Cylinder Offset Changes Everything
Let's imagine two engines made from the same parts. They have the same crankshaft, the same piston, the same wrist pin and the same connecting rod. The only difference between them is that this engine has the cylinder center offset from the crankshaft center whereas in this engine they are perfectly aligned.
If you observe these two engines in rotation you can see that they do the same thing. The crankshaft rotates, the piston reciprocates, the rod does it’s own thing. However this is nothing other than a superficial illusion, because this little offset actually changes everything. Despite being made from the same parts these two engines are fundamentally different. The cylinder offset impacts power and efficiency as well as engine size, it dramatically influences engine balance and it disrupts the length and duration of the piston strokes. And in this video we will explain how and why all of this happens and why many recent engines employ an offset cylinder configuration. We will start simple and then gradually increase the level of mind-bogglingness until you get completely sick and disgusted of looking at these two engines and close this video. Let’s see how long you can last.
So let’s start easy. Heres’ the first fact: The offset cylinder engine makes more power and is more efficient. Why? Let’s imagine that both pistons are just a bit past the start of the combustion event
So we have combustion pressure building inside the chamber resulting in massive forces pushing down on the piston. But the piston is obviously connected to the crankshaft via a wrist pin which means that the piston also pushes down on the rod and then the rod pushes down on the crankshaft. The problem lies in the fact that the rod is inclined at a certain angle. The downward force exerted on the rod is directed at the small end of the rod, meaning that this force is actually trying to spin the rod or flip it over if you will. As the rod tries to flip over it ends up pushing the piston against the cylinder wall which increases friction. The sharper the angle of the rod the harder the rod pushes the piston into the cylinder wall and the greater the friction. As you can see the offset cylinder allows us to noticeably reduce the angle of the rod which reduces friction. Reduced friction means that less of the energy generated by the engine gets wasted on friction which means that there’s more available to be converted into usable work a.k.a power.
Next up let’s talk about size. Yamaha on their website claim that an offset cylinder engine is more compact. Now this isn’t a lie per se, but this statement is only true under certain conditions. As you can see in our example both engines are of the same size. In fact the offset actually makes this engine wider overall. So why did Yamaha say this? Well they said it because the only other way to reduce cylinder friction is to make the connecting rod longer. As you can see if we make a zero offset engine with a longer rod the resulting rod angle ends up being noticeably reduced which leads to reduced friction, however the a longer rod obviously leads to a much taller engine. So basically what Yamaha is trying to say is that a zero cylinder offset engine can’t have reduced friction without being taller because of its increased rod length. So the offset cylinder engine is only more compact than when compared against a zero offset engine with a longer rod.
Now let’s address something that you have probably already noticed. The offset cylinder engine obviously has a longer stroke. How is this possible if the crankshaft is the same? As we know, an engine’s stroke or the distance the piston travels from top dead center to bottom dead center is determined by the length of the crankshaft throw or the distance between the center of the main journal and the rod journal. This distance is what determines the diameter of the imaginary circle drawn by the crankshaft during rotation and the distance between these two points on the circle ends up being the stroke of the piston.
On the offset engine bottom dead center is here. As you can see the line which connects the crankshaft with the piston is obviously longer in the case of the offset engine because this line is at an angle. Now what connects the piston to the crankshaft is obviously the connecting rod which means that in order to retain the same stroke the offset engine would have to employ a longer rod. If you keep the rod length the same it means that this line is forced to become shorter which pulls down the piston an additional distance which increases stroke.
00:00 Power and efficiency
03:31 Stroke length
05:35 Unequal strokes
15:06 Balance
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14:45 time is a false measurement here. It would be better to operate with a angle*momentum sum across the combustion stage. Here the difference in top dead points is kicking in: making the momentum more linear, normalizing piston speed, increasing fuel burning duration thus allowing fuel to burn completely.
Balance issue is not an issue actually. Vankel engine has same offset geometry, and solves the problem with excentric geometry of the crankshaft
That is interesting and makes sense as it's making more out of what it's given eg the time, so I'm thinking with different compression stroke,less time, would it be better for boosted engines be that supercharged or turbo
I love that you made this video. This is such a great lesson on engineering. Sometimes what may initially seem weird or counterintuitive identifies an aspect that can lead to creative gains.
I wonder if alternately offsetting the pitons would help the balance. You might need to have a different firing order and inlet and exhaust valves also on alternating sides. I am too tired to get my head around it at the moment, but I might think about it when a bit fresher.Great explanation, thanks.
Your calm, gentle tone without any background music or sudden, "startling" audio tracks makes this channel leagues ahead of others. No distractions. Just pure education. Thank you! ❤❤❤❤
I think you'd like Hexibase. KZhead him!
Amen
Nah, I think he should keep showing cascading stacks of hundred-dollar bills, and show fake film projector scratches, as though it is old footage, and he should add a fake A.I. "narrator" who can't pronounce words, names, or numbers right. And some crappy music. :) BTW I never knew this about engines, even though I run engines all the time and know a few good mechanics. Very interesting stuff!
