Ryan121b

I have been running it in but only a handful of hours, I plan to complete the 25 hour break-in recommended by the Continental manual. I have been looking at the data but haven't seen a specific drop in temperatures across the board, and I'm still running on break-in oil at the moment.

That's a good point, I've seen the other rocket / missile owners claiming 28.5 gph minimum, up to 30 gph for takeoff around sea level like where I'm based, so I will be increasing that in the near future which should help overall CHT temps. I was having an A&P pushing back on my higher FF request, since the Continental books advise 26.5 gph max, but it just isn't enough. Ideally my CHTs should be 380, or at least sub 400 on takeoff unless it's a hotter day. Hopefully the combination of better seals, higher FF will get me in a consistently safe CHT range.

These photos are current day, the last photo is pre-strike inspection condition. Admittedly I knew little of the flexible baffle seals until recent troubleshooting, I'm concerned with the holes / wear from punctures on the left side of the engine, as well as the mis-formed section at the left rear of cylinder #2. On the back right side, the flexible seal is sliced, which seems like it was done to allow the seal to bend but also seems like it would allow far too much air through the back via all the gaps. Pre-strike-inspection condition:

Initially I swapped the probes between #2 and #4 cylinders as #2 was the coldest on the left side. They indicated that #4 cylinder (read by the #2 probe on the #4 cylinder) was still higher than the others. Afterwards I did have the #4 CHT probe replaced with a new gasket probe, since it had some fraying, but the temperatures remained consistently high on that cylinder. And that's a great point on the baffle photos, I've reached out to the mechanic for photos they may have.

Thanks for taking a look, takeoff fuel flow is now set to 27 gph for takeoff, I've read that other folks have set it higher though. I am looking into the baffle install photos from the teardown, it was off-station so I wasn't present during the process, I'm reaching out to the mechanic now. pre prop strike flight: https://apps.savvyaviation.com/flights/shared/flight/7133120/a36ca306-f2c9-48e4-bb61-cde5ac113fff

https://apps.savvyaviation.com/flights/shared/flight/7405304/b463ddf0-9c5c-4698-970d-be99e497cd5d https://apps.savvyaviation.com/flights/shared/flight/7186313/e0c92d2e-9c62-4961-8b9c-0ad0c6e12f7b Here is the engine monitor data from the previous two flights. I had the engine borescoped after the first flight, and had the total fuel flow increased to help reduce temps during takeoff, but still had high CHT. The other CHTs appear normal, I haven't closely examined the internal baffles. The timing has been verified twice to be within limits, although an exhaust leak would hopefully be an explanation for the CHT readings. I debated swapping the CHT probe to the top spark plug position to see if that would cause a big difference.

Hey all, I have an M20J Missile with an IO-550A. After a prop strike inspection early this year and annual, the #4 CHT is excessively high on initial climbout now that I'm at my home field (NW LA). I'm hoping someone might be able to point out a potential area I may have missed. I'm having a hell of a time finding an A&P to help, so I'm hoping to have the issue narrowed down before they show up. CHT #4 reached 490F briefly during takeoff on an 85F day, once airspeed increased, temps reduced below 440F, but still not where I need them to be. CHT gasket probes are installed on the lower spark plugs on all cylinders. CHT probes were swapped around and ultimately replaced, they are valid readings and still high CHT on #4 Flexible baffle seals will be replaced: they are split / deformed in various areas, but I can't believe this alone would be the root cause of such a high CHT spike on just the #4 cylinder Rigid baffle seals appear normal GAMI injector nozzles: checked / visually verified clear. I'm considering whether the nozzle may need to be adjusted by GAMI, but I can't get an in-flight test until I mitigate the high CHT before my next takeoff. Fuel line 'bottle test' (without injectors attached on the lines). #4 was the highest by a small amount, I believe issues would arise if it were excessively more lean than the others #1 cyl - 3.15 fl oz #2 cyl - 2.95 fl oz #3 cyl - 3.45 fl oz #4 cyl - 3.50 fl oz* #5 cyl - 3.20 fl oz #6 cyl - 3.20 fl oz Cylinder borescope showed nothing significant / concerning EDIT: Spark plugs were checked and reinstalled If anyone has any insights or potential areas to target, it would be greatly appreciated. I'm hopeful the flexible baffle seals will help, then thinking of having GAMI modify the #4 injector.. other than that, I'm a little stuck.