Continental XI-1430

Source: Wikipedia, the free encyclopedia.
I-1430
I-1430-11 at the National Air and Space Museum
Type Piston aircraft engine
Manufacturer
Continental Motors
First run 1939
Major applications Lockheed XP-49
McDonnell XP-67
Number built 23

The Continental XI-1430 Hyper engine (often identified as the IV-1430) was a liquid-cooled

Curtiss XP-55, an extremely radical (for the time) pusher-engine fighter design that would not reach production.[1]

Development

In the late 1920s

Wright Field to build a high-power cylinder using conventional poppet valves. The engineers, led by Sam Heron, used a variety of techniques to raise the allowable RPM, which was the key to increased power without requiring a larger engine.[2]

The USAAC was interested in very large bomber designs, and in engines that could be buried in the wings in order to improve streamlining.

cylinder block that combined the cylinders and the crankcase, leading to much stiffer engines, that were better able to handle increased power.[4]

The USAAC proposed an engine of about 1200 cubic inches (20 L), hoping the engine's smaller size would lead to reduced drag and hence improved range. By 1932, the USAAC's encouraging efforts led the Army to sign a development contract with Continental Motors Company for the continued development of the engine design. The contract limited Continental's role to construction and testing, leaving the actual engineering development to the Army.[5]

A second cylinder was added to Hyper No. 1 to make a horizontal-opposed engine for evaluation of an opposed-piston 12-cylinder engine. After running the modified engine with different combinations of cylinder bore and stroke, it was found that the high coolant temperatures required to maintain the required output were impractical. A third high-performance single-cylinder engine was then constructed with lower operating parameters. This one-cylinder engine was designated "Hyper No. 2", and became the test bed for developing the cylinders that would become the Continental O-1430 ("O" for "opposed") engine. It would require a ten-year development period which changed the layout to first an upright V-12 engine and later, an inverted V-12 engine, before becoming reliable enough to consider for full production as the Continental I-1430 in 1943.[6]

During development, interest in the "buried engine" concept faded. Improvements in conventional streamlining, notably the

B-17, using radial engines for power, starting to enter production, the need for new bomber designs became less pressing and the Army turned its attention to new pursuit models. For this role the O-1430 was not terribly useful, so Continental modified the basic design into a V-12, and then into an inverted-V-12, the I-1430.[7]

Design

The I-1430 featured cylinders with "hemispherical" combustion chambers and, like the 1936-designed Junkers Jumo 211 inverted V12 German aviation powerplant, using twin exhaust valves, with the I-1430 adding sodium-filled exhaust valves in its own multi-valve design. Although it retained separate cylinders, the change to a V-layout allowed the individual cylinder heads to be cast as a single piece. Mounted at either end, a Y-shaped plate provided stiffness, while containing the camshaft drives. Continental built the first I-1430 engine in 1938 and successfully tested it in 1939.[1] At the time it was an extremely competitive design, offering at least 1,300 hp (970 kW) from a 23-liter displacement; the contemporary Rolls-Royce Merlin offered about 1,000 hp (700 kW) from 27 L displacement, while the contemporary German competitor to the 35-litre displacement Junkers Jumo 211 engine, the Daimler-Benz DB 601 inverted V12, offered slightly more power at 1,100 hp (820 kW), but was much larger, at 33 L displacement, with some 19,000 examples produced in its various versions.

While the engine was producing exceptional power for its displacement, the reason it was not put into production may have had to do with its weight. Both the

Bell XP-76, which was canceled before production began.[1] In 1944 it was also tested in the McDonnell XP-67.[1]

Interest in the design had largely disappeared by then; piston engines with the same power or greater ratings were widely available, the Merlin for example had improved tremendously and was offering at least 1,500 hp (1,120 kW), and the military and aircraft builders were already starting to focus on jet engines.

Only twenty-three I-1430 series engines were delivered, later redesignated the XI-1430 to indicate the purely experimental use.[8]

A 24-cylinder H-style engine, the XH-2860, based on the XI-1430 was designed but probably not built.

Specifications (I-1430-1)

Data from Aircraft Engines of the World 1946 [9]

General characteristics

  • Type: 12-cylinder, liquid-cooled, inverted Vee
  • Bore: 5.5 in (139.7 mm)
  • Stroke: 5 in (127.0 mm)
  • Displacement: 1,425 cu in (23.35 L)
  • Dry weight
    :     1,615 lb (732.6 kg)

Components

  • Valvetrain: Overhead cam with 4 valves per cylinder
  • Supercharger: Gear driven centrifugal 5.97:1 gear ratio
  • Turbocharger: 1 x General Electric turbo-charger with intercooler
  • Fuel system: 1 x Bendix-Stromberg PD-12P2 updraught injection type carburetor with automatic mixture control
  • Fuel type: 100/130 grade aviation gasoline
  • Oil system: Pressure feed at 100 psi (689,475.73 Pa) with dry sump, 100–120 S.U. (20.5–25.1 cs) grade oil
  • Cooling system: liquid, 50% Glycol, 50% water
  • Reduction gear: 0.385:1 spur reduction gear

Performance

  • Power output: *(take-off) 1,600 hp (1,193.1 kW) at 3,300 rpm at 61 in (1,549.4 mm) Hg / +15.5 lb (7.0 kg) boost
  • (emergency) 2,100 hp (1,566.0 kW) at 3,400 rpm at 25,000 ft (7,620 m)
  • (military) 1,600 hp (1,193.1 kW) at 3,300 rpm at 25,000 ft (7,620 m)
  • (normal) 1,150 hp (857.6 kW) at 3,000 rpm at 25,000 ft (7,620 m)
  • (cruising) 920 hp (686.0 kW) at 2,780 rpm at 25,000 ft (7,620 m)
  • Specific power: 1.47 hp/cu in (67.18 kW/L)
  • Compression ratio: 6.5:1
  • Specific fuel consumption
    :     0.47 lb/hp/hr (0.286 kg/kW/hr)
  • Oil consumption: 0.025 lb/hp/hr (0.015 kg/kW/hr)
  • Power-to-weight ratio: 1.45 hp/lb (2.384 kW/kg)

See also

Comparable engines

Related lists

References

Notes

  1. ^ a b c d e Balzer p 28
  2. ^ White p 375
  3. ^ Balzer p 27
  4. ^ Neal p 36
  5. ^ White pp 375, 376
  6. ^ White p 376
  7. ^ White p 391
  8. ^ National Museum of the USAF, I-1430 fact sheet
  9. ^ Wilkinson, Paul H. (1946). Aircraft Engines of the World 1946. London: Sir isaac Pitman & Sons Ltd.

Bibliography

Wilkinson, Paul H. (1946). Aircraft Engines of the World 1946. London: Sir isaac Pitman & Sons Ltd.

External links

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