So many of academic books seem like they are written for people who already understand topic at hand. Your approach is complete opposite of those boring and soul crushing books. Thank you! D4A channel is top tier! Your passion and dedication shows, and it's obvious you have a lot of empathy and understanding for those of us who are at the beginning of our learning journeys.
Offset cylinder is called desax
In the trucking world the offset cylinder (commonly referred to as downsped engine) does wonders for the engine performance. Slower piston speed means more torque at lower rpms while increasing fuel efficiency. It also increases exhaust temperatures which helps with all the emissions components. Pretty amazing to move up to 80000lbs at 950rpms at 65mph and getting 10-12mpg.
This means that it also has a lower rpm limit, 1000 rpm on a diesel would be equivalent to 1.5k rpm on a gas engine, they move at the same speed.
Is this guy talking about Chrysler's 1959 slant 6? For all you "this changes everything" modern day idealists... please keep in mind quad copter drones were invented in the 1920's, and were among the first successful heavier-than-air flight "VTOL" vehicles preceding helicopters, and electric cars were around from the very begining of personal trasportation. With the first example of an electric car in 1830, but by 1900 were 38% of Americas automobile market, with steam taking 40%, gasoline 22%, and diesel just recently invented in 1893 as a means to use cheaper low grade fuels. Diesel is only more expensive because the government puts a TAX on diesel fuel, and now also requires DEF as well.... I'm still waiting for someone to re-introduce steam vehicles, so this guy can make a video about how THIS CHANGES EVERYTHING.
@@Ed-ty1kr Starting in 2007 here in the USA the feds mandated "ultralw sulphur" diesel fuel, among other emissions reduction devices and systems. (Think DEF, DPF, along with some other ideas integrated into these new systems). It's unfortunate how technology has improved dramatically in the diesel industry just to be negated by the over the top emissions reduction systems mandated by the fed. In 2007 they essentially raised the price of diesel per unit, gallon here in the states, which of course became a permanent raise in cost, supposedly to offset the cost in the manufacturing and distribution of the required ultra low sulphur fuel...all the while achieving this new standard of reduced sulphur by simply taking said substance out of the "mix"...in other words charging us significantly more per unit of fuel by the reduction or even elimination of a key component which in the past was used to lubricate the moving parts of the fuel system itself. Well not just moving parts but also critical yet stationary parts like the body itself of a diesel fuel injector. This whole concept of what went down here in America around 2007 is so frustrating to me. As a life long mechanic with experience in internal combustion gasoline, compression ignition diesel, 2 and 4 stroke gas, and even electrical (EV) powered vehicles found in the forklift and equipment fields. In addition to the wrenching experience and understanding I also worked a relatively small window of time in the refinery business around this time of 2007. Much work was needed for the refineries to be "ready" to make, distribute and sell this new "ultra low sulphur" fuel and therefore refineries everywhere went under humongous updating projects. Many bodies and brains were needed for this task. I hired in at the Marathon refinery as a contractor at their elaborate plant here in Detroit, basically i-75 and Fort st./Schaeffer Rd, near outer drive amd Dix Ave...anyone from around the knows the plant and it's location. I found that job very interesting, despite being temporary I still spent about 2 years on site learning something new every day about the refinery process, which honestly, was rather rewarding. In summary, it's almost as if some kind of globalist cabal who secretly run things from behind closed doors and it's almost as if these people didn't want more efficient diesel engines which essentially move and power this entire world we live in, where every aspect of our daily lives are affected by a diesel powered something somewhere along the way. All these EPA backed emissions reduction acts and mandates have crippled the Diesel engine industry to where people actually believe EV's could save the entire world right now...which they cannot. Ever. Efficiently. Replace ice and diesel. In a dream last night I actually imagined the newest most bestest thing ever...a vehicle powered by... Coal! Then I woke up and had to pee.
