Continental IO-550-D Engine – Factory New or Rebuilt

The Continental IO-550-D is a legendary 300 HP, fuel-injected engine commonly installed in Cessna 185 and 188 aircraft. Whether you're restoring a rugged bush plane or revitalizing an ag aircraft, this powerplant delivers reliable performance, smooth operation, and modern fuel efficiency.

Air Power, Inc. is Continental’s largest worldwide engine distributor and preferred partner, offering factory new and rebuilt IO-550-D engines at the best pricing with rapid delivery and unmatched technical support.

Engine Specifications

• Model: IO-550-D
• Displacement: 552 in³ (9.05 L)
• Configuration: 6-cylinder, horizontally opposed
• Power Output: 300 HP @ 2700 RPM
• Compression Ratio: 8.5:1
• Weight: Approx. 440-470 lbs depending on configuration
• Fuel Type: 100/100LL AvGas
• TBO: 1,700–1,900 hours (based on model/year)

Aircraft Compatibility

The IO-550-D is factory-installed or STC-approved in the following aircraft:

• Cessna 185 Skywagon
• Cessna 188 Agwagon / Agtruck
• Experimental aircraft requiring rugged, high-output performance

Performance for Demanding Missions

The IO-550-D is prized for its balance of power and reliability in utility and backcountry operations. It maintains strong performance at takeoff and cruise, even in hot-and-high environments, making it a favorite for bush pilots and ag operators alike.

Frequently Asked Questions

• Q: Is the IO-550-D available new or rebuilt?
  A: Yes. We offer both factory new and Continental factory rebuilt IO-550-D engines. Rebuilt engines come with new serial numbers and are certified to the same tolerances as new units.
• Q: What magneto configuration is included?
  A: The IO-550-D typically ships with impulse coupling magnetos. Retard breaker systems are generally not standard, but available in special configurations. Confirm with your installation spec.
• Q: Is this a 12-volt or 24-volt system?
  A: The default configuration is 24-volt. A 12-volt configuration may be available depending on airframe and electrical system requirements.
• Q: Does it come with an alternator?
  A: No. The alternator is optional and not included by default. We can bundle alternators based on aircraft application—ask your sales rep.
• Q: Which oil cooler is used?
  A: Continental IO-550-D engines are compatible with multiple cooler options. Niagara 20002A or Stewart Warner types are common, but check airframe compatibility and mounting.
• Q: Is an altitude-compensated fuel pump included?
  A: The standard configuration includes a non-altitude compensated fuel pump. An altitude-compensated option is available as a factory customization.
• Q: Is a quick-start primer kit included?
  A: No. The quick-start primer kit is sold separately and recommended for cold climate operations or frequent restarts.
• Q: Does the IO-550-D use a 4-point or 6-point engine mount?
  A: Most IO-550-D installations use a 4-point mount system. Verify compatibility with your Cessna airframe or STC documentation.
• Q: Is the engine equipped with an integral oil filter or screen?
  A: Continental offers both options. The most common setup includes a spin-on oil filter integral to the oil pump housing. A screen-only configuration is available if required for STC compatibility.

Talk to an Expert

Our sales team at Air Power can walk you through every option for your aircraft and mission profile. We’ll confirm voltage, magnetos, mounts, and oil system specs before shipping so your installation is seamless. Call us today for a quote or to reserve your engine.