Continental IO-520

O-520
	Preserved IO-520
Type	Piston aircraft engine
National origin	United States
Manufacturer	Teledyne Continental Motors
First run	1963
Major applications	Beechcraft Bonanza ; Beechcraft Baron ; Cessna 206 ; Cessna 210 ; Cessna 310 ; Cessna 340 ; Cessna 421
Produced	1964-present
Developed from	Continental IO-346
Developed into	Continental IO-550

Last updated June 14, 2025

The Continental IO-520 is a six-cylinder, horizontally opposed aircraft engine produced by Teledyne Continental Motors. First run in 1963 as a development of the IO-346, it has been produced in versions incorporating fuel injection (IO-520), turbo-charging (TSIO-520), and gearing (GTSIO-520).

Design and development

The IO-520 series engines normally produce 285 to 310 horsepower (210 to 230 kW) and are used in numerous aircraft such as certain models of the Bellanca Viking 300 and Super Viking, the Beech Bonanza and Baron, and Cessna 185- 206-, 210-, 310-, and 400-series aircraft. The IO-520 remained in production in 2019.^[1]

The geared GTSIO-520's most common applications are the twin-engine Cessna 404 and 421, where it is rated at 375 hp (280 kW). The 'G' prefix indicated the incorporation of propeller reduction gearing.

Variants

IO-520

IO-520-A: 285 hp (213 kW)^[2] (Meyers 200)
IO-520-B: 285 hp (213 kW)^[2] (Beech 35-C33A Debonair, s35, model 36 Bonanza)
IO-520-BA: 285 hp (213 kW)^[2]
IO-520-BB: 285 hp (213 kW)^[2]
IO-520-C: 285 hp (213 kW)^[2]
IO-520-CB: 285 hp (213 kW)^[2]
IO-520-D: 300 hp (224 kW)^[2]
IO-520-E: 300 hp (224 kW)^[2]
IO-520-F: 300 hp (224 kW)^[2]
IO-520-J: 285 hp (213 kW)^[2]
IO-520-K: 300 hp (224 kW)^[2] (Bellanca Viking)
IO-520-L: 300 hp (224 kW)^[2]
IO-520-M: 285 hp (213 kW)^[2]
IO-520-MB: 285 hp (213 kW)^[2]
IO-520-N: 300 hp (224 kW)^[2]
IO-520-NB: 300 hp (224 kW)^[2]
L/IO-520-P: 250 hp (186 kW)^[2]

TSIO-520

TSIO-520-A: 255 hp (190 kW)^[3]
TSIO-520-AE: 250 hp (186 kW)^[3]
LTSIO-520-AE: 250 hp (186 kW)^[3]
TSIO-520-AF: 310 hp (231 kW)^[3]
TSIO-520-B: 285 hp (213 kW)^[3]
TSIO-520-BB: 285 hp (213 kW)^[3]
TSIO-520-BE: 310 hp (231 kW)^[3]
TSIO-520-C: 265 hp (198 kW)^[3]
TSIO-520-CE: 325 hp (242 kW)^[3]
TSIO-520-D: 285 hp (213 kW)^[3]
TSIO-520-DB: 285 hp (213 kW)^[3]
TSIO-520-E: 300 hp (224 kW)^[3]
TSIO-520-EB: 300 hp (224 kW)^[3]
TSIO-520-G: 285 hp (213 kW)^[3]
TSIO-520-H: 265 hp (198 kW)^[3]
TSIO-520-J: 310 hp (230 kW)^[3]
TSIO-520-JB: 310 hp (230 kW)^[3]
TSIO-520-K: 285 hp (213 kW)^[3]
TSIO-520-KB: 285 hp (213 kW)^[3]
TSIO-520-L: 310 hp (230 kW)^[3]
TSIO-520-LB: 310 hp (230 kW)^[3]
TSIO-520-M: 285 hp (213 kW)^[3]
TSIO-520-N: 310 hp (230 kW)^[3]
TSIO-520-NB: 310 hp (230 kW)^[3]
TSIO-520-P: 310 hp (230 kW)^[3]
TSIO-520-R: 310 hp (230 kW)^[3]
TSIO-520-T: 310 hp (230 kW)^[3]
TSIO-520-U: 300 hp (224 kW)^[3]
TSIO-520-UB: 300 hp (224 kW)^[3]
TSIO-520-VB: 325 hp (242 kW)^[3]
TSIO-520-WB: 325 hp (242 kW)^[3]

