200:, using individual cylinders bolted to a single aluminum crankcase, wrapped in a cooling jacket made of a nickel-copper alloy. Later versions used a brazed-on steel jacket instead. Cylinder heads were also attached to the crankcase, using X-shaped tie-downs on the top of the head attached to the block via four long bolts. Fuel was carbureted near the rear of the engine, then piped to the cylinders via two T-shaped pipes, the cylinders being arranged so the intake ports of any two in a bank were near each other. The cylinders had one intake and one exhaust valve, the exhaust valve operated by a pushrod from a camshaft running between the banks and inlet valve operated by a pull rod/tube working from the same camshaft. This arrangement caused the outer exhaust valves to have a rather long rocker arm. The push/pullrods were arranged one inside the other, the exhaust valve rod being on the inside and the intake valve rod a tube around it. The aluminum camshaft bearings were a split type bolted together and held in place by lock screws. The pistons were cast aluminum.
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the US for primary training was four times less than the advanced training rate in France (virtually all US airmen getting advanced training in France), approximately 2800 flying hours in the US primarily in OX-5 powered JN-4s per fatality to 761 hours per fatality in France in other types. Very few fatal accidents were caused by engine failure, although the lack of power may have been the cause of the many
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compared with the need (by the time the J-1s were grounded in June 1918 JN-4s were in sufficient supply) led to the rejection of this idea. The successful civilian post-war use of the OX-5 (even in civilian purchased and converted J-1s) was due to its relative reliability in the more aerodynamically advanced designs of the 1920s, its simplicity of operation, and its low cost. By comparison the
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German engines. Built by several contractors in large numbers, the OX-5 suffered from uneven quality control. However, while the overwhelming majority of training accidents in the U.S. were in JN-4s, this was because JN-4s were flown by the vast majority of trainee pilots, and the accident rate in
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that took about forty five percent of training lives. Anyone seeing a JN-4 today struggling into the air with an OX-5 can see very quickly that the JN-4 had to be flown in a narrow envelope. Also, the replacement of the A7A in
Standard J-1s was contemplated, but the cost of $ 2,000 per aircraft
152:
in 1902. A modified version of one of these early designs was sold as an aircraft engine in 1906, and from then on the company's primary market was aircraft. The basic design had slowly expanded by adding additional cylinders until they reached the V-8 in 1906. They also started enlarging the
215:
were producing about 100 hp (75 kW), and newer inlines were becoming available with 160 hp (120 kW) or more. Nevertheless, the OX-5 had fairly good fuel economy as a result of its slow RPM, which made it useful for civilian aircraft. The OX-5 was used on the
261:-1, the substitute primary trainer. In particular the valve gear was fragile, and it had no provisions for lubrication other than grease and oil applied by hand, leading to an overhaul interval as short as fifty hours. Additionally the engine featured a single
252:
The engine was considered unreliable, but unreliable is a relative term: aviation engine technology had not fully matured at the end of World War I. Certainly the JN4 with the OX-5 was underpowered, but the OX-5 proved a much better engine than the
132:. It was the first American-designed aircraft engine to enter mass production, although it was considered obsolete when it did so in 1917. It nevertheless found widespread use on a number of aircraft, perhaps the most famous being the
136:. Some 12,600 units were built through early 1919. The wide availability of the engine in the surplus market made it common until the 1930s, although it was considered unreliable for most of its service life.
244:, and some models of the Jenny. The primary reason for its popularity was its low cost after the war, with almost-new examples selling as low as $ 20. It was often used in boats as well as in aircraft.
185:. The Curtiss O was further developed into the 90 hp Curtiss OX. OX series production began in 1913. The OX-5 was built between 1915 and 1919 and was by far the most popular OX variant.
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record for 16 years. Curtiss continued the development of their V8 engines with demand for higher power outputs being largely driven by the
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cylinders as well, but this led to cooling problems that required the introduction of liquid cooling in 1908. These early engines used a
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A Curtis OX-5 modified for marine use, reportedly in a Chris Craft, is on public display at the Iowa Great Lakes
Maritime Museum.
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valve arrangement, which eventually gave way to a cross-flow cylinder with overhead valves in 1909, leading to improved
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298:-built version of the 150 hp Hispano-Suiza HS-8a V8 engine in the nearly 930 examples of the later production
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in each cylinder, and a single ignition system, in an era when ignition equipment was less reliable, with
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created such a bad impression during the war that very few, if any, were used by civilian operators.