@@williamstamper442 EPA and DOT measures became overreaching sometime around 1969, with 5mph bumpers that by the early 1970 made American muscle cars sinfully ugly, with huge protruding bumpers, and emission systems that dropped 350 to 426 horsepower cars down to slow, heavy, and gutless 150 hp gas guzzlers. But this actually goes back to 1913 and Woodrow Wilsons Jackyl Island treason, that the British Royalty literally paraded him through London for. Henry Ford was quoted as saying its just as well the American people are ignorant to finance, cause if they knew, there would be a revolution by morning. Not an exact quote but something to thar effect. Which got really bad around 1964, post Kennedys famous secret societies and proceedings speech, which was just weeks prior to his assasination. Funny thing you mention Globalists cause it was with George H.W. Bush involvment, a known and admitted Globalist within the CIA, who later became Regans VP as Regans alzheimer's set in. Then became President giving the world his famous New World Order speech, with creepy undertones saying things like "and when we are successful, and we will be". Followed by a short Clinton break, with MK Ultra and Tuskegee human experimentation on American citizens admittal and lame appology, and then by his son and fellow Bonesman" George W. Bush Jr. There is a documentary you can still watch on Internet Archive made in 1982 called The Killing of America, that although is aimed at gun control, still documents the drastic decline of American society into violence, mass redrum and general crime up to that point in 1982. Directly links Kennedys assasination with the crime rate, violence, and general depravity as if some great evil had decended upon the land. Which only got worse thanks to the CIAs Contra Cocaine "conspiracy" and introduction of crack cocaine onto Americas streets, only now trumped by fentanyl. Which... started with LSD's introduction, the first poison unleashed on the nation. And who created that? Look it up, it was nothing new, it was as if it was deliberately released onto the soft heads of Americas youth, by design, on a large scale, and almost immidiately in the late 60s post assasination like clockwork. So now its fentanyl but its the same game, new millenium. Look into a book called The Psychopath Machine, written by an MK Ultra survivor, who claims MK Ultra was not to create psychopaths, but to identify and install psychopathy in prominent positions. By identifying through tests and examinations all existing sociopathic personalities, so as to find candidates for the military industrial complex bureaucracy, top medical professionals and doctors, university psychologysts, federal judges, top law enforcement professionals, and the now famous Wall Street American Psycho business personelle. Everyone thinks MK Ultra was to create psychos, but why create something if you can recruit existing? Anyhow... As far as Globalism the world we see today is a direct product of their actions. Just look up the definition of GLOBALISM and see if that fits the world we live in. Look up World Economic Forum videos and whitepapers, they dont hide much, for they assume we are all just ignoranr commoners. I still recall Ross Perots "Great Sucking Sound" speech he gave with Geroge Bush Sr. on his right, and Bill Clinton on his left, as he told the nation we will see our jobs sent to Mexico and overseas if we elect either one of those two candidates. Thar was 1992, and Boy was he right, they literally sent all Americas industry... tooling included.. to Mexico and mostly to China, because the "Chicoms", view communist China as the model for their New World Order or Great Reset. Where they can Build Back Better their tyrannical dystopia where you own nothing, live in 15 minute prison cities, have no privacy whatsoever, and eat a diet of bugs. But only after they tear it all down and bring the western world to its knees, cause you must tear it down to build it back. Looking further down the now well proven and documented rabbit hole we see the same mass migration mentioned in Globalisms definition, in both Europe and the United States, with the 3rd definition for globalism given as : An ideology based on the belief that people, goods and information ought to be able to cross national borders unfettered. So we see our boarders disolved or non-existant, with our military or "defense" spread out to hundreds of bases world wide, and fighting or aiding in just about every conflict anywhere including Ukraine. Which was a military industrial complex and George Soros color revolution construct, designed to fight Putins refusal to play along with NATO's clear rejection of the treaty written up by Gorbachev while the Soviet Union was disolving, not to impose NATO onto Russias doorstep. People dont know about any of that, and how can you blame them they dont work at the United Nations, so they support whatever the media tells them. But it was actually over a treaty that was not upheld by NATO, and the nordstream pipeline that has most of Europe now feezing to death. They did it by first meddling in their already fraudulent elections, playing dirty games with Ukrainian oligarchs who are actually just the corrupt businessmen and gangsters that came out of an empires collapse. They got involved with installing of puppets like Zelensky, possibly even Putin himself for all we know, and subverting their society through color revolutions that are always signified by the famous RAISED FIST. Running criminal bribery based public private partnerships which is basically just a soft modern term for fascism, first coined by Mussolinni the italian dictator during WW2. This tactic then was turned inward onto the American people in 2020, and we ended up with cities burning, and public private partnerships set up during the Bush era that is now no longer just working for the government as contractors, but now controlled the government through public private partnerships. Anyway it is FASCISM, its set up and ran by Globalist wealthy self declared elite stakeholders, and it is just a means to impose a world government tax on the common people ONLY, while they continue to jet set and yacht around the globe in vehicles the DO NOT ACCRUE CARBON CREDITS... Yes you read that correctly, private jets as well as vessels above a certain size do not have to abide by carbon credit global government taxation. They solve nothing, they impose all these measures like forced injections and central bank digital currencies linked to social credit scores... but they serve absolutely nothing except to make them richer and more powerful. It is an ideology of haves and have nots, of serfdome, a cass system, a communist fascist socialist dystopia where your only rites are to depopulate yourself by assisted suicide, with their war on carbon being a war on all of us carbon based life forms. Sorry for typos, and sorry for it being so long, I couod write a book on the globalist tyrannical nightmare society they are building. And yes , they penetrate the cabinets as Klaus Schwab says, and destroy whatever they lay their greedy, grubby, filthy paws on. Period
@@williamstamper442 LOL ... I got a good example of Globalism for you Will... Nevermind these wasteful batteries that lose God knows how much energy being tranfered down sometimes hundreds of miles of power lines, with losses through resistance clearly shown by simply looking at them through a thermal camera.. But can you explain to me how does this Gloablist process make any sense to you? They source cod or chicken or whatever perishable refrigirated commodity here in the United States... only to ship it to China to be sliced up and packaged. Then ship it BACK to the U.S. to be placed in supermarkets. Is that globalism in a nutshell or what?