GTSIO-520

GTSIO-520-C: 340 hp (254 kW)^[4]
GTSIO-520-D: 375 hp (280 kW)^[4] (Cessna 421)
GTSIO-520-F: 435 hp (324 kW)^[4]
GTSIO-520-H: 375 hp (280 kW)^[4] (Cessna 421B)
GTSIO-520-K: 435 hp (324 kW)^[4]
GTSIO-520-L: 375 hp (280 kW)^[4] (Cessna 421C)
GTSIO-520-M: 375 hp (280 kW)^[4] (Cessna 404)
GTSIO-520-N: 375 hp (280 kW)^[4] (Cessna 421C)
GTSIO-520-S: 375 hp (280 kW)^[4] (Tecnam P2012 Traveller)

Specifications (GTSIO-520-D)

Data fromContinental Motors.^[5]

General characteristics

Type: 6-cylinder horizontally opposed aircraft engine
Bore: 5.25 in (133 mm)
Stroke: 4.00 in (102 mm)
Displacement: 520 cu in (8.5 L)
Length: 63.63 in (161.6 cm)
Width: 34.04 in (86.5 cm)
Height: 26.63 in (67.6 cm)
Dry weight: 484 lb (219.5 kg) without accessories

Components

Valvetrain: Overhead valve
Fuel system: TCM fuel injection
Fuel type: 100/130 Octane avgas
Cooling system: Air-cooled

Performance

Power output: 375 hp (280 kW) (Maximum continuous operation at 3,400 rpm)
Compression ratio: 7.5:1
Power-to-weight ratio: 0.77 hp/lb (1.27kW/kg)

References

↑ Continental Aerospace Technologies (2022). "500 Series Engines". continentalmotors.aero. Archived from the original on 8 November 2022. Retrieved 8 November 2022.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Federal Aviation Administration (8 March 2022). "Type Certificate Data Sheet No. E5CE Revision 27". Archived from the original on 8 November 2022. Retrieved 8 November 2022.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Federal Aviation Administration (6 April 2020). "Type Certificate Data Sheet No. E8CE Revision 24". Archived from the original on 8 November 2022. Retrieved 8 November 2022.
1 2 3 4 5 6 7 8 9 Federal Aviation Administration (8 September 2022). "Type Certificate Data Sheet No. E7CE Revision 20". Archived from the original on 8 November 2022. Retrieved 8 November 2022.
↑ Product data sheet GTSIO-520-D Archived 2006-07-17 at the Wayback Machine Retrieved: 21 November 2012

External links

Media related to Continental O-520 at Wikimedia Commons

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[official-1] Continental Aerospace Technologies (2022). "500 Series Engines". continentalmotors.aero. Archived from the original on 8 November 2022. Retrieved 8 November 2022.

[E5CE-2] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Federal Aviation Administration (8 March 2022). "Type Certificate Data Sheet No. E5CE Revision 27". Archived from the original on 8 November 2022. Retrieved 8 November 2022.

[E8CE-3] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Federal Aviation Administration (6 April 2020). "Type Certificate Data Sheet No. E8CE Revision 24". Archived from the original on 8 November 2022. Retrieved 8 November 2022.

[E7CE-4] 1 2 3 4 5 6 7 8 9 Federal Aviation Administration (8 September 2022). "Type Certificate Data Sheet No. E7CE Revision 20". Archived from the original on 8 November 2022. Retrieved 8 November 2022.

[5] Product data sheet GTSIO-520-D Archived 2006-07-17 at the Wayback Machine Retrieved: 21 November 2012

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