| MODEL | ARIEL 4F SQUARE FOUR 500 1931 |
| Year | 1931 |
| Engine Type | Square four, double-twin arrangement, overhead cams |
| Displacement / Capacity | 498 cc / 30.39 cu in |
| Bore X Stroke | 51 x 61 mm / 2.0 x 2.4 in |
| Compression Ratio | 6.9:1 |
| Cooling System | Air |
| Max Power | — |
| Max Torque | — |
| Ignition | — |
| Induction | Amal carburettor |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | Wet sump |
| Gear Box | 4-speed, Burman |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Tubular single loop |
| Front Suspension | Spring girders |
| Rear Suspension | Rigid |
| Front Brakes | Expanding brake (drum) |
| Rear Brakes | Expanding brake (drum) |
| DIMENSION SPECS | |
| Overall Length | 2100 mm / 82.7 in |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | 1385 mm / 54.5 in |
| Ground Clearance | — |
| Dry Weight | 193 kg / 425.5 lb |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.25-19 |
| Rear Tyre | 3.25-19 |
| FUEL SYSTEM | |
| Fuel Capacity | 13.25 Litres / 3.5 US gal |
| Fuel Consumption | — |
| Top Speed | 120.7 km/h / 75 mph |
The first production Ariel Square Four, nicknamed the Squariel, was a 500 cc air-cooled engine made of two vertical twins geared together, with overhead camshafts. It gave a smooth, multi-cylinder feel in a conventional rigid-framed touring chassis with girder forks and a four-speed Burman gearbox.