I am a automobile teaching professor the degree angle of rotation was explained phenomenaly hats off i will recommend this video to my students and show this video in my coming lectures
I love these videos, you have a great ability to take deep dive into a complicated, almost nerdy subtopic, and illustrate it in a lighthearted and engaging manner.
Big facts 💯👆 very well said
if this is ALMOST nerdy to You, im scared to ask what is really really nerdy XD
@@jesusfreakpl I'm currently watching a live stream of two astrophycisists debating a scientific paper discussing the nature of a particular, albeit peculiar asteroid; that is full nerdy by my standards
@@jaybruce593 please tell me Neil D Tyson is not one of them 😩
@@jaedanoeugene4004 Don't worry, it was Avi Loeb and Bian Keating, discussing Oumuamua. I like Neil De Grass Tyson, but nearly everything he does these days has his side kick "chuck" who always derail the science to make dumb jokes, or the conversation gets dumbed down to a point where he, as a non scientist can follow it.
People are always surprised how well these videos take complicated topics and explain them clearly step by step. That's what we need to teach kids in school - the way to organise your thoughts in to small chunks, put them in a timeline in a correct order and present them to others. It's reading, writing and critical thinking working together to produce successful communication. That way you accurately express your thoughts, the other person understands them as you meant it and everybody is on the same page. Also, that's how you teach others. Also, it's THE way to erradicate common misunderstandings and arguments people get into simply cause they got each other wrong. All the fights in the comments sections, under news articles, in the public arena, in the media... You need to learn to think like an engineer, in logical steps. Then you can explain a trip to Mars to a 5-year old.
To achieve that you need a "teacher" with an intimate understanding of the subject to begin with.
True. Thanks man.
@@MrCanonballs And, of course, students with a keen interest and willingness to engage and learn.
thank you one more super good video but i did,t undurstant how they finale balans out the engine ? ? ?
Idk what school y’all go to but they teach that stuff in my school
Not a engine person at all but you break down the Physics so simply and speak with such a passion that its a joy to watch.
Many years ago as a student I visualized this idea of an offset crank and wondered if it would develop more torque. Thanks for so thoroughly exploring and explaining this topic. Fascinating.
Cranks get modified for offset grinds to increase stroke. Machine shops have been doing it for decades.
@@johnhendel7357exactly my dad and I talked about this years ago. his best friend was an engine machinist at the time.
There are two ways to apply offset. You can either "move" the crankshaft off the centre line of the cylinder or you incline the cylinder slightly. The effect is the same. This has been done for at least 80 years to my certain knowledge. In the 1950's it was normal to rebore an engine after as little as 25,000 miles. This was done with the block in situ. If you didnt allow for the offset when setting up the borer you destroyed the block. Later the cylinder was offset laterally to make maintenance easier. This information is hidden in works maintenance and overhauling manuals.
Thank you for sharing your knowlegde ❤@@davidh3486
I'm a mechanic with some engineering experience and your videos are amazing for bridging the gap between practical and theoretical knowledge. The way you teach by gradually introducing the mathematical concepts alongside the practical demonstrations make your explanations work. I'm sure someone with no engine experience would struggle, but I think your videos are an excellent resource for people like me who need more theory, or people like engineers who understand the theory but rarely work with the actual application.
Ever heard of David Vizard? He has a channel and is essentially an engine-building legend. He also donates to St. Jude"s. He offset an engine's bores what I'd guess was decades ago.
I am as you and agree.
Changes everything, I bet it won't change the colour of my car.
If you're an engineer, you surely realize the offset engine has a longer rod or longer rod bearing distance from crank center to do this. They are not the same as the centerline rotating engine. This is part of where the "increased intake gas" comes from. That point was completely skipped over, intentionally I suspect.
Most certainly agree !
It's amazing how changing a single parameter (crankshaft offset) produces such complicated knock-on effects for a multitude of other parameters. Thank you for breaking it down and making such a complicated amalgamation of forces understandable!
Hi sir im a big fan of yours i always watch your videos and i realy love it, im a racing mechanic i do upgrades with bigger cc and defferent engine configurations i hope that you recognize me sir
Hello
engine knock-on
I had no idea of this technology . Your explanation of this was very clear. I can only imagine the time spent editing this video. Thank you for your time and effort to create this.
I made it to the end! When I was young I raced bicycles. All of the dynamics you have mentioned are directly related to bicycles. When you are starting at the line no one in they’re right mind would set the peddle at the twelve o clock point. You might even hurt yourself if the peddle can move freely in reverse. Seat position forward and back are important as is seat height. I never thought about why some of the practices we used were helping. Great video!
Great point you have made, about applying some of this science to a common bicycle. As a mechanic, car guy, drag racer and all those dirty things I still love my bicycles too. Now you got my brain smoking overtime as these principles are applied to our pedal powered all capable machines!
I uses to race bmx also Jack pine lodge , in bath mi. 1979 , 1980 ( i think ) I showed up with a hacked up huffy street bike , that i cut the crank and lengthened the pedal stroke , if you werent careful you could stub your tow and twist them backwards , i had it that long , But it worked great , i was out in front most of the time , that area at that time hadnt seen much experimenting like that , but it caught on quick , and i picked up shwinn in east lansing as a sponser , got me a fancy schwinn mongoose , they just came out back then ..
