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). So now, six months later (that's another long, sordid story!), the airplane is back together and flyable. I have a brand new prop (manufacture date 2/20/03!), the engine has been torn down, inspected and reassembled with what was essentially a major overhaul, I have a recently overhauled governor, and everything should work as advertised, right? Wrong!!! First flight after rebuild, same exact strange RPM behavior!!! We adjust the pitch stops on the prop such that we should see a 200 rpm increase, per instructions from Hartzell. I fly. NO CHANGE!!! Cannot get more than 2500 RPM until in level (or descending) flight with airspeed above about 140 KIAS. Excuse my language, but WHAT THE HELL IS WRONG WITH MY AIRPLANE!!!! Thanks in advance for any help you can offer. Lee "Q-Tip" Metcalfe N320WH - Kansas City (IXD) ------_=_NextPart_001_01C2F874.64B42F8A Content-Type: text/html Message

OK, all you powerplant experts, here's a good one for you. I apologize for the length of this post, but it's a long, sordid story.

I have an LNC2 with an IO-320-D1C (160 hp) and a Hartzell HC-F2YL-1F prop (the standard prop supplied by Lancair). When I bought my plane (flying since 1992, 450 hrs.) last year, RPM control and behavior were perfectly normal. On take-off, RPM would go to 2700 at full throttle/full increase. RPM control in flight was exactly as you would expect.

After having flown the plane for about 10 hours, I decided to have a JPI EDM-700 installed (by the way, I wish I'd gone for the 800 now, but that's a different story). During the installation the A&P discovered that the oil pressure and temperature pick-ups were reversed from their normal locations. The pressure pick-up was at the front of the engine at the far end of the oil galley and the temperature sensor was on the back of the engine at the oil pump. He said they should be the other way, so I OKed the change. After that change (and completion of the EDM installation), the first run-up I did I noticed oil pressure was up to 120#! It had been in the 80# range before. I took the plane back to the A&P and he threw a pressure gauge on it and confirmed the pressure at 120. He concluded that the previous owner must have cranked up the pressure because he was getting a low reading due to the pressure pick-up being in the wrong place. It appears that the plane had been flown all of its 450 hrs. with the oil pressure over red-line (the engine was factory new when installed). So the A&P cranked down the pressure and I went to test fly it. Pressure was reading right in the 80-85 range during run-up, so I attempted a take-off. Upon applying full throttle (prop and mixture controls full forward) the engine accellerated smoothly to 2500 RPM and stayed there. I pulled the prop control back until I got a drop in RPM then ran it back to the full increase stop. RPM went back to 2500. Everything else looked good and the airplane wanted to fly, so I took off and orbited over the airport. I climbed to 2,000' agl at 120 KIAS with the RPM stable at 2500 (still full throttle and full increase. As I levelled off and airspeed began to increase, the RPM began to increase, just like a fixed pitch prop! Accellerating through 160 KIAS the RPM was passing through 2700, so I pulled the prop control back to maintain 2700, which the governor maintained as normal. I then tried a zoom climb, and as the airspeed came down, so did the RPM. I then descended and the RPM came back up.

Back on the ground, the A&P checked the prop control cable and linkage and found no problems. I didn't think he believed me about the RPM behavior, so I took him for a ride and he fiddled around with the prop control while I flew, and it behaved exactly the same for him. He then concluded I had a bad governor. I asked whether messing with the oil pressure setting could have anything to do with the RPM problem. He said it shouldn't, because the prop governor has it's own pump that boosts the engine oil pressure up into the 200-250# range for prop control. But just to make sure, he cranked the engine oil pressure back up to about 110 and I flew. No change in the odd RPM behavior.

So off comes the governor for an overhaul (it had 450 hrs. since new!). Prop shop found no obvious problems with the gov and a normal overhaul was done. Gov is reinstalled. I go fly. No change in the strange RPM behavior!! A&P says prop needs overhauled (450 hrs. since new, but ten years since manufactured). I am skeptical. Also, I have two important trips coming up (annual Canadian fishing trip and Oshkosh!) and don't want the plane AOG. I start communicating with Hartzell. They give me a couple of diagnostic procedures to check the setting of the stops on the governor linkage and the pitch stops on the prop. I pass those on to the A&P. He claims he has already checked those settings. Over the next month I fly the plane to Canada and Oshkosh (actually Fond Du Lac) with the strange RPM behavior continuing. I essentially have to fly as though I have a fixed-pitch prop, except that I can adjust RPM in level flight and the governor will hold it.

After Oshkosh I am slowly beginning to accept that I'm going to have to pop for a prop overhaul (but still not convinced that is the solution). Then I have my prop strike incident (I swear, it really was an accident! http://lancaironline.net/lists/lml/Message/18655.html).

So now, six months later (that's another long, sordid story!), the airplane is back together and flyable. I have a brand new prop (manufacture date 2/20/03!), the engine has been torn down, inspected and reassembled with what was essentially a major overhaul, I have a recently overhauled governor, and everything should work as advertised, right? Wrong!!! First flight after rebuild, same exact strange RPM behavior!!! We adjust the pitch stops on the prop such that we should see a 200 rpm increase, per instructions from Hartzell. I fly. NO CHANGE!!! Cannot get more than 2500 RPM until in level (or descending) flight with airspeed above about 140 KIAS.

Excuse my language, but WHAT THE HELL IS WRONG WITH MY AIRPLANE!!!!

Thanks in advance for any help you can offer.

Lee "Q-Tip" Metcalfe

N320WH - Kansas City (IXD)

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