31:
335:, introduced a 3-speed countershaft gearbox with integral kick-starter, which posed a design problem for motorcycles with transversely-mounted flat-twin engines. This gearbox could be relatively easily located behind a single-cylinder or V-twin engine, however this arrangement would result in an excessively long wheelbase for flat-twin engines. Solutions to this problem included using a countershaft below the engine (as used by the Douglas Fairy), or a gearbox located above the engine, although in some cases the cylinders were short enough to use the gearbox in the traditional location behind the engine.
171:
406:
198:, which used a flat-twin engine. This engine had an unusual design of two counter-rotating crankshafts, with each piston attached to its crankshaft by a thick connecting rod. Each piston was also connected to the other crankshaft by two thinner connecting rods, causing the two pistons to move on the same axis. It also had the torque reaction of one crankshaft cancel the torque reaction of the other, cancelling torque reaction in the engine. Lanchester used this engine design until 1904.
301:
88:
475:
119:
325:, one of Light Motors' suppliers, when the Light Motors Company folded in 1907. Later in 1907, Douglas changed the drivetrain from the chain and pulley design to a belt-drive system driven directly from the engine. Later developments of the Douglas motorcycle were made with the cylinders in line with the frame until the Second World War.
388:
435:
Longitudinal mounting also means that the torque reaction will twist the motorcycle to one side (such as on sharp acceleration/deceleration or when opening the throttle in neutral) instead of shifting the weight balance between the front and rear wheels. However, many modern motorcycles reduce this
78:
The
Australian lawnmower manufacturer Victa also produced a flat-twin engine push mower from August 1975 to 1980 dubbed the āTwin 500ā, and later the āSupremeā. These engines were manufactured in Canada. They are very sought after as only small numbers were produced, most likely due to ignition- and
320:
was built in 1905 by the Light Motors
Company in the United Kingdom. Originally named the FĆ©e (renamed "Fairy" soon after its introduction), it was designed as a "bicycle engine system" which transmitted power to a pulley on the rear wheel via a chain. Manufacture of the Fairy was taken over by the
1714:
are turned on (this engine can also be started manually by pulling a cable). After the Riedel unit has reached a speed of about 300 rpm, it automatically engages the compressor shaft of the turbojet. At about 800 rpm of the starting engine, the starting fuel pump is turned on, and at 1,200 rpm the
71:
car released in 1900. The flat-twin engine was used in several other cars since, however a more common usage is in motorcycles; early models oriented the cylinders in line with the frame, however later models switched to the cylinders being perpendicular to the frame to provide even cooling across
431:
with a V-twin with the cylinders in line with the frame. A side benefit is that the cylinders provide protection to the rider in the event of a collision or fall, and keeps their feet warm in cold weather. The downsides are that the engine cannot be mounted as close to the ground (otherwise the
145:
during each inward piston stroke and de-pressurisation during each outward piston stroke, since both pistons are moving inwards or outwards at the same time. This crankcase pumping effect (also found on single-cylinder engines and 360Ā° parallel-twin engines) is usually addressed by means of a
312:
The benefits of using a flat-twin engine mounted with the crankshaft running perpendicular to the frame (therefore the cylinders being in line with the frame) are a low centre of gravity and that a belt-drive or chain-drive system can be used to transmit drive to the rear wheel. However, the
1779:
The twin, or 72 as it was commonly referred to, was used primarily as a source of power for the Maytag washing machines. Even as late as the early '30s, some brands of washers were hand operated; thus a ready power source such as the twin had a great deal of influence on
Americans' work
106:
and are therefore called "boxer-twin" engines. In a boxer-twin engine, the 180Ā° crankshaft moves the pistons in phase with each other, therefore the forces generated by one piston are cancelled out by the other, resulting in excellent primary balance. The evenly spaced
133:, which is a simple ignition system using a double-ended coil firing both spark plugs on each revolution (i.e. during both the compression and exhaust strokes). This system is distributorless and requires only a single contact breaker and coil for the engine.
1715:
main (J-2) fuel is turned on. The starter engine is kept engaged until the turbojet attains 2,000 rpm, at which time the starter engine and starting fuel are turned off, the turbojet rapidly accelerating to rated speed of 9,500 rpm on the J-2 fuel
422:
The main benefit of mounting a flat-twin engine with the crankshaft in line with the frame (therefore the cylinders sitting sideways in the frame) is that an air-cooled engine receives the same amount of cooling for each cylinder. The
574:) produced flat-twin two-stroke petrol engines during World War II which were used for generators and other military uses. After 1945, Enfield produced flat-twin diesel engines, with applications including farm and marine use.
1364:
However, it does create some problems for longitudinal development of the bike because the boxer cylinders have to be positioned high up from the ground in order to protect them from scraping the ground when leant over in
585:
for boats, as they were smoother than single-cylinder engines. In the 1940s, they were largely replaced by straight-twin two-stroke engines, which were easier to start and no longer had excessive amounts of vibration.
1431:
By arranging the rest of the engine internals to rotate in the opposite direction to the crankshaft their forces are cancelled out without having to resort to the weight, complexity and friction associated with two
493:
and double acting pistons. In 1908, the French company
Dutheil-Chalmers began production of flat-twin aircraft engines, which used two counter-rotating crankshafts. The Dutheil-Chlamers engine was used by the 1907
858:
One crank lived above the other, and each piston had three connecting rodsātwo light outer ones and a heavier one in the centre. The light rods went to one crank, the heavy rods to the other, and the two shafts
746:
578:
introduced a diesel version of its existing 688 cc petrol flat-twin in 1932, and went on to produce flat-twin diesel and petrol engines for a variety of industrial and marine uses into the 1950s.
