George,
You need to do a proper fuel system setup (SID 97-3). Once that is done you’ll be able to look for other problems.
You don’t say what engine you have. If it is a TSIO-550, then indeed, an expensive piece of test gear is required which references fuel pressure against upper deck pressure. Although it is inconvenient, best move is to find a competent shop which has the gear. If you have an IO-550, then all that is needed is a couple of calibrated gauges of sufficient resolution, plus hoses and fittings. This is all spelled out in SID 97-3.
SID 97-3 is supposed to be performed every annual, every 100 hours, and any time the fuel system has been opened.
Jay Phillips
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of George Wehrung
Sent: Tuesday, September 02, 2014 6:46 AM
To: Lancair Mailing List
Subject: [LML] Engine Oil Temps; May need fuel system setup
All,
I am experiencing higher than normal oil temps. It’s not unusual to see 210˚F in the climb. And then the oil temps remain above 200˚ during cruise.
In the last annual, there was nothing done to the fuel system. The magnetos were spot on. We also checked the temp sensor to ensure its accuracy against three different thermometers and ran it up and down using a deep fryer with water. We also pulled the Vernatherm out of the bottom of the oil cooler to ensure it was working. I also called Rosta mfg to discuss the vernatherm operation. It cracked open at 150˚ and was full extended by 185˚ per the manufacturer.
In flight, I started playing with the fuel flow to see if I could lower the temps. What I noticed was that If I put the fuel flow about 250˚ Rich of Peak I could move the oil temp down below 180˚. I could then hold it using about 225˚ ROP. I also cooled the motor by reducing the RPM to 2300.
Anytime I ran the motor below 200˚ROP the oil temp would climb again. This is counterintuitive according to the Oklahoma guys recommendations on running the EGT temps.
As another point of data, I ran the engine LOP and noticed that I could stabilize the temp at 184˚ by running about 45-50˚ LOP.
After talking to the TCM support staff it would appear that I might need a fuel system setup but I don’t know of anyone that has a fuel pressure system, which will necessitate me taking the plane to a repair station. That system that TCM recommends is about $5,500.
Here are some numbers from yesterday’s flight:
Does anyone have any recommendations?