About the Stag

Stag specs

2,997 cc Triumph V8

145 bhp At 5,500 rpm

170 lb ft At 3,500 rpm

190 km/h Top speed

Mk1 and Mk2

Four Stags

The Stag barely changed in seven years. Here's how to tell them apart. Triumph never called them Mk1 and Mk2; owners came up with the names later, so you'll see the line drawn in slightly different places.

Mk1, 1970 to 1973. Silver-grey grille and badges, body-colour sills, gauge needles pointing down, and a soft top with rear quarter windows. Illustration by Graeme Jenner, Graeme's Car Portraits, prints available

Mk2, 1973 to 1975. Black grille background, matt black sills and tail panel, twin coachlines and a smaller steering wheel. Illustration by Graeme Jenner, Graeme's Car Portraits, prints available

Mk2, late 1975 to 1977. Stainless sill covers and a body-colour tail panel; alloys and tinted glass now standard. Illustration by Graeme Jenner, Graeme's Car Portraits, prints available

Mk2 with the hardtop. Most Stags left the factory with one, and Australian cars got it as standard. Illustration by Graeme Jenner, Graeme's Car Portraits, prints available

Inside the Stag

3D cutaway, Mk2

Tap a number to see what's there.

Cutaway drawing of a Triumph Stag Mk2 with hardtop, showing the V8, suspension, seats and fuel tank

Mk2 cutaway drawing, from the original triumphstag.info.

Specifications

The numbers

For UK and Australian cars as tested when new. US cars had lower compression and about 127 bhp. Sources differ by a few per cent; these are the commonly quoted figures.

Configuration

Front engine, mounted lengthwise, gearbox in line, rear-wheel drive
2+2 seat, two-door luxury tourer
Soft top, with a removable steel hardtop
All-steel monocoque with a T-bar roll-over hoop

Engine

Triumph V8, 90 degree vee, 2,997 cc (182.9 cu in)
Bore 86 mm, stroke 64.5 mm (oversquare)
One overhead camshaft per bank, chain driven, 16 valves
Cast iron block, five main bearings, aluminium heads
Compression 8.8:1 (lowered for US cars)
Twin Zenith-Stromberg 175 CDSE carburettors
145 bhp (108 kW) at 5,500 rpm
170 lb ft (230 Nm) at 3,500 rpm

Chassis

Front: MacPherson struts, coil springs, anti-roll bar
Rear: independent semi-trailing arms, coil springs, rubber-insulated subframe
Power-assisted rack and pinion, about 3 turns lock to lock
Steering column adjustable for reach and rake
Servo brakes, split circuit: 270 mm discs front, 228 mm drums rear

The Stag's own V8: in effect two of Triumph's slant-fours on a common crank, with a single jackshaft driving the water pump, oil pump and distributor. The Car Spy, CC BY 2.0

Gear ratios

Manual with overdrive
First	2.995
Second	2.100
Third	1.386
Fourth	1.000
Overdrive third	1.100
Overdrive fourth	0.797 (J-type)
Reverse	3.369
Final drive	3.70

Borg-Warner automatic
First	2.39
Second	1.45
Third	1.00
Reverse	2.09
Final drive	3.70

Manual: a strengthened four-speed with a 9 inch diaphragm clutch. Overdrive on third and top was optional on early cars and standard on manuals from late 1972. About half of all Stags were automatics.

Dimensions and weight

Length	4,420 mm
Width	1,613 mm
Height (hardtop)	1,257 mm
Wheelbase	2,540 mm
Front track	1,330 mm
Rear track	1,342 mm
Ground clearance	157 mm
Turning circle	10.4 m
Kerb weight	about 1,270 to 1,300 kg
Fuel tank	63 litres

Wheels and tyres

Steel wheels with trims at launch; US cars of 1971 and 1972 had 72-spoke wires
GKN five-spoke alloys: optional, then standard from late 1975
5½J x 14, four studs on 114.3 mm (4½ inch) PCD, 28 mm offset
185 HR 14 radials, 175 section from 1976

Equipment

Power windows and power steering
Smiths instruments in a walnut dash
Fully reclining front bucket seats
Lockable glovebox with parcel shelf
Door courtesy lights and quad headlamps
Hardtop with heated rear window
Air conditioning optional (rare outside the US)

Performance

Top speed about 185 to 190 km/h (115 to 118 mph)
0 to 100 km/h about 9 to 9.5 seconds (manual), 11.5 seconds (auto)
Standing 400 m in 17 to 18 seconds
About 13 to 14 litres per 100 km overall

Know your car

Commission numbers

Every Stag carries a commission number on a small plate riveted to the left-hand door pillar, where the door shuts. It starts LD (LE on US cars), and the plate also carries the paint and trim codes. The number tells you roughly when the car was built, and the letters after it say how it left the factory.

Look yours up in the Register, which carries on John Powell's Australian National Triumph Stag Register. Every car's page there reads its number for you.

LD1 Late 1969
Pre-production cars built at Canley from November 1969. On sale in June 1970
LD10001 November 1971
"Sanction 2" cars, with the revised cooling system on the way
LD20001 October 1972
First Mk2 built. On sale early in 1973
LD21231 1973
J-type overdrive replaces the A-type
LD40001 October 1975
Stainless sills, body-colour tail panel, alloys and tinted glass standard
LD41994 October 1976
Borg-Warner 65 automatic replaces the 35
LD45722 June 1977
The last Stag

The letters after the number

O	Overdrive (the letter O, not a zero)
BW	Borg-Warner automatic, used until about early 1974
A	Borg-Warner automatic, from about early 1974
L	Left-hand drive (not US cars)
U	US car, from the 1972 model year
K	Right-hand drive with a km/h speedo: Australian cars from 1975

So LD45581AK is an automatic, Australian car with a km/h speedo, built in 1976 or 1977. The change from BW to A happened gradually over late 1973 and early 1974.

The number ranges

1 to 3900	1970 to 1971, early Mk1Sanction 1, including the 1970 pre-production cars
10001 to 14158	1972, Mk1Sanction 2, with the uprated cooling
20001 to 25443	1973, early Mk2Sanction 3: matt black sills and tail panel. Built from October 1972
30001 to 36714	1974 to 1975, Mk2Sanction 4
40001 to 45722	1976 to 1977, late Mk2Sanction 5: body-colour tail panel, stainless sill covers, alloys standard

Triumph built the cars in batches called sanctions. Numbers between these ranges were never used, so a number that falls in a gap has usually been written down wrongly.

Where to find the numbers

Commission number: plate on the left-hand door pillar, with the paint and trim codes.
Engine number: LF, then the number, then HE (for example LF 11246 HE). Stamped at the back of the block between the distributor and the bellhousing; on roughly the first thousand engines, on a boss between the two rear spark plugs on the left bank. It's usually close to, but not the same as, the commission number.
Body and trim numbers: two small plates on the front crossmember beside the left bonnet hinge, often painted over. They rarely match the commission number, so use them as a cross-check, not the car's identity.

For proof of how a car left the factory, the British Motor Industry Heritage Trust at Gaydon holds the build records and issues Heritage Certificates for a fee.

Chassis number changes from Classic & Sports Car's Stag buyer's guide and the Vintage Triumph Register. Number ranges, letters and plate locations from the Stag Owners Club magazine (March 2020) and The Stag Archive.

Photos