MODEL DESIGNATIONS:
1983 Triumph Bonneville T140AV.................... Anti-Vibration
1983 Triumph Bonneville T140ES.................... Electric Start
1983 Triumph Bonneville TSS....................... 8-valve
1983 Triumph Bonneville TSX....................... Factory custom
ENGINE:
Engine type....................................... OHV vertical twin
Horsepower at RPM............................ 49 BHP @ 6,200 rpm
Bore................................................ 76mm / 2.79"
Stroke............................................. 82mm / 3.23"
Displacement.................................... 744cc / 40 cu. in.
Compression Ratio............................. 8.6:1
Valve Clearance (cold):
Inlet................................................ 0.05mm / 0.002"
Exhaust............................................ 0.10mm / 0.004"
Valve Timing:
Inlet Valve Opens.............................. 34 degrees BTDC
Inlet Valve Closes.............................. 55 degrees BTDC
Exhaust Valve Opens.......................... 55 degrees BTDC
Exhaust Valve Closes.......................... 27 degrees BTDC
IGNITION:
Ignition Breaker Gap............................. 0.4mm / 0.015"
Spark Plug Gap.................................. 0.50mm / 0.020"
Timing (static).................................14 degrees BTDC
Timing (fully advanced):........................ 38 degrees BTDC
CARBURETORS:
Type................................................ Bing Type 94 CV
Throat Size....................................... 32mm
Main Jet........................................... 210
Needle Jet........................................ .107
Needle Position.................................. 2
Needle Type.......................................D
Throttle Valve.................................... 2
Pilot Jet............................................ 25
TRANSMISSION:
Speeds.............................................. 4
Gear Ratios:
5th - Top........................................... 4.7
4th - Fourth........................................ 5.59
3rd - Third......................................... 6.58
2nd - Second...................................... 8.63
1st - Bottom...................................... 12.25
CLUTCH:
Type................................................ Multi-plate, wet
Number of Plates:
Drive Plates...................................... 6
Driven Plates.................................... 6
SPROCKETS:
Engine............................................. 29 teeth
Clutch............................................. 58 teeth
Gearbox.......................................... 20 teeth
Rear Wheel...................................... 47 teeth
:
Primary, pitch.................................. 3/8" triplex
Primary, length................................. 84 links
Final Drive, pitch............................... 5/8" X .400" X 3/8"
Final Drive, length............................. 106 links
CAPACITIES:
Fuel (US versions)............................. 2.5 Imp. gal.
Fuel (UK & export versions)................. 4 Imp. gal.
Oil Tank........................................... 5 pints / 3 L
Gearbox........................................... 1 pt / 500cc
Primary Chaincase............................. 1/4 pt / 150cc
Front Forks....................................... 6.4 oz. / 190cc
TIRES:
Front............................................... 3.25 X 19"
Rear................................................ 4.00 X 18"
SUSPENSION:
Front............................................... Telescopic Forks
Rear................................................ Swing Arm
BRAKES:
Front............................................... 10" / 12.9cm disk
Rear................................................ 7" / 17.78cm SLS
DIMENSIONS:
Seat Height...................................... 32.5" / 77.5cm
Wheelbase........................................ 54.5" / 140.3cm
Length.............................................. 85.5" / 202cm
Width............................................... 28.5" / 72cm
Ground Clearance.............................. 5" / 12.7cm
Weight, unladen................................ 403 lbs / 183kg
The TSS was essentially a standard Triumph T140ES Bonneville with the addition of an entirely alloy cylinder & head which was based on the old Westlake 8-valve racing heads of the 1960s, with some technical help from Westlake & a license to produce them. The engine cases were standard T140ES, with an all new crank turning on higher-spec bearings, supposedly able to spin to 10,000 rpm. This one-piece forging had larger diameter 1.875" big-end journals & thicker webs. Interestingly, the bore centers were spread apart by 1/2" so offset connecting rods were used to make up the difference. The top end cooling fins were of a higher pitch than traditional Bonnies, and more square. Compression ratio was 9.5:1 & the conventional head gasket was replaced with 2 Cross-rings that seated in the head. There were still 10 head bolts, but the outer 4 were now studs running all the way through the cylinder block to the crankcase. The 4 valves per cylinder were now more steeply angled than before (the valves in a traditional Triumph 650/750 twin are at a 90-degree angle relative to each other; the TSS valves were at 60 degrees, which allows for better flow) & were actuated by forked rocker arms, each operating 2 valves apiece. The head was cast such that the rocker shafts no longer rode in detachable rocker boxes, instead they were supported by beefy bosses cast right into the head. This is an improvement that would have benefited the traditional Triumph Bonneville engine greatly, since the detachable rocker boxes are under such rocking forces, stresses while torquing down the head (pre-1971) & the were prone to leaking. The entire top cover could be removed on the TSS revealing the valve gear & making it much easier to adjust the valve clearances.
