Another RV-7A takes its first flight!

[hesty]

https://www.dropbox.com/s/c5shc1jagz..._4942.JPG?dl=0
https://www.dropbox.com/s/xnmthbd064..._9366.JPG?dl=0
https://www.dropbox.com/s/xgolqdr2rn..._9368.JPG?dl=0
https://www.dropbox.com/s/irxblzv5g3..._9373.JPG?dl=0
https://www.dropbox.com/s/vnivpf5edb..._9414.JPG?dl=0




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

[Mike S]

Chad------big Congrats on the new fledgling

Photos ------ aint official until the photos, ya know..........

[TS Flightlines]

CHAD====congrats my friend on a major milestone!!
Tom

[DeltaRomeo]

Congratulations Chad!!!! Looking forward to more flying posts down the road.

v/r,dr

[PilotjohnS]

Congrats. Now that I am building this means more to me than when I was a lurker.

[Kyle Boatright]

Installing your wheel pants will make a noticeable improvement in your CHT's.

My experience with break in was there was no step change in CHT's.

[jrs14855]

Think of two separate scenarios for CHT. Before the rings seat and after the rings seat.
Before the rings seat every effort should be made to keep the CHT below 400, a momentary excursion to 425 is unlikely to glaze the cylinders.
After the rings are seated longer periods at or just below 425 are unlikely to hurt anything.
I have a lot of experience with Pitts Aircraft, parallel and angle valve 0 360 and parallel valve 540.I don't recall ever flying a Pitts with a CHT gage. Those engines likely saw a lot of CHT time at or near the red line. Never a problem.
I had to break in my 0 320 in 110-120 temps in July in Havasu. On the climb if the CHT started past 400 I pulled the power back and leveled off.
I never did see a significant CHT drop in cruise, just in climb. Never burned any oil from hour number one.

[jcarne]

Congrats good sir!

[Raymo]

What Kyle B. said. The landing gear creates a LOT of drag that the engine must overcome with power/heat. Once the fairings are installed, you'll see 15-20 Kts faster cruise and can climb faster at the same power settings so you'll have more cooling air over the engine.

Mine did the same thing. Go ahead and install the nose gear fairings and you should see some improvement. If you have P-Mags, retard their timing a few degrees until the mains are installed.