Massey Harris Modell 12-20
Built: 1929–1935 · Series: WALLIS-Baureihe
More machines from model year 1929
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Massey-Harris Wallis series (1913 to 1930s) – the tractors from Racine that made Massey-Harris a tractor builder: Model J, K, OK, 12-20 and 20-30, the numbers as drawbar and belt power
The Wallis tractors come from Racine, Wisconsin, where Henry Wallis built tractors from 1913 whose rolled steel pan served as frame and oil bath at once – the unit-frame layout that made Wallis the pioneer of the light, enclosed tractor. In 1928 Massey-Harris of Toronto bought the company and thereby got its own tractor for the first time, the Canadian farm-machinery group having previously bought tractors in; the Wallis models continued into the 1930s as Massey-Harris and became the basis of its own Pacemaker and Challenger ranges. The type logic: the early types carry letters – Model B, C and D the giants of the 1910s with up to 23 litres of displacement and over seven tonnes, Model J and K the smaller successors, OK the revised version – the later ones the convention of the time with drawbar and belt power in hp: 12-20 and 20-30. The engines are four-cylinders for kerosene, started on petrol, at 650 to 1,050 rpm.
Read on 3 more paragraphs
The register lists 7 versions with 9.2 to 22.4 kW from four-cylinders of 4,059 to 23,167 cm³, unladen weights from 1,517 to 7,257 kg, lengths from 3,073 to 4,343 mm, widths from 1,397 to 2,337 mm and heights from 1,295 to 2,210 mm.
The Wallis 12-20 is regarded as one of the most advanced tractors of its time; the range made Massey-Harris the tractor maker that merged with Ferguson in 1953 into Massey Ferguson.
Used Wallis tractors are museum pieces: completeness, originality of engine, carburettor and magneto, the condition of the steel pan and wheels and provenance count; parts are reproduced by collectors.
Sources: SpecCodex register, model data: Massey-Harris Wallis-Baureihe, Massey-Harris (Wikipedia)
Technical data
Engine
| Fuel | Kerosin/Benzincorrect |
|---|---|
| Power | 12.5 hp (9.2 kW)correct |
| Rated speed | 1,000 rpmcorrect |
| Cylinders | 4correct |
| Displacement | 4,059 cm³correct |
| Bore | 98.43 mmcorrect |
| Stroke | 133.35 mmcorrect |
| Cooling | water-cooledcorrect |
Dimensions and weights
| Length | 3,073 mmcorrect |
|---|---|
| Width | 1,397 mmcorrect |
| Height | 1,295 mmcorrect |
| Wheelbase | 1,981 mmcorrect |
| Unladen weight | 1,556 kgcorrect |
Drivetrain and chassis
| Drive | rear-wheel drivecorrect |
|---|---|
| Gearbox | 3 V/1 Rcorrect |
| Front tyres | 711 x 127correct |
| Rear tyres | 1.118 x 254correct |
| Top speed | 7 km/hcorrect |
Origin and approval
| Construction | U-frame constructioncorrect |
|---|
Where this model stands
Power-to-weight ratio: 5.9 kW/t (9 kW / 1.6 t)
Power class: Compact (< 40 hp)
Stronger than 2% of the tractors in the register — out of 15,663 models with a stated power figure.
Calculated from the documented figures above — not a rating.
Frequently asked questions
How much power does the Massey Harris Modell 12-20 have?
The Massey Harris Modell 12-20 delivers 12.5 hp.
How much does the Massey Harris Modell 12-20 weigh?
The unladen weight is 1,556 kg.
What engine does the Massey Harris Modell 12-20 have?
4 cylinders, 4,059 cm³ displacement, Kerosin/Benzin.
How fast does the Massey Harris Modell 12-20 go?
Top speed is 7 km/h.
What are the dimensions of the Massey Harris Modell 12-20?
3,073 mm × 1,397 mm × 1,295 mm.
When was the Massey Harris Modell 12-20 built?
Production years: 1929–1935.
What to check before buying
- Check the hour meter against the service records — a replaced instrument is the most common gap.
- Compare the data plate and chassis number with the papers.
- Check the weights in the papers against the figures here — attachments change them.
- Check front and rear tyre sizes: mismatched pairs strain the drivetrain.
- Shift the gearbox cold and warm — jumps only show up at temperature.
- Load the hydraulics and watch for sag.
- Ask about parts availability for this build year — the running costs hang on it.
A general list for this type of machine — no substitute for an inspection or an appraiser.
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This page carries 20 individual figures for this model. They come from 1 recorded source; every figure can be traced there. What we cannot document is not here — we leave gaps open rather than estimate them.
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Other models in this series
Sources: Wikibooks Traktorenlexikon (CC BY-SA 4.0) (retrieved August 2026) · How we check the data
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