Diesel engines are not stoichiometric by design. stoichiometric simply means all the oxygen in the intake charge is consumed in a given combustion cycle. Diesel engines are lean burning in general and air/fuel ratio is varied to control the speed of the engine. Not all oxygen in each intake charge is consumed in a combustion cycle. This is the number one reason diesel engines tend to emit higher levels of NOx. The leftover oxygen in the cycle forms oxides of nitrogen which is AKA smog. This is mostly corrected by the SCR and urea (diesel exhaust fluid) injection. Diesel engines often also employ cooled EGR to reduce the oxygen level in the intake charge during part throttle conditions. Stoichiometric is only applicable to gasoline engines.
@@TheRobertChannel U said a vacuum line could melt lmfao, only way that would happen is if its too close to something too warm, u think hot air goes into a vacuum line?! XDDD
We use E100 since 70’s in Brazil. Ethanol is a bit aggressive to fuel system but keep the engines clean of carbonization, and not dissolve oil film like gas. The cars before flex ( ethanol only ) work with 13:1+ CR and is more efficient.
Wow that sound like a hot rodders Paradice. Unfortunately, here an America, the perception that we (USA) are the only ones who can have and create cool things. I know this isn't true, and I have known this for a very, very long time. This (your comment) is an example of an environment where a car/engine nut could go crazy and make power, but it isn't available in the USA. We don't always have the cool stuff, we could have.
Today's ethanol blends alter the standard 14:7 stoich. With a typical E10 fuel stoich is roughly 14:2-14:4 and with a carbed engine it generally requires going a bit richer on the jetting from stock jets. At a steady state 'cruise' one can run cooler at an AFR of 16-17 than you can with an AFR of 13-13:5 (same scenario) non turbo or boost application. But you will need vac advance or an EFI set up for the leaner burn at part throttle condition (no/light load).
Eng knock can also be avoided by running a higher octane fuel, don't get confuse higher octane does not mean higher volatility. Octane rating is an anti knock rating, developed in the second word war by the SAE to ensure that every batch of fuel for the spitfires was the same quality
llew virtue Correct except it was before ww2. Harry Ricardo came up with octane rating and his research got published in the early 1930. He also came up with the Merlin so yes you are correct, but it was earlier.
Something interesting about diesel and gas is that the “combustion chamber” on the gas is in the cylinder head and on the diesel, its in the piston head. I dont know which is better for mpgs and/or power, i just thought that was neat.
That isn't really all that interesting actually. It just has to do with the fact that diesel engines operate at much higher compression ratios, and a straightforward way this is achieved is having a tiny clearance volume, ie; a cutout in the piston head.
As a lifelong car nut.... this was very well done. I actually learned a few things. I have trouble explaining a/f ratios to others, I think I will use this video as a reference to that. I will definitely subscribe and look for more.
would love to see a video on what is the best path to take when designing aero for a race car for the grass roots racer. what will yeild the best resaults for the least cost, modifications ect. cheers
Bear in mind that more fuel does not always mean safer/cooler engine. What this guy doesn't show on the graph is that cylinder temp. (and highest risk of knock) is highest and makes max power BEFORE 14.7, the top EGT. Safest is to run very rich or very lean. At economy cruise you'd want to lean past peak EGT to the point where you lose some power or rpm. I've seen so many videos where people take a LONG finding and staying at peak EGT, which is not good for the engine. And the worst part is that they then make the mixture a bit richer which puts them at worst possible cyl. temp. Unfortunately this is taught by a lot of flight schools. Watch a video called "obsessed with EGT", for reference.
Cool stuff. This is relevant for small aircraft engines; these usually run very rich for takeoff to increase detonation margin, and lean off for cruise. In fact, most engines have manual mixture control, so it's useful to know what happens when you pull the red lever to lean the mixture for cruise. These engines have no ignition timing change (except a timing retardation for starting the engine); everything is simple and mechanical. Aviation gasoline still contains lead, but that will come to an end, and we will see how that works for high-performance engines, which still require an anti-knock index of 130 for takeoff power at full rich mixture. You say Diesel engine *often* don't have a throttle body. Are there Diesel engine that do?
