15-411: (Redirected from J-Type ) J type or Type J may refer to: J-type asteroid MG J-type , a sports car Morris Commercial J-type , a van Renault J-Type engine Caudron Type J , an airplane Type J thermocouple , an electrical device See also [ edit ] J class (disambiguation) Type J1 submarine Topics referred to by
30-524: A set of eccentrics and guide slots to the axle of the supercharger, the Powerplus actively controls the position of these vanes, such that they maintain a constant small clearance from the walls of the housing. This is enough spacing to avoid friction, but close enough to keep pumping efficient. The obvious advantage of the Powerplus over the Roots was avoidance of the need to machine the complex-shaped rotors. With
45-476: Is different from Wikidata All article disambiguation pages All disambiguation pages MG J-type The MG J-type is a sports car that was produced by MG from 1932 to 1934. This 2-door sports car used an updated version of the overhead camshaft , crossflow engine, used in the 1928 Morris Minor and Wolseley 10 and previously fitted in the MG M-type Midget of 1929 to 1932, driving
60-514: The Mille Miglia (both reprinted in ) Although these were not intended as everyday road cars, MG set out to produce competitive 'clubman's' racing cars at an affordable production-line price. In 1934 a K3 Magnette with racing bodywork and a pre-selector gearbox cost £795, around twice the price of the Magnette saloons. Eyston also held many other patents related to similar pumps. The innovation of
75-461: The crankshaft , between the chassis dumb irons . The valance here was given a central bulge, capped with MG's octagon badge. The carburettor was a single large SU , mounted upstream of the blower for suck-through operation. Perhaps the most famous of all supercharged MGs was the 1,087 cc K3 Magnette . Eyston was also a noted racer of MGs, particularly his K3 Magnette in the 1933 Isle of Man and 1934 Northern Ireland Tourist Trophy races and
90-460: The 1950s TF. The top speed of a standard car was 65 mph (105 km/h), but a specially prepared one tested by The Autocar magazine reached 82 mph (132 km/h). The car cost £199. The most serious of the J2's technical failings is that it has only a two-bearing crankshaft which may break if over-revved. The overhead camshaft is driven by a vertical shaft through bevel gears, which also forms
105-590: The M type by having cut-away tops to the doors. The J1 was the four-seat car in the range. The engine was the 847 cc unit previously seen in the C-type with twin SU carburetors giving 36 bhp. The car cost £220 in open and £225 in Salonette form. The J2, a road-going two-seater, was the commonest car in the range. Early models had cycle wings, which were replaced in 1933 by the full-length type typical of all sports MGs until
120-458: The Powerplus was to take the sliding-vane design and to address its main drawbacks. Although the simple sliding-vane design is straightforward to manufacture, having simply shaped component parts, the spring-loaded vanes rub on the housing and this friction requires lubrication. In the 1920s, it was common for supercharged cars to have large consumable oil tanks mounted alongside the supercharger. Their HC exhaust emissions are not recorded. By adding
135-450: The armature of the dynamo. Thus any oil leak from the cambox seal goes into the dynamo brushgear, presenting a fire hazard. Rather than hydraulic brakes the car has Bowden cables to each drum. Although requiring no more pedal force than any other non-power-assisted drum brake if they are well maintained, the drums themselves are small, and even in-period it was a common modification to replace them with larger drums from later models. The J3
150-451: The manufacturing technology of 1930, this was a serious consideration. Eyston himself already held patents related to these manufacturing difficulties. The problem with Powerplus was firstly its complexity. Although each component was of simple form, there was some number of them, including a separate Bosch oil pump. This reduced reliability, compared to the simplicity of a Roots (once manufactured). Secondly, studies by NACA revealed that
165-599: The rear wheels through a four-speed non- synchromesh gearbox. The chassis was from the D-Type with suspension by half-elliptic springs and Hartford friction shock-absorbers all round with rigid front and rear axles. The car had a wheelbase of 86 in (2,184 mm) and a track of 42 in (1,067 mm). Most cars were open two-seaters, but a closed salonette version of the J1 was also made, and some chassis were supplied to external coachbuilders. The open cars can be distinguished from
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#1733084658495180-408: The same term [REDACTED] This disambiguation page lists articles associated with the title J type . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=J_type&oldid=813702620 " Category : Disambiguation pages Hidden categories: Short description
195-634: The supercharger to obtain 72 bhp (54 kW). Powerplus supercharger The Powerplus is a design of supercharger that was used to boost the performance of car engines in the 1930s. It is a mechanically driven positive displacement pump , operating on the sliding-vane principle . Powerplus is best known through its use on some MG cars of the 1930s. MG specialised in small, lightweight "Midget" cars. Use of supercharging allowed engines of under 750 cc, 850 cc or 1,100 cc to generate competitive amounts of power, whilst still remaining in these small-engine classes. The Powerplus design
210-497: Was a racing version with the engine capacity reduced to 746 cc by shortening the stroke from 83 to 73 mm and fitted with a Powerplus supercharger . The smaller engine capacity was to allow the car to compete in 750 cc class racing events. Larger brakes from the L-type were fitted. The J4 was a pure racing version with lightweight body work and the J3 engine, but using more boost from
225-528: Was the invention of Captain George Eyston , the land speed record holder. Supercharging first appeared on production MGs with the C type or Montlhéry Midget, inspired by Eyston's EX120 record-breaker of 1930 – the first 750 cc car to break 100 mph. In the 850 cc class, the 846 cc J3 and the rare (only nine were built) pure-racing J4 of 1932 used the Powerplus. All of MG's superchargers were mounted ahead of and roughly in-line with
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