Model Page
Triumph Dolomite Sprint
Engine: |
1998cc Straight 4 SOHC 16v |
|---|---|
0-60: |
8.4 secs |
Max Speed: |
119mph |
Production Run: |
22,941 |
Production Dates: |
1973-1980 |
Produced: |
Canley (UK) |
The Triumph Dolomite Sprint was produced to take the fight directly to more exotic Italian and German vehicles available at the time. In the early seventies, Triumph was being somewhat overshadowed by more powerful and glamorous cars such as the Alfa 2000GTV and BMW 2002. In an attempt to match and overhaul these rivals Triumph decided to develop a high end, high performance Dolomite for the range. This would give an extra appeal and boost sales further down the range.
Triumph Dolomite Sprint in Blue
The Triumph Dolomite Sprint filled this niche, neatly fitting in between these two cars, offering similar performance at significantly less cost but with more comfort. Similar priced cars available at the time such as the RapierH120 and Fiat 125 coupe did not come anywhere close to matching the Sprints’ level of comfort or performance. The Dolomite Sprint was claimed to be the first truly mass produced 16 valve car.
The Sprint engine was an evolution of the Triumph slant – 4 engine, this was developed in house by Lewis Dawtry and Harry Webster. Development had been underway for some time in extracting extra horsepower from the engine that was used in 1850 capacity. As with many BL projects, cost constraint ensured that the design of the engine could not stray too far away from the use of existing production components. In particular the bottom half of the engine had to be retrained.
Triumph Dolomite Sprint
The new version of the engine retained the 78mm stroke, whilst the cylinder bores were increased to 90.3mm, this resulted in the engine having a 1998cc capacity. At one point a double overhead camshaft arrangement had been considered but this was later discarded with the engineers opting to run the 16 valve head off a single camshaft.
This inventive setup operated with the inlet valve operating via the tappets and the exhaust valves operating via the rockers off the same eight cam lobes. This design allowed for the spark plugs to be located in the centre of the cylinder head – the optimum position. The engine was fed fuel by twin HS6 SU Carburettors, these were chosen over the Stombergs that were usual place in the smaller slant four engines. The innovative design won a British Design Council award in 1974, an award that Triumph fully exploited in their advertising literature for the model.
In factory form the engine produces approximately 127bhp, an interesting side note is that engine correctly built and tune had on the factory test-bed been proven to reliably develop 150bhp. The engine developed maximum power output at 5,700rpm and generated a very usable torque curve with 108lb/ft being output at 2,000rpm. Such flexible characteristics ensure that the Sprint was chosen to be used by a number of Police forces throughout Britain.
Triumph Dolomite Sprint Engine Bay
The engine was initially to be designated the Dolomite 135 as it was anticipated that the engine would be capable of producing 135bhp. However when it became clear that the factory were unable to produce the engines consistently in this state of tune the model designation was changed to Sprint.
Visually the car was very similar to the 1850, changes included the fitment of alloy wheels as standard which at the time was first for a British production car, a vinyl roof, front spoiler, twin exhausts and lowered suspension.
Mechanically the gearbox and differential were upgraded to units from the TR and 2000 model range, the gearbox was slightly modified to include closer gear ratios to match the output characteristics of the free revving 16valve engine. The brakes were upgraded with a larger servo, larger drums and different pads – a must to help slow down the car now that it sported 40 bhp more than the 1850. Optional extras to the car included a limited slip differential, overdrive and automatic gearbox.
Triumph Dolomite Sprint Interior
The interior specification was an up-market affair, featuring wood lined door caps and dashboard featuring an array of instrumentation and thick carpets, the cloth interior from the 1850 was also fitted. The steering wheel was adjustable to offer a more comfortable driving position.
The car was generally received with an enthusiastic response from public and press. The Triumph Dolomite Sprint did gain a perhaps unfair reputation for offering poor reliability and fragility. A number of factors exaggerated the situation the first being that the engine design was completely new and the dealerships had not received adequate training the maintenance requirements of the engine. The cooling systems on the engines had to be maintained in tip top condition to maintain sufficient cooling or significant damage would occur during overheating – head gasket failures being a frequent and expensive. Secondly the car was introduced at a turbulent time in British Leyland’s history with the factory displaying poor quality control.
The Facts
Engine: |
Triumph Slant 4 SOHC |
|---|---|
Capacity: |
1,998 cc |
Valves: |
16 |
Compression Ratio: |
9.5:1 |
Fuel System: |
Twin SU Carburettors |
Maximum Power: |
127bhp @ 5,200 rpm |
Maximum Torque: |
122lb ft @ 4,500 rpm |
Transmission: |
Manual 4 Speed with Overdrive |
Top Gear: |
23.6 mph per 1000 rpm (Overdrive) |
Brakes: |
Servo Assisted Vented front discs / rear drums |
Kerb Weight: |
991 Kg |
0-60: |
8.4 secs |
Max Speed: |
119 mph |