Great video.have you ever heard of a chevy 350 with hyperutictic pistons breaking the ring lands between compression rings? Only on one side, I mean all 4 on left side! No damage to cyl walls, valve, or top of pistons! Compression ratio was 10.9. Ran 93 octane.
I am interested in a video covering the suspension differences in a "street performance" car like say the Z06 and a GT car like say a Porsche GT CUP car. I'm interested to know where the break point is for something like too much total dampening, or what real world usable spring rates would look like. I have a hard time finding an example to compare the overall setup / experience.
In order to better understand air fuel ratios you need to show the optimum air intake temperature for efficient burn . For example optimum temperature for petrol is 60 degrees Celsius and LPG is around 90 to 110 degree's Celsius. Of course all of the fore mentioned temperatures rely upon an exhaust valve that is under proper temperature control.
Hope you enjoy the video guys! Here's the link to the High Performance Academy Engine Courses, some are free, some are paid, but they are all great! bit.ly/KyleDrives_HPAcademy p.s. Seeing a few people comment on mass/volume, I would've thought it was pretty obvious, a 2.0L at 2000rpm, 50%VE sucks 1000L of air a minute, and clearly you don't burn 68L/min petrol under these conditions. But to clarify, AFR is by mass.
KYLE.DRIVES can you please do a video on torsional rigidity? In japanese car shows i see the pro drivers they bring sometimes comment "oh this car feels rigid", and its not the that the shocks or springs are stiff! I googled the topic and got no where on how to "feel" rigidity and why is that a good thing for a sports car! Please make a video about this.
Thank you, very informative from a very wide range of fuels. Can you do one on oil tempt and oil pressure and what to look for when reading the gauges thanks
Just what I needed. With Lambda I wasn't sure if low was high or low and visa versa. "Thanks for taking the time and posting, it was a "great education for me". I have a custom LS engine where the overkill cam and high compression causes me Knock grief and blow-by has been way high since new. Running so rich now its sort of embarrassing with the fumes and overlap especially with forged almost everything in it.
pumsjd Please think about your statement. Lean and rich is not about the absolute amount of air or fuel in the chamber, but merely about a ratio. Call it percentage if you will. At a given rpm and throttle position the engine will generally always suck the same amount of air into the chamber. With more or less fuel injected the condition can be either more lean or more rich. But the amount of air doesn’t change. So no, the purpose of a lean condition is not to have more air so you can burn more fuel. You actually lean out the mixture when you’re at part throttle in order to save gas and make sure that you don’t have any unburned fuel. The cylinder pressure is lower at part throttle and therefore you have slower flame propagation which means that it takes more time to burn up all the fuel particles, while your time window for combustion stays constant.
Interesting video.. Maybe you might know the fuel to Kw produced per quantity of fuel.And how much kw of power you can get running lean and running longer with the fuel you save. Again the ability to get that spark to set off the mixture is very important. No bang and the engine must go around again and try to fire off. If it don't get a bang, it will eventually die off. Would a vapor fuel like natural gas be more likely to detonated on very lean mixtures?
hello!! love your videos! concerning this subject, you must study about airplane engines running lean of peak or rich of peak! youre gonne love it!!! Best regards from brazil!
Is H_vap of the fuel really the source of cooling that makes rich AF mixtures run cooler? Thing is, there’s so little mass of fuel being vaporized that I don’t think this cooling effect would make much difference. I believe the real reason lean mixtures cause knocking is because it burns slower, too slow at high RPM, which means less of that energy can get extracted as work and is therefore leaves your working fluid hotter which heats the engine to a point that can lead to knocking.
Can you please do an update to this video to show what it means when engines are using E10 fuel? Then, show how this impacts the 2022 F1 car power unit development
You don't get much power gain from headers and a tad bigger exhaust even with a 7 litre. Its "part" of the much bigger puzzle but on its own is only a minor gain. More for sound, show and pose.
Well, when the air goes into your lungs, it starts out mostly as regular air then the O2 content drops as the CO2 content increases. So depending on which one you want to define as lean or rich, it starts out as one and changes to the other. As the for the actual stoichiometry, the carbs and sugars get "burnt" in your body at the perfect stochiometric ratio as far as I know.
