JA Prestwich Industries
J. A. P. (short JAP) was a British built-in motor manufacturer. The company's business is derived from the initials of the company founder John Alfred Prestwich. In the 1920s and 1930s was A. J. P. 's second largest supplier of OEM engines in Europe.
Description
J. A. P. began around 1904 in London Tottenham producing complete motorcycles, however, the motorcycle production in 1908 abandoned in favor of motor production and motor development. Famous brands that respect before the First World War, J.- A. -P.- engines, were, among others, BAT, Chater - Lea, Martin, Matchless, Sunbeam, Trump, Triumph, Zenith, but also Morgan, then a manufacturer of Threewheelern. After 1918, not least as businesses Brough Superior for the further popularity of these engines at. J. A. P. delivered at the beginning of the 1920s, high-performance engines in almost all displacement classes. From the late 1920s, J.- A. -P.- engines were widespread throughout Europe and America.
Many motorcycle manufacturers who build their own engines could not afford to build J.- A. -P.- engines. In addition, special engines were produced with a displacement up to 1400 cc (V2 ), for example, for track cars.
In racing, many manufacturers are familiar straight to the 250cc, 350cc, 500cc and 1000cc engines, but also P. A. J. built 175er, 200er, 300er, 680er, 750er, etc. in various designs: with side valves, overhead valve, with automatic inlet valves and the mid-1920s engines with overhead camshaft. A 1000- V2 -Racing -J. A. P. could run on ethanol quite make up to 70 hp. For record purposes, these engines were partially charged with compressors.
The heyday for J. A. P. was over by 1932/1933. Firstly, many motorcycle manufacturers were forced to close their doors due to the economic crisis, on the other hand the German market due to import restrictions broke almost completely gone and finally built many " survivors " of the world economic crisis now own engines. For J. A. P. primarily remained the market for specialty engines, for example, sand and grass track racing. Up until the 1960s the sport of J. A. P. was dominated and then still ran engines on J.- A. -P.- base. The company, was incorporated in 1945 by the Birmingham Motor Manufacturers Villiers Ltd.. In 1957 they built only industrial engines.
Number key
At least the engines that were built from 1920 onwards, can be broken down based on the chosen on the crankcase letter codes. So is the first letter for bore × stroke and the resulting displacement:
- Z = 175 cm ³ (55 x 73 mm )
- V = 175 cc (60 x 62 mm )
- N = 200 cc ( 55 × 83 mm )
- P = 250 cc (62.5 × 80 mm)
- B = 250 cm ³ ( 64.5 × 76 mm)
- A = 300 cc (70 × 78 mm )
- F = 300 cc (70 × 76 mm)
- G = 350 cc (70 × 88 mm )
- I = 350 cm ³ (70 × 90 mm)
- S = 350 cm ³ (74 × 80 mm)
- E = 375 cc (74 x 85 mm)
- M = 300 cc (70 × 97 mm )
- J = 500 cc (80 x 99 mm )
- K = 500 cm ³ ( 85.5 x 85 mm)
- L = 550 cm ³ ( 85.5 × 97 mm )
- U = 600 cc ( 85.5 × 104 mm )
In a two- cylinder now a "T" for Twin would follow.
- GT = 680 cm ³
- MT = 750 cc
- KT and JT = 1000 cm ³
Now, the letters come for the respective versions:
- O = OHV control ( overhead valves / overhead valves )
- W = water-cooled
- S = short stroke or special motor
- R = race engine
- Z = dry sump lubrication
- C = Motor Sport
- Y = dual exhaust / dual-port - cylinder head
The letters were combined. Now follows a slash and then the year of construction, according to the following letter is quoted:
So 1920 starts with the letter "P " of the word PNEUMATICS and ends for 1929 "S". W = 1930, H = 1931, Y = 1932, Z = 1933, D = 1934, R = 1935, V = 1936, F = 1937, O = 1938, G = 1939
After the serial number follows.
A KTOYZ / I 22312 so would be for example, a 1000 V2 overhead valve, twin port cylinder heads and dry-sump lubrication from the year 1927.
Automobile production
Between 1904 and 1905 it also manufactured automobiles in America. This was around trikes with a single rear wheel. The engine with 593 cc displacement and 4.5 horsepower was mounted at the front of the vehicle. The open body could accommodate two people side by side.