Seth Posted March 12, 2012 Report Posted March 12, 2012 I gave it a shot - I tried LOP operations yesterday in the early evening (around 6:00 PM) and the engine ran smoothly. I gently brought the IO-550 on the Missile past peak and then until all cylanders were lean of peak. The cylander temp was low enough the entire time (280 to 340). Most of the exaust temps went low, but one stayed a bit higher and when lowering it, the engine started runing rough. So one of the exuast temps was only about 50 or 60 degrees lean of peak while the others were much more lean of peak. I have an JPI - 830 - Great piece of equipment. The Mooney was running smoothly at about 10.5 to 11 GPH. 2300 RPM. I didn't really track the TAS during that, and this was all at 5200 feet, but I'll get some more exentsive testing in time. I flew around watching for any issues and didn't see any. My question to those LOP operators out there, what are your exact procedures and where do you like to sit in the LOP arena? ROP for the climb, LOP for cruise, when do you go back to LOP? Decent? Landing? Do you like to stay at least 50 degrees LOP? As much as the engine will take? Please explain away as I'd like to hear from your practices and learn what is best to do without hurting my engine and exaust. I realize there is a ton of debate on ROP / LOP ops. That is not what I'm asking about right now - I'm just asking about LOP opertators and how about they fly their aircraft LOP. Mine seems to operate just fine in that zone, and for just making holes in the sky, 11 gph seems better than 15 to 17 gph. How do you fly your plane LOP and do you have any tips or tricks. Thanks! -Seth Quote
Hank Posted March 12, 2012 Report Posted March 12, 2012 Nah! I think he just made somebody's day! From what I've read, Seth, you're on the right path. I can't give you any assistance, since my carb doesn't do LOP very well. But at 9-10K, peak seems to work well for me, too. But now that I've resealed my tanks, overall fuel consumption seems to be down, so I get to refigure everything. My favorite feed run went from 8 gals to only 6 gals, so I'm a happy camper and don't mind re-learning my fuel use. Darn, honey, we have to go fly more, and visit family again, to see how much fuel it REALLY takes to get there! Quote
MARZ Posted March 12, 2012 Report Posted March 12, 2012 Quote: Hank But now that I've resealed my tanks, overall fuel consumption seems to be down, so I get to refigure everything. My favorite feed run went from 8 gals to only 6 gals, Quote
Hank Posted March 12, 2012 Report Posted March 12, 2012 Not if she had sat for a week or two, topped off after flying. There's a little variability in the gap I leave [1/2-3/4"] for expansion, too. Now, however, I know there's not a gallon per tank variation! Fly, top off, park for a day, or two-three weeks in winter. Fly, top off, determine gph [high due to leaks]. Now my gph is down significantly! :-) If only $ per gallon would also go back down . . . Quote
jetdriven Posted March 12, 2012 Report Posted March 12, 2012 Seth, start by reading the Pelican Perch and Mike Busch articles on the web. Then search "LOP" here, BeechTalk, and Vansairforce.com forums. read them all. Now, basically, you want to run ~50 -100 LOP on a Continental 6 cylinder in cruise for most efficiency. Bonanza guys have that figured out. Do not run it hot. 2. Make sure it runs smoothly. Do not exceed 380 on any cylinder, preferably run them at 360 or less. Learn where the "red box" is. You cannot hurt it below 65% power with the mixture. Quote
testwest Posted March 13, 2012 Report Posted March 13, 2012 Hi Seth! Excellent post on your experience with LOP. The more you understand the engine, the better pilot you'll be. Have you downloaded the EZTrends software from JPI yet? If not, I would advise that you do, and learn how to then download and plot the data from your EDM-830 on your computer. One of the nifty things EZTrends will do is an automatic analysis of your GAMI spread. I am using that to great benefit on our twin Mooney (Aerostar 601P). We are currently installing an EDM-930 in our 201 right now, and I really look forward to sharing our data with the group. Be sure to set the data rate to the shortest possible interval, I think it is 2 seconds. You will have more that enough memory even at that rate if you download and archive your data every so often. Annual time would be perfect for that. It is amazing how much efficient performance you can get out of a Mooney, when you decide to STC Your Brain. (trademark pending!) Quote
John Pleisse Posted March 13, 2012 Report Posted March 13, 2012 With an IO-550, you should be able run LOP without issue. Unlike 4 cylinder Lycomings, there are published procedures. Quote
