Triumph TR4

The Triumph TR4 was a sports car built in the United Kingdom by the Standard Triumph Motor Company and introduced in 1961. Code named "Zest" during development, the car was based on the chassis and drivetrain of the previous TR sports cars, but with a modern Michelotti styled body. 40,253 cars were built during production years. The TR4 proved very successful and continued the rugged, "hairy-chested" image that the previous TRs had enjoyed.
The new TR4 body style did away with the classical cutaway door design of the previous TRs to allow for wind-down (roll-up) windows (in place of less convenient side-curtains), and the angular rear allowed a boot with considerable capacity for a sports car.
Advanced features included the first use of adjustable fascia ventilation in a production car and the option of a unique hard top that consisted of a fixed glass rear window (called a backlight) with an integral rollbar and a detachable, steel centre panel (aluminium for the first 500 units). This was the first such roof system on a production car and preceded by 5 years the Porsche 911/912 Targa, which has since become a generic name for this style of top.
On the TR4 the rigid roof panel was replaceable with an easily folded and stowed vinyl insert and supporting frame called a Surrey Top. The entire hard top assembly is often mistakenly referred to as a "Surrey Top". In original factory parts catalogues the rigid top and backlight assembly is listed as the "Hard Top" kit. The vinyl insert and frame are offered separately as a "Surrey Top".
Features such as wind-down windows were seen as a necessary step forward to meet competition and achieve good sales in the important US market, where the vast majority of TR4s were eventually sold. However, dealers had concerns buyers might not fully appreciate the new amenities so a special short run of TR3A (commonly called TR3"B") were produced in 1961 and '62.
The pushrod 4 cylinder engine based on the early design of the Ferguson tractor engine, was continued from the earlier TR2/3 models, however the displacement was increased from 1991cc to 2138cc in the TR4 by using a larger diameter piston. Gradual improvements in the manifolds and cylinder head allowed for some improvements culminating in the TR4A model. Although, the 1991cc engine became a no-cost option for those cars destined to race in the under-two-litre classes of the day. Some cars were fitted with vane-type superchargers, as the three main bearing engine was liable to crankshaft failure if revved beyond 6,500 rpm. Superchargers allowed a TR4 to produce much more horse-power and torque at relatively modest revolutions. The standard engine produced 105 bhp (78 kW) SAE but supercharged and otherwise performance-tuned a 2.2 litre I4 version could produce in excess of 200 bhp (150 kW) at the flywheel. It should be noted that the TR4, in common with its predecessors, was fitted with a wet-sleeve engine, so that for competition use the engine's cubic capacity could be changed by swapping the cylinder liners and pistons, allowing a competitor to race under different capacity rules (ie below or above 2 litres for example).
Other key improvements over the TR3 included a wider track front and rear, slightly larger standard engine displacement, full synchromesh on all forward gears, and rack and pinion steering. In addition , the optional Laycock de Normanville electrically operated overdrive could now be selected for 2nd and 3rd gear as well as 4th, effectively providing the TR4 with a seven-speed manual close ratio gearbox.
TR4 were originally fitted with 15x4.5" disc wheels. Optional 48 lace wire wheels could be ordered painted the same colour as the car's bodywork (rare), stove-enamled (matte silver with chrome spinners, most common) or in matte or polished chrome finishes (originally rare, but now more commonly fitted). The most typical tyre originally fitted was 165x15 bias ply. In the US at one point, American Racing alloy (magnesium and aluminium) wheels were offered as an option, in 15x5.5" or 15x6" size. Tyres were a problem for original owners who opted for 48 spoke wire wheels, as the correct size radial ply tyre for the factory rims was 175x15, an odd sized tyre at the time that was only available from Michelin at considerable expense. The much more common 185x15 radials were too wide to be fitted safely. As a result, many owners had new and wider rims fitted and their wheels re-laced.
In 1965, the TR4A with IRS or independent rear suspension superseded the TR4. Apart from the rear suspension, which used trailing arms and a differential bolted to the redesigned chassis frame and a number of small styling changes and refinements, the two models appear nearly identical. In fact, an estimated 25% of TR4As were not equipped with IRS, but instead reverted to a live axle design similar to the TR4, which was adapted to fit the new chassis.