This video reminded me of the Shimano “Biopace” chainrings in the early-mid 80’s designed to take advantage of that bicycle pedal stroke.
I love your style. The combo of personality, accuracy, detail and pace is perfect. I've been teaching for 27 years and it's is rare to find these properties, all in one presenter. Thank you.
The "classic" mechanical name for crankshaft offset from center bore line is "DeSaxe" offset. It has been used for nearly 90 years (off and on) for Two Stroke engines (especially Model Airplane engines), but there were even some stationary steam engines which were "DeSaxe'd". Up until only recently, vibration and harmonics were always a problem. Kawasaki first used it on some of their big bikes in the early 2000's but didn't quite get it right for some time. Now, it's pretty common. Back in the early 1990's my automotive mechanical engineering professor said there was nothing new (un-tried) in internal combustion engines for nearly 60 years... he was right. Many of the first attempts were way ahead of the technology (particularly materials, and understanding the concepts of good combustion chamber design). We take for granted CAD and Fluid Dynamics modelling software and digital ECUs. Back then, they had slide rules, sine and cosine tables. Perhaps the most advanced thing available in the late 1950's was something akin to an oxygen sensor (the size of a tanker desk) in the engineering area... times have changed. Great Video!
@Matthew Helton Reading your comment made me really smile. Back in 1972 when I was doing my final work (diploma) for my degree in Mechanical Engineering (Lucerne, Switzerland) one of my student fellows was given an assignment by the Head of the Engineering Department at SULZER Switzerland (back then famous for ship diesel engines powering big oil tankers and freight ships). The task was a principle study of a variable offset diesel engine and to investigate what advantages and consequences could be expected from such a design. Since I had completed my task a week early and was bored, I suggested to my colleague that I would write a FORTRAN program to calculate the friction losses over the four cycles as a function of the variable offset. The result was a surprise for both my professor and the expert from SULZER. By the way, even then we had something more than just slide rulers and sine and cosine tables, namely an IBM 1130 with 20K main memory and a 5 MB disk. Nowadays, most people are surprised that you even could do anything with it at all.😀 Kind regards Florian Eggenberger
I'm curious how this technology could be applied to stationary steam engines. The steam engines I'm familiar with have a power stroke in each direction because they admit steam to a piston face at both ends of the stroke. Could you point me in the direction of an example I could examine?
Haven't learned as much about an engine since I learned about combustion cycles at 8, about 35 years ago! Great video!
Explaining relatively complex things in a comprehensive way requires serious knowledge. Great video! Thank you for sharing it!
picture that, i interrupted a political video to watch this as soon as i noticed the notification
I know right, I stopped browsing auto-trader at cars I’m never going to buy to watch this.
@GTRT-KiloWatts aaaaaaaaaa❤❤❤❤qqqqqqqqqq
So did I 😂
Me tooo! So much more relaxing!
Same. Lol
the author has a talent for explaining complex things in simple terms!
All I can say is "Every thing is simple, we only make things simple complicated.
My grandfather worked in the early 1900's in Detroit as an automotive engineer perfecting the aluminum piston (Nelson-Bolen steel strut piston) and my father-in-law taught auto repair for decades. Me? I grow plants, but I am fascinated by engines and the human genius that makes them possible. Thank you for your in-depth yet understandable videos!
Seeing this video is a bit of a shock! I proposed this idea to General Motors (I was a Chevy guy then) about 60 years ago! I had built a flat model where I could tilt the "cylinder" to create an offset and crudely measure the change in intake/power strokes to the compression/exhaust strokes. I sent them a letter and some drawings mostly stressing the benefits of increased duration of the intake and power strokes. I had figured out most of what you cover in your video save for the vibration issues. I believed the vibration wouldn't change with a cylinder offset. I think I also missed the different stroke lengths but hey, I was only 15 or so at the time. To my great surprise, GM responded! They said they had tested the idea and it didn't yield any noticeable benefit. Did they just blow me off or had they really tested it? If they did test it, did they change the ignition and valve timing, I'll never know. Great video! 👍
GM in particular, but all the big three have been using offset wrist pin placement for well over the past 50+ years in everyday production. Most of this was to reduce piston slap, thrust wear on piston skirt when cold and in general quiet the engines down. With that said they also had slight increases in torque in mind, across the board at relatively low rpm levels seen in our daily transportation still to this day. "free" torque improvements are an increase in efficiency and we all like the way that sounds. Unfortunately the way the oems have done offset wrist pins in order to quiet down cold starts and such ended up cancelling each other as one bank on a V8 would be offset in favor for small increases in efficiency, but the other bank on a V8 were offset to just take the load off the thrust side of piston skirt with a net negative effect on efficiency. That's what I meant by any gains were cancelled out on the other side of the engine. They still achieved their goal of reduced engine noise however
Nascar engines were allready using it acording to articles written by smoky unick it dose decrease piston and cylinder life to a degree
Excellent video! You missed one very important point. The offset cylinder moves the point of maximum combustion pressure closer to the point of maximum mechanical advantage. Also, the same effect is often achieved with an offset piston pin location in the piston design. The lengthened intake stroke duration is very helpful in naturally aspirated engines. Getting air in is much more difficult than getting it out!