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The OX-5 was not considered particularly advanced, nor powerful, for its era. By this point
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Like most engines of the era, the OX-5's high-temperature areas were built mostly of
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557:"Glenn H. Curtiss: An Early American Innovator in Aviation and Motorcycle Engines"
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already being fitted to more advanced aviation powerplants like the French V-form
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designed V engines, which started as a series of air-cooled V-twins for
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181:. By 1912 Curtiss V8’s were developing 75 hp and were known as the
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161:. By this point engine design was a team effort; the team included
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The
Curtiss standard model OX aeronautical motor hand book
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The OX-5 itself would be replaced by the well-proven
331:
Top overhead view of OX-5 at Lone Star Flight Museum
700:The Curtiss OX-5, Aircraft Maintenance Technology
311:A Curtis OX-5 engine is on public display at the
887:
420:One intake and one exhaust valve per cylinder,
757:
464:105 hp (78 kW) at 1,800 rpm for brief periods
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497:0.53 lb/(hp·h) (0.32 kg/(kW·h)) at 75% power
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737:The Museum of Flight Digital Collections
681:. New York: Aircraft Publications, 1940.
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273:and the inline-six cylinder series of
192:Curtiss OX-5 at Canada Aviation Museum
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688:. Somerset: Haynes Publishing, 1995.
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144:The OX-5 was the last in a series of
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488:8.0 US gal/h (30.8 L/h) at 75% power
439:Gear-pump 40 to 60 psi 3-gallon sump
702:. Cygnus Business Media, July 2009.
609:
548:
503:0.5 US gal/h (1.9 L/h) at 75% power
76:Curtiss Aeroplane and Motor Company
24:
709:. McGraw-Hill Book Company, 1981.
686:World Encyclopedia of Aero Engines
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257:that was the Achilles heel of the
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35:
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313:Aerospace Museum of California
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13:
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901:1910s aircraft piston engines
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408:
346:8-cylinder water-cooled 90°
7:
10:
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654:Angle, 1940, pages 244-246
461:90 hp (67 kW) at 1,400 rpm
242:Buhl-Verville CW-3 Airster
222:Pitcairn PA-4 Fleetwing II
855:
782:
493:Specific fuel consumption
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34:
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896:Curtiss aircraft engines
218:Swallow Airplane Swallow
707:Aircraft Piston Engines
338:General characteristics
626:Gunston, 1995, page 47
332:
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140:Design and development
44:Preserved OX-5 engine
555:Rinek, Larry (1994).
512:0.27 hp/lb (440 W/kg)
508:Power-to-weight ratio
473:0.21 hp/in (9.5 kW/L)
383:56.75 in (1441.45 mm)
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323:Specifications (OX-5)
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171:power-to-weight ratio
159:volumetric efficiency
663:Smith, 1981, page 47
606:Fisher, 2009, page 7
545:Smith, 1981, page 12
536:Smith, 1981, page 46
395:36.75 in (933.45 mm)
389:29.75 in (755.65 mm)
296:Wright Aeronautical
177:’s requirement for
167:Manly–Balzer engine
698:Fisher, Scott M.,
333:
306:Engines on display
302:H Jenny biplanes.
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705:Smith, Herschel,
677:Angle, Glenn D.,
486:Fuel consumption:
478:Compression ratio
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16:(Redirected from
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163:Charles M. Manly
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679:AEROSPHERE 1939
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404:390 lb (177 kg)
368:5.0 in (127 mm)
359:4.0 in (102 mm)
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284:stall and spins
271:Hispano-Suiza 8
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226:Travel Air 2000
183:Curtiss Model O
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569:. Retrieved
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300:Curtiss JN-4
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275:Mercedes D.I
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207:such as the
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134:JN-4 "Jenny"
115:Curtiss OX-5
114:
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91:Number built
450:Performance
437:Oil system:
248:Reliability
213:Gnome-Rhône
150:motorcycles
890:Categories
807:Challenger
517:References
432:Carburetor
416:Valvetrain
409:Components
400:Dry weight
263:spark plug
259:Standard J
82:First run
567:: 927–945
424:-actuated
209:Oberursel
198:cast iron
179:seaplanes
128:built by
106:Curtiss O
277:through
155:flathead
122:American
822:Model K
773:Curtiss
422:pushrod
393:Height:
381:Length:
175:US Navy
130:Curtiss
95:12,600
875:R-1454
865:H-1640
842:V-1570
713:
692:
571:31 Dec
387:Width:
364:Stroke
240:, the
236:, the
230:Waco 9
870:R-600
482:4.9:1
344:Type:
279:D.III
85:1915
49:Type
30:OX-5
832:OX-5
817:K-12
812:D-12
711:ISBN
690:ISBN
573:2022
355:Bore
232:and
113:The
18:OX-5
847:V-2
837:OXX
802:C-6
797:B-8
792:A-2
565:103
348:Vee
211:or
119:V-8
53:V-8
892::
735:–
631:^
611:^
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234:10
228:,
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827:O
765:e
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20:)
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