Tuesday, December 23, 2008

Changing the Propeller Governor

As we mentioned before there are some things that need to be changed to get the Lycoming IO-540 C4B5 to fit our use on the RV 10. One of these is the propeller governor. The original unit for the Piper Aztec won't work for several reasons. First it's too bulky to fit under the RV cowl, but more importantly being it is used on a twin engine aircraft it feathers the opposite direction from what we need.

In the picture you can see the difference between the original on the right and the MT governor on the left, which is available through Van's Aircraft.

Of course the fun doesn't stop here! As you can see in the photo the mounting flange on the MT unit is thicker. So the mounting studs will need to be replaced with the longer ones. These are available from Lycoming, however I purchased mine through ECI (Engine Components, Inc.) at about half the cost. Yes, they will deal with us builders. The ECI part number for the new studs is AEL31C16. If ECI sounds familiar it's because they make Titan engine cylinders and other aircraft engine parts. Their website is www.eci.aero.

Make sure you get you Lycoming engine manual out and install the new bolt studs according to the manual. If this is new to you ask your EAA technical conselor or and A&P. Engine cases are too expensive to mess-up!