769:
489:(which would later become one of the first aircraft to achieve flight) was powered by a flat-twin engine built on a farm by a hobbyist inventor. This engine used the unusual design of a single shared
1398:
Though the
Valkyrie also has a longitudinal crankshaft, this torque reaction has been eliminated by making some of the components, such as the alternator, spin the opposite direction of the engine.
153:
boxer-twin engine took advantage of this pumping effect to maintain a partial vacuum inside the crankcase, in order to reduce oil leaks when an oil seal malfunctions. This was achieved by using a
2033:
313:
downsides are uneven heat distribution (the front cylinder is more heavily cooled than the rear cylinder) and a longer wheelbase is often required due to the length of the engine.
79:
fuel-related problems in early models. In the
Supreme (the later model) all these problems were fixed with a rear-domed piston, crankcase mixers and refined ignition system.
224:, produced from 1948 to 1990, was one of the first front-wheel drive cars to use a flat engine. The 2CV was powered by an air-cooled boxer-twin engine. Also in 1948, the
328:
Other early flat-twin motorcycles used a similar layout, with their cylinders aligned along the frame and therefore with the crankshaft running transverse to the frame.
1710:
Starting procedure is as follows: Starting engine is primed by closing electric primer switch, then ignition of turbojet and ignition and electric starting motor of
846:
1324:
Mechanically, the large cooling fins stuck straight out in the breeze, reportedly keeping the XA's oil temperature 100 degrees cooler than a standard Harley 45.
754:
366:
8 hp (6.0 kW), and the
Bayerische Flugzeugwerke Helios (the predecessor to BMW's first motorcycle). Models produced in the United States included the
777:
563:'Model 72' flat-twin enginesā produced from 1937 until some time between 1952 and 1960ā were used in various applications including clothes washing machines.
1378:
451:
was another early example of a longitudinally-mounted flat-twin engine, although it this case the power was transmitted to the rear wheel via a shaft drive.
1756:
268:
used an in-house developed water-cooled boxer-twin engine (Enertron engine) and the
Volkswagen air-cooled boxer-four in several models from 1988 to 1994.
2026:
1212:
Like the early
Douglases, the Model O had its engine placed in the frame with the cylinders facing fore and aft, rather than sticking out to each side...
1689:
228:
was released with front-wheel drive and an air-cooled boxer-twin engine. Other cars following World War II using boxer-twin engines were the 1945-1954
1676:
Both lecturers discussed the claims of the auxiliary engine for supplying service power. This is a well-known
British example, the A.B.C. flat twin.
512:
Most piston-engined aircraft used more than two cylinders, however other flat-twin aircraft engines from the 1920s and 1930s include the American
2588:
2019:
1869:
958:
911:
566:
Electrical generators using flat-twin engines were built by Norman Engineering Company from 1932 to 1968 and by Douglas during World War II.
75:
Flat-twin engines were also used in several aircraft up until the 1930s and in various stationary applications from the 1930s to the 1960s.
427:, which used a flat-twin engine with the cylinders across the frame, maintained an oil temperature 100 Ā°F (56 Ā°C) cooler than a
1444:
432:
cylinders can scrape the ground during cornering) and that it exposes the cylinders and valve covers to the danger of collision damage.
1600:
1512:
1080:
2144:
1739:
1351:
1305:
1258:
1235:
1192:
1038:
998:
880:
814:
630:
30:
252:. Several rear-engined cars were also produced with boxer-twin engines originally designed for motorcycles, such as the 1957-1975
1411:
181:
The beginnings of the flat-twin engine were in 1896, when Karl Benz obtained a patent for the design. A year later, his company
1793:
1855:
1956:
1882:
Often equipped with a foot pedal kick-starter, Maytag motors were available in both single-cylinder and opposed-twin formats.
338:
In 1916, most flat-twin motorcycles still used a transversely-mounted engine. The European models at this time included the
1823:
1498:
202:
2237:
2164:
668:
170:
836:
2578:
2573:
2060:
1920:
1894:
1162:
1109:
1056:
703:
646:
53:
1859:
1386:
405:
1764:
2314:
2154:
548:
495:
189:
111:
also assists in reducing vibration. The equal and opposite forces in a boxer-twin engine do however generate a
1697:
447:
at the gearbox to change the direction of the drive through ninety degrees. BMW's first motorcycle, the 1923
371:
194:
1134:
157:(a leather or rubber flap over a hole in the crankcase), to let air escape the crankcase but not enter it.
2309:
2264:
2174:
2107:
359:
2583:
2299:
2294:
2274:
2199:
2159:
2149:
2102:
2097:
1656:
1278:
In building the Sport Twin, Harley took Douglas' lead in orienting the cylinders in line with the frame.
1123:
347:
339:
322:
305:
56:
with the cylinders on opposite sides of the crankshaft. The most common type of flat-twin engine is the
34:
1145:
501:
experimental airplane, with later versions of this airplane being produced with flat-twin engines from
2304:
2284:
2279:
2269:
2247:
2189:
2080:
2075:
2042:
536:
363:
1227:
1219:
2538:
2362:
2289:
2184:
2134:
428:
2357:
2227:
2222:
2179:
2117:
463:
436:
effect by rotating flywheels or alternators in the opposite direction to that of the crankshaft.
424:
394:
351:
343:
112:
1574:
1377:
Friedman, Art; Trevitt, Andrew; Cherney, Andrew; Elvidge, Jamie; Brasfield, Evans (April 2000).
