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Quick question vintage Mooney officianado's, I've put roughly 35 hours on my new to me 67 M20F since taking ownership and finally was able to download the EDM 700 data. The engine is a Lyc remanufactured IO-360-A1A installed in Feb of this year by prior owners. Normal cowl but it does have the lower cowl cover. I'm seeing a consistent temp split between my #2 (hottest) and #1 (coolest) cylinder of ~70-80 deg F. (attached pic of data from one flight). Engine now running Aeroshell 100+...max fuel flow indicated during takeoff ~15-16 gph She runs smooth, during runup with the JPI Norm mode, all appears to respond as expected. Figured I'd ask if there is a 'normal' or expected temp differential between hottest and coldest cylinder...thoughts ?

I fly a M20K 231 with Merlyn intercooler and wastegate making it fly like a 252. We recently had an engine overhaul that caused the TIT to run considerably hotter than on our "old" engine. The "new" engine is in fact the same core, just overhauled to new specifications. The temperature probes are the same as well, so they may be inaccurate, but they should be measuring the relative temperature differences correctly. We had a Mooney Service Center set the fuel flow system at the high and low end per the Continental Service Instruction. This supposedly is very important because an out of whack setup could create many problems. At full power on takeoff (36 inches due to the intercooler), we are seeing 22 gph. That is about 2-4 gph lower than before the overhaul. In cruise (28 inches, 2500 rpm, mixture full rich) we get 15 gph, about 1 gph more than on the old engine. The really concerning thing though is that with the mixture full rich, we see TIT temperatures between 1520 and 1560. We have no ability to decrease that temperature by running significantly rich of peak. On the previous engine with what was probably a poor fuel flow setup, we could cool the TIT to less than 1480 degrees by enrichening the mixture. So my question to the community is 1) should we be concerned with flying the airplane in cruise at 1560 TIT, and 2) should we be concerned that we don't have any "mixture authority" at normal cruise conditions in case CHTs start rising or something like that. The STC that added the intercooler was approved without any change to the performance charts, so we don't know exactly what fuel flow would be expected with certain power settings. If anyone has a copy of a 252 power chart, it would be most appreciated. Thank you.