Before I make a comment, please note I am no expert on others running LOP. However, I do consider myself to be an expert on running MY engine LOP.
My comment has to do with your CHT numbers being displayed. I would not expect your CHT's to be 400+ while running LOP!
Another thing I notice with those CHT's is the spread between each cylinder. Your scale does not give a close enough breakdown to see how closely the temps are to each other. Do you have information on exactly what your CHT temps are for each cylinder? In my case, when running LOP in cruise my CHT's are 10 degrees or less from each other. They ebb and flow as one unit staying within that 10 degree range of each other. In your pics it appears cylinders 1 & 3 and cylinders 2 & 4 are close together but the two banks are separated by a fairly large margin of temps with 2 & 4 looking uncomfortably high.
I do see that you are running pretty fast up high and burning around 7.8-8.1 GPH. Even so, I would want those CHT's below 400. In fact a lot lower than 400. Too much written on the temps of CHT's and how the higher temps (400 +) contribute to shortened piston life.
Below is a pic of one of my flights with similar engine parameters to what you show in your pics. The one important main difference being the speed at which the two planes were flying. Make a note that my instrument speeds you see on this picture are all in statute MPH not in nautical miles per hour (KTS). You are flying considerably faster than I was in this pic. That is definitely an important distinction to note in examining the two operations. However, I wanted to point out the CHT's while running LOP in this flight. First off, note the temps are well below the 400 degree temp. I consider that 400 degrees as the bottom temp of the DANGER zone for running LOP. Anything 400 deg or higher means I am at a greater potential risk of cylinder damage so I stay well clear of that threshold temperature when running LOP. The other point is the temp range of all four cylinders. the low is 324, the high is 334. All within 10 degrees of each other. Not as critical as CHT, but you might also note the EGT's are also within a small range of each other. Everything humming along nicely together. This pic does not show it, but on the engine monitor page the EFIS shows me a trend line for CHT's and EGT's for all four cylinders for the entire flight. That trend line is always as if it were one line, even though there are four separate lines, one for each cylinder in that trend graph. Me likey that alot!
As noted concerning the speed, that margin I allow, to stay clear of the 400 degree temp, does come at the cost of airspeed. I do give up some airspeed but then again, I am not in a race when flying. Racing is a totally different environment where one most likely will be pushing the engine to its limits, but that is not my mission. So, I stay away from that operating regime with hopes to keep my engine purring happily along for a very long time while still running LOP and saving fuel. Oh, speaking of that, it is hard to see in this pic but this pic shows I was burning 7.0 GPH on this flight. Slower flight than yours but cooler running engine, 1 gph less in fuel burn and still clipping along around 160 mph or so. If speed were of concern I could still push it up to more like your 8.0 gph but I would still make sure to keep my CHT temps below 400 in doing so.
Just my take on LOP and considering this is all unsolicited input, worth to you just about what you payed for it I am sure.
Live Long and Prosper!
LOP operations and plug wires
Linear Mode