1696:. United States Army Air Force - Turbojet and Gus Turbine Developments, HQ, AAF. Archived from
2347:
2232:
2217:
2194:
1992:
1952:
1946:
1865:
1735:
1347:
1337:
1309:
1293:
1262:
1246:
1231:
1196:
1076:
1034:
994:
954:
932:
907:
876:
810:
721:
626:
506:
317:
284:
241:
1980:
1452:
1180:
1030:
1021:
901:
897:
707:
2337:
486:
300:
2011:
1608:
2352:
2342:
2256:
2209:
2112:
575:
440:
272:
229:
439:
One of the first motorcycles with a longitudinally-mounted flat-twin engine was the 1916
2122:
1711:
841:
582:
544:
521:
478:
367:
332:
280:
276:
237:
225:
221:
174:
150:
1549:
2567:
2533:
2523:
2380:
2169:
2087:
2046:
1419:
571:
517:
513:
182:
1801:
532:
is an oil-cooled flat twin for ultralight aircraft that is currently in production.
443:, which was built in the United Kingdom. To accommodate chain drive, the ABC used a
87:
2065:
1727:
1473:
455:
233:
210:
206:
130:
122:
108:
1341:
948:
275:
was an air-cooled flat-twin engine produced from 1961 to 1976. Introduced in the
2324:
2129:
2070:
712:
474:
214:
185:
unveiled the first flat-twin engine, a boxer design called the "contra engine".
154:
99:
91:
2497:
2492:
2487:
2454:
2449:
2444:
2439:
2434:
2429:
2424:
2412:
2400:
2139:
2092:
1830:
540:
444:
245:
103:
42:
1996:
1346:(English ed.). St. Paul, MN USA: Motorbooks International. p. 118.
1313:
1266:
1200:
725:
679:
2482:
2419:
2407:
2395:
2390:
2385:
1385:. Source Interlink Media. "Take a Spin" section, paragraph 4. Archived from
490:
412:
355:
142:
64:
547:
firm in Germany designed and manufactured a two-stroke flat-twin engine as
454:
Over time, longitudinal mounting became more common for flat-twin engines.
118:
2548:
2543:
2528:
2507:
2502:
2477:
2472:
2464:
2372:
529:
525:
459:
253:
17:
1898:
654:
41:"Flat Twin" redirects here. For Soviet radar nicknamed "flat twin", see
502:
448:
261:
257:
249:
115:, due to the offset distance between the pistons along the crankshaft.
1734:(Second ed.). Cambridge, England: Patrick Stephens. p. 141.
993:(Third impression ed.). The Hamlyn Publishing Group. p. 23.
387:
1537:
560:
265:
1071:
Partridge, Michael (1976), "1905 2 1ā2hp Joseph Barter motorcycle",
350:
2.75 hp (2.05 kW) and 4 hp (3.0 kW) models, the
1763:. Topeka, Kansas, United States: Ogden Publications. Archived from
1226:. Lincolnwood, Illinois, USA: Publications International. pp.
1798:
Old Iron and Other Americana: The collections of the Kinney family
551:
for the Junkers Jumo 004, BMW 003 and Heinkel HeS 011 jet engines
473:
299:
169:
117:
86:
67:
in 1896 and the first production flat-twin engine was used in the
29:
1550:"Richard Pearse : New Zealand Pioneer Aviator (1877 - 1953)"
953:(e-book ed.). Poundbury, Dorchester, UK: Veloce Publishing.
60:, where both pistons move inwards and outwards at the same time.
1073:
Motorcycle Pioneers: The Men, the Machines, the Events 1860-1930
2015:
1601:"Principal Aero Engines of 1910: Page 141 - Horizontal Engines"
1655:
Chaplin, R. H.; Nixon, F. (1939-04-06). Poulsen, C. M. (ed.).
1022:"The Origins of BMW: From Flying Machines to Driving Machines"
1864:. Motorbooks Workshop. MotorBooks International. p. 42.
1690:"Design Analysis of BMW 003 Turbojet - "Starting the Engine""
1630:
1379:"Sport Cruisers Comparison - Seven Sport-Cruiser Motorcycles"
1979:
Holcolmb, Hank (October 1964). Juettner, Walter R. (ed.).
458:
has a long history of flat-twin engine motorcycles, as do
141:
The boxer-twin configuration can cause pressuring of the
1513:"Richard Pearse Designed and Built Early Flying Machine"
535:
In larger aircraft, flat-twin engines have been used in
942:
940:
27:
Piston engine with two cylinders in opposing directions
1575:"Dutheil-Chalmers Ćole Opposed-Piston Aircraft Engine"
669:"2CV Stuff: A Series Ignition System - Specifications"
244:
sportscar and several front-wheel drive models from
2516:
2463:
2371:
2323:
2255:
2246:
2208:
2053:
1166:. Iliffe & Sons Ltd.: 400ā403 November 9, 1916.
720:(1). Newport Beach, CA US: Hachette Magazines: 14.
201:Other early uses of flat-twin engines were 1903-04
1020:
950:The Complete Catalogue of British Cars 1895 - 1975
903:Ford Model T: The Car that Put the World on Wheels
678:. Grantham, Lincolnshire, UK: Oui2. Archived from
279:subcompact car, the U engine was also used in the
543:in the 1920s and 1930s. During World War II, the
331:In 1914 the main supplier of rear-hub gearboxes,
1075:, David & Charles (Publishers), p. 42,
1732:The Development of Jet and Turbine Aero Engines
809:. Feltham, Middlesex, UK: Hamlyn. p. 140.
621:Wilson, Hugo (1995). "The A-Z of Motorcycles".
354:3.5 hp and 6 hp (4.5 kW) models, the
1418:. Stephen Battisson. p. 3. Archived from
1060:. Iliffe & Sons Ltd.: 283 October 5, 1916.
2027:
1113:. Iliffe & Sons Ltd.: 274 27 August 1914.
984:
982:
980:
978:
976:
974:
972:
970:
8:
1029:. New York, NY, USA: Beekman House. p.
