Brief Description: Front Mounted Prop Governor Cable Routing - Part 1
I was quite perplexed with connecting the control cable to the front-mounted governor on the IO-390 because the intake snorkel takes up most of the left baffle floor and there's not a lot of room for running a control cable for the governor down through the same area. A special bracket would unquestionably be required.
Since the McCauley governor I had was for a rear mount and not a front mount it had the wrong gear ratio (.866 to 1 rear vs .947 to 1 front), I had to order a replacement. A couple of Listers turned me onto the PCU5000 http://www.pcu5000.com/ which is similar in size and mounting to the MT that Van's sells but seems to have less problems with oil flow. I ordered it with the 947:1 gear ratio for the front mounted boss on the IO-390 and with a CLOCKWISE control rotation which means that the control arm turning clockwise *increases* the pitch. The part number for the PCU5000 mounted on an IO-390 is P-520-029/A-947 which can be found on their application chart here: http://www.pcu5000.com/pcu5000x.htm
I scratched my head for quite a while trying to figure out an elegant way of attaching the control cable. I made no less than three complicated brackets out of .063 trying to get the cable to come up from the bottom through the left floor. They mostly worked, but I just wasn't that happy with the operation and the fact that I would have drill a hole in the floor for the cable.
Then I started playing around with the standard VA-153-PC governor bracket and discovered that by drilling two new holes in the bracket in just the right location, I could run the control cable back over the engine and through the rear baffle. The best part is that the control action is really smooth and I'm getting full Max-to-Min travel!!
