Engineering:Triumph TR3

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Short description: British sports car produced between 1955 and 1962
Triumph TR3
Triumph TR3 (1957) - 18320015345.jpg
1957 Triumph TR3
Overview
ManufacturerStandard Motor Company
Production1955–1962
Assembly
Body and chassis
ClassSports car
LayoutFR layout
Powertrain
Engine
  • 1,991 cc (121.5 cu in) I4 (TR3, TR3A)
  • 2,138 cc (130.5 cu in) I4 (TR3B)
Transmission4-speed manual, optional overdrive[4]
Dimensions
Wheelbase88 in (2,235 mm)[5]
Length151 in (3,835 mm)[5]
Width56 in (1,422 mm)[5]
Height50 in (1,270 mm)[6]
uk|uk|Kerb|Curb}} weight955 kg (2,105 lb)[7]
Chronology
PredecessorTriumph TR2
SuccessorTriumph TR4

The Triumph TR3 is a British sports car produced between 1955 and 1962 by the Standard Motor Company of Coventry, England. A traditional roadster, the TR3 is an evolution of the company's earlier TR2 model, with greater power and improved braking. Updated variants, popularly but unofficially known as the "TR3A" and "TR3B", entered production in 1957 and 1962 respectively. The TR3 was succeeded by the mechanically similar, Michelotti-styled Triumph TR4.

The rugged ‘sidescreen’ TR, so named for its use of removable plexiglass side curtains, was a sales and motorsport success. With approximately 74,800 TR3s sold across all variants, the model was the company's third best seller in the TR range, behind the TR7 (111,500 units) and TR6 (94,500 units) models.[8]

TR3

Although the base car is an open two-seater, an occasional rear seat and bolt-on steel hard top were available as extras.

The TR3 is powered by a 1,991 cc (121.5 cu in) Standard wet liner engine. This OHV straight-four initially produced 95 bhp (71 kW; 96 PS), an increase of 5 hp over the TR2 thanks to larger SU H6 carburettors. This was later increased to 100 bhp at 5000 rpm[6] by the addition of a "high port" cylinder head and enlarged manifold. The four-speed manual gearbox could be supplemented by an electrically engaged overdrive, controlled by a switch on the dashboard. In 1956, the front brakes were changed from drums to discs, a first for a British series production car.[9]

Front suspension is by double wishbones, manganese bronze trunnions, coil springs and telescopic dampers, with an optional anti-roll bar.

Steering is a worm and peg system. Unlike MGs of the same period, the steering mechanism and linkage have considerable play and friction, which increase with wear.[citation needed]

The rear suspension comprises leaf springs, a beam axle, and lever arm dampers. The (box) frame rails are slung under the axle. Wheels are 15 inches in diameter and 4.5 inches wide (increased from 4 inches after the first few TR2s), with 48-spoke wire wheels optional. Wire wheels were usually painted, either body colour or argent (silver), but matte chrome and bright chrome were also available.

Under most conditions the car is responsive and forgiving, but it has some handling issues.[citation needed] The chassis, which is shared by the TR2, TR3, TR3A, TR3B, and TR4, has limited wheel travel. As a result, on very hard cornering, the inside rear wheel can lift, causing sudden oversteer due to the increased load on the outside rear tyre. This is particularly true with radial tyres; the original TR2/3/3A suspension was built for crossply tyres. The wheel lifting is more sudden than that of other cars, because it is caused by coming to the end of the suspension travel while there is still load on the tyre, so the load on the other (outside) rear wheel is a discontinuous function of cornering load, rather than just changing slope.

The TR3 is a true roadster, designed for sunny weather but with removable rain protection. It has a convertible hood that snaps on and off and removable side curtains, allowing very low doors with padding for the driver's arm to rest on. There are holes in the floor, with rubber plugs, so that the originally supplied jack might be used from inside the car, as in the Jaguar XK120.[clarification needed] The optional heater is poor, and the shut-off valve is under the bonnet.

