The release of Lycoming’s 210HP IO-390A had many RV 7 and 8 builders wondering if they could install the more powerful engine in place of the recommended angle valve IO-360.
Vans has recently completed an in-depth review of horsepower limitations for the RV-7/7A and RV-8/8A and has now approved the installation of the IO-390A. With the IO-390A there will be just 10 HP increase to the maximum horsepower limit – from 200 to 210 hp.
There were initial concerns of exceeding the Vne limitation of 200 KTAS. The extra horsepower will result in a top speed increase, however, it will not be significant enough change to raise concern, providing the pilot continues to abide by the existing 168 KTAS Vc (max-cruising) speed and 200 KIAS/KTAS Vne (never-exceed) speed limitations.
Van’s Aircraft strongly recommend that the aircraft be equipped with or upgraded to an EFIS system with an audible voice warning of Vne. Over-speed events may occur in manoeuvring flight (such as aerobatics) when the pilot’s attention is turned away from the airspeed indicator. A voice annunciation, coupled with standard screen-displayed warnings, will help warn the pilot of impending danger.
Use of the IO-390A on a RV-7/7A or RV-8/8A will require some modifications to the standard IO-360 angle-valve firewall-forward kit sold by Van’s. The plans supplied with the aircraft or kit will unfortunately not reflect these modifications as Van’s has not done a complete evaluation to compile a list of modifications, nor will they any-time soon.
Van’s are as always open to hearing feedback from installers of an IO-390A engine, so they may better serve other builders who choose this engine in future.