I was imagining these concepts in my head
Okay, cool. So could a small block Chevy, for example, be improved in power output by forging pistons with a crank pin hole drilled a few thousanths offset? (Obviously keeping it small enough to avoid destructive vibrations) Is this being done, say in the drag cars? Is there an emerging cottage industry? Seems a manufacturer could take advantage of this without an entire redesign. Is the old Rambler 6 in my Jeep good for another 8 hp? I’ll keep it under 10,000 rpm, promise!
@@russbell6418 just spin the pistons. They already have a little offset. It will be noisier and vibrate more though
Loss of stroke but also loss of resistance to push the crank twelve to twelve o one
Don’t even start about what the other cylinders are doing to change all the math.
I learn so much from your channel. I've built several engines in my lifetime and have worked as a mechanic in the past. Videos like this show me the gap between what I KNOW and what I fully UNDERSTAND. Thank you and please keep the lessons coming.
Sir, your presentation is top notch and so easy to follow. I have a pretty good knowledge of automotive technology but was never aware of cylinder offset. Your animations are so valuable in helping to illustrate all the complex geometry that takes place during crankshaft rotation.
Your videos on these complicated topics of motors and explanations are a pleasure to watch. Keep up the good work.
I'm an accountant but I'm always fascinated by these videos & drawn to being able to understand complex mechanical engineering
I love these videos. I've watched your engine balance videos MANY times. I find all of your videos extremely informative, easy to follow, and easy to understand. You make intimidating and complex topics interesting and easy to learn. Please keep them coming. I have been curious about the V12 recently. Not a lot of good content out there on how these engines work and I have read conflicting information about the bank angle and engine balance. Would love to see a video about how these engines work.
I agree. Very good work explaining complicated thought processes while all the time keeping us engaged, well done!
Great, thank you for the fantastic explanation. As you say, it’s all compromise and the engine concept depends what you want in the end. I guess the off-set engine is good for racing, the zero-offset good for keeping your teeth and spine in good condition for longer drives/rides. 😊
Off the top of my head, what I remember from a V12 is that it can be built such that it is perfectly self-balancing, without balancing shafts.
Regarding balancing V12s are often inherently balanced through any V angle because they can be arranged as 2 inline 6's merged together, and the inline 6 is intrinsically balanced using the right firing sequence.
@@peterjohnson9438 yeah, but why? V12 is always said to be balanced but people who say it does not explain why in any appreciable detail.
I love that you built this up from basic to eye watering! Brilliant.
Awesome presentation with great graphics and clear, concise explanations of how off-setting a piston changes the dynamics of an engine balance, efficiency and power. Thanks!
I really didn't have much interest in ICE before coming across your channel, your in depth clear explanations made me appreciate engines a lot more. Watched it all the way through too! I would love a video regarding the R1 or ZX10R engines; however, I would understand if the material on the balancing of these engines would be hard to get.
He already did a video on the R1 engine: kzhead.info/sun/qLFmqceAimurqa8/bejne.html
If you're talking about the modern crossplane R1 there is lots out there about its inner workings, Not so sure about the ZX10 however
I'm interested what you meant by "not much interest in ICE." Did you mean you were interested in cars but only electric ones?
@@jaredlancaster4137 Perhaps like me, I took ICE for granted. I use them, wasn't really curious about them. I'm interested in electric motors, but for industrial applications, not cars!
The Toyota 1.5L 1NZ-F(X)E was a relatively early example in the economy car segment. Sounds like a tractor, vibrates noticeably at idle, but returns 50+mpg on a run and makes good usable torque from 2500-6000rpm. I'd say it's a fairly typical example of what you described.
My car gets 55 mpg at 2000cc 😎
@@TheSuperBoyProject what çar is that exactly?
On paper it got good mileage but it has a very narrow torque curve and was coupled to a gear box with very high ratios. Also built like a lawnmower engine making extensive use of pressure die cast parts.
I noticed the 'suped-up' engine mount/damper at 19:25 I thought who would just build the engine and counter the vibration issues during fittment of said engine? Well thanks Henry Rolt, Toyota did! In this day and age I think, given the option, most consumer car buyers would opt for extra mpg over a smoother ride. In fact, if a car returned 125mpg but rattled your fillings out, it would sell like hot-cakes and come witha free gumshield!
Fiat 850 from the '60s in the first one I ever worked on.
Absolutely well done! I plan to show this video to my engineering students during machine design lecture! Thank you so much!
This guy has a wonderful cadence and intonation for lecturing. very few discernable edits. well done!
I'm more impressed with the fact that English is not your first language, and yet you explain the engineering and technical points in your videos better than many native English speakers, and that your content is on point, and illustrated clearly makes it easy for people of *ALL* engine / engineering experience levels to increase their knowledge.
