Lycoming's Certified IO-390 Series Engine
The growl of the engine being put through its paces on the "Dyno" was impressive. When the testing of this new, soon-to-be-certified Lycoming IO-390 was completed, I got the thumbs-up that the performance numbers were validated and the engine performed as expected. I decided that the story of the 390 Series engine's journey to certification had to be told.
I searched the archives at 652 Oliver St, Williamsport, PA for the history of the 390 Series engine. A meeting with Lycoming's engineers revealed that the idea of a 210-220hp normally aspirated four-cylinder engine had been in play for some time.
I tracked the origin of the 390 back to the early 1970's. According to documentation, Lycoming engineers were working on an IO-400-X engine some thirty-five years ago.
The original IO-400-X was a derivative of the tried and true Lycoming 360 Engine family. Several variations were designed, assembled and tested. Bore was expanded and the stroke extended. Test results appeared positive and the project progressed. Then the original launch customer decided to go a different direction, and the 390 project was shelved.
Two decades later, Lycoming was working to develop and certify a 580 Series engine. The 580 Series was built off the proven Lycoming 540 Series rotating system. The extra horsepower and displacement was achieved mainly through expanded cylinder bore and a small increase in compression. To certify the powerplant, Lycoming had to go through several generations of 580 Series cylinder development.
During this same timeframe, Lycoming engineers were working on a four-cylinder version of the big bore engine. Again, several variations were assembled and tested. Test results appeared positive, but, again, with no OEM customer, the project was put back on the shelf.
Lycoming officially launched the IO-390-X Engine at the 2002 EAA AirVenture. The engine was touted as Lycoming's largest 4-cylinder engine. At 308 lbs, the engine is rated for 210hp at 2700rpm. Lycoming was able to deliver more horsepower at the same weight and footprint as the successful IO-360, 200hp engine models. The engine was an instant success in the Experimental Market.
Today, in 2008, the IO-390-X Series Experimental engine is a mainstay in production at 652 Oliver St. Many aircraft, including Van's RV-7/8, Glasair's Sportsman, Lancair FG's and others are powered by the IO-390-X. Lycoming offers this engine through OEM Kit Manufacturers such as Glasair, directly to kitbuilders through Thunderbolt Engines (Lycoming's Custom Engine Shop) and through 8 exclusively selected Kit Engine Shops around the world.
The 390 success story continues as we near 2008 EAA AirVenture. Since its initial launch, many owners of aircraft such as the Cessna Cardinal 177RG, Mooney M20's and Piper Arrow have been asking Lycoming when the IO-390 Series will be certified. Owners also want to know when an STC to re-power these airframes would be available. Additionally, OEM Airframe Manufacturers have expressed interest in a higher horsepower four-cylinder engine that weighs the same and has the same footprint as the IO-360, 200hp engine models.
This year, at EAA AirVenture, Lycoming will showcase and announce that in November 2008, the first 390 Series, the IO-390-A1A6 is expected to be certified by the FAA. This powerplant has gone through many phases since its inception in the early 1970s. The current configuration includes a robust rotating system closely derived from the TIO-360-C1A6D, specifically developed cylinders, tuned induction system, Lycoming's roller tappets, Slick Start ignition and front facing fuel injection. As with any journey, progress is one step at a time and Lycoming will continue to certify different versions of the IO-390 to fit customer needs.
Lycoming is certainly very proud of the new Certified IO-390. Like all other Lycomings, the people that build these engines build them like they are going to fly them themselves. Please stop by the Lycoming display at EAA AirVenture or visit us at www.lycoming.com for additional information.