Hillman 20 8-cylinder
| Hillman Straight-Eight Hillman Vortic |
|
|---|---|
| Overview | |
| Manufacturer | Hillman Motor Car Co Ltd |
| Model years | 1929, 1930 |
| Body and chassis | |
| Class | Executive car |
| Body style |
|
| Layout | FR |
| Powertrain | |
| Engine |
|
| Transmission | single plate dry clutch, 4-speed gearbox, Hardy Spicer propellor shaft with metal universal joints is mated with a half-floating spiral bevel driven back axle |
| Dimensions | |
| Wheelbase |
|
| Length | 175 in (4,445 mm) |
| Width | 68.25 in (1,734 mm) |
| Kerb weight |
|
| Chronology | |
| Predecessor | none |
| Successor | Hillman Wizard 75 |
| Hillman Straight Eight | |
|---|---|
| Combustion chamber | |
| Configuration | straight 8-cylinder |
| Displacement | 2,620 cc (159.9 cu in) |
| Cylinder bore | 63 mm (2.48 in) |
| Piston stroke | 105 mm (4.13 in) |
| Cylinder block alloy | cast iron, aluminium alloy die cast pistons, 5-bearing crankshaft with a vibration damper at the front |
| Cylinder head alloy | cast iron |
| Valvetrain | overhead valves with double springs operated by pushrods; timing by chain; inlet manifold square section with 4 branches; 5-branch exhaust manifold with a double outlet |
| Combustion | |
| Fuel system | carburettor fed from vacuum tank on dash, main reservoir 12 gallons at back of car |
| Fuel type | petrol |
| Oil system | forced. pump is outside sump and pressure may be adjusted |
| Cooling system | water, impeller combined with fan, true honeycomb radiator (protected by a shell), thermostatically-controlled shutters |
| Output | |
| Power output |
|
| Chronology | |
| Predecessor | none |
| Successor | Hillman Wizard 75 |
The Hillman Straight Eight and its successor the Hillman Vortic were moderate priced mid-sized 20 tax-horsepower executive cars made by Hillman from 1929 to 1930. The lowest priced eight-cylinder car on the market the car was scarcely in full production when sales were hit by the onset of the Great Depression.
This pair of cars has been described as "the complete lemon". The straight eight engine was subject to bearing failure. The name was changed to Vortic and some modifications made including a silent third gear but it was to try to sell off unwanted stock. They were still offered in 1932.
The straight eight was replaced in Hillman's catalogue in April 1931 by their six-cylinder Wizard 65 and 75.
Though announced in September 1928 in good time for that year's Olympia Motor Show no photographs appeared or display advertisements until mid-March 1929 and a detailed description of the car had to wait for May 1929. However it is true a two-door four-seated Segrave fabric coupé was shown on the Hillman stand at the 1928 Motor Show with a Straight Eight engine beside it but very little information was supplied to press or public about either object.
The 2.6 Litre long-stroke engine has eight cylinders in line, their bore and stroke 63 mm by 105 mm. The eight pistons are aluminium alloy and die cast. The overhead valves operate by pushrods, the valve gear and all other parts that need it receive forced lubrication. Timing is controlled by chain which also has a positive oil feed. The oil's pressure may be varied by hand and there is a float oil-level indicator on the right hand side. An impeller made as part of the fan assembly circulates cooling water to the honeycomb radiator which is protected by a shell and has thermostatically controlled shutters in the grille in front of it.
The crankshaft carries a vibration damper at its front end and both crankshaft and camshaft have five bearings. No further information about the bottom of the engine was supplied to readers.
Engine, single plate dry clutch and gearbox are assembled together as a unit and supported at four points.
The four-speed gearbox has its change control on the off-side next to the driver's right hand and works in a visible gate with a catch for reverse.
The chassis is said to somewhat resemble the chassis of Hillman's 14 horsepower car.
The Straight Eight is provided with wire wheels. The springs are half-elliptical, splayed front and back and underhung at the rear and controlled both front and back by friction shock absorbers.
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Wikipedia