Indianarob Posted October 9, 2012 Report Posted October 9, 2012 Guys I have have a 77 M20J with a Lycon balanced and blueprint IO360 engine and I see many of you guys are flying lean of peak. Can you inform me as to the procedure you are following to do this. Look forward to you feedback. thanks Quote
Becca Posted October 10, 2012 Report Posted October 10, 2012 I am going to give you the benefit of the doubt here since you look like a new member and you aren't just stirring the pot with our ever favorite LOP/ROP debates! This is one of the most widely discussed topics on this forum. Go use the search function, read up, then come back here and post any questions rather than asking people to rehash what they've also posted. Also, consider reading the Van's Forum for RV's, many have the same engine we do, and they have a running topic on LOP advice forum too. Also, before any one begins to give you any advice, they are going to need to know a few things - do you have a multi point engine monitor? GAMI injectors? what's your GAMI spread? Quote
201er Posted October 10, 2012 Report Posted October 10, 2012 LOP is satanic. How can an engine run on air rather than fuel!? Quote
BigTex Posted October 10, 2012 Report Posted October 10, 2012 Check out Mike Busch's very excellent webinar on leaning. He goes into detail on how best to fly LOP. Quote
AndyFromCB Posted October 10, 2012 Report Posted October 10, 2012 Only socialists fly LOP, just ask Byron ;-) Quote
aviatoreb Posted October 10, 2012 Report Posted October 10, 2012 Only socialists fly LOP, just ask Byron ;-) You guys are mean! Its true though Idndianarob, LOP/ROP is highly controversial and there is lots and lots written about it on this forum and just about every other type forum in aviation. Besides the webinars and writings of Mike Busch, I also like the Pelican's Perch by Deakins. These are a good place to get started on how-to. Quote
jetdriven Posted October 10, 2012 Report Posted October 10, 2012 Only socialists fly LOP, just ask Byron ;-) First we take your guns.... Then we take your fuel! Quote
AndyFromCB Posted October 10, 2012 Report Posted October 10, 2012 First we take your guns.... Then we take your fuel! If you take my wife too, I'll throw in some fuel Quote
fantom Posted October 10, 2012 Report Posted October 10, 2012 First we take your guns.... Then we take your fuel! We have guns because we won't let ANYONE take our fuel Quote
DaV8or Posted October 10, 2012 Report Posted October 10, 2012 First we take your guns.... Then we take your fuel! My ROP bullets in my ROP guns work just fine... Quote
Piloto Posted October 10, 2012 Report Posted October 10, 2012 My experience on LOP. 1.You need to have a digital numerical readout of EGT for each cylinder. 2. Either Unison or Tempest spark plugs. With either massive or fine wire (better) electrodes. Champion plugs internal resistance has too wide resistance variations that causes engine roughness at LOP. 3. Clean fuel injectors 4.Find the peak EGT for the cylinder with hottest CHT, when above 6,000 ft 5.Lean mixture (about one turn CCW) and check for EGT temp drop. 6.Check CHT for temp drop. 7.Check engine roughness. As you go from ROP to LOP you will loose about 5kts. This is normal. A good compromise is about 20 deg LOP. I normally run at 20 deg LOP because it keeps CHT about 10 to 15 deg cooler. Also oil temp is cooler at LOP. At higher RPM settings the engine will run smoother at LOP. I normally run at 2500 RPM My 2 cents José Quote
jetdriven Posted October 10, 2012 Report Posted October 10, 2012 1977 has a lever and the difference between peak and 20 LOP is about .030". an extremely small amount. Further, you must make your final leaning movement in an aft direction. Overshooting your 20f LOP EGT target requires you to bump the mixture lever forward a hair and re-lean to your target. If you push the level forward as your final leaning action, the slop in the cable will cause the mixture to richen by sometimes 30 degrees. Making the final movement aft keeps the cable under tension and the mixture setting does not drift. That's all advanced info. But good to know when calculating the GAMI spread, which is the first thing you should do. Quote
John Pleisse Posted October 10, 2012 Report Posted October 10, 2012 (sniff...sniff...sniff)....you smell something? Quote
jetdriven Posted October 10, 2012 Report Posted October 10, 2012 I smell something. Something like the fuel savings over 2000 hours pays for your replacement engine. Something else, at and below 75% power, for decades, Lycoming authorized operation at peak EGT. Something else, Lycoming no longer objects to running your engine LOP. 1 Quote
John Pleisse Posted October 10, 2012 Report Posted October 10, 2012 Well, I am sure, in time, the IO360A3B6 will have a similarly legendary safety record running LOP. Quote
jetdriven Posted October 10, 2012 Report Posted October 10, 2012 What safety record do you refer to, J? Quote
KSMooniac Posted October 10, 2012 Report Posted October 10, 2012 start here: www.advancedpilot.com and you'll learn more than you can ever imagine about total engine management. Quote
