The simplest engine leaning explaination ever

hey welcome back everybody this video is about Lee Mina the engine and I will be completely honest when I was a student pilot I really didn't maybe fully understand or maybe really care about leading the engine it wasn't my gasoline I was paying a wet rate though what do I care if I save any gas well guess what now one is an airplane owner into as a pilot flying five hours a day I'm trying to conserve fuel I do care about Lee knee and I care about taking care of this engine because I'm over some hostile terrain and I want to make sure that it is healthy for both me and the next guy who flies it so let's check this out I hope the video makes sense and please like and subscribe and thumbs up and all that stuff if you would be so kind okay welcome back flying fans today we're going to talk about leaning of our engine let me get rid of that leaning of our engine the fuel air ratio mixture what I am NOT going to try and tell you is the run rich of peak I'm not going to try to tell you to run lean of peak we will discuss what they are that those are highly charged opinions that are best left to the owner/operator of a particular aircraft so let's jump right in an engine an engine needs three things to run we all know what they are we need some fuel we need some air and we need a spark like a lightning bolt fuel and air and our little so it just so happens that the perfect ratio between fuel and air to ensure complete combustion is one part fuel gasoline 14.7 parts of air this is by max it can be one pound it can be one gram doesn't matter it's a ratio and this ratio is called stoichiometry ratio right the ratio at which there is complete fuel burned nothing left over a residual now stick with me for a second we're talking about a normally aspirated basic internal combustion engine okay I'm not talking about turbo chargers or superchargers or anything else chargers okay so when I say the following don't jump all over the flame bandwagon we can only control I'm sorry we can only control the amount of fuel that goes in engine we cannot control the amount of air that goes in the engine if we're at five thousand feet altitude there is going to be less air going into our engine okay just roll with me on there so in order to keep this ratio alive we have to reduce the amount of fuel that's going in all right so very basically if we put air over here and fuel over here there exists a point where certain volume I'm sorry certain mass of air requires a certain mass of fuel less air requires less fuel okay so I hope that all makes sense what we are going to look at now is leanin of the engine Graff here down here we're gonna talk mixture or essentially fuel and as we go this way to the right it's more lean they were taking fuel out over this way on the graph we're adding fuel in and right here is the temperature of our engine so if we are 100% full rich we're gonna have very low temperature engine temperature why because the gasoline has a cooling effect on the engine and as we start to take gasoline out or away that engine temperature is going to rise why because there's less fuel excess fuel that is cooling our engine so let's start to take some gasoline out here we're climbing an altitude the maybe our density altitude is higher for the day there's less amount of air entering the engine so we need less fuel going in so we start to lean our mixture the red knobs coming out coming out and at some point we notice that it starts to flatten ok and if we continue to lean then it drops off and the engine gets cold again alright how do we see this well on many basic aircraft you don't have anything you don't have any gauge at all so you don't see this rise you don't see this temperature going up all you see or hear is the engine increasing in rpms and then decreasing well that increase in RPMs that's essentially the temperature going up because we are approaching that optimum stoichiometric ratio okay however many light aircraft have an egt gauge cylinder head temperature gauge will also work a lot of airplanes have these nowadays and what we see on the dial is something like this there's a needle over here let's down here and there are no there are no values associated with this age with this style there's just like hash marks and each one made probably represents 25 degrees a lot of them say that 25 degrees Fahrenheit but what we see as we begin to lean out our mixture is this needle starts to rise okay and it goes up and then at some point it starts to fall when it falls it's coming back down okay well the point at which it achieves its maximum temperature that's peak that's right here okay everything on this side is called rich of peak everything on this side is called lean of peak so as you pull the red mixture knob out and this needle gets to its highest point and then it comes back down that is peak that's what you're looking for okay now many Poh is say to run rich of peak again I'm not going to go into the merits of each or what equipment you need but we're gonna talk about rich of peak here okay so in the 172 that I fly I'm instructed to run rich of peak that's what my boss says so that's what I do so when I see this temperature gauge new color for you when I see this temperature gauge start to fall I start to rich in backup okay and then it'll get to its peak value and then if I continue to rich rich in the mixture it will start to fall again why because we're right here we're coming back down and as I add excess gasoline in it cools the engine so I'll come down for Mark's new color I'll come down 25 50 75 100 I'll