1948:The World guide to automobile manufacturers
1247:"Classics: 1922 Harley-Davidson Sport Twin"
873:Standard Catalog of American Cars 1805-1942
800:
798:
796:
794:
770:"The engine that Benz built still survives"
2252:
2034:
2020:
2012:
1897:. Maytag Collector's club. Archived from
1155:
1153:
1094:
1014:
1012:
1010:
947:Culshaw, David; Horrobin, Peter (2013) .
837:"The 10 Most Unusual Engines of All Time"
581:Two-stroke flat-twins were often used as
1919:Brown, Roland (NovemberāDecember 2007).
1755:Shelton, Charles L. (MarchāApril 1999).
747:"Citroen 2CV engine operation animation"
616:
614:
612:
610:
608:
606:
604:
602:
600:
598:
830:
828:
826:
594:
1991:(4). New York, NY USA: Hearst: 34ā35.
1412:"Developing the V6 - Taming The Beast"
1107:"A Sturmey-Archer Countershaft Gear".
845:. Hearst. Lanchester Twin-Crank Twin.
706:(January 1992). Edwards, David (ed.).
539:(APUs). A notable example was made by
37:80 Plus motorcycle engine (circa 1950)
1794:"Maytag Engine-Driven Wringer Washer"
63:The flat-twin design was patented by
7:
1501:. University of Waikato. 2012-04-26.
989:Willoughby, Vic (1977) . "Douglas".
875:. Krause Publications. p. 572.
1294:"Classics: 1942 Harley-Davidson XA"
906:. Minneapolis, MN USA: Motorbooks.
129:A commonly used ignition system is
625:. London, UK: Dorling Kindersley.
623:The Encyclopedia of the Motorcycle
25:
1856:"Short Profiles of Manufacturers"
1757:"Maytag Twins or 'Look-a-Likes'?"
1306:American Motorcyclist Association
1259:American Motorcyclist Association
1193:American Motorcyclist Association
1179:Wood, Bill, ed. (October 2001b).
776:. Toronto, Canada. Archived from
647:"BMW Motorcycle Engine Animation"
283:small commercial vehicle and the
1829:. pp. 11ā16. Archived from
1343:Motorcycle Design and Technology
1027:BMW - Bavaria's Driving Machines
404:
386:
1245:Wood, Bill, ed. (March 2001a).
1181:"Classics: 1917 Indian Model O"
849:from the original on 2012-07-03
342:3.5 hp (2.6 kW), the
1951:. Facts on File Publications.
1292:Wood, Bill, ed. (March 1999).
898:"Chapter 1 Before the Model T"
1:
1824:"Maytag Service Instructions"
1220:"The Early Years (1903ā1928)"
264:. The Brazilian manufacturer
98:Most flat-twin engines use a
2589:Piston engine configurations
1895:"Maytag Multi-Motor Engines"
1854:Hunn, Peter (Jun 13, 2005).
1792:Kinney, Keith (2007-02-27).
1688:Schulte, Rudolph C. (1946).
1499:"Richard Pearse's monoplane"
1054:"The engine of the future".
195:Lanchester 8 hp Phaeton
1410:Battisson, Stephen (1997).
1191:(10). Pickerington, OH US:
1135:Drawing of 1932 Douglas K32
835:Smith, Sam (October 2010).
768:English, Bob (2010-04-29).
323:Douglas Engineering Company
2605:
1981:"Inside Today's Outboards"
1657:"Ancillary Power Services"
1445:"BMW Motorrad USA - Bikes"
1304:(3). Pickerington, OH US:
1257:(3). Pickerington, OH US:
805:Rogliatti, Gianni (1973).
568:Enfield Industrial Engines
524:, and the Czechoslovakian
217:models from 1910 to 1937.
54:internal combustion engine
40:
1861:The Small-Engine Handbook
1694:legendsintheirowntime.com
1538:Drawing of replica engine
1224:Harley-Davidson Chronicle
549:jet engine starter motors
190:Lanchester Engine Company
177:engine (viewed from rear)
1921:"1955 Douglas Dragonfly"
1338:"Chapter 11: The Engine"
896:Brooke, Lindsay (2008).
496:Santos-Dumont Demoiselle
481:II installed in aircraft
192:began production of the
94:crankshaft configuration
1667:(1580). London: 357ā359
1579:www.oldmachinepress.com
1336:Cocco, Gaetano (2004).
1146:Drawing of 1926 Douglas
1124:Drawing of 1911 Douglas
1019:Norbye, Jan P. (1984).
871:Kimes, Beverly (1996).
372:Harley-Davidson Model W
69:Lanchester 8 hp Phaeton
2175:Single-acting cylinder
2108:Double-acting cylinder
1945:Baldwin, Nick (1987).
1631:"HKS Aviation Engines"
1218:Mitchel, Doug (1997).
651:www.animatedpiston.com
482:
309:
178:
126:
102:configuration for the
95:
38:
2043:Engine configurations
1700:on September 29, 2018
1478:www.nzhistory.govt.nz
1298:American Motorcyclist
1251:American Motorcyclist
1185:American Motorcyclist
537:auxiliary power units
477:
378:Longitudinal mounting
303:
173:
121:
90:
33:
2145:Oscillating cylinder
1927:. Ogden Publications
933:Specification tables
364:Williamson Flat Twin
316:The first flat-twin
232:van,, the 1961-1976
146:crankcase breather.
2238:Two-and four-stroke
2140:Intake over exhaust
1925:Motorcycle Classics
1761:Gas Engine Magazine
1517:www.worldhistory.us
1449:bmwmotorcycles.com/
991:Classic Motorcycles
757:on 19 January 2019.