For what it's worth, I really enjoy the engine balance videos that you make. You are able to make complicated topics accessible to someone like myself who isn't a mechanical engineer.
Your delivery, humour and insight are absolutely perfect. It's not often I laugh out loud watching videos like this and I'm only ashamed it's taken me so long to stumble onto your channel.
Very impressive videos all around. Great, detailed, flowing explanations of the concepts, excellent graphical aids, etc. It's like getting a mechanical engineering seminar in 30 minutes. You have very few equals in this genre.
As a german engineer I appreciate your videos a lot. Thank you for your engagement to drill down the topics to the key points. 👍🏻
Thank you very much for your detailed videos. I'm now 41, if I had watched your videos when I was 15-18 I would surely had become a car mechanic.
The last part of the video really gets interesting. It's all about the differential equations that governs the system. The small axis shift produces a new interpretation of the engine. These are things that deserves the mathematics explained in exhaustive detail. Tribology is a fascinating discipline that deserves a place here youtube.
This man just engrained in me knowledge I couldn't obtain myself.
This was a brilliant piece of work! Just the time spent on the CAD animations must have immense. Thank you, I really enjoyed it.
In the early 1990's I read a paper on how a longer rod length affects power characteristics and I remember the classroom discussion was along the lines of, "we've been doing this long enough that we're now able to look at smaller details than ever before." Offset engines are a surprisingly simple and subtle change to how it's always been done, but as soon as I saw your first charts, I was able to see some of how it would be an improvement. Very well taught.
Steam engines used offset engines over 100 years ago, and the Volkswagen vr6 and vr5 are off set, but instead of offsetting the crank, they would offset the angle of the cylinder bore.
@@klubstompersI guess I could sleeve my engine then bore the cylinders off center.
@@wannabecarguy Yea, you'd only have to that and mill the block top at and angle, fill all oil and coolant passages the angle interferes with in the block, re-drill new ones, custom crank balanced for the rod angle, custom harmonic balancer, run a custom timing chain system or belt, custom header or down pipe to accommodate angle, all for zero HP gains. Cake!! :D
Love your engine dynamics videos. You are the legend!! Keep them coming. Thank you for them
this channel is so helpful for me! i now understand so many things that never before! thank you so much!❤❤
Wow, you have explained so many things that us ordinary mechanics never think about it . Fuel, compression, spark, it runs. Yay....
You are always able to explain these difficult and tedious concepts in a very clear way, I'm not saying I could engineer an offset engine now but I completely get the concept and complexity involved. I love your channel.
Beautifully described, wonderfully precise and enthralling to the very end. Thank you.
Brilliantly explained: I understood everything! Compliments and great respect!
you know, this channel is the best or one of the best for anyone that interest about detailed technical thing especially on ICE. I always happy when this channel uploaded a video and for some time never missed the new video. Thanks for the effort.
Impressive. I've read a bit on offset engines, but your explanations are much more complete. Thanks a lot for this. I missed how big the offset can be and when the cons are greather than the pros depending on it.
The offset usually ranges between 4mm to 10mm, too large leads to diminishing gains. But there are engines with as much as 12.5 and as little as 2.5 agaik. Offset in the video is exaggerated to 15mm to make effects more obvious.
@@d4a hi, is the suggestion that 7 mm offset is an average? or is the optimal offset based on the stroke/ rod ratio?
@@d4a I'm probably misunderstanding but if the offset decreases the rod angle and therefore the friction on one side of the cylinder wouldn't the increased rod angle while it's on the other side cause increased friction, negating the benefit?
@@dr.brianadams6542 the highest side load is during the combustion stroke. The difference is not small either. Go back to the vid on Miller, Otto and Atkinson cycle engines for another benefits.
I first found this out when I saw Toyota's ZZ engine drawing when it just came out and thought this was simply amazing.
Still rewatch this myself. So well done man.
Gotta be one of the best engine design channels out there!!! I am always amazed how new videos can cover things that I had no real comprehension of while making it simple and entertaining to watch.
Like answering questions I didn't know enough to be able to ask...
I thought I was pretty familiar with 4 -stroke reciprocating engines. And many of the subtleties that effect their performance parameters. Torque /HP vs RPM. Subtle changes in intake and exhaust flow vs. RPM resulting in changing Torque/HP curves. Every time I watch your channel, I learn something totally new to me. Thanks.
As an engineer not specalized in combustion engines I always enjoy some good lecture about amazing technology
So many people show there interesse on this channel, and I count myself among them, only because your talent, your ability to make so complicated topics, maybe not uncomplicated, but for sure more digestibile for us ordinary mortals. The fascinating world of motoring is reviled before us, with you helping, so it gets even more fascinating. Thank you for that! 🤓👍🙋
We're all ordinary mortals ☺️
@@d4a maybe you are, but thanks to denial I'm immortal.
This offset cylinder idea is the Désaxé design, started I think on steam engines. Early adopters of the Désaxé principle included Henry Ford who would fully implement the Désaxé offset into the Ford Flathead V8 engine throughout the 1930s while adopting greater offsets into the 1940s.