Perhaps the most rare production TR4 model is the Dové GTR4 (and GTR4A) — a TR4 rebuilt as a coupé by a specialist coachbuilder for the Dove dealership in Wimbledon, London; only 43 were produced. The conversions were by Harrington Motor Bodyworks, mostly known for construction of the Harrington Alpine, a similarly converted Sunbeam Alpine. Although most were based on the TR4 model, the sales brochure pictures a TR4A version of these cars. The engines came with such period extras as a heater in the water jackets to assist early morning starts. Some were fitted with fully balanced motors by Jack Brabham Motors or Laystall Engineering in London, which was offered as an option in the sales catalogue. Two jump seats were placed behind the driver's seat using identical materials to the originally equipped standard TR4. A wood-rimmed wheel with riveted perimeter was fitted to some models along with auxiliary lamps under the front bumper bars. A metallised identifying sticker with "Dové" on it was fitted to the glovebox lid. On the rear deck to the left below the lid, was another identifying badge with the Dové logo. The side window glasses were specially shaped with a flat top edge to fit the new roof line. Each Dové was an individual order and some variation occurred in each car. Tinted swing-down see-through acrylic sun visors were custom fitted. The aerodynamics of the Dové gave it good acceleration from 80 mph (130 km/h) to 100 mph (160 km/h) in comparison with the standard version of the car. They were originally conceived by L.F. Dove & Co. as their attempt to fill the GT category for Europe, hence the French nomenclature with an inflection at the end of the word Dové. The cars were priced at £1250, almost as much as a Jaguar E-Type, and as such were uncompetitive price-wise. One example was exported for sale through Australian Motor Industries in Melbourne, Australia. A road test of one of these cars was reported in Autocar magazine dated June 7, 1963. Up to a dozen of the cars are known to still exist.
TR4 fact file
Cost When New - £1095
Top Speed - 120 mph (190 km/h)
Overall Fuel Consumption - 22.5 miles per imperial gallon (12.6 L/100 km; 18.7 mpg-US)
Axle Ratio - 3.7
Unladen Weight - 2,184 lb (991 kg)
Performance data
Speed Time
0 - 30 mph (48 km/h) 3.7 s
0 - 50 mph (80 km/h) 8.3 s
0 - 60 mph (97 km/h) 10.7 s
0 - 90 mph (140 km/h) 20.9 s
The Triumph TR4A was built between 1965 and 1968 by the Triumph Motor Company in the United Kingdom.
The TR4A was an evolution of the TR4, updated with a new chassis. It was hoped the new, but more complex independent rear suspension would address the buying publics' desire for more comfortable riding sports cars. This version has an "IRS" badge on the rear. It's estimated 75% of TR4A were built with IRS. In 1965, the TR4A IRS sold in the United Kingdom for approximately £968, with wire wheels being another £36, overdrive £51, heater £13 and seat belts £4 each.
In response to dealer requests, approximately 25% of TR4As were produced with a solid rear axle option (also called a live axle), similar to the earlier TR4. The TR4A was the first vehicle to ever offer an option for axle type.
The new suspension eventually proved itself with the buying public and in racing, with three TR4A IRS models posting a team win and finishing 1st, 2nd and 3rd in class at the Sebring 12-hour race of 1966. Albeit now the live axle is superior in racing due to its much better power to weight ratio, also besting the TR6.
In 1968 the TR4A was replaced by the 6-cylinder TR5 (European model with fuel injection) and TR250 (U.S. model with twin carburetors), both of which continued to use the same body design.
Specifications
Engine: 2138 cc, 4 cylinder, 86 mm bore, 92 mm stroke, 9:1 compression ratio, 104 bhp (78 kW). The long stroke gave this engine much of its torque.
Turning circle: 10.1 m (33 ft)
Capacities:
Fuel tank: 53.4 L (11.75 imp gal; 14.11 US gal)
Engine sump: 6.2 L (1.36 imp gal; 1.64 US gal)
Gearbox: 0.85 L (0.19 imp gal; 0.22 US gal)
Acceleration in top:
30 to 50 mph (48 to 80 km/h): 8 s
40 to 60 mph (64 to 97 km/h): 8 s
60 to 80 mph (97 to 130 km/h): 11 s