429:Harley-Davidson WLA
296:Transverse mounting
2579:Automobile engines
2574:Motorcycle engines
1635:www.hksengines.com
1383:Motorcycle Cruiser
774:The Globe and Mail
483:
425:Harley-Davidson XA
395:Harley-Davidson XA
310:
260:and the 1959-1965
179:
137:Crankcase pressure
127:
96:
52:is a two-cylinder
39:
2561:
2560:
2557:
2556:
2257:Inline / straight
2155:Overhead camshaft
1871:978-0-76032-049-5
1605:www.oldengine.org
1554:www.monash.edu.au
960:978-1-845845-83-4
913:978-0-76032-728-9
751:www.discourse.com
318:motorcycle engine
285:Toyota Sports 800
242:Toyota Sports 800
58:boxer-twin engine
16:(Redirected from
2596:
2253:
2248:Cylinder layouts
2036:
2029:
2022:
2013:
2007:
2006:
2004:
2003:
1976:
1970:
1969:
1967:
1965:
1942:
1936:
1935:
1933:
1932:
1916:
1910:
1909:
1907:
1906:
1891:
1885:
1884:
1879:
1878:
1851:
1845:
1844:
1842:
1841:
1835:
1828:
1819:
1813:
1812:
1810:
1809:
1800:. Archived from
1789:
1783:
1782:
1776:
1775:
1769:
1752:
1746:
1745:
1724:
1718:
1717:
1707:
1705:
1685:
1679:
1678:
1673:
1672:
1652:
1646:
1645:
1643:
1641:
1627:
1621:
1620:
1618:
1616:
1611:on 3 August 2019
1607:. Archived from
1597:
1591:
1590:
1588:
1586:
1571:
1565:
1564:
1562:
1560:
1546:
1540:
1535:
1529:
1528:
1526:
1524:
1509:
1503:
1502:
1495:
1489:
1488:
1486:
1484:
1474:"Richard Pearse"
1470:
1464:
1463:
1461:
1460:
1451:. Archived from
1441:
1435:
1434:
1428:
1427:
1407:
1401:
1400:
1395:
1394:
1374:
1368:
1367:
1361:
1360:
1333:
1327:
1326:
1321:
1320:
1289:
1283:
1280:
1275:
1273:
1241:
1214:
1209:
1207:
1174:
1168:
1167:
1157:
1148:
1143:
1137:
1132:
1126:
1121:
1115:
1114:
1104:
1098:
1092:
1086:
1085:
1068:
1062:
1061:
1051:
1045:
1044:
1024:
1016:
1005:
1004:
986:
965:
964:
944:
935:
930:
924:
923:
921:
920:
893:
887:
886:
868:
862:
861:
855:
854:
832:
821:
820:
802:
789:
788:
786:
785:
765:
759:
758:
753:. Archived from
743:
737:
736:
734:
732:
700:
694:
693:
691:
690:
684:
673:
665:
659:
658:
657:on 27 June 2017.
653:. Archived from
643:
637:
636:
618:
487:Pearse monoplane
408:
390:
256:, the 1957-1959
240:, the 1965-1969
236:, the 1961-1978
209:, the 1905-1906
205:, the 1904-1905
72:both cylinders.
50:flat-twin engine
21:
2604:
2603:
2599:
2598:
2597:
2595:
2594:
2593:
2564:
2563:
2562:
2553:
2512:
2459:
2367:
2319:
2242:
2204:
2049:
2040:
2010:
2001:
1999:
1978:
1977:
1973:
1963:
1961:
1959:
1944:
1943:
1939:
1930:
1928:
1918:
1917:
1913:
1904:
1902:
1893:
1892:
1888:
1876:
1874:
1872:
1853:
1852:
1848:
1839:
1837:
1833:
1826:
1822:
1820:
1816:
1807:
1805:
1791:
1790:
1786:
1773:
1771:
1767:
1754:
1753:
1749:
1742:
1726:
1725:
1721:
1703:
1701:
1687:
1686:
1682:
1670:
1668:
1654:
1653:
1649:
1639:
1637:
1629:
1628:
1624:
1614:
1612:
1599:
1598:
1594:
1584:
1582:
1573:
1572:
1568:
1558:
1556:
1548:
1547:
1543:
1536:
1532:
1522:
1520:
1511:
1510:
1506:
1497:
1496:
1492:
1482:
1480:
1472:
1471:
1467:
1458:
1456:
1443:
1442:
1438:
1425:
1423:
1422:on July 8, 2011
1409:
1408:
1404:
1392:
1390:
1376:
1375:
1371:
1358:
1356:
1354:
1335:
1334:
1330:
1318:
1316:
1291:
1290:
1286:
1271:
1269:
1244:
1238:
1217:
1205:
1203:
1178:
1175:
1171:
1163:The Motor Cycle
1159:
1158:
1151:
1144:
1140:
1133:
1129:
1122:
1118:
1110:The Motor Cycle
1106:
1105:
1101:
1093:
1089:
1083:
1070:
1069:
1065:
1057:The Motor Cycle
1053:
1052:
1048:
1041:
1018:
1017:
1008:
1001:
988:
987:
968:
961:
946:
945:
938:
931:
927:
918:
916:
914:
895:
894:
890:
883:
870:
869:
865:
859:counterrotated.