Some 13,377[10] examples of the original "pre-facelift" TR3 were produced, of which 1,286 were sold within the UK; the rest were exported mainly to the US. As of Q1 2011 there were approximately 826 licensed and 115 SORN TR3/3As registered with the DVLA.[11]

Specifications

  • Production period – October 1955 to Summer 1957
  • Original price (basic model) – £950
  • Suspension – Front: independent by unequal-length double wishbones, coil springs and telescopic dampers. Rear: live axle, half-elliptic springs, lever arm dampers.
  • Brakes – First 4408 models (1955–56): 10-inch (254 mm) drums all around. Remaining 9000 (1956–57): front discs; rear drums.[12]
  • Tyres - 5.50-15 crossply or 155HR15 Pirelli Cinturato CA67
  • Factory options – Triumph offered a wide range of options and accessories for both the competition-minded owner and those simply wishing to personalise their vehicle. While many of these items were factory fitments, local dealers supplied some as well. Among these were: overdrive, wire wheels (48-spoke, 60-spoke available from 1959), steel hardtop kit (part No. 900711), occasional rear seat (No. 801264), push-button radio, interior heater, leather upholstery, windscreen washer (No. 553729), cast aluminium sump (No. 502126), aluminium ‘Al-fin’ brake drums (No. 202267 or No. 301590 (9- and 10-inch respectively)), spot and fog lamps (Nos. 501703, 501702), and a continental touring kit (No. 502022, spares for travels in remote regions).[13]

Performance

British auto magazine The Motor tested a hardtop TR3 with overdrive in 1956. The car returned a top speed of 105.3 mph (169.5 km/h) and could accelerate from 0–60 mph (97 km/h) in 10.8 seconds. A fuel consumption of 27.1 miles per imperial gallon (10.4 L/100 km; 22.6 mpg‑US) was recorded. The test car cost £1,103 including taxes.[6]

Other figures recorded included:

Speed Time
0–30 mph (48 km/h) 3.6 s
0–50 mph (80 km/h) 7.5 s
0–60 mph (97 km/h) 10.8 s
0–90 mph (140 km/h) 28.8 s
Distance Time
Standing ​1⁄4 mile 18.1 s

TR3A

Triumph "TR3A"

In 1957 the TR3 was updated, and this revised model was commonly referred to as the Triumph "TR3A". The cars were not, however, badged as such, and the "TR3A" name was not used officially,[14][15] as is evident from contemporary sales brochures.[16] Changes included a new full-width front grille, exterior door handles, and a lockable boot handle. The previously optional full tool kit became standard equipment. The "TR3A" carried over the standard front disc brakes introduced on later TR3s. The car was known for its superior braking ability with its larger tyres (5.90-15 crossply or 165HR15 Pirelli Cinturato), making it an autocross favourite.

In 1959 other changes were made to the car, including raised stampings under the bonnet and boot hinges and under the door handles, as well as a redesigned rear floor section. In addition, the windscreen was attached with bolts rather than the Dzus fasteners used on the early "A" models.

Although the facelifted TR3 is often referred to as the TR3A, it is badged as "Triumph TR3"

The "TR3A" was built between 1957 and 1962.[17] Total production was 58,236 cars, making it the third best-selling TR in its own right. The TR3A was so successful that the original panel moulds eventually wore out and had to be replaced. It is estimated that only 9,500 of the original 58,000 built survive today.[citation needed]

The "TR3A" is often seen in vintage and production racing today. Despite being over 50 years old, it is still competitive in Sports Car Club of America (SCCA) E-production class.

In June 1977, Road & Track magazine published an article titled "Driving Impressions: TR3A & TR250" in its 30th anniversary issue. It published a 0–60 mph (97 km/h) time of 12.0 seconds, power output of 100 bhp (75 kW) at 4800 rpm, observed kerb weight of 2,090 lb (950 kg) and fuel consumption of 28 miles per imperial gallon (10 L/100 km; 23 mpg‑US).[18]

TR3B

Triumph "TR3B"

"TR3B" is the unofficial name given to the final version of the Triumph TR3, which was produced in 1962. It was sold concurrently with the TR4, which started production in 1961. The "TR3B" was a special short-production run in response to dealer concerns that the buying public might not welcome the TR4.

The appearance of most "TR3B"s is identical to that of the late US-model "TR3A", with the same wider headlamp rims, wider grille, and door handles. Two series of this version were made. 530 cars with a commission number preceded by TSF were produced, 29 of which were built as Triumph Italias. 2,804 cars were produced with commission numbers preceded by TCF. Both series were partly produced in parallel. The TSF cars, like the last run of TR3As, have a 1991 cc engine and a transmission with no synchroniser on first gear. The TCF series has a fully synchronised transmission and a 2138 cc version of the Standard wet-liner engine with a 9:1 compression ratio. Fitted with two SU H6 carburettors, it makes 105 hp (78 kW) at 4,650 rpm and 172 N⋅m (127 lbf⋅ft) of torque at 3,350 rpm. It gets between 20 and 30 miles per US gallon (11.8 and 7.8 L/100 km; 24 and 36 mpg‑imp). Top speed is limited to about 110 mph (177 km/h) by the gear ratio, unless fitted with an overdrive unit. An electrically operated Laycock de Normanville Type A overdrive, operating on second, third, and fourth gears, was offered as an option. The car weighs 2,137 lb (969 kg).

