128:. The symmetry of the arrangement, in which one bank of three cylinders is mirrored by the other bank, means that there is no net force from any given mirrored cylinder pair along the axis of movement of the pistons. So not only is there no net primary or secondary reciprocating effect, there is no net turning force - moment - that would try to rotate the engine back and forth about its engine mountings. (The moment is not quite zero in practice because each cylinder pair is offset slightly from the other, or else they would clash at the crankshaft.) In this regard, the six cylinder boxer engine is the same as a flat-four boxer engine, which also does not experience any rocking couple.
366:
458:
260:
148:
246:
384:
27:
407:, which used an engine based on a flat-four engine with two cylinders added. The Wilson-Pilcher was a front-engined car with the crankshaft in-line with the chassis and the cylinders between the chassis rails. Reports on this car quote it as being "remarkably silent and smooth running" and "almost total absence of vibration".
594:
As the years passed, Bernard
Pietenpol taught himself how to repair televisions and radios. By 1960, Chevrolet introduced the six cylinder air-cooled Chevrolet Corvair. This would be the last engine Bernard would experiment with in powering his Air Camper. In 1966 Bernard completed his first Corvair
636:
Note: A low-revving engine is eminently suitable to drive a propeller, which is typically most effective at about 2,000 rpm. If a valve in a side-valve engine should stick open, it cannot hit the piston and cause engine failure; the engine will continue with just that cylinder inoperative. This is
86:
sports car, which has used flat-six engines continuously since 1963. Several other car manufacturers, including Subaru, have produced flat-six engines at times. Flat-six engines have also occasionally been used in motorcycles, and commonly in general aviation aircraft, along with the
117:. As in other six-cylinder engines, the overlapping of the power strokes of the different cylinders (with a firing interval of 120 degrees in a four-stroke engine) reduces the pulsating of the power delivery relative to that of similar engines with fewer cylinders.
295:
182:
Flat engines largely replaced the historically more popular radial engines in small aircraft after World War II because they were less expensive to manufacture. The smaller frontal area compared with a radial engine also results in less drag.
418:(air-cooled). Both are rear-engined cars with rear-wheel drive. Chevrolet produced over 1.8 million Corvairs of various types and utilized a turbocharger on some models; one of the first uses of a turbocharger on a mass-produced automobile.
296:
60:
engine, where each pair of opposed cylinders moves inwards and outwards at the same time. An alternative configuration for flat engines is a 180-degree V engine, where both cylinders move to the right then the left at the same time.
473:
touring motorcycle has used a water-cooled flat-six engine since 1988. Initially, the engine had a displacement of 1.5 L (92 cu in), until it was enlarged to 1.8 L (110 cu in) in 2001.
278:
68:) and being well suited to air-cooling. The disadvantages are a large width (which can limit the maximum steering angle when used in a front-engined car), a large intake manifold being required when a central
294:
449:
engine was introduced in 2007 and was produced until 2019. All engines were used in front-engine cars with all-wheel drive, plus the XT and
Alcyone SVX were also available with front-wheel drive.
573:
276:
706:
277:
198:
compact car. Compared with the engines used in cars, flat-six engines used by helicopters have large displacements and are low revving, producing more torque and less power.
222:, the massively over-square (1.295:1) D-Motor is a very simple, low-revving, compact, reliable lightweight aero-engine (without the heavy (and bulky) complication of
647:
855:
297:
728:
607:
218:. Although the side-valve format has long been abandoned for most automotive applications because its combustion chamber is a bar to high engine
581:
64:
The advantages of the flat-six layout are good engine balance (for reduced vibration), a low center of gravity, short length (compared with an
287:
848:
714:
548:
421:
Japanese manufacturer Subaru produced water-cooled flat-6 engines from 1988–1996 and 2000–2019. Their first flat-6 engine, the
1395:
841:
525:
481:
F6C (1997–2003) was a cruiser based on the GL1500 Gold Wing. The limited edition 2004 Valkyrie Rune was based on the GL1800.