852:
850:
834:
833:
824:
817:
804:
803:
792:
783:
781:
767:
766:
762:
745:
744:
740:
730:
728:
702:
701:
697:
688:
686:
682:
671:
667:
666:
662:
645:
644:
640:
633:
620:
619:
596:
592:
583:outboard motors
576:Coventry Victor
557:
472:
420:
419:
418:
417:
416:
409:
400:
399:
398:
391:
380:
358:6 hp, the
298:
293:
273:Toyota U engine
230:Jowett Bradford
168:
163:
139:
125:ignition system
85:
46:
28:
23:
22:
15:
12:
11:
5:
2602:
2600:
2592:
2591:
2586:
2581:
2576:
2566:
2565:
2559:
2558:
2555:
2554:
2552:
2551:
2546:
2541:
2536:
2531:
2526:
2520:
2518:
2514:
2513:
2511:
2510:
2505:
2500:
2495:
2490:
2485:
2480:
2475:
2469:
2467:
2461:
2460:
2458:
2457:
2452:
2447:
2442:
2437:
2432:
2427:
2422:
2417:
2416:
2415:
2405:
2404:
2403:
2393:
2388:
2383:
2377:
2375:
2369:
2368:
2366:
2365:
2360:
2355:
2350:
2345:
2340:
2335:
2329:
2327:
2321:
2320:
2318:
2317:
2312:
2307:
2302:
2297:
2292:
2287:
2282:
2277:
2272:
2267:
2261:
2259:
2250:
2244:
2243:
2241:
2240:
2235:
2230:
2225:
2220:
2214:
2212:
2206:
2205:
2203:
2202:
2197:
2192:
2187:
2182:
2177:
2172:
2167:
2162:
2160:Overhead valve
2157:
2152:
2150:Opposed-piston
2147:
2142:
2137:
2132:
2127:
2126:
2125:
2115:
2110:
2105:
2100:
2095:
2090:
2085:
2084:
2083:
2078:
2068:
2063:
2057:
2055:
2051:
2050:
2047:piston engines
2041:
2039:
2038:
2031:
2024:
2016:
2009:
2008:
1971:
1957:
1937:
1911:
1886:
1870:
1846:
1814:
1784:
1747:
1740:
1719:
1680:
1647:
1622:
1592:
1581:. 20 July 2017
1566:
1541:
1530:
1504:
1490:
1465:
1436:
1416:The Laverda V6
1402:
1369:
1352:
1328:
1284:
1282:
1281:
1242:
1236:
1215:
1169:
1160:"Flat Twins".
1149:
1138:
1127:
1116:
1099:
1095:Partridge 1976
1087:
1082:0-7153-7-209-2
1081:
1063:
1046:
1039:
1006:
999:
966:
959:
936:
925:
912:
888:
881:
863:
842:Car and Driver
822:
815:
790:
760:
738:
704:Cameron, Kevin
695:
660:
638:
631:
593:
591:
588:
556:
553:
522:Bristol Cherub
520:, the British
507:ClƩment-Bayard
479:Bristol Cherub
471:
468:
410:
403:
402:
401:
392:
385:
384:
383:
382:
381:
379:
376:
368:Indian Model O
333:Sturmey-Archer
297:
294:
292:
289:
281:Toyota MiniAce
277:Toyota Publica
266:Gurgel Motores
238:Toyota Publica
226:Panhard Dyna X
213:. and several
183:Benz & Cie
167:
164:
162:
159:
138:
135:
113:rocking couple
84:
83:Typical design
81:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
2601:
2590:
2587:
2585:
2582:
2580:
2577:
2575:
2572:
2571:
2569:
2550:
2547:
2545:
2542:
2540:
2537:
2535:
2532:
2530:
2527:
2525:
2522:
2521:
2519:
2515:
2509:
2506:
2504:
2501:
2499:
2496:
2494:
2491:
2489:
2486:
2484:
2481:
2479:
2476:
2474:
2471:
2470:
2468:
2466:
2462:
2456:
2453:
2451:
2448:
2446:
2443:
2441:
2438:
2436:
2433:
2431:
2428:
2426:
2423:
2421:
2418:
2414:
2411:
2410:
2409:
2406:
2402:
2399:
2398:
2397:
2394:
2392:
2389:
2387:
2384:
2382:
2379:
2378:
2376:
2374:
2370:
2364:
2361:
2359:
2356:
2354:
2351:
2349:
2346:
2344:
2341:
2339:
2336:
2334:
2331:
2330:
2328:
2326:
2322:
2316:
2313:
2311:
2308:
2306:
2303:
2301:
2298:
2296:
2293:
2291:
2288:
2286:
2283:
2281:
2278:
2276:
2273:
2271:
2268:
2266:
2263:
2262:
2260:
2258:
2254:
2251:
2249:
2245:
2239:
2236:
2234:
2231:
2229:
2226:
2224:
2221:
2219:
2216:
2215:
2213:
2211:
2210:Stroke cycles
2207:
2201:
2198:
2196:
2193:
2191:
2188:
2186:
2183:
2181:
2178:
2176:
2173:
2171:
2168:
2166:
2163:
2161:
2158:
2156:
2153:
2151:
2148:
2146:
2143:
2141:
2138:
2136:
2133:
2131:
2128:
2124:
2121:
2120:
2119:
2116:
2114:
2111:
2109:
2106:
2104:
2101:
2099:
2096:
2094:
2091:
2089:
2086:
2082:
2079:
2077:
2074:
2073:
2072:
2069:
2067:
2064:
2062:
2059:
2058:
2056:
2052:
2048:
2044:
2037:
2032:
2030:
2025:
2023:
2018:
2017:
2014:
1998:
1994:
1990:
1986:
1982:
1975:
1972:
1960:
1954:
1950:
1949:
1941:
1938:
1926:
1922:
1915:
1912:
1901:on 2009-05-27
1900:
1896:
1890:
1887:
1883:
1873:
1867:
1863:
1862:
1857:
1850:
1847:
1836:on 2011-01-25
1832:
1825:
1818:
1815:
1804:on 2010-01-17
1803:
1799:
1795:
1788:
1785:
1781:
1770:on 2011-10-06
1766:
1762:
1758:
1751:
1748:
1743:
1741:1-85260-586-3
1737:
1733:
1729:
1728:Gunston, Bill
1723:
1720:
1716:
1713:
1712:Riedel engine
1699:
1695:
1691:
1684:
1681:
1677:
1666:
1662:
1658:
1651:
1648:
1636:
1632:
1626:
1623:
1610:
1606:
1602:
1596:
1593:
1580:
1576:
1570:
1567:
1555:
1551:
1545:
1542:
1539:
1534:
1531:
1519:. 1 July 2017
1518:
1514:
1508:
1505:
1500:
1494:
1491:
1479:
1475:
1469:
1466:
1455:on 2008-08-22
1454:
1450:
1446:
1440:
1437:
1433:
1421:
1417:
1413:
1406:
1403:
1399:
1389:on 2010-05-02
1388:
1384:
1380:
1373:
1370:
1366:
1355:
1353:0-7603-1990-1
1349:
1345:
1344:
1339:
1332:
1329:
1325:
1315:
1311:
1307:
1303:
1299:
1295:
1288:
1285:
1279:
1268:
1264:
1260:
1256:
1252:
1248:
1243:
1239:
1237:0-7853-2514-X
1233:
1229:
1225:
1221:
1216:
1213:
1202:
1198:
1194:
1190:
1186:
1182:
1177:
1176:
1173:
1170:
1165:
1164:
1156:
1154:
1150:
1147:
1142:
1139:
1136:
1131:
1128:
1125:
1120:
1117:
1112:
1111:
1103:
1100:
1097:, p. 42.