KSMooniac Posted March 13, 2012 Report Posted March 13, 2012 Easiest thing to do is go here and get educated: http://www.advancedpilot.com/ I fly anywhere from 5 or so LOP down to 50 LOP once I get to cruise altitude. I leave the mixture alone until I kill the engine at my hangar, or if I need to do a go-around or missed approach. Takeoff is full rich at lower altitudes, or else leaned to my target EGT if higher. I lean in the climb to the target EGT as well. Quote
testwest Posted March 15, 2012 Report Posted March 15, 2012 ....and that is exactly how we do it as well. I personally view KSMooniac's operating procedures as the "approved solution"... For Seth, since the Missile has automatic mixture control, the target EGT part of the climb is handled automatically. Quote
DaV8or Posted March 15, 2012 Report Posted March 15, 2012 Quote: KSMooniac Easiest thing to do is go here and get educated: http://www.advancedpilot.com/ I fly anywhere from 5 or so LOP down to 50 LOP once I get to cruise altitude. I leave the mixture alone until I kill the engine at my hangar, or if I need to do a go-around or missed approach. Takeoff is full rich at lower altitudes, or else leaned to my target EGT if higher. I lean in the climb to the target EGT as well. Quote
jetdriven Posted March 15, 2012 Report Posted March 15, 2012 During this cool weather and high altimeter settings, I have found myself limiting MP to 27" at altitudes below 2 or 3K. . It wont always run smoothly at 30", 2500 RPM, and 8 GPH Quote
Shadrach Posted March 15, 2012 Report Posted March 15, 2012 Byron, I wonder why you're having an issue. On Sat the baro at HGR was 30.51. I was tooling around the state at 2500 WOTRAO (MP gauge indicating about 30.7") and about 35LOP with no problems. OAT was about 40DF all CHT <325 at 155KIAS. We've never had a problem running LOP at high MPs. How far lean are you at 8GPH and 30"? Quote
jetdriven Posted March 15, 2012 Report Posted March 15, 2012 Ross, I usually leave the throttle firewalled but lately I have been flying at 1000' due to clouds etc, and at 10.0 GPH thats a 360-380 CHT. Leaning further to ~8 GPH is around 200? LOP, and it begins to not run smooth. So the choice is hot and fast, or a little slower and not smooth. Limiting MP to 27" allows me to get to the ~8 GPH range with some leeway as far as mixture. Quote
Shadrach Posted March 15, 2012 Report Posted March 15, 2012 I do not understand why my engine runs so cool at high power while LOP. Are the OATs that much hotter where you are? I would really have to try to get 380 in cruise unless I was high and hot. I was experimenting the other day at the previously mentioned conditions and settings. going from 35LOP to full rich made almost no difference in CHTs, maybe ~5 degrees either way, #1 went from 298 to 295, #2 went from 302 to 298, #3 went from 323 to 328, #4 301 to 297. I gave it about 90 seconds to settle after setting full rich, but after seeing such a small difference, I decided to stop puking gas through it. Maybe I need to do some extended testing. I hope to have FF added to my JPI at annual (starting in April...ugh!), so I can get a better idea of power levels. As of now I go off airspeed which was pretty well planted in lower yellow arc at ~155kts. Quote
Cruiser Posted March 15, 2012 Report Posted March 15, 2012 Ross, Your CHTs are very low, probably the lowest I have seen reported. What do you have the timing set to? Quote
Seth Posted March 16, 2012 Author Report Posted March 16, 2012 Thank you for the suggestions. I've read and researched a lot about LOP at this point and will take the aircraft up again tomorrow to fiddle around some more to better understand what will become by standard LOP settings. Do most of you keep LOP in the decent? If so, when do you switch back to ROP for landing? -Seth Quote
Parker_Woodruff Posted March 16, 2012 Report Posted March 16, 2012 Quote: Seth Thank you for the suggestions. I've read and researched a lot about LOP at this point and will take the aircraft up again tomorrow to fiddle around some more to better understand what will become by standard LOP settings. Do most of you keep LOP in the decent? If so, when do you switch back to ROP for landing? -Seth Quote
jetdriven Posted March 16, 2012 Report Posted March 16, 2012 A couple times below 3000' sometimes enrich very slightly to keep it smooth. I cross over from LOP usually when reducing power abeam the numbers, when making the final power reduction for landing. I go to an approximate "peak" setting (1/2-3/4" from full forward) then. I think you have the automatic mixture control, and those Bonanza guys never touch the mixture crom cruise unless they go around or level off and increase power. Quote
Shadrach Posted March 16, 2012 Report Posted March 16, 2012 Quote: Cruiser Ross, Your CHTs are very low, probably the lowest I have seen reported. What do you have the timing set to? Quote
danb35 Posted March 17, 2012 Report Posted March 17, 2012 Quote: Seth Do most of you keep LOP in the decent? If so, when do you switch back to ROP for landing? Quote
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