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26-510: The Ten launched in 1912 was a great success for Singer with possibly as many as 6000 being made. The engine was a four-cylinder unit of 1096 cc initially with side valves but changing to overhead valves in 1923. The three speed transmission was initially located with the rear axle but moved to the centre of the car in 1922 and from 1923 was in-unit with the engine. The chassis had rigid axles front and rear with semi-elliptic leaf springs until 1922 when they changed to quarter elliptic. Braking

52-469: A Solex carburettor. Two versions with saloon bodies were available, the basic "Popular" with a three speed gearbox and the Super with four speeds and a remote gearchange. The Popular had leathercloth seat covers but the Super had real leather and also featured a sunroof . Although a version with open coachwork was listed in 1939 it is not known if any were actually made. The Popular was not listed in 1939 and

78-422: A T-head four-cylinder in-line motorcycle engine in the 1920s. Valvetrain A valvetrain is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine . The intake valves control the flow of air/fuel mixture (or air alone for direct-injected engines) into the combustion chamber, while the exhaust valves control the flow of spent exhaust gases out of

104-417: A metallic timing chain or a set of gears. Pushrods are long, slender metal rods that are used in overhead valve engines to transfer motion from the camshaft (located in the engine block) to the valves (located in the cylinder head). The bottom end of a pushrod is fitted with a lifter , upon which the camshaft makes contact. The camshaft lobe moves the lifter upwards, which moves the pushrod. The top end of

130-567: A revised gearbox. Only the Super Ten was listed. Exports restarted almost immediately with a shipment to Australia in March 1946. The Super Ten was produced from 1946 to 1949. Post War it was only offered as a 4-door saloon, although in Australia a locally-built tourer was also available. A top speed of 62 mph (100 km/h) was possible. 10,497 were built. The car was replaced by

156-453: A sidevalve engine are poor gas flow, poor combustion chamber shape, and low compression ratio, all of which result in a low-revving engine with low power output and low efficiency. Because sidevalve engines do not burn the fuel efficiently, they suffer from high hydrocarbon emissions. Sidevalve engines can only be used for engines operating on the Otto principle . The combustion chamber shape

182-502: Is not above the piston (as in an OHV (overhead valve) engine) but to the side, above the valves. The spark plug may be sited over the piston (as in an OHV engine) or above the valves; but aircraft designs with two plugs per cylinder may use either or both positions. "Pop-up pistons" may be used with compatible heads to increase compression ratio and improve the combustion chamber's shape to prevent knocking . "Pop-up" pistons are so called because, at top dead centre , they protrude above

208-510: Is true for V-type flathead engines but less of an issue for inline engines which typically have the intake and exhaust ports on the same side of the engine block.) Although a sidevalve engine can safely operate at high speed, its volumetric efficiency swiftly deteriorates, so that high power outputs are not feasible at speed. High volumetric efficiency was less important for early cars because their engines rarely sustained extended high speeds, but designers seeking higher power outputs had to abandon

234-431: Is unsuitable for Diesel engines , which require a high compression ratio for ignition to occur. In a sidevalve engine, intake and exhaust gases follow a circuitous route, with low volumetric efficiency, or "poor breathing", not least because the exhaust gases interfere with the incoming charge. Because the exhaust follows a lengthy path to leave the engine, there is a tendency for the engine to overheat . (Note: this

260-1003: The Ford flathead V8 engine and the Ford Sidevalve engine . Cadillac produced V-16 flathead engines for their Series 90 luxury cars from 1938–1940. Packard produced flathead inline 8-cylinder engines until 1954. Also in the British Morris Eight , and Morris Minor series I. After WWII , flathead designs began to be superseded by OHV (overhead valve) designs. Flatheads were no longer common in cars , but they continued in more rudimentary vehicles such as off-road military Jeeps . In US custom car and hot rod circles, restored examples of early Ford flathead V8s are still seen. The simplicity, lightness, compactness and reliability might seem ideal for an aero-engine , but because of their low efficiency, early flathead engines were deemed unsuitable. Two notable exceptions were

286-453: The SM1500 model. Flathead engine A flathead engine , also known as a sidevalve engine or valve-in-block engine , is an internal combustion engine with its poppet valves contained within the engine block , instead of in the cylinder head , as in an overhead valve engine . Flatheads were widely used internationally by automobile manufacturers from the late 1890s until

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312-828: The American Aeronca E-107 opposed twin aero engine of 1930 and the Continental A40 flat four of 1931, which became one of the most popular light aircraft engines of the 1930s. Two modern flatheads are the Belgian D-Motor flat-fours and flat-sixes . These are extremely oversquare and compact aero-engines with direct drive to a propeller. Flathead designs have been used on a number of early pre-war motorcycles, in particular US V-twins such as Harley-Davidson and Indian , some British singles, BMW flat twins and Russian copies thereof. The Cleveland Motorcycle Manufacturing Company produced

338-454: The Super gained a chromium-plated radiator grille. The Solex was replaced by a downdraught SU Carburettor . The chassis had beam axles front and rear and suspension by half elliptic leaf springs and hydraulic dampers. The brakes used a Lockheed hydraulic system. After World War II the car was re-launched in January 1946 with a slightly larger 1194 cc engine developing 37 bhp and

