About 6 months ago I made a post about prop bolts for my wood Sensenich, and the discussion turned to what a cruise prop my 74/66 was. I barely made static RPM on run up, and it used a lot of runway to get airborne. A few weeks ago I finally took Dan C.s advice and checked my tach with a hand held electronic tach, and found out it was reading almost 100 RPM high so I really wasnt making static, and I was barely making it on climbout. No wonder I thought my climb was anemic. This got me off of my duff to install an Aeromatic that I had on the shelf. WOW, what a difference! The airport owner said I lifted off in much less distance than I usually do ( I dont know how much less), but the rate of climb was 300 to 400 fpm greater than I used to get. The biggest difference was when I took it down to almost stall speed and then hit full throttle . I actually had that pushed back in your seat feeling for a few seconds, and the plane started to climb almost instantly. I have had a couple of scary go around,s with my 150 Franklin and I feel that the Aeromatic has made for a much safer plane. The flight RPM (high speed) part of the adjustment came out a little above red line, so tomorrow I will add the recommended counter weights and get it just right.__IT SURE FELT GOOD.____Grant.
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Installed my Aeromatic today!
- Thread starter gjordan
- Start date
flyncowboy
New member
Hello grant,
I had the same situation on my 14-13-2. I also have the 150 franklin. The aeromatic is about the best match for this engine in my opinion. Getting the weights right is something of a chore. It took me some time and lots of test flights to get the cruise portion correct. Right now at 2200 rpm I am getting 130 mph at just a touch over 8 gpm. The climb is wonderfull and here with 110 degree temps and 3000 ft elevation I really appreciate having the climb.
Dan
I had the same situation on my 14-13-2. I also have the 150 franklin. The aeromatic is about the best match for this engine in my opinion. Getting the weights right is something of a chore. It took me some time and lots of test flights to get the cruise portion correct. Right now at 2200 rpm I am getting 130 mph at just a touch over 8 gpm. The climb is wonderfull and here with 110 degree temps and 3000 ft elevation I really appreciate having the climb.
Dan
You are correct to say the adjustments are a chore. I did my first static run up with the shims that were in it ,since it had been on a Cruisair before. With the counter weights removed it went to 2580 RPM,which I felt was great. I then put the weights back on that had worked on the other Cruisair. I turned 2580 RPM again on run up , so I flew it. It performed wonderfully, but the high speed run came out at 2700 RPM. Next morning I added the correct weights to lower the RPM 100 at high speed, and expected it to be just right._____(WRONG.)_____ Static only went to 2400, and climb was at 2400 which still felt good but the addition of counter weights should not have had that effect. Tomorrow I will strip the counter weights off and go through the whole procedure again. Oh Well!____side note. I looked at the Flotorp prop listings and they list the 74/66 as a climb prop, and a 74/68 as a cruise prop. I would have needed a 5000 ft runway to get up with a 74/68.___(the never ending saga.)___Grant.
I had the same experience. Set it up with the RPM a little high on the ground. My thought was I could always throttle back. Take off and climb was great, but cruise was about 110. Added weight and take off and climb are better, but not great. About 300 ft per minute better then with my wood fitched pitch and my cruise is about 130 now. I think I might be able to fine tune some, but have not got around to it.
The Saga continues; since I was sure that adding the weights would give the needed adjustment, I went ahead and put the spinner on. When I went to remove the spinner so that I could start over, I decided to do the daily Aeromatic test of putting a finger into the spinner to feel where the wood goes into the flange, and wiggle the blade tip to see if there is any movement. I almost fainted when one blade had movement. This prop has less than 5 hours on it since a complete overhaul by the shop in Hemit Calif. It spent a long time stored inside and about 4 hours on a friends Cruisair, so I could not figure out how a blade could have developed rot. I took the spinner off and really looked close, and discovered that it wasnt the blade moving in the flange, but the flange was moving in the hub. This is a MAJOR problem! and off came the prop. Kent Tarver is at Oshkosh this week, so when he gets back I will be making a trip to Nevada to try to sort this out. More time and more money, but after the short test flight I am sure it will be worth it. The slow turning wood club is back on now._____Grant.