wheel (when the column-mounted shift lever is in Park). seemed a mere nicety that had little earthshaking value. A telescoping steering column or the now-common-place tilting wheel—of a combination such as the new Cadillac has—is a far more useful and convenient sort of arrangement. The swing-aside design, however, possibly does make it easier for the overly rotund to climb out of the cockpit.
The test Landau hardtop, complete with vinyl-covered top, was equipped with everything except automatic throttle control. The testers had hoped to try this particular type since it is built by Curtiss-Wright. exclusively for Thunder-bird and somewhat different in operation from other such units (see "Automated Accelerators”- October CL). Then, too, it would have helped as a warning—through the built-in throttle pedal pressure—that speed limits were being exceeded. It may have been more than mere coincidence, regarding the previously mentioned ease of inadvertently increasing cruising speeds, that several instances of police-stopped cars observed during that trip involved '64 Thunderbird’s.
Aside from the go fast, stop quick characteristics of the 'Bird. it is hardly a driver's sort of car. It has a discouraging degree of body roll which does little to enhance its somewhat meager cornering abilities. Once off the smooth ribbons of expressways, it is at a loss to know how to act. The ultra-supple suspension is hard-pressed to exhibit much control with less than ideal road surfaces. Steering, to be sure, is precise enough, but that is little comfort when the wheels want to flap around so much. Even rain on a good road surface is enough to induce the rear tires to seek some other path than that intended by the driver.
But then, the Thunderbird has been around long enough in substantially its present form for few Americans to expect much else from it. It has. After all. more symbolism than stature. Only the blessedly ignorant view it as anything more than what it is: A luxury-class car for those who want to present a dashing sort of image, who worry about spreading girth and stiffening arteries, and who couldn't care less about taste.
Even when viewed in that light. however, the Thunderbird must be admired. Its roof line, its bucket seats and console have inspired dozens of lesser imitations which, by their very imitation, prove the 'Bird a beast. And certainly when viewed from outside, the body lines of the present version have an overall cohesiveness and sense of dynamism that few mass-produced automobiles seem able to match. With brakes now capable of coping with modern traffic conditions, the T-Bird has taken a great step forward as an investment for those whose inclinations lie toward this sort of luxury car.
Article reprinted here was first published in Car Life, November 1965.
Raph Tripp is a passionate classic car enthusiast and writer, former owner of a 1966 Thunderbird (among others) and founder of TunnelRam.net. This is an original Tunnel Ram production ©2021 Tunnel Ram. All content not created by us remain the property of the original copyright holders.