1983 Triumph Bonneville T140AV.................... Anti-Vibration
1983 Triumph Bonneville T140ES.................... Electric Start
1983 Triumph Bonneville TSS....................... 8-valve
1983 Triumph Bonneville TSX....................... Factory custom
ENGINE:
Engine type....................................... OHV vertical twin
Horsepower at RPM............................ 49 BHP @ 6,200 rpm
Bore................................................ 76mm / 2.79"
Stroke............................................. 82mm / 3.23"
Displacement.................................... 744cc / 40 cu. in.
Compression Ratio............................. 8.6:1
Valve Clearance (cold):
Inlet................................................ 0.05mm / 0.002"
Exhaust............................................ 0.10mm / 0.004"
Valve Timing:
Inlet Valve Opens.............................. 34 degrees BTDC
Inlet Valve Closes.............................. 55 degrees BTDC
Exhaust Valve Opens.......................... 55 degrees BTDC
Exhaust Valve Closes.......................... 27 degrees BTDC
IGNITION:
Ignition Breaker Gap............................. 0.4mm / 0.015"
Spark Plug Gap.................................. 0.50mm / 0.020"
Timing (static).................................14 degrees BTDC
Timing (fully advanced):........................ 38 degrees BTDC
CARBURETORS:
Type................................................ Bing Type 94 CV
Throat Size....................................... 32mm
Main Jet........................................... 210
Needle Jet........................................ .107
Needle Position.................................. 2
Needle Type.......................................D
Throttle Valve.................................... 2
Pilot Jet............................................ 25
TRANSMISSION:
Speeds.............................................. 4
Gear Ratios:
5th - Top........................................... 4.7
4th - Fourth........................................ 5.59
3rd - Third......................................... 6.58
2nd - Second...................................... 8.63
1st - Bottom...................................... 12.25
CLUTCH:
Type................................................ Multi-plate, wet
Number of Plates:
Drive Plates...................................... 6
Driven Plates.................................... 6
SPROCKETS:
Engine............................................. 29 teeth
Clutch............................................. 58 teeth
Gearbox.......................................... 20 teeth
Rear Wheel...................................... 47 teeth
:Primary, pitch.................................. 3/8" triplex
Primary, length................................. 84 links
Final Drive, pitch............................... 5/8" X .400" X 3/8"
Final Drive, length............................. 106 links
CAPACITIES:
Fuel (US versions)............................. 2.5 Imp. gal.
Fuel (UK & export versions)................. 4 Imp. gal.
Oil Tank........................................... 5 pints / 3 L
Gearbox........................................... 1 pt / 500cc
Primary Chaincase............................. 1/4 pt / 150cc
Front Forks....................................... 6.4 oz. / 190cc
TIRES:
Front............................................... 3.25 X 19"
Rear................................................ 4.00 X 18"
SUSPENSION:
Front............................................... Telescopic Forks
Rear................................................ Swing Arm
BRAKES:
Front............................................... 10" / 12.9cm disk
Rear................................................ 7" / 17.78cm SLS
DIMENSIONS:
Seat Height...................................... 32.5" / 77.5cm
Wheelbase........................................ 54.5" / 140.3cm
Length.............................................. 85.5" / 202cm
Width............................................... 28.5" / 72cm
Ground Clearance.............................. 5" / 12.7cm
Weight, unladen................................ 403 lbs / 183kg
The TSS was essentially a standard Triumph T140ES Bonneville with the addition of an entirely alloy cylinder & head which was based on the old Westlake 8-valve racing heads of the 1960s, with some technical help from Westlake & a license to produce them. The engine cases were standard T140ES, with an all new crank turning on higher-spec bearings, supposedly able to spin to 10,000 rpm. This one-piece forging had larger diameter 1.875" big-end journals & thicker webs. Interestingly, the bore centers were spread apart by 1/2" so offset connecting rods were used to make up the difference. The top end cooling fins were of a higher pitch than traditional Bonnies, and more square. Compression ratio was 9.5:1 & the conventional head gasket was replaced with 2 Cross-rings that seated in the head. There were still 10 head bolts, but the outer 4 were now studs running all the way through the cylinder block to the crankcase. The 4 valves per cylinder were now more steeply angled than before (the valves in a traditional Triumph 650/750 twin are at a 90-degree angle relative to each other; the TSS valves were at 60 degrees, which allows for better flow) & were actuated by forked rocker arms, each operating 2 valves apiece. The head was cast such that the rocker shafts no longer rode in detachable rocker boxes, instead they were supported by beefy bosses cast right into the head. This is an improvement that would have benefited the traditional Triumph Bonneville engine greatly, since the detachable rocker boxes are under such rocking forces, stresses while torquing down the head (pre-1971) & the were prone to leaking. The entire top cover could be removed on the TSS revealing the valve gear & making it much easier to adjust the valve clearances.