aaronk25 Posted October 10, 2012 Report Posted October 10, 2012 I really like how clean the oil stays even after 30 hours when compared to ROP. ROP is really dirty combustion. Also like how clean the plugs are even after 100hours of LOP, Oh and how clean the heads are when looked at from borescope camera when compared to ROP. I even heard a mooney dealer tell me that ROP will wear out cylinders!!! ah let me think, the oil takes care of the cylinder barrells and the heards valves only care that they don't get to hot and being that they are cooler LOP means that they last longer! Everyone can choose how to operate there aircraft, but I know when the times comes for me to buy another, I am going to ask how the engine was operated, and take into account the hours and may or may not pass on a plane based on how it was operated...... Quote
Piloto Posted October 10, 2012 Report Posted October 10, 2012 I really like how clean the oil stays even after 30 hours when compared to ROP. ROP is really dirty combustion. Also like how clean the plugs are even after 100hours of LOP, Oh and how clean the heads are when looked at from borescope camera when compared to ROP. I even heard a mooney dealer tell me that ROP will wear out cylinders!!! ah let me think, the oil takes care of the cylinder barrells and the heards valves only care that they don't get to hot and being that they are cooler LOP means that they last longer! Everyone can choose how to operate there aircraft, but I know when the times comes for me to buy another, I am going to ask how the engine was operated, and take into account the hours and may or may not pass on a plane based on how it was operated...... You can tell how the engine was run by looking at the exhaust stain on the belly. A white/yellowish stain indicates LOP operation. A brown stain indicates ROP operation. Be suspicious of oily stains. José Quote
jetdriven Posted October 10, 2012 Report Posted October 10, 2012 ours has that light tan stain as well. I think its lead bromide from the fuel. Quote
jetdriven Posted October 10, 2012 Report Posted October 10, 2012 Its a symptom of burning valves and camshafts. Didnt you read that NTSB report on the dangers of LOP? Quote
Indianarob Posted October 10, 2012 Author Report Posted October 10, 2012 WOW I really didn't mean to stir up all these opinions and no I am not a novice at flying I have more than 3000 hours of Mooney time both lycoming and continential. I run the IO550, 50 degrees LOP and it performs very well about 12.7 gallons per hour and all the termperatures are fine. I don't run my lycoming LOP but I can tell you havei have a balance, flow matched and ported engine and at 50 LOP it runs fine which is outragious for a 4 cylinder engine, but I am not convinced it is doing the engine any good. I understand the cylinder termperatures are down, I have studied the books and see how the cylinder temps fall off very fast after LOP is achieved, but what about valve cooling and lubrication. I have had induction leaks and guess what you burn the intake valve. More than anything I wanted to see what the consinense was with regards to LOP operation. As far as I am concerned the loss in power isn't worth it, after all way do we fly Mooney, for the speed. Also i have discussed this topic with Lycoming Eng. and they absolutely say don't do it, unless you are in a lab enviorment you don't have enough instrumentation in a typical airplane to success at succesfully. Sorry for stirring up a hornets nest. thanks for all the feedback. Quote
BigTex Posted October 10, 2012 Report Posted October 10, 2012 WOW I really didn't mean to stir up all these opinions and no I am not a novice at flying I have more than 3000 hours of Mooney time both lycoming and continential. At this point, you'll just need to set back and let it run its course... Quote
Indianarob Posted October 10, 2012 Author Report Posted October 10, 2012 I believe you are correct. WoW this is a sensitive topic. Quote
jetdriven Posted October 11, 2012 Report Posted October 11, 2012 I have studied the books and see how the cylinder temps fall off very fast after LOP is achieved, but what about valve cooling and lubrication. I have had induction leaks and guess what you burn the intake valve. More than anything I wanted to see what the consinense was with regards to LOP operation. As far as I am concerned the loss in power isn't worth it, after all way do we fly Mooney, for the speed. Also i have discussed this topic with Lycoming Eng. and they absolutely say don't do it, unless you are in a lab enviorment you don't have enough instrumentation in a typical airplane to success at succesfully. Sorry for stirring up a hornets nest. thanks for all the feedback. If you have an induction leak in a LOP engine it will not run smoothly LOP. This is your clue something is not right. Finish the flight well ROP and a low power setting and investigate. An induction leak in a ROP engine is masked by the ROP. The leaking cylinder will run leaner than the others, and 50 ROP might put it at peak, where, depending on the % of power, can very well ruin it Especially at takeoff power. My friend's Bonanza runs 440 CHT's on takeoff and climbout. How small of an induction leak will make it run hotter, say 550 degrees? our 201 loses exactly 5.6 knots (154.7 to 149.1 KTAS) to go from 80 ROP to 25 LOP at 7000'. FF drops from 11.7 GPH to 9.8 GPH. CHT drops 30 degrees. NM/GAL goes from 15.01 to 17.1, or a 14% improvement. Actually 15 LOP is only 4 knots slower on another .1 GPH FF. Flat engines have been plagued by valve problems and early top overhauls longer than I have been alive, yet LOP is a rather new thing. Its caused from either running inside the "red box" at too high a power setting, too high of a CHT, or improper machine work on the valves. This is not an exhaustive list of causes. Quote
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