Continental IO-520-D Engine – For Cessna A185E, Bellanca Viking 300, and More

The Continental IO-520-D is a 285 horsepower, fuel-injected, 6-cylinder engine designed to power rugged taildraggers, high-performance singles, and utility aircraft. This model is commonly installed in the Cessna A185E and Bellanca Viking 300, and occasionally in specialized models like the Cessna A188 ag-plane and USAF U-17 series. Known for torque, durability, and broad configurability, the IO-520-D is a favorite among bush pilots, working fleets, and performance enthusiasts alike.

Each engine shipped by Air Power includes a Tempest Spin-On Oil Filter (unless a screen-type is specified) and a full set of Tempest Spark Plugs—included standard for performance and protection.

Aircraft Applications

• Cessna A185E (Skywagon)
• Bellanca Viking 300
• Cessna A188 (Ag Pickup)
• USAF U-17

Engine Specs & Notes

• 285 HP @ 2700 RPM
• 520 cubic inches / 8.5L displacement
• Fuel injected, air-cooled, horizontally opposed
• All IO-520-D engines include a nitrided magneto drive gear

Bellanca Viking Owners:

Please reference Service Information Letter SIL98-6B to ensure the core engine's fuel system configuration matches your aircraft requirements.

What We Need to Know to Properly Spec Your Engine

This engine family includes a wide range of specifications—getting the correct configuration is essential. When requesting a quote or placing an order, please provide the following details:

• New or rebuilt preference
• Aircraft make and model
• Magneto Type: S6RN-1225 or S6RN-25?
• 12V or 24V electrical system?
• Alternator included? Most IO-520-D specs do not include one by default
• Oil Cooler Size: 7.88", 8.88", or 9.82" decongealing cooler?
• Oil Filter Type: Spin-on or screen-style?
• Engine Mount Leg: Does it have an alternator mount provision?
• Oil Cooler Location: Mounted on the engine or the airframe?

Continental RFQ Process

If your aircraft or configuration is uncommon, Air Power will initiate a Request for Quote (RFQ) with Continental Aerospace Technologies. This process ensures an accurate build spec, price, and delivery timeline for your exact needs.

• Average turnaround time: 5–7 business days
• Includes: Factory-confirmed quote and estimated lead time

Why Buy from Air Power?

As the largest worldwide distributor of Continental engines, Air Power has the experience and product depth to make sure your IO-520-D matches your aircraft's electrical system, engine mount, cooling configuration, and performance profile. We’re also Continental’s preferred distributor, offering both factory new and rebuilt engines with full warranty support.

Request your quote today—and let our experts handle the spec matching for you.