Engineering:Ducati 350 Scrambler

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Short description: SOHC motorcycle by Ducati
Ducati 350 Scrambler
Ducati 350 Scrambler 1972.jpg
1972 Ducati 350 Scrambler
ManufacturerDucati
Also calledDucati 350 SS
Ducati 350 SCR
Production1968-1974
ClassOn/off road
Engine340.2 cc (20.76 cu in) Air-cooled bevel drive SOHC single cylinder four stroke
Bore / stroke76 mm × 75 mm (3.0 in × 3.0 in)
Compression ratio9.5:1
Top speed130 km/h (81 mph)
Power24 bhp (18 kW) @ 8,500 rpm
TransmissionMultiplate wet clutch, 5 speed
Frame typeSingle cradle
SuspensionFront: telescopic forks
Rear: swinging arm
BrakesDrum front & rear
TyresFront: 350x19
Rear: 400x18
Wheelbase1,330 mm (52 in)
DimensionsL: 2,120 mm (83 in)
W: 940 mm (37 in)
Seat height770 mm (30 in)
Weight139 kg (306 lb) (dry)
Fuel capacity11 L (2.4 imp gal; 2.9 US gal)
Footnotes / references
[1][2][3]

The Ducati 350 Scrambler, also known in the US as the Ducati 350 SS and in Europe as the Ducati 350 SCR is an on/off road 340 cc (21 cu in) single cylinder bevel drive SOHC motorcycle produced by the Italian manufacturer Ducati from 1968 to 1974. It was the first of the 'wide case' Ducati singles produced[2] and aimed at the American Market.[3] Total production was around 11,500 machines.[4]

The model was also produced under licence in Spain by MotoTrans from 1974 to 1976.[5]

History

Although some 350 Scramblers may have been produced in 1967 by fitting the 'narrow case' Sebring engine into 250 Scrambler,[6] the model wasn't officially introduced until May 1968.[7] It was the first model to use the improved wide case engine that was based on the 250SCD and 350SCD (Sport Corsa Desmo) racing engines.[8]

A hotter camshaft was fitted in 1969 along with a square-slide Dell'Orto carburettor.[9]

Few 350s were imported to the US and UK during 1970-71 as the importers (Berliner in the US and Vic Camp in the UK) were in dispute with the factory over prices.[10]

Some of the last of the model made in 1974 used Spanish engines from MotoTrans.[9] The factory ceased production of OHC singles in 1974. The remaining stocks were purchased by the then British importer Coburn & Hughes, who continued to sell them until early 1976.[10]

Technical details

Engine and transmission

The single cylinder bevel drive OHC engine was of a vertically spilt unit construction[11] and had alloy head and alloy barrels with austenitic liners.[12] Ball bearings were used in the main bearings and roller bearings for the big end.[13] Hairspring valve springs were used to close the valves.[14] Bore and stroke were 76 mm × 75 mm (3.0 in × 3.0 in) giving a displacement of 340 cc (21 cu in). A high compression 9.5:1 piston was fitted. Claimed power output was 24 bhp (18 kW) @ 8,500 rpm, giving the machine a top speed of 130 km/h (81 mph).[citation needed] The kickstart mechanism has been upgraded from the earlier models[15] and a decompression lever fitted to non-desmo models to aid kicking the engine over.[16]

Fuel was supplied by a 29mm Dell'Orto SSI carburettor.[3] A square-slide Dell'Orto VHB carb was fitted from 1969.[9] Wet sump lubrication was used and ignition was by battery and coil.[1]

Primary drive was by helical gears to a multi-plate wet clutch[17] to a 4 speed gearbox.[1] Chain drive took power to the rear wheel.[18]

Cycle parts

The single cradle frame was a strengthened version of the 'narrow case' bikes and used the engine as a stressed member.[15] Rear suspension was by swinging arm with twin 3-way adjustable Marzocchi shock absorbers. At the front 31.5 mm (1.24 in) telescopic forks were fitted.[19] Brakes were drums, the front being 180 mm (7.1 in) diameter front and 160 mm (6.3 in) rear.

References

  1. 1.0 1.1 1.2 Walker 2003, pp. 217-218.
  2. 2.0 2.1 Garlitos 2012.
  3. 3.0 3.1 3.2 Bonhams.
  4. Falloon 2016a, p. 280.
  5. Lamaneta.
  6. Falloon 2016a, p. 138.
  7. Walker 2003, p. 223.
  8. Ducati Classics.
  9. 9.0 9.1 9.2 Walker 2003, p. 224.
  10. 10.0 10.1 Walker 2003, p. 16.
  11. Walker 2003, p. 50.
  12. Walker 2003, p. 40.
  13. Walker 2003, pp. 34,52.
  14. Walker 2003, p. 44.
  15. 15.0 15.1 Falloon 2016b, pp. 92-95.
  16. www.motociclismo.it.
  17. Walker 2003, pp. 72,74,103.
  18. Walker 2003, p. 103.
  19. Walker 2003, p. 114.

Bibliography

External links