VAF Community,
After 7.5 years my "QB" RV-7A finally got airborne last week and I already have 10 hours on her. A great moment and I was able to share it with a builder friend who came with though the FAA Qualified Pilot program. I am concentrating almost entirely on the proper engine break-in/seating of rings. I have a few questions for the VAF guys in the know. As I have close to 10 hrs, I am expecting the rings to seat very soon and CHT's to drop. I am wondering what kind of drop I should see. As I am doing the phase one unfortunately a little too late for ideal cool temps in the Las Vegas area. Oil consumption seems somewhat minimal, buy higher than I would expect if the rings had already seated. The highest I've seen is about 418 for a couple min on the initial climb. It's a new stock lycoming IO360-M1B engine. MT CS prop. Wheel pants are not installed. Nose leg/pant is complete and can be installed, but the mains are not completed yet. Below are some cruise reference numbers to help build a picture...
4500 ft, 7170 ft DA, WOT, 2400RPM, OAT 82F, oil temp 184, 130 IAS kts
CHT's: 388,391,373,391
4500 ft, 7130 ft DA, WOT, 2500RPM, OAT 82F, Oil temp 186, 132 IAS kts
CHT's: 392, 397, 375, 382
4500 ft, 7160 ft DA, WOT, 2450RPM, OAT 83F, Oil temp 184, 131 IAS kts
CHT's: 388, 394, 372, 389
My biggest question is when should I expect the seating to occur? Will it be sudden? What kind of drop in CHT's should I see?
If the temp drop is not significant, I think I will need to make cowling adjustments to lower the CHT's so the plane is useful in warm weather.
Thanks for any insight and input. I have read a bit on VAF about the break-in process, but have not seen what to expect.
Chad Hesterman
N11ZH
Boulder City, NV
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