carry capacity.”
Four Wheeler magazine stated, “Ford engineers have come up with extra-ordinary paved road ride. Because the noise level is already far below average for four-wheel-drive (4WD) rigs, long trips are far less fatiguing. On the trail, this springing combination pays off in an extremely comfortable ride over all but the roughest of trails.”
One of the earliest shots from the driver’s seat of a Bronco was taken in June 1965 when Motor Trend editors traveled to the Ford Proving Ground in Dearborn for their first drive of Ford’s new filly. A Rotunda tachometer and Falcon horn button are visible in front of the nattily attired driver. (Photo Courtesy Motor Trend Group, LLC)
Jan Norbye, writing in Popular Science, went so far as to say, “The Bronco behaved like a real sports car.” The Bronco’s extremely good maneuverability (turning circle of less than 34 feet) was also universally praised. The coil springs allowed the front wheels to be cut up 37 degrees; far tighter than on comparable leaf-sprung vehicles.
Highway travel was a mixed bag with reviewers. Zero-to-60 tests ranged from 15.8 seconds (Mechanix Illustrated) to a more believable 25.4 seconds (Science and Mechanics). Most testers noted that they topped out the Bronco speed at between 80 and 85 mph. Popular Science again was positive, noting that “the ride was better than in many taxicabs, the directional stability excellent, the noise level inside the vehicle quite tolerable.”
Science and Mechanics opined, “As a highway vehicle, the Bronco more than holds its own. It’s quieter than most other four wheel drives.”
Tom McCahill, writing in Mechanix Illustrated magazine, felt that the 170-ci 6-cylinder “proved more than ample for keeping the Bronco up with fast-moving traffic. For many miles, it cruised over Michigan’s freeway at 70 mph without distress.”
Car Life had a different take, “A tour of Southern California freeways immediately demonstrated the low-geared Bronco should be given its head in back country. A comfortable highway cruise for this particular Bronco was 55 mph–slow by the majority of freeway standards. A speed of 60 mph created tight winding of the smallish engine and audible workings of transmission and transfer cases.”
The reason for the disparity in testers’ impressions is likely due to differences in test vehicles’ axle ratios, with testers finding the 4.11:1 ratio acceptable and the optional 4.57:1 axle ratio too low for sustained highway travel.
Four Wheeler, looking at the new truck from an off-roader’s perspective, felt that the hub assemblies on the front axles stuck out too far and would be targets for passing rocks. They also felt that the locking hubs might be undone by passing rocks or branches, leaving the driver in a potentially dangerous position if the hubs were accidentally unlocked.
McCahill, the dean of automotive writers in the mid-1960s, faulted the Bronco for the lack of what he referred to as a “stump-catcher.” That, according to McCahill, was essentially a thick steel skidplate that hung from the front bumper to below the lowest point on the front axle, thereby protecting the front of the “adventure car” from low tree stumps hidden in the grass (common in the South) and from sharp rocks (out West). He also recommended steel armor protection for the crankcase and the transmission and felt that the bumpers were too flimsy.
After all the pros and cons of the new Bronco were considered, Car Life probably summed up the new truck best by stating, “The International Harvester Scout, the Toyota Land Cruiser, the Kaiser Jeep, and the Land Rover all have idiosyncrasies which those people accustomed to conventional vehicles find disturbing. Of the total group, the Bronco seems to possess fewest of these detractions which would prevent buyer transition from passenger car to four-wheel-drive sports-utility vehicle.”
That’s exactly what Ford Motor Company was aiming for when it introduced the Bronco.
Engines
Following their penchant for using as many existing parts as possible, Ford selected examples from their existing engine families to drop into the Bronco’s engine compartment.
170 I-6
At the Bronco’s introduction, the sole powerplant offered was the 170-ci 6-cylinder engine, euphemistically called the “spirited Big Six power” in early sales brochures. The 170 offered a maximum gross horsepower rating of 105 at 4,400 rpm and a maximum gross torque rating of 158 ft-lbs at 2,400 rpm. Bronco’s standard engine bested all of its competition. The closest was Scout’s 152-ci 4-cylinder, which came within 3.3 ft-lbs of Bronco’s net torque rating.
The Bronco debuted in August 1965 with a 170-ci 6-cylinder engine and a gross output of 105 hp. Often referred to as the “Falcon Six,” it was actually sourced from the Econoline van line and used solid lifters instead of the Falcon’s hydraulic units. The 1966 radiator had an offset cap; all other years’ radiators were centered. (Photo Courtesy Tim Hulick)
The 170-ci Six was known as the “Falcon Six,” having been introduced as an upgrade to the original 144 ci in the Falcon lineup in 1961. With a bore of 3.5 inches and stroke of 2.94 inches, the oversquare engine featured four main bearings and an intake manifold that was integrally cast with the cylinder head, limiting its performance potential. The compression ratio was a healthy 9:1. Typical of inline 6-cylinder engines, the 170’s torque curve was fairly flat, with 90 percent of maximum torque developed at an engine speed of 1,000 rpm. The Bronco version of the engine was actually developed from the Econoline van version of the engine, which featured solid mechanical lifters in lieu of the hydraulic lifters used in the Falcon engines.
Because Ford engineers knew that the Bronco would see more angles and inclines that cars would never travel, they modified the 1-barrel carburetor and mechanical fuel pump to provide a positive fuel supply under all conditions. On top of the carburetor, an oil-bath air cleaner was added for maximum air filtration. The Bronco’s oil pan held 7 quarts of oil; the Econoline version made do with 4.5 quarts.
The road tests of the first Broncos didn’t specifically complain about the lack of power with the 170, but instead obliquely made comments such as “No power options exist now, but compartment is big enough for a V-8” (Popular Science) and “A V-8 could easily slip in there” (Car Life photo caption).
Ford clearly intended to install a V-8 between the frame rails of its pony. As early as the first quarter of 1964, Ford documents indicated that Advanced Development Engineering was working on studies to provide for a 289-ci V-8 engine in the truck.
289 V-8
The 289 V-8 was introduced in the Bronco on March 2, 1966, and as a result, the Bronco leaped to the top rung of the horsepower and torque ratings ladder in the sport utility stable.
The 289 was the latest iteration of Ford’s small-block V-8 family that was introduced in July 1961 as a small, compact, lightweight V-8 to replace the Y-block series of engines. Using thin-wall casting techniques to save weight, and displacing 221 ci, the engines were first introduced in the mid-size 1962 Ford Fairlane and Mercury Meteor cars. In mid-1962, the displacement grew to 260 ci, with the displacement again increased to 289 ci by 1964.
At the time of the Bronco’s introduction, three iterations of the 289 were in production. It had become a popular engine because of its widespread use in the Mustang and was a natural fit for the Bronco with its size and power output.
For the Bronco, Ford selected the 2-barrel version, which had the lowest compression ratio (9.3:1) and the lowest torque peak (282 ft-lbs at 2,400 rpm) of the three versions. The installation of the V-8, which Ford described as “the power of a tractor