49:
190:
engine, produced from 1985 to 1991, was based on the engine used in the
Porsche 911 sports car. Several examples of the
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966:
822:
672:
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430:
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437:, the replacement for the Subaru XT. Following a hiatus of flat-6 engine production for four years, the
321:, a rear-engined sports car which has used flat-six engines exclusively since 1963. The engines were
1136:
976:
171:
in their model codes for flat-layout engines as a designation for “opposed” cylinder layouts. The
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8:
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648:"Flat Sixy: The Evolution of Porsche 911 Engine Size, Technology, and Output in the U.S."
132:
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1001:
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125:
72:
is used, and duplication of the inlet and outlet connections for water-cooled engines.
815:
Honda
Motorcycles: Everything You Need to Know About Every Honda Motorcycle Ever Built
696:"The Wilson-Pilcher Petrol Cars", The Automotor Journal, April 16th, 1904, pp. 463-468
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Two
American manufacturers briefly produced cars with flat-six engines—the 1948
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powered Air Camper, then another in 1970 which was dubbed "the Last
Original".
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215:
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Some aircraft have used flat-six engines originally designed for cars. The
121:
106:
46:
131:
These characteristics result in low vibration for flat-six engines (as in
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Most motorcycles use engines with four or fewer cylinders, however the
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homebuilt monoplane aircraft have used the air-cooled engine from the
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which began production in 1942. Several manufacturers use the letter
136:
135:), especially when compared with the imbalances that are present in
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383:
332:
Other
Porsche models that use flat-six engines are the 1970–1972
205:
176:
414:(water-cooled, based on the Franklin O-335) and the 1960–1969
863:
400:
The first car to use a flat-six engine was the 1904–1907
574:"Pietenpol Official Pietenpol Air Camper Family Website"
201:
A notable recent flat-six aero-engine is the 4-litre
82:
car. The most notable use of flat-six engines is the
75:
The first production flat-six engine was in the 1904
759:"Subaru history in the USA: the models, the changes"
729:"Flat-6 Club: 1993 Subaru Impreza w/ Legacy 6-Cyl"
673:"7 Flat-Six-Powered Vehicles That Aren't Porsches"
317:The flat-six engine is often associated with the
124:configuration, a flat-six engine does not have a
56:. The most common type of flat-six engine is the
19:"Flat-six" redirects here. For the interval, see
1387:
52:with three cylinders on each side of a central
849:
637:an important safety feature for aero-engines.
608:"The Lycoming O-540 Engine and Why We Use It"
549:"The Physics of: Engine Cylinder-Bank Angles"
16:Horizontally opposed 6-cylinder piston engine
580:. Pietenpol Aircraft Company. Archived from
856:
842:
808:
806:
804:
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244:
163:which began production in 1940, and the
146:
109:flat-six engine is able to have perfect
25:
812:
801:
325:until 1999, when Porsche started using
1388:
513:
425:, was added to the model range of the
355:
837:
520:. Butterworth-Heinemann. p. 13.
452:
229:
211:, a modular variant of the 2.7-litre
159:Early flat-six engines include the
13:
614:. 18 November 2015. Archived from
517:Light and Heavy Vehicle Technology
441:engine was introduced in the 2000
308:Problems playing these files? See
258:
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139:with a 90-degree bank angle.
1396:Piston engine configurations
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155:air-cooled aircraft engine
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33:air-cooled aircraft engine
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875:
612:www.hieldsaviation.co.uk
578:community.pressenter.net
43:horizontally opposed-six
817:. Krause Publications.
433:engine was used in the
241:Porsche flat-six engine
997:Single-acting cylinder
930:Double-acting cylinder
813:Mitchel, Doug (2005).
466:
350:Porsche Boxster/Cayman
263:
253:
156:
34:
865:Engine configurations
460:
443:Subaru Legacy/Outback
348:), and the 1996–2021
288:2006 Porsche Cayman S
262:
248:
239:Further information:
150:
99:Further information:
31:Continental O-470-13A
29:
967:Oscillating cylinder
739:on 21 September 2019
733:www.dailyturismo.com
651:www.caranddriver.com
618:on 19 September 2019
553:www.caranddriver.com
514:Nunney, M J (2007).
