RV8

From Matronics

Changing from Prince fixed pitch to constant speed prop. Is this a major project? I purchased an RV8 with a Prince fixed pitch prop and am not really happy with the take off and climb of the aircraft. It has a 200hp Lycoming IO360 A-1-B. I flew with Alex De Dominicis in his RV6 with the constant speed prop for a checkout and the difference is remarkable. My question is this something that is relatively easy to do. I know I will need the quadrant modified, cables for the prop, governor and oil lines, etc., but will it require something major that I'm not thinking about. I know if the crank doesn't have a plug in the front for the oil line that may stop me in my tracks, but will have to check that out first. Any thing else that I'm missing. I didn't build it and will admit up front that I will be getting in over my head without lots of help. thanks for your comment and ideas ahead of time.

Jerry Morris RV8 81324, based at 9A0, Dahlonega, GA.

Jerry, This does qualify as a major project. Your engine probably has a hollow crankshaft, if not, then you will need a new crankshaft. The crankshaft will probably require the installation of a plug (disc) at the aft end of the crankshaft bore to allow the oil pressure in the crankshaft to operate the propeller. Of course, the front crankshaft plug is removed to allow the oil to get to the prop. The governor will have to be installed on the accessory case of the engine. You will need a new prop spinner and back plate that will fit the new prop. The change will also necessitate letting the FAA know about the change, because it is a major modification, putting you back into the test phase for another five hours. You'll also have to do a new weight and balance, because there will be a significant change in the weight and center of gravity. These notes pertain to a hydraulic constant speed prop. An electric variable pitch prop would have other considerations.

Carl Franz EAA TC/FA

Thanks for the info Carl, I don't know if I want to delve into a major project like that due to cost and weight considerations. I am now thinking about putting another Prince fixed pitch prop, the one they recommend is a 68x80 that is recommended for this engine on the 8. If I am just putting a different pitch prop, same manufacturer, same weight, does that qualify as a major project.

Jerry