Motorsports

Competition 1960 Triumph TR3 2.2 litre in pit lane

Building on the enviable legacy of the TR2,[8] the TR3 enjoyed much success in international motorsport competition. It was campaigned in races, hill climbs, and rallies across Europe and North America, with several outright, team, and class victories to its credit.

After the 1955 Le Mans disaster, the French government moved to restrict sports car rallying in that country to little more than long distance road races. In response, Triumph competition manager Ken Richardson had steel hard tops bolted to 100 TR3s, homologating the new sports car as a "grand touring" coupé, the GT class still permitted to race on French public roadways.[8] A 'grand touring kit' was made available to customers as an optional extra (part No. 554313).[13]

TR3s were campaigned in the RAC, Monte Carlo, Circuit of Ireland, Alpine, Liege-Rome-Liege, International Tulip, Scheveningen-Luxembourg, Tour de France, Douze Heures de Huy, Lyon-Charbonnieres, Acropolis, Chimay National, and Corsica rallies, among others, achieving numerous outright, team, and class victories including six "Coupes des Alpes" awards. With its robust engine and rugged reliability, the TR was a popular competitor in continental hill climbs, such as the Ollon Villars and Eberbach Bergrennen, and endurance races like the 12 Hours of Sebring and the Mille Miglia.[19][20]

At the 1959 24 Hours of Le Mans, three extensively modified TR3s, referred to as 'TR3S' models, were run. Resembling the production TR3, the Le Mans cars employed glass fibre body shells, were six inches longer than the production vehicle, and were powered by the prototype 1,985 cc (121.1 cu in) twin-cam 'Sabrina' engine.[21] The Jopp/Stoop TR3S ran as high as seventh place overall before being forced to retire due to mechanical difficulties with just over an hour remaining in the race.[8]

Citations

  1. ↑ Watson 2018, p. 64, 65.
  2. ↑ Australia for Everyone.
  3. ↑ 3.0 3.1 3.2 Piggott 2009, p. 138.
  4. ↑ carfolio.
  5. ↑ 5.0 5.1 5.2 Manwaring 1960.
  6. ↑ 6.0 6.1 6.2 The Motor 1956.
  7. ↑ TR2 Manual 1982, p. 7.
  8. ↑ 8.0 8.1 8.2 8.3 Harvey 1983.
  9. ↑ Robson 2006.
  10. ↑ Piggott 1991.
  11. ↑ Department for Transport.
  12. ↑ Robson 1980.
  13. ↑ 13.0 13.1 Piggott 1998.
  14. ↑ Piggott 2009, p. 139.
  15. ↑ RideDrive 2011.
  16. ↑ Triumph brochures.
  17. ↑ The Times 1958, p. 14.
  18. ↑ Bryant 1977.
  19. ↑ Allen & Strome 1959.
  20. ↑ Robson 1993.
  21. ↑ Piggott 1995.

References

  • Manwaring, L. A., ed (1960). The Observer's Book of Automobiles. London: Frederick Warne & Co. Ltd.. 
  • Piggott, Bill (2009). Collector's Originality Guide — Triumph TR2 TR3 TR4 TR5 TR6 TR7 TR8. Motorbooks International. ISBN 978-0760335765. 
  • Piggott, Bill (1991). Original Triumph TR — The Restorer's Guide to TR2, TR3, TR3A, TR4, TR4A, TR5, TR250, TR6. Motorbooks International. ISBN 978-1-870979-24-5. 
  • Robson, Graham (September 1980). "Development of the Breed". Thoroughbred and Classic Cars. 
  • Piggott, Bill (1998). Original Triumph TR2/3/3A (Vol 1). Motorbooks International. ISBN 1901432033. 
  • "The Triumph TR3 Hard-top Coupé". The Motor. 4 April 1956. 
  • "The Standard Motor Company. Lord Tedder Describes Expansion And Development". The Times (54316): p. 14. 24 Nov 1958. 
  • Bryant, Thomas L. (June 1977). "Driving Impressions: TR3A & TR250". Road & Track. 
  • Allen, Dave; Strome, Dick (1959). Triumph Guide. New York: Sports Car Press. 
  • Robson, Graham (1993). The Works Triumphs — 50 Years in Motorsport. Haynes Publishing. ISBN 0854299262. 
  • Piggott, Bill (1995). Triumph By Name, Triumph By Nature. Dalton Watson Fine Books. ISBN 1-85443-107-2. 

Further reading

External links



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