put the needle right there and now I am 100 degrees rich of peak okay I hope that makes sense you can operate Lena peak and I encourage you to read about that and see if it's right for you and if your engine or if you have the right equipment to do that again this is not a debate on that but this was simply to show you the where peak is where rich of peak is and where lean of peak is so we are gonna go out to the airplane now I am going to take off we will climb will probably climb pretty high and somewhere near nine thousand nine thousand five hundred and I'll show you this leaning process now keep in mind it is a slow process because you can easily blow through this peak very quickly if you are so quick fast on the mixture knob you'll never see peak and the needle will just it will rise and then it will fall and you don't know where you're so it's a slow process bear with but it's important that you see what it looks like on the gauge okay here we are 7,500 feet I'm all leveled out I'm doing 20 about 2,300 rpm again I have when I see that get you in here I got nowhere to go and all day to get there so why be in a rush mixture is full rich the egt gauge is showing very at the very bottom here and remember this does not have a numerical value although it says 25 degrees per division it does not mean it's at $1000 degrees or 1200 or 600 or anything it's simply this needle shows a trend what the engine is doing we got fuel flow over here a lot of airplanes don't have that the smaller GA side but it's pretty nice to have it and we'll see what happens here so what I'm gonna start doing they start leaning out the mixture and three reality is you can start doing this at any altitude but it's more most pronounced when we're up here higher at altitude so I can't get both in the same frame but just watch what our egt gauges does here remember we're rich at peak now where we're running full rich now I'm just mixed pulling the mixture out here slowly give it a second see what it does alright I've got nothing so far hey there you go you GT is starting to rise we're pulling the gasoline out we're getting closer to that perfect ratio stoichiometric ratio for 7,500 feet whatever it is you also notice that our fuel flow went down we're saving gas well let's pull this out a little bit more [Applause] listen to the engine make sure we're not losing rpm all right Nadel stuck a little bit there so big jump and in case you're wondering this is a I mean do it this way this is a movable needle it's just a marker just an indicator so I can set down at the peak and kind of remind myself of where it's at [Applause] alright let's pull a little more out on the mixture see if we get to peek here we're still rich a peek I'm still leaning it out alright needles gone up another 25 or degrees at one hash mark [Applause] we're down about seven ish gallons per hour the important thing is don't pull the mixture out too fast you're gonna blow right through peak and you'll never know where it was that's it's a patience king who's got to be patient and I'm still waiting I'm not pulling any mixture out it's still in the rise a little bit okay let's pull I can kind of hear the engines start - maybe stubble just a little bit and if you miss it if you miss the peak and you go to to lean you'll know because the one the engine will start running rough and - you'll start to lose the the temperature here so I'm gonna set this marker here so I'm getting close I know that I overlay that now let me pull some more mixture out and see what happens okay we've got a drop in rpm and a drop in egt so now I'm lean a peak let's go back to peak okay engine picks up a little rpm there if you didn't have a GT that would be a great way to do it listen for the engine stumble and then reaching it up a little bit it's not an exact science at that point but it's it sure gives you a better than it was before you leaned it I'm gonna go rich a little bit more see what happens I'm just doing a quarter to eight the eighth to a quarter turn at a time I gained a little bit of temperature there [Applause] not much [Applause] okay I just written did a little bit more [Applause] okay another little rich and a little bit more now you see the needle starting come down so that was peak that little eighth of a turn that I did has brought the temperatures back down eighth of a turn making it richer so I came down one hash mark so I came down 25 degrees let's go a little bit more rich all right I'm down another hash mark so there is 50 degrees rich of peak I'm going to rich in a little bit more [Applause] again just small small turns at any one time looking to see what happens [Applause] all right it's almost down three all right so there is three hash marks at 75 degrees rich of peak though you can set your engine wherever you want 75 100 150 rich Lena whatever you want to do but that's how you find Richa Peak or Lena peak and with a simple instrumentation like this you can float pull the fuel flow down pretty good and pretty accurately and look we're running about seven and a half gallons per hour way better than the 10 that we were before though that is Richa peak and Lena peak okay that's it that is how you lean your engine that's how you find rich a peak or Lena peak doesn't matter either one the concept and procedure is the same and remember if you liked the video please subscribe like and all that stuff and help spread the word we'll see you later

Channel: Captain Chris

Views: 80,029

Keywords: flying, cessna, piper, engine leaning, aviation

Id: Yq0XW8K5CrU

Length: 16min 35sec (995 seconds)

Published: Sat Jun 16 2018