1964 Triumph TR4

In the immediate years following World War II, Triumph produced a small luxury four-seater car known as the Mayflower, large saloons known as the Renown and 2000 Saloon, the short-lived Italia 2000 Coupe, and the TR2/TR3 sports car. At the dawn of the 1960s, with production of the TR3A and TR3B winding down, Triumph introduced its successor, the TR4. Based on its predecessor's chassis and drivetrain, the TR4 wore modern styling by Michelotti, and during its five-year production lifespan, a total of 40,253 examples were built.

The TR4's Successors
The TR4A was produced from 1965 to 1967 as an evolution of the Giovanni Michelotti-styled TR4, with the TR4's Hotchkiss drive system replaced with an independent rear suspension, indicated by an 'IRS' badge attached to the TR4A's rear. The TR5 of 1967 to 1968 utilized a more powerful Lucas mechanical fuel-injected 2.5-liter straight-6 engine offering 150 horsepower. A less powerful carbureted version was developed to adhere to strict emissions standards in the United States and was known as the TR250. The production of the TR6 (1968 to 1976) nearly reached 92,000 units, with the majority being exported to the United States. The 'wedge-shaped TR7, built in coupe and cabriolet configurations, was produced for six years ending in 1981 with well over 100,000 units built.

The Triumph TR4
Unveiled in 1962 as a rival to the MG Midget and Austin-Healey Sprite, the TR4 had several significant modern updates to its styling, usability, and mechanical specifications. Most noticeable was the styling which did away with the low door, side-curtained roadster persona of the previous TR Series in favor of a modern design with roll-up windows and a slightly curved windshield. The cockpit interior and luggage space were enhanced, and the ventilation and heater system was updated. In the front was a wide horizontal-bar grille that was slightly recessed. The headlights were positioned below the hood humps that formed small lids. In both the front and the rear were wraparound bumpers.

The TR4 had a similar chassis configuration to the TR3A with a wider track (front and rear), full synchromesh on all forward gears, a rack and pinion steering setup, and a slightly larger standard engine displacement. The optional Laycock de Normanville electrically operated overdrive could now be selected for second and third gears as well as fourth. 15 x 4.5-inch disc wheels were originally part of the standard equipment list, and optional 48-lace wire wheels could be ordered painted the same color as the car's bodywork, stove-enameled, or in matte or polished chrome finishes.

Powertrain
The engine was a larger 2138cc (up from 1,991cc) Standard engine with 86mm pistons in 'wet liners' delivering 105 (SAE) horsepower and 128 foot-pounds of torque. Further updates to the engine, including to the manifolds and cylinder heads, birth the TR4A model. The 1,991cc engine was offered as a no-cost option and was popular with privateers who wanted to compete in under-two-liter classes. As a wet-sleeve engine, the cubic capacity could be altered by replacing the cylinder liners and pistons, allowing it to compete in various different classes (below or above 2 liters).

Dimensions
The Triumph TR4 rested on an 88.1-inch wheelbase with a 156-inch length, a width of 57.5 inches, and a height of 50 inches. Compared to the TR3A, the wheelbase sizes were nearly identical (88 compared to 88.1 inches), 5 inches longer in length (156 compared to 151 inches), 1.5 inches wider (57.5 inches compared to 56 inches), and had the same height.

Styling
During development, the TR4 was code-named 'Zest' and the styling was penned by Giovanni Michelotti. The previous side curtains were replaced with wind-down (roll-up) windows, an angular rear trunk (boot) allowed for more storage, and a new optional removable roof system incorporated a fixed backlight (a fixed glass rear window), and integral roll bar with a detachable rigid steel (aluminum was used for the first 500 examples) center panel.

The TR4 had a removable vinyl insert and supporting frame called a Surrey Top. (The original factory parts catalog described the rigid top and backlight assembly as the Hardtop Top kit.

Standard TR4 colors included Spa White, Powder Blue, British Racing Green, and Signal Red. The soft tops were available in either black or white. The upholstery was red, blue, or black.

by Daniel Vaughan | Dec 2011