Engine Break In Speed Report

[201er]

Here's some raw data I collected on a 4 hour xcountry to Wisscaset Maine (lobster rolls) and back. I know others of you here are in the process of breaking in engines as well so I wonder if mine still has improvement ahead. I am now at about 15 hours into this factory rebuilt engine. Should I consider it broken in or lots more to go? I never had a drop in CHTs and oil consumption has been minimal all along. I've only added a quart at about the 11 hour mark.

7000ft 2600RPM 24.0"MP 12.6GPH 120ROP 8C-OAT 139KIAS 157KTAS 166GS CHTS-315,355,379,366

7000ft 2600RPM 24.1"MP 10.3GPH 20LOP 7C-OAT 130KIAS 146KTAS 155GS CHTS-301,322,360,353

6000ft 2500RPM 24.7"MP 12.2GPH 120ROP 10C-OAT 140KIAS 155KTAS 138GS CHTS-319,361,383,369

6000ft 2500RPM 24.7"MP 9.9GPH 12LOP 13C-OAT 134KIAS 149KTAS 136GS CHTS-306,331,363,355

Numbers look pretty consistent to me and were taken based on the average flight condition. Seems close to what I was able to cruise at on the A3B6d but not quite there. More like 160-165KTAS 100ROP and 150KTAS 20LOP at similar density altitudes and power settings.

I also have engine data from the EDM830 so if anyone is expert at analyzing those and might be able to tell me something I don't know, would be appreciated. Anyone else breaking in an engine or flying behind an A3B6, I'd appreciate your numbers and feedback. For the full power 3 leg speed test I got 159KTAS average based on GPS at 1500ft DA, KIAS was also 159.

[jetdriven]

Mike, try to get a 3-track NTPS spreadsheet. It is accurate to one knot if stabilized. Fly 3 eqilateral tracks over the ground such as 360-120-240 and note stqbilized groundspeed. The IAS must subtract 2 KIAS to arrive at calibrated airspeed, then you correct for air density from there. I dont think that window on your airspeed indicator is accurate to 3 or 4 knots.

here is the spreadsheet: http://www.ntps.edu/...nts/gps-pec.XLS

here is our results. All speeds include cowl flaps closed, roof scoop cabin air and eyeball vent opened fully, max available manifold pressure, and 2500 RPM Takeoff and climb 130 MPH IAS to 12000 density altitude (10,500)

Cowl flaps trailed and leaned to 1285 target EGT on EGT 3

12000

80 ROP 148.9 KTAS 9.5 FF

peak 147.2 8.3

15 LOP 142.9 7.8

7000

80 ROP 154.7 KTAS 11.7 GPH

peak 150.7 9.9

25 LOP 149.1 9.8

2392 density alt

16 GPH (Approx 200 ROP) 160 KTAS, 16 gph

[eaglebkh]

Compression check and oil consumption are pretty good indicators of break-in completion. My MSC wanted to check compression at 25 hrs. All was good, but he mentioned that there was still some blow-by occuring and wanted me to go 10 more hours to complete break-in.