1096:
1091:
1088:
1084:
1078:
1074:
1067:
1064:
1059:
1058:
1050:
1047:
1042:
1040:0-517-42464-9
1036:
1032:
1028:
1023:
1015:
1013:
1011:
1007:
1002:
1000:0-600-31870-2
996:
992:
985:
983:
981:
979:
977:
975:
973:
971:
967:
962:
956:
952:
951:
943:
941:
937:
934:
929:
926:
915:
909:
905:
904:
899:
892:
889:
884:
882:0-87341-428-4
878:
874:
867:
864:
860:
848:
844:
843:
838:
831:
829:
827:
823:
818:
816:0-600-33401-5
812:
808:
801:
799:
797:
795:
791:
780:on 2013-12-20
779:
775:
771:
764:
761:
756:
752:
748:
742:
739:
727:
723:
719:
715:
714:
709:
708:"TDC: Pumped"
705:
699:
696:
685:on 2012-03-16
681:
677:
670:
664:
661:
656:
652:
648:
642:
639:
634:
632:0-7513-0206-6
628:
624:
617:
615:
613:
611:
609:
607:
605:
603:
601:
599:
595:
589:
587:
584:
579:
577:
573:
572:Royal Enfield
569:
564:
562:
554:
552:
550:
546:
542:
538:
533:
531:
527:
523:
519:
518:Aeronca E-113
515:
514:Aeronca E-107
510:
508:
504:
500:
497:
492:
488:
485:In 1902, the
480:
476:
469:
467:
465:
462:(Russia) and
461:
457:
452:
450:
446:
442:
437:
433:
430:
426:
414:
407:
396:
389:
377:
375:
373:
369:
365:
361:
357:
353:
349:
345:
341:
336:
334:
329:
326:
324:
319:
314:
307:
302:
295:
290:
288:
286:
282:
278:
274:
269:
267:
263:
259:
255:
251:
247:
243:
239:
235:
231:
227:
223:
218:
216:
212:
208:
204:
199:
197:
196:
191:
188:In 1900, The
186:
184:
176:
172:
165:
160:
158:
156:
155:one-way valve
152:
147:
144:
136:
134:
132:
124:
120:
116:
114:
110:
105:
101:
93:
89:
82:
80:
76:
73:
70:
66:
61:
59:
55:
51:
44:
36:
32:
19:
2584:Flat engines
2539:Split-single
2332:
2325:Flat / boxer
2185:Swing-piston
2000:. Retrieved
1988:
1985:MotorBoating
1984:
1974:
1962:. Retrieved
1947:
1940:
1929:. Retrieved
1924:
1914:
1903:. Retrieved
1899:the original
1889:
1881:
1875:. Retrieved
1860:
1849:
1838:. Retrieved
1831:the original
1817:
1806:. Retrieved
1802:the original
1797:
1787:
1778:
1772:. Retrieved
1765:the original
1760:
1750:
1731:
1722:
1709:
1704:September 3,
1702:. Retrieved
1698:the original
1693:
1683:
1675:
1669:. Retrieved
1664:
1660:
1650:
1638:. Retrieved
1634:
1625:
1613:. Retrieved
1609:the original
1604:
1595:
1583:. Retrieved
1578:
1569:
1557:. Retrieved
1553:
1544:
1533:
1521:. Retrieved
1516:
1507:
1493:
1481:. Retrieved
1477:
1468:
1457:. Retrieved
1453:the original
1448:
1439:
1432:crankshafts.
1430:
1424:. Retrieved
1420:the original
1415:
1405:
1397:
1391:. Retrieved
1387:the original
1382:
1372:
1363:
1357:. Retrieved
1342:
1331:
1323:
1317:. Retrieved
1301:
1297:
1287:
1277:
1270:. Retrieved
1254:
1250:
1223:
1211:
1204:. Retrieved
1188:
1184:
1172:
1161:
1141:
1130:
1119:
1108:
1102:
1090:
1072:
1066:
1055:
1049:
1026:
990:
949:
928:
917:. Retrieved
902:
891:
872:
866:
857:
851:. Retrieved
840:
806:
782:. Retrieved
778:the original
773:
763:
755:the original
750:
741:
729:. Retrieved
717:
711:
698:
687:. Retrieved
680:the original
675:
663:
655:the original
650:
641:
622:
580:
567:
565:
558:
534:
511:
498:
484:
453:
438:
434:
421:
337:
330:
327:
315:
311:
287:sports car.
