aviatoreb Posted May 20, 2011 Report Posted May 20, 2011 Quote: donshapansky GAMI says many rockets will run LOP without much change due the good airflow designed into the intercoolers, compared to the Cessna twins that use this engine the intercooler causes serious airflow disruptions from one side of the engine to the other. What I have found now that I flown over 30 hrs LOP is that the density altitude directly relates to where the TIT and EGT's will peak. The flight to MN was the closest to STD I have seen and the fuel flow ended up at 16.5 gph to get all cylinders 50 LOP head temps were all in the 350 - 360 F range excpet NO 2 which the hottest always at 370 F. Today at 9000 the OAT was 18C RPM 2450 MAP 32.5", fuel flow was 15.5 gph with No 2 50 LOP and CHT 365 hottest. My EDM 930 said we were getting 13.5 NMPG @ 215 KT GRD Speed. Quote
donshapansky Posted May 20, 2011 Report Posted May 20, 2011 If you can stay within .5 gph and get all cylinders to peak there is no need to do anything. Download the GAMI spreadsheet and do the numbers at cruise then circle each peak and look at the gph chnage from the first to the last. Try to step in .2 gph increments. Quote
donshapansky Posted May 20, 2011 Report Posted May 20, 2011 TAS at 6,500 on a close to standard day was 187 KTAS, today at 9,000 way above STD (I think it was 17C) true was 185 KTS. The EDM today calculated power was 70% at 32.5" and 2450 RPM and 15.5 gph. TIT was 1565F today. Prior to my cylinder overhaul my TIT would shoot to 1700 quickly, now I never see over 1650 F for a brief period, much less stressfull, I don't do the big pull. I just slowly roll it leaner and watch each cylinder EGT peak and fall to at least 50 LOP that way I can see a direct correlation to effect DA has on where the engine peaks on each flight, you also get the max speed as you can work the mixture to keep the power up as much as possible, I find a gallon per hour difference between a close to standard day and typical Texas summer day. GAMI's prediction of fuel flows of 16.5 gph were accurate for a standard, day my engine guru has the same engine in his C210, his prediction was bang on of 15.5 gph on a typical OK summer day. Quote
aviatoreb Posted May 20, 2011 Report Posted May 20, 2011 Quote: donshapansky If you can stay within .5 gph and get all cylinders to peak there is no need to do anything. Download the GAMI spreadsheet and do the numbers at cruise then circle each peak and look at the gph chnage from the first to the last. Try to step in .2 gph increments. Quote
aviatoreb Posted May 20, 2011 Report Posted May 20, 2011 Quote: donshapansky TAS at 6,500 on a close to standard day was 187 KTAS, today at 9,000 way above STD (I think it was 17C) true was 185 KTS. The EDM today calculated power was 70% at 32.5" and 2450 RPM and 15.5 gph. TIT was 1565F today. Prior to my cylinder overhaul my TIT would shoot to 1700 quickly, now I never see over 1650 F for a brief period, much less stressfull, I don't do the big pull. I just slowly roll it leaner and watch each cylinder EGT peak and fall to at least 50 LOP that way I can see a direct correlation to effect DA has on where the engine peaks on each flight, you also get the max speed as you can work the mixture to keep the power up as much as possible, I find a gallon per hour difference between a close to standard day and typical Texas summer day. GAMI's prediction of fuel flows of 16.5 gph were accurate for a standard, day my engine guru has the same engine in his C210, his prediction was bang on of 15.5 gph on a typical OK summer day. Quote
donshapansky Posted May 20, 2011 Report Posted May 20, 2011 To keep the engine CHT's below 390F ROP running 29" @ 2450 would take 22 gph after the cylinders were OH so it's 5.5 - 6.5 gph! and much cooler CHT's. The exhaust tip has changed from white to colorless no carbon deposit, I hope the internals are the same. The oil stays golden color right to 30 hrs when it's changed. Quote
aviatoreb Posted May 20, 2011 Report Posted May 20, 2011 Quote: donshapansky To keep the engine CHT's below 390F ROP running 29" @ 2450 would take 22 gph after the cylinders were OH so it's 5.5 - 6.5 gph! and much cooler CHT's. The exhaust tip has changed from white to colorless no carbon deposit, I hope the internals are the same. The oil stays golden color right to 30 hrs when it's changed. Quote
KSMooniac Posted May 20, 2011 Report Posted May 20, 2011 LOP ops really shine in a turbo bird! I'm quite envious.... Quote
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