On my scanner I have a FUEL AIR COMMANDED EQUIVALENT RATIO of exactly 1.00. So I guess I'm good? I have a 2005 Ford 500 Limited with the 3.0L Duratec DOHC V-6.
Lambda is also an engine name. For the Kia Carnival of all things.... it's a hyundai engine and the version 2 with GDI is in the genisis (except the V8).
So if one were to say run a renesis rich via fuel tweaking and adjusting oil mix aswell it should be fine bar maybe needing sparkplugs and a oil service earlyer at the most ?
If you could produce some charts utilising a data logger like a LM-2 innovate motor sport wide-band meter, on a typical 350 small block Chev (mild built) with typical Holley vac sec Carb that would be awesome! There are heaps of resources out there for fuel injected cars, but not much for the older school cars. Seeings as technology is now cheaper and more accessible I think a lot more people will be using data loggers on their old cars like myself :)
I'm not sure, but I think he's kinda wrong or rather leaves out a bit: At stochiometric mixture, you'll have the highest temperatures (= danger of knock), both rich and lean will reduce temperatures altough rich mixture has a stronger effect. There's a rather big difference between manufacturers and tuning: 1. Manufacturers have to run lean (unless you somewhat cheat around it and have some kind of load based ECU or something that goes from lean to rich outside the emission cycle loads... ) because rich means fuel consumption and Co2 emissions go up (the cooling comes from the extra fuel changing from liquid to gas). And they also want to keep the temperatures low in order to avoid NOx emissions (which basically go up at high temperatures). 2. For tuning (especially in the WTAC and so on), you're always in the rich, the question is actually about "less rich" rather than lean... but some still say lean to "not rich enough" which causes confusion. 3. In racing, you'll often see fuel-flow limits, meaning you can only inject up to a maximum of fuel... so they tend to run lean to keep temperatures down / avoid knock. I'm quite sure the LMP1 Cars run lean. If someone reading this aims to tune his car: Yes, you can gain more power from going from lean up, but you should actually go directly towards the rich side in order to keep the temperatures reasonable (if you don't have the tools to measure temperature etc.) rather than aiming for a 14.7. A big danger of running rich however, is that your fuel pump may not always be able to provide enough fuel to sustain the ratio, especially when G-Forces are involved.
MadIIMike Max power is at about 15% rich of stoic for gasoline and this is well known since 1930 or so. I think the engineers designing fuel systems take this into account 🙂
Only to a point. Go too lean and you lose power. With your typical air cooled two stroke, they often are pretty lacking in cooling and depend on the oil in the fuel for lubrication so they are tuned rich to keep them cool and lubricated. Therefore yes, leaning it will make more power but again, only to a point.
Bill Hollingsworth LPG consists of short chain saturated hydrocarbons with a slightly lower oxidation state than gasoline, but more importantly much smaller molecules and thus overall less oxygen needed per unit volume of vapour as compared to gasoline. Stoichiometric ratio between that of diesel and ethanol therefore, not exactly sure how to be honest though.
I think you're confusing the "air screw" adjustment on a 2 stroke for actually controlling the amount of air. It does not. 99% of the time all the screws on a carburetor control a fuel circuit. When people think they're leaning out the mixture by adding air with the "air screw" they are actually adding fuel. I've literally never seen a single 2 stroke that gained power by closing the "air screw" and leaning the AFR. 100% of the time, from factory settings, 1/8 or more turns out, richening the AFR, adds power and RPM. This is especially true for the last couple decades or so that the EPA has been meddling in the industry.
Gasoline isn't actually octane. We compare gasoline stability to pure octane stability in order to make an "octane ratting" but gasoline is mostly a blend of n-heptans and some octane (and that's the reason gasoline is less stable than pure octane, otherwise gasoline would be octane ratting 100).
That figure of 14.5: 1 with diesel is not correct with trucks about 17:1 is the smoke threshold also a huge factor of ambient air density before and after the turbo and intercooler
stoichiometric ratio for diesel is 14.5:1. all this means is that the ratio of fuel to oxygen is perfect for both reactants to be consumed in the combustion process. likely in the real world not all of the diesel fuel atomizes and burns so leaner ratios are in order.