270:
234:DAF Daffodil
219:
211:Ford Model F
207:Ford Model C
203:Ford Model A
200:
193:
187:
180:
161:Applications
148:
140:
131:wasted spark
128:
123:Wasted spark
109:firing order
97:
77:
74:
68:
62:
57:
49:
47:
2228:Five-stroke
2223:Four-stroke
2180:Split cycle
2118:Free-piston
2061:Atmospheric
807:Period Cars
713:Cycle World
466:(Ukraine).
445:bevel drive
362:6 hp,
291:Motorcycles
222:Citroƫn 2CV
215:Jowett Cars
175:Citroƫn 2CV
166:Automobiles
151:Citroƫn 2CV
2568:Categories
2233:Six-stroke
2218:Two-stroke
2135:Heron head
2093:Cam engine
2002:2013-05-18
1958:0816018448
1931:2010-12-28
1905:2009-01-08
1877:2012-07-05
1840:2010-12-27
1808:2009-01-08
1774:2010-12-28
1671:2010-12-29
1459:2008-12-22
1426:2010-09-10
1393:2010-09-10
1359:2013-09-09
1319:2015-04-19
919:2013-05-18
853:2013-05-17
784:2013-12-19
689:2013-05-18
590:References
555:Other uses
541:ABC Motors
413:BMW R 60/2
360:Montgomery
306:Douglas N3
104:crankshaft
43:5N65 radar
1997:1531-2623
1730:(1997) .
1640:10 August
1615:10 August
1585:10 August
1559:10 August
1523:10 August
1483:10 August
1314:0277-9358
1267:0277-9358
1201:0277-9358
726:0011-4286
676:2CV Stuff
570:(part of
491:crank pin
356:Matchless
344:Brough HB
143:crankcase
65:Karl Benz
18:Flat-twin
2165:Pentroof
2113:Flathead
2103:Compound
2081:Rotative
1272:19 April
1206:19 April
847:Archived
731:17 April
530:HKS 700E
526:Praga B2
470:Aviation
449:BMW R 32
370:and the
340:Bradbury
254:Puch 500
2373:V / Vee
2190:Uniflow
2123:Stelzer
2098:Camless
2076:Cornish
1964:4 March
1780:habits.
1308:: 127.
1261:: 127.
503:Darracq
348:Douglas
262:BMW 700
258:BMW 600
250:Panhard
246:Citroƫn
35:Douglas
2534:Radial
2524:Deltic
2170:Rotary
2088:Bourke
1995:
1955:
1868:
1768:(aspx)
1738:
1661:Flight
1365:turns.
1350:
1312:
1265:
1234:
1199:
1195:: 71.
1079:
1037:
997:
957:
910:
879:
813:
724:
629:
561:Maytag
545:Riedel
528:. The
499:No. 20
415:engine
397:engine
352:Humber
346:, the
308:engine
2517:Other
2200:Wedge
2066:Axial
1834:(PDF)
1827:(PDF)
1228:44ā45
683:(PDF)
672:(PDF)
464:Dnepr
411:1967
393:1942
304:1912
100:boxer
92:Boxer
2195:Watt
2130:Hemi
2071:Beam
2054:Type
2045:for
1993:ISSN
1966:2015
1953:ISBN
1866:ISBN
1736:ISBN
1706:2016
1642:2019
1617:2019
1587:2019
1561:2019
1525:2019
1485:2019
1348:ISBN
1310:ISSN
1274:2015
1263:ISSN
1232:ISBN
1208:2015
1197:ISSN
1077:ISBN
1035:ISBN
995:ISBN
955:ISBN
908:ISBN
877:ISBN
811:ISBN
733:2015
722:ISSN
627:ISBN
559:The
516:and
505:and
460:Ural
271:The
248:and
220:The
149:The
2508:W30
2503:W24
2498:W18
2493:W16
2488:W12
2455:V24
2450:V20
2445:V18
2440:V16
2435:V14
2430:V12
2425:V10
2413:VR6
2401:VR5
2363:F16
2358:F12
2353:F10
2315:I14
2310:I12
1989:114
456:BMW
441:ABC
2570::
2483:W8
2478:W6
2473:W3
2420:V8
2408:V6
2396:V5
2391:V4
2386:V3
2381:V2
2348:F8
2343:F6
2338:F4
2333:F2
2305:I9
2300:I8
2295:I7
2290:I6
2285:I5
2280:I4
2275:I3
2270:I2
2265:I1
1987:.
1983:.
1923:.
1880:.
1858:.
1796:.
1777:.
1759:.
1708:.
1692:.
1674:.
1665:35
1663:.
1659:.
1633:.
1603:.
1577:.
1552:.
1515:.
1476:.
1447:.
1429:.
1414:.
1396:.
1381:.
1362:.
1340:.
1322:.
1302:53
1300:.
1296:.
1276:.
1255:55
1253:.
1249:.
1230:.
1222:.
1210:.
1189:55
1187:.
1183:.
1152:^
1033:.
1031:15
1025:.
1009:^
969:^
939:^
900:.
856:.
839:.
825:^
793:^
772:.
749:.
718:31
716:.
710:.
674:.
649:.
597:^
509:.
374:.
48:A
2549:X
2544:U
2529:H
2465:W
2035:e
2028:t
2021:v
2005:.
1968:.
1934:.
1908:.
1843:.
1821:*
1811:.
1744:.
1644:.
1619:.
1589:.
1563:.
1527:.
1487:.
1462:.
1240:.
1043:.
1003:.
963:.
922:.
885:.
819:.
787:.
735:.
692:.
635:.
45:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