Did Ford stop applying offset on their V8s?
Yeah thats also what im wondering. Also did chrysler/gm do same offset thing during 50s and 60s?
The Moto Guzzi postwar Falcon 500 singles were Desaxe designs, I always wondered why. Now I know! Great video.
Yamaha has the offset too but it's in the piston!
Some of these engines suffered from assymetric wear, and were harder to overhaul, and had shorter working lives.
It is just amazing that reciprocating internal combustion engines have been so successful, particularly 'four-stroke' variants. You look at it and say, _'There's gotta be a better way!'_ Yet, not only were they the first commercially successful ICE engines, but 125 years later they are still dominant. The effect of offsetting the cylinder is among their most fascinating characteristics.
Excellent video. Very well explained. Thanks!
I love your videos man! Some of us out here are capable of understanding more complex concepts of engine dynamics than just the basic functions offer. Your moving diagrams help out a lot. Thank you for filling this void.
I'm definitely going to need to watch this more than once.
You're killing it! U make the vids that EE should've done so thanks for the info. Very comprehensive you never lost me so good job
This is some quality educational content you never knew you needed, until you've watched it.
I have been watching your videos occasionally for some time. It is amazing to see how well you have improved over the years. Keep up the excellent work!
Hello John how are you doing 😊
Good stuff. I've studied engines both internal and external combustion from some pf the earliest designs all my life. I love how much I learn in minutes that used to takes hours and days reading old design books or observing actual engines broken down, which was exceedingly rare. Thanks for all your efforts.
Amazing work on this video! This is the first one I've seen from your channel, and I'm incredibly impressed with your knack for explaining these concepts in a way that truly helps with understanding the underlying mechanics and physics. Wish we all had more teachers like you!!!
Brilliantly cogent explanation of this new engine design !!! I've worked with quite a few mechanical engineers who couldn't even begin to approach your clarity of explantion. Keep up the great work with your vids
Used offset pistons in a Ford 289 years ago with 11.6 to 1 compression ration. It was a torque monster, and nearly unbeatable in a 1963 Fairlane Sport Coup. Surprised many a 396 Comero and 440 GTX owners who just could not believe what just blew past them after giving them a head start from a 30 mph roll, only to inquire when catching up afterwards about my healthy "big block". That offset made a huge difference.
im sure being a 500 lbs lighter than the camaro and 900+lbs lighter than the GTX played a small contributing role as well : )
You were already very good with explainations, but this video is next level. The 3D model with all the measurements make your statements very simple to explain. Thanks for the good work and sharing.
This is my first D4A video on any engine design. All I can say is great job of taking the complication out of complicated concepts. Personally, I wasn't even aware of cylinder offset, much less its pros and cons, but now have at least a rudimentary understanding. I wish you would have done a little more about solving the balance issues associated with the offset design. Maybe it's already done in another video, but I'll find out as I watch others.
Brilliant explanations of complicated concepts. Very interesting and informative. Thank you.
Thank you, professor! I have a horizontally opposed, air-cooled, VW engine that I increased from 1.6 to 2.0l by increasing stroke to 78mm and bore to 90.5mm. The pistons are offset by design and the arrows stamped on the piston head aid in proper installation. I now understand why, even though I took great care in balancing the rotational elements I still get slightly annoying vibrations which I cannot tune away. So, I can stop pulling my hair now.😂 I would also add that I increased the rod length from 5.4" to 5.5". I can't recall now why but probably the compression ratio which is approximately 7.8:1.
Piston offset is something entirely different than offset rods. Piston offset is there since the Ice Age. It' s goal is to slightly increase piston dwell time at top dead centre thus decreasing piston slap (a ringing sound) and decreasing load on the wrist pins and small end of the rod. Same is achieved with offset rods, but that is only one aspect of offset rods.
puerco, opuestos no es boxer paul, i get what u say bout offset rod but piston ofset ain't know wy t wld b diffrnt
@@Xayuap with offset piston the piston rod and crankshaft are still inline
t ain't dat w r xplainn n d vid?
Neat thing about the secondary balance in an offset engine, is you can just ignore the small forces and balance out the larger ones. As well, because they are not uniform in distribution, they are less likely to cause catastrophic issues from resonance.
I forgot the most important part, which is that the direction of the pump assembly depends on the spark rate, and if there are errors in the direction of the offset, the spark time will be advanced, and other things, the intrinsic strength of the air loaded with gasoline and water and how it is used to separate the fuel.
I have seen your videos of the 4-V, 4-opposed boxer engines, and found them very interesting allowing me to reduce my ignorance in such subtle differences. I really see the balanced engine as great, maybe I sense that it lends itself to a quick massive application in opposed-cylinder engines or even in boxer, even better. And the coolest thing is that it would never have occurred to me, "advancing the crankshaft", turning it when the piston reaches TDC, is really a new way of extending intake timing, generating "ignition advance" and reducing engine speed. expansion effort after the explosion with a lever arm helping to rotate the crankshaft. The concept that he has so