429:coupe. In 1991, the
327:water-cooled engines
192:Pietenpol Air Camper
133:straight-six engines
1060:Two-and four-stroke
962:Intake over exhaust
677:www.carthrottle.com
356:Other manufacturers
179:light helicopter.
653:. 13 December 2013
467:
453:Use in motorcycles
435:Subaru Alcyone SVX
264:
254:
230:Use in automobiles
157:
41:, also known as a
35:
1383:
1382:
1379:
1378:
1079:Inline / straight
977:Overhead camshaft
707:"Corvair History"
584:on April 23, 2017
527:978-0-7506-8037-0
491:Inline-six engine
416:Chevrolet Corvair
340:), the 1986–1993
298:
279:
270:1967 Porsche 911R
196:Chevrolet Corvair
115:secondary balance
66:inline-six engine
1408:
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1070:Cylinder layouts
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735:. Archived from
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717:on 22 June 2014.
713:. Archived from
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188:Porsche PFM 3200
175:was used in the
89:flat-four engine
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471:Honda Gold Wing
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143:Use in aircraft
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39:flat-six engine
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479:Honda Valkyrie
463:Honda Valkyrie
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403:Wilson-Pilcher
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373:Wilson-Pilcher
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352:(mid-engine).
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173:Franklin O-335
165:Lycoming O-435
161:Franklin O-265
153:Franklin O-335
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126:rocking couple
96:
95:Engine balance
93:
78:Wilson-Pilcher
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1032:Stroke cycles
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788:www.honda.com
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334:Porsche 914/6
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226:valve-gear).
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50:piston engine
48:
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40:
32:
28:
22:
1401:Flat engines
1361:Split-single
1164:
1147:Flat / boxer
1007:Swing-piston
814:
793:23 September
791:. Retrieved
787:
778:
768:23 September
766:. Retrieved
762:
753:
743:21 September
741:. Retrieved
737:the original
732:
723:
715:the original
710:
701:
692:
682:21 September
680:. Retrieved
676:
667:
657:21 September
655:. Retrieved
650:
642:
632:
622:10 September
620:. Retrieved
616:the original
611:
602:
593:
586:. Retrieved
582:the original
577:
568:
556:. Retrieved
552:
543:
533:24 September
531:. Retrieved
516:
509:
476:
468:
420:
409:
401:
399:
331:
316:
307:
216:D-Motor LF26
209:D-Motor LF39
200:
185:
181:
168:
158:
130:
119:
104:
76:
74:
63:
57:
47:six-cylinder
42:
38:
36:
1050:Five-stroke
1045:Four-stroke
1002:Split cycle
940:Free-piston
883:Atmospheric
558:9 September
447:Subaru EZ36
439:Subaru EZ30
431:Subaru EG33
423:Subaru ER27
391:Subaru EZ36
346:rear-engine
342:Porsche 959
319:Porsche 911
251:Porsche 911
107:boxer-style
101:Flat engine
84:Porsche 911
21:Minor sixth
1390:Categories
1055:Six-stroke
1040:Two-stroke
957:Heron head
915:Cam engine
502:References
461:1997–2004
389:2007–2019
338:mid-engine
323:air-cooled
310:media help
203:side-valve
151:1945–1975
137:V6 engines
70:carburetor
54:crankshaft
784:"Touring"
496:V6 engine
427:Subaru XT
412:Tucker 48
213:flat-four
58:boxer-six
987:Pentroof
935:Flathead
925:Compound
903:Rotative
485:See also
405:18/24 HP
80:18/24 HP
1195:V / Vee
1012:Uniflow
945:Stelzer
920:Camless
898:Cornish
235:Porsche
206:Belgian
177:Bell 47
111:primary
45:, is a
1356:Radial
1346:Deltic
992:Rotary
910:Bourke
821:
588:May 6,
524:
465:engine
445:. The
393:engine
375:engine
1339:Other
1022:Wedge
888:Axial
371:1904
249:1966
122:boxer
120:In a
1017:Watt
952:Hemi
893:Beam
876:Type
867:for
819:ISBN
795:2019
770:2019
745:2019
684:2019
659:2019
624:2019
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