If you can make Video on How to Run Aftermarket Fuel System on K20A2 with RBC Intake Manifolds ported and Bored if you running Walbro 255 Fuel Pump and Aftermarket Fuel Pressure Regulator without IAV !!! Thx in Advance !!!
Banks Diesel just proved that modern diesel engines can safely handle 16.1:1 to 17.0:1 with their newest version of the i-dash system without having any emission problems and increase power by 10 to 15 percent which means Banks I-dash system runs leaner. Burning more fuel increases EGT's just look at engine dynos with high performance gasoline engines on with or without turbos or superchargers the exhaust system is almost glowing white because the EGT's are through the roof because they are burning so much fuel.
So running lean air fuel ratio and adding hho in the fuel mixture would take care of the high temperature issue? as gas generated by hho systems is cooler?
I search for "car running rich vs lean"...instead , RU-vid decided to give me a scientific explanation of the,which I'm even more confused about...I just want to know whether my car is running rich or lean...🤦
@@chaztitan6457HA ha.. I know hot and dangerous applies even to women, but you misunderstood my stupid comment and that I ment that it means your car weighs less because its lean on fuel and runs faster. 🤣👍..
It all depends on the conditions where the engine runs lean. At low load and moderate engine speed you lose small amount of power and save some fuel running the engine slightly lean (~ AFR 15.0 gasoline). At high load and engine speed, running even leaner will result in engine destruction either by knock destroying pistons, valves and head, either by overheating the combustion chamber to the point the head gasket will get cooked letting fluids to leak, and possibly melting exhaust valves and pistons crowns...
I put k04 on my mk6 gti and reflagged and since the cars running super rich. I don’t know if it’s just the tune running rich or what. The whole fucking hatch will get like black soot covered on it after a good drive
question: if my engine runs over-rich due to the use of a BOV on a MAF car, will this have some positive effects in that more fuel is being injected, resulting in cooler engine temps?
install new s/plug,,blast it,,view plug ,will tell you rich/lean,,,then AFTER that,,cruise its some and view plug again and will tell you if needles are correct hight
I understand Lambda. I really don't see an advantage. If using Lambda, one still needs to determine the actual AFR value of Lambda. Now, if that value can just be plugged in as a constant for a particular fuel, then I could see some benefit.
@@jzxtrd337 I fail to see how carbonic acid, an extremely weak acid, would cause damage when extremely acidic NO2 formed in combustion doesn't. NO2 is an acidic gas and also forms nitrous and nitric acid with moisture in the air.
Only in theory. Practically you cant run a diesel engine rich nowadays, because the turbo charger, there are barely any diesel engines that dont have one anymore, adds the maximum amount of air into the chamber without a throttle body while power is completely regulated by the amount of injected fuel, as there are no carburated diesel engines at all. They just work completely differently than gasoline engines.
If you mean rolling coal then no thats cooler. If you mean gray exhaust smoke, hells yeah brother you are making POWER! If clear, cool you can make decent power too and good fuel economy! Dad had a truck made 1200ft'lbs at the tires, would light them up with a full load on the back and trailer if you looked the pedal funny haha Never puffed a bit of smoke!
Cars computer management system will try and maintain the correct fuel/air ratio. So really doesn't matter too much to the cylinder if the computer is adjusting fuel input to keep ideal combustion conditions. So unless your Long Term Fuel trims are getting way out of control...15-20% Really not much point in spending a ton of money to fix the problem (vacuum leak, fuel pump, EGR) unless you have an expensive car.
chances are you vehicle is only making those corrections under limited conditions. see closed loop fuel control. so yes fix these problems especially a fuel pump issue which could cause an excessive lean condition that can damage engine components. some modern vehicles will do wideband closed loop fuel control but even those cannot react fast enough to keep you engine safe if there are problems.
But if we want to achieve the maximum speed or torque in diesel engines we still want a leaner mixture, since in most of the diesel engines the accelerator pedal is directly connected to the fuel injectors, the more we accelerate the more fuel will be injected in the cylinders and hence more speed.
I have an engine light on and doing a OBD test on "measuring blocks" I have a continuous switching lean to rich mixture but with a preponderant rich mixture. I also have a P0420 catalytic converter error. Solutions?