364-523: The car was sold under the Coventry Premier brand in 1923. The 10/26 was an updated version of the Ten. The engine was enlarged to 1308 cc and rated at 26 bhp. Four wheel brakes were added in 1926. The car could reach 50 mph (80 km/h). Around 15,500 were made. The Ten name was revived in 1932 for a small car available as a saloon , 4 seat coupé or 4 seat open tourer. The car

390-455: The combustion chamber once combustion is completed. The valvetrain layout is largely dependent on the location of the camshaft. The common valvetrain configurations for piston engines, in order from oldest to newest, are: The valvetrain consists of all the components responsible for transferring the rotational movement of the camshaft into the opening and closing of the intake and exhaust valves. Typical components are listed below in order from

416-551: The combustion chamber, thus increasing torque, especially at low rpm. Better mixing of the fuel/air charge improves combustion and helps to prevent knocking. An advance in flathead technology resulted from experimentation in the 1920s by Sir Harry Ricardo , who improved their efficiency after studying the gas-flow characteristics of sidevalve engines. The difficulty in designing a high-compression-ratio flathead means that most tend to be spark-ignition designs, and flathead diesels are virtually unknown. The sidevalve arrangement

442-413: The crankshaft to the valves. The timing and lift profile of the valve opening events are controlled by the camshafts , through use of a carefully shaped lobe on a rotating shaft. The camshaft is driven by the crankshaft and, in the case of a four-stroke engine, rotates at half the speed of the crankshaft. Motion is transferred from the crankshaft to the camshaft most commonly by a rubber timing belt ,

468-457: The mid-1960s but were replaced by more efficient overhead valve and overhead camshaft engines . They are currently experiencing a revival in low-revving aero-engines such as the D-Motor . The valve gear comprises a camshaft sited low in the cylinder block which operates the poppet valves via tappets and short pushrods (or sometimes with no pushrods at all). The flathead system obviates

494-429: The need for further valvetrain components such as lengthy pushrods, rocker arms, overhead valves or overhead camshafts . The sidevalves are typically adjacent, sited on one side of the cylinder(s), though some flatheads employ the less common "crossflow" "T-head" variant. In a T-head engine, the exhaust gases leave on the opposite side of the cylinder from the intake valve. The sidevalve engine's combustion chamber

520-434: The piston gets very close to the flat portion of the cylinder head above, and the resultant squish turbulence produces excellent fuel/air mixing. A feature of the sidevalve design (particularly beneficial for an aero-engine) is that if a valve should seize in its guide and remain partially open, the piston would not be damaged, and the engine would continue operating safely on its other cylinders. The main disadvantages of

546-576: The pushrod pushes on the rocker arm, which opens the valve. Depending on the design used, the valves are actuated by a rocker arm , finger , or bucket tappet . Overhead valve engines use rocker arms, which are actuated from below indirectly (through the pushrods) by the cam lobes . Overhead camshaft engines use fingers or bucket tappets, which are actuated from above directly by the cam lobes. Most modern engines use poppet valves , although sleeve valves , slide valves and rotary valves have also been used at times. Poppet valves are typically opened by

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572-559: The sidevalve. A compromise used by the Willys Jeep , Rover , Land Rover , and Rolls-Royce in the 1950s was the "F-head" (or "intake-over-exhaust" valving), which has one sidevalve and one overhead valve per cylinder. The flathead's elongated combustion chamber is prone to preignition (or "knocking") if compression ratio is increased, but improvements such as laser ignition or microwave enhanced ignition might help prevent knocking. Turbulence grooves may increase swirl inside

598-687: The top of the cylinder block. The advantages of a sidevalve engine include: simplicity, reliability, low part count, low cost, low weight, compactness, responsive low-speed power, low mechanical engine noise, and insensitivity to low-octane fuel. The absence of a complicated valvetrain allows a compact engine that is cheap to manufacture, since the cylinder head may be little more than a simple metal casting. These advantages explain why side valve engines were used for passenger cars for many years, while OHV designs came to be specified only for high-performance applications such as aircraft , luxury cars , sports cars , and some motorcycles . At top dead centre,

624-539: Was especially common in the United States and used for motor vehicle engines, even for engines with high specific power output. Sidevalve designs are still common for many small single-cylinder or twin-cylinder engines, such as lawnmowers , rotavators , two-wheel tractors and other basic farm machinery . Multicylinder flathead engines were used for cars such as the Ford Model T and Ford Model A ,

650-612: Was on the rear wheels only. On 11 July 1914, Beatrice Blore drove a Singer Ten car up the cable track of the Great Orme , with a gradient of 1 in 3 in places, becoming the first woman to drive up the steep and challenging headland. She was six months pregnant at the time and the drive was a publicity stunt developed by her partner George Wilkin Browne to help sell the cars at his Llandudno garage, North Wales Silver Motors. The cars were advertised for sale for £195. A basic version of

676-512: Was powered by a 1261 cc sidevalve engine with coil ignition. The suspension used semi-elliptic springs front and rear and the brakes were mechanically operated. The number made is uncertain. A new Ten was shown at the 1937 London Motor Show with deliveries commencing in 1938. It had an 1185 cc overhead camshaft engine that was essentially an enlarged version of the one used in the Singer Bantam and shared its 95mm stroke. It used

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