Lukon Posted October 28, 2018 Report Posted October 28, 2018 I read the leaning for newbs thread and it was very helpful, but it raised some questions with me. Someone mentioned watching the correct cylinder; which one would that be? The hottest one? I’m talking EGT btw, as the heads are pretty cool for me cruising at altitude... the EGTs vary quite a bit between my cylinders, and the variation seems to increase over time when I cruise at altitude for an extended time. Quote
Bob - S50 Posted October 28, 2018 Report Posted October 28, 2018 1 minute ago, Lukon said: I read the leaning for newbs thread and it was very helpful, but it raised some questions with me. Someone mentioned watching the correct cylinder; which one would that be? The hottest one? I’m talking EGT btw, as the heads are pretty cool for me cruising at altitude... the EGTs vary quite a bit between my cylinders, and the variation seems to increase over time when I cruise at altitude for an extended time. You need to have an instrument that shows all four cylinders at the same time. However, with that said, I have learned the following about MY engine: #4 has the highest EGT so I use if for leaning during the climb. #1 is the richest so if I just want a quick and dirty move to LOP, I just watch the #1 EGT rather than using the lean find procedure. #3 runs with the highest CHT so I watch it and will adjust my mixture to keep it below 400F. Quote
Lukon Posted October 28, 2018 Author Report Posted October 28, 2018 (edited) My instrument ticks through them, or I can focus on one. So for climb, I can focus on the hottest one, and for cruise I can focus on the coolest one? I like to keep my CHTs south of 375 degrees, and they’re south of 350 degrees in high cruise... Edited October 28, 2018 by Lukon sp Quote
Marauder Posted October 28, 2018 Report Posted October 28, 2018 My instrument ticks through them, or I can focus on one. So for climb, I can focus on the hottest one, and for cruise I can focus on the coolest one? I like to keep my CHTs south of 375 degrees, and they’re south of 350 degrees in high cruise... What is instrument do you have? If it is fairly modern, it should have a lean find function.Sent from my iPad using Tapatalk Pro Quote
carusoam Posted October 28, 2018 Report Posted October 28, 2018 Lukon, See if you can follow me on this... Search Gami spread... 1) You will learn a lot about your engine and its monitor. 2) Leaning is all about EGTs... 3) CHTs are partly a function of EGTs, then add cooling details... 4) Most often you will find the one cylinder that is first to peak. So it’s not the hottest EGT at all... this temp number has a lot of variability for instruments added outside of the factory... For this exercise we are simply watching the first and last to peak, and any anomalies that occur along the way... 5) When running LOP you want to know last to peak... 6) When using LF... Lean Find functions... you need to set LOP/ROP in the monitor so it knows to pick the first or the last to peak... small detail... 7) a tight Gami spread, difference in FF at first cylinder to peak, vs. FF at last cylinder to peak... is a good sign of excellent fuel distribution... 8) a wide Gami spread... is a good sign of opportunities to be expanded upon... Gami sells balanced fuel injectors specific to your engine... requires some tests and data sharing with Gami. 9) A wide Gami spread with three cylinders that are close, and one cylinder doing its own thing... a good sign of a blocked/dirty fuel injector... 10) finding a blocked fuel injector is a test called the baby food jar test... running all FIs into identical open glass containers for a set time, to visually see which one fills slowest... a good scale can be pretty helpful too. 11) Cleaning FIs can be done with Hopp’s (#7 gun cleaner?) and an ultrasonic cleaner... use care to collect what is causing the blockage to know what is falling apart upstream... 12) What are these rubber bits in my FI? Possibly the liner of a rubber fuel hose that has deteriorated... 13) More about Gami spreads, collecting and sharing your engine data can be found st Savvy.com... 14) We have a really active MSer with really good Saavy experience... extra helpful when the questions get harder... 15) We also have many MSers that can look at EGT / Cht data and make recommendations immediately... 16) posting pics always helps identify what you are seeing. 17) printing the user manual for your engine monitor can be very helpful for setting it up properly... find the data collection rate. Find the leaning modes. Find the data download procedure... take good notes... remembering which two buttons to push can be a challenge on a busy flight... The power of MS on a Sunday! Our flying weather turned crummy this morning... PP thoughts only, I have a JPI 700 monitoring six cylinders. Its Gami spread was near 0.1gph at 1600hrs on the engine. No signs of having Gami FIs in the logs... The engine could be leaned near 90°F LOP at lower altitudes before it shut off. 50°F at alts over 10k’ before it shut off... Lukon, still with me? Did I miss anything? Need more detail? Best regards, -a- 2 Quote
Lukon Posted October 28, 2018 Author Report Posted October 28, 2018 (edited) Lmfao @carusoam I think I understood almost half of what you said there. My engine is carbureted. I just got the plane. There are a couple digital engine monitors that tick through EGTs and CHTs. Right now I just run old school and lean till rough at altitude and richen it a bit till smooth. She flies beautifully, but I need to shoot for good mileage at altitude, as a couple of my missions are near the edge of the envelope range-wise. I want to go about 710 statute miles without stopping for gas at a decent pace. I should be able to do this with nearly an hour reserve, if I get it dialed in... I’ll pour over the stuff I’ve got and look for the brand of monitors I have. I doubt they’re very new or sophisticated. I doubt they report anything but temps. Edited October 28, 2018 by Lukon Quote
David Lloyd Posted October 28, 2018 Report Posted October 28, 2018 Lukon, Take a look at other MSers information. It would help answering questions if you included your aircraft type and location. Quote
gsxrpilot Posted October 28, 2018 Report Posted October 28, 2018 Leaning is based on EGT only and the actual temperatures don't matter. You're only interested in the movement of the temps. You want to watch to see which EGT peaks first (quits going up and starts coming down). As you continue to lean, you also watch to see which EGT is the last to peak. When someone says as an example, "25° LOP" they are looking at the last EGT to peak and it has come down 25° from its peak temperature as they continued to lean. When someone says as an example, "50° ROP" they are looking at the first EGT to peak and then has richened it back up to bring that EGT 50° back down from its peak as they richened the mixture back up. or what @carusoam said. Having said all that, leaning a carbureted engine to LOP, is a bit of a black art, is only successful part of the time, and impossible with some engines. 3 Quote
carusoam Posted October 28, 2018 Report Posted October 28, 2018 +1 @Lukon update your avatar to indicate which plane you have... +1 Nice explanation, Paul! knowing your Gami spread can be helpful explaining why your engine is behaving the way it does... Also helpful for leaning, up to a point... @Hank has written much detail about leaning techniques for carbureted M20Cs... Unfortunately, adjusting fuel flow distribution with two fuel jets in a carb is the reason somebody invented fuel injection... It is possible under some circumstances to run LOP with a carbed engine but it won’t happen perfectly or accidentally... Knowing what monitor you have, will help other people help you... and if you have a FF gauge would really help too... Flying long distances is best to know FF fuel flow during each stage of the flight... It may take a few/several flights to gather this info without a FF gauge... FF changes from near 20gph to closer to 10gph from climbing, to cruising... Hard to quantify while flying... especially after a long climb... mixture adjustments really change FF a lot... Flying long periods of time with unknown or in exact fuel burn details would be courageous, if it were 1918... Keep good notes... Cruise on one tank, climb on the other. Collect lots of use data... then expand your horizons... know how well your fuel floats are working. PP thoughts from prior M20C experience... no engine monitor, not FF gauge, no carb temp either... and took a while to get my fuel level floats operating correctly... not a CFI... Best regards, -a- 3 Quote
gsxrpilot Posted October 28, 2018 Report Posted October 28, 2018 When I flew an M20C, I got some pretty amazing range using a GEM G2 engine monitor with fuel flow. This included several flights over 700 nm. One 720 nautical mile flight was exactly 41 gal. Fly high, fly lean, and know EXACTLY how much fuel you have at all times. 1 Quote
Hank Posted October 28, 2018 Report Posted October 28, 2018 Ahhh, leaning a carbureted engine. Forget everytbing above except the definitions of "peak." We have no injectors, therefore no GAMI spread between cylinders. All mixing of fuel and air, and distribution to the cylinders, happens right there in the carb and is pretty much not adjustable. Climb full throttle, full RPM and full rich. Level off and let the plane accelerate. I generally don't do anything until my C is indicating >130 mph above ~6000 msl, or above 140 or so below that. Then I set the throttle an inch below where I want it, and reduce RPM (which makes Manifold Pressure rise). Use the Performance Charts in your Owners Manual for this. I used to use anything outside the Tach's redline as long as the numbers on Manifold Pressure gage and Tach added up to 46 or less. Now I've pretty much settled on three power settings by altitude: Low level (< ~3500 msl): 23" / 2300 Mid-level (> ~3500 -- 7000 msl): 22" / 2400 High cruise (7500 msl and up ): WOT- / 2500 Once power is set, then lean the mixture. As mixture leans out, the plane will accelerate. Watch EGT, it will rise; when it stops rising, yiu are at peak. With plent nof altitude (8000 msl or so), you can cruise at peak, but I rarely do. It's difficult to make a carbed engine run smoothly Lean of Peak, but you can try the following tricks: Reduce throttle slightly (I pull it back enough to make the MP needle just start to move = Wide Open Throttle minus [WOT-]). This will cock the throttle plate in the throat of the carb and hopefully create some turbulence there for better atomization of the fuel and better mixing with the air. Crack the carb heat open a little bit. Experiment to see how much to use, and if it helps. Gently ease the mixture back so that it is leaner than peak. If your engine continues to run smoothly, you can cruise there. Check for loss of airspeed; I lose more speed than the injected models when even slightly LOP. If your engine is rough, push mixture forward and run ROP. (This is what I do.) Work with your A&P if your engine is rough when slightly LOP. Look for induction leaks, lead balls in your spark plugs, etc. I was finally able to run smoothly LOP after rebuilding my carb heat box, but even then only to about 20-25° LOP. Flying this way, 50° ROP (the thought of which bothers many people here), WOT- / 2500, I can confidently cruise 4-1/2 to 5 hours with an hour's reserve. When flying, learn to think of your range in hours, not in miles, as the distance you can cover is affected by the wind during your flight. Leaned at altitude in level cruise, indicating over 140 mph, my groundspeed has been as high as 186 knots and as low as 68 knots . . . . My wife and I have flown 4:45 twice, and both times I had 11-12 gallons left out of the 52 I started with for 8.4 gph average. One of those was 3 legs: home from Mooney Summit (an hour), short flight for fuel (~20 minutes) but pump wouldn't work, then off on my 3-1/2 hour trip to furthest WV. Congratulations, welcome aboard Lukon and fly safe! Hope to meet you sometime; where are you based? 4 Quote
Lukon Posted October 29, 2018 Author Report Posted October 29, 2018 12 hours ago, Hank said: Ahhh, leaning a carbureted engine. Forget everytbing above except the definitions of "peak." We have no injectors, therefore no GAMI spread between cylinders. All mixing of fuel and air, and distribution to the cylinders, happens right there in the carb and is pretty much not adjustable. Climb full throttle, full RPM and full rich. Level off and let the plane accelerate. I generally don't do anything until my C is indicating >130 mph above ~6000 msl, or above 140 or so below that. Then I set the throttle an inch below where I want it, and reduce RPM (which makes Manifold Pressure rise). Use the Performance Charts in your Owners Manual for this. I used to use anything outside the Tach's redline as long as the numbers on Manifold Pressure gage and Tach added up to 46 or less. Now I've pretty much settled on three power settings by altitude: Low level (< ~3500 msl): 23" / 2300 Mid-level (> ~3500 -- 7000 msl): 22" / 2400 High cruise (7500 msl and up ): WOT- / 2500 Once power is set, then lean the mixture. As mixture leans out, the plane will accelerate. Watch EGT, it will rise; when it stops rising, yiu are at peak. With plent nof altitude (8000 msl or so), you can cruise at peak, but I rarely do. It's difficult to make a carbed engine run smoothly Lean of Peak, but you can try the following tricks: Reduce throttle slightly (I pull it back enough to make the MP needle just start to move = Wide Open Throttle minus [WOT-]). This will cock the throttle plate in the throat of the carb and hopefully create some turbulence there for better atomization of the fuel and better mixing with the air. Crack the carb heat open a little bit. Experiment to see how much to use, and if it helps. Gently ease the mixture back so that it is leaner than peak. If your engine continues to run smoothly, you can cruise there. Check for loss of airspeed; I lose more speed than the injected models when even slightly LOP. If your engine is rough, push mixture forward and run ROP. (This is what I do.) Work with your A&P if your engine is rough when slightly LOP. Look for induction leaks, lead balls in your spark plugs, etc. I was finally able to run smoothly LOP after rebuilding my carb heat box, but even then only to about 20-25° LOP. Flying this way, 50° ROP (the thought of which bothers many people here), WOT- / 2500, I can confidently cruise 4-1/2 to 5 hours with an hour's reserve. When flying, learn to think of your range in hours, not in miles, as the distance you can cover is affected by the wind during your flight. Leaned at altitude in level cruise, indicating over 140 mph, my groundspeed has been as high as 186 knots and as low as 68 knots . . . . My wife and I have flown 4:45 twice, and both times I had 11-12 gallons left out of the 52 I started with for 8.4 gph average. One of those was 3 legs: home from Mooney Summit (an hour), short flight for fuel (~20 minutes) but pump wouldn't work, then off on my 3-1/2 hour trip to furthest WV. Congratulations, welcome aboard Lukon and fly safe! Hope to meet you sometime; where are you based? ‘Thanks Hank, i think I followed your formula to get the plane home. I flew LaMesa, TX to Gila Bend, AZ one leg about 645 sm with well over an hour reserve left, and this was with a two knot headwind and a couple unplanned altitude changes. I flew at 10,500’’ (mostly) WOT minus a hair and 2500 rpm. I leaned till rough, then richened a hair till smooth. I've got a red box around 2100 to 2350 rpm where the prop/engine is not supposed to cruise, so the low altitude setting of yours is not an option. I’ll play with the carb heat a bit down the road when I’ve got the rest optimized, and I know better what to look for. The plane is a 1965 M20C I added the info to my profile. I’m based out of Chino, CA - KCNO 1 Quote
Hank Posted October 29, 2018 Report Posted October 29, 2018 @Lukon, something changed between your C and mine; my red line on the tach is 2000-2250. Just experiment within the limits of your Performance Charts and fund what works for you. The formula MP + ALT = 46 should be fine. Quote
jaylw314 Posted October 29, 2018 Report Posted October 29, 2018 21 hours ago, Lukon said: Lmfao @carusoam I think I understood almost half of what you said there. My engine is carbureted. I just got the plane. There are a couple digital engine monitors that tick through EGTs and CHTs. Right now I just run old school and lean till rough at altitude and richen it a bit till smooth. She flies beautifully, but I need to shoot for good mileage at altitude, as a couple of my missions are near the edge of the envelope range-wise. I want to go about 710 statute miles without stopping for gas at a decent pace. I should be able to do this with nearly an hour reserve, if I get it dialed in... I’ll pour over the stuff I’ve got and look for the brand of monitors I have. I doubt they’re very new or sophisticated. I doubt they report anything but temps. If you're mission is flying at altitude, then you have the right idea--just lean until the edge of roughness. You can't possibly be making enough power above a certain altitude to damage the engine, so why make it more complicated than what you're doing? The big question is what that minimum altitude is. Lycoming says you can lean to any setting above 5000'. If you want to go conservative, tell yourself anything about 7000' just lean the way you do and keep it simple. If you really wanted to make your life more complicated, then read the comments above from @carusoam and @gsxrpilot carefully. You can use your monitor to run specifically at a mixture setting of 100 ROP, 25 ROP, peak EGT or even LOP if you can with a carbureted motor, and this might be important if you're cruising below 3000' at high power. Since it is unlikely you can run LOP, for anything ROP, you want to base it off your LEANEST cylinder, which is the one that peaks at the highest fuel flow or mixture setting, NOT the highest EGT or highest CHT. If your monitor doesn't have a lean-find function or have a way of downloading your data, the only way you might be able to do this is with a co-pilot who writes down all the EGT's manually as you decrease mixture notch-by-notch. Alternatively, setting up a camera to watch your monitor, and then decreasing the mixture every 10 seconds or so Quote
Marauder Posted October 29, 2018 Report Posted October 29, 2018 I read the leaning for newbs thread and it was very helpful, but it raised some questions with me. Someone mentioned watching the correct cylinder; which one would that be? The hottest one? I’m talking EGT btw, as the heads are pretty cool for me cruising at altitude... the EGTs vary quite a bit between my cylinders, and the variation seems to increase over time when I cruise at altitude for an extended time. The hottest cylinder is the hottest cylinder for the day. In this video, it was the #4 cylinder's turn. 3 Quote
Lukon Posted October 30, 2018 Author Report Posted October 30, 2018 ... If you're mission is flying at altitude, then you have the right idea--just lean until the edge of roughness. You can't possibly be making enough power above a certain altitude to damage the engine, so why make it more complicated than what you're doing?... My thoughts exactly. For my long distance missions, cruising at altitude is exactly what I need to do. I think 8,500’ - 12,500’ is where I’ll be when traveling more than 300 miles or so. I think what I’m doing should work well enough. I just need some time to get better at it. I’ll go ahead and make the extra stop for gas for a while, till I have a clearer idea what I can expect. Quote
gsxrpilot Posted October 31, 2018 Report Posted October 31, 2018 The best speed mod for our birds... is accurate fuel information. Nothing shortens a trip quite like skipping a fuel stop. 2 Quote
carusoam Posted October 31, 2018 Report Posted October 31, 2018 Nice video editing, Chris! Do you have the matching LOP video too? Best regards, -a- Quote
Marauder Posted October 31, 2018 Report Posted October 31, 2018 Nice video editing, Chris! Do you have the matching LOP video too? Best regards, -a- What’s LOP? Me like going fast. Quote
carusoam Posted October 31, 2018 Report Posted October 31, 2018 Good early morning, @Marauder! I was wondering if the JPI900 was always set in ROP mode. When leaning LOP, I seem to need to set the mode each flight... on the JPI700... O procedures for climb... ROP / blue box on ship’s gauge using 7th TC... analog/rough O procedure for cruise... LOP JPI digital/precise Memory challenge... always requires changing to LOP mode, via multiple secret button code to get there... Wondering if there is a way to leave the JPI in LOP mode... Best regards, -a- Quote
ArtVandelay Posted October 31, 2018 Report Posted October 31, 2018 Good early morning, [mention=9886]Marauder[/mention]! I was wondering if the JPI900 was always set in ROP mode. Memory challenge... always requires changing to LOP mode, via multiple secret button code to get there... Wondering if there is a way to leave the JPI in LOP mode... Best regards, -a- There is, see pilot settings in manual. 1 Quote
N201MKTurbo Posted October 31, 2018 Report Posted October 31, 2018 LOP for dummies... Lean until your engine starts to miss. Richen until it just stops missing. You are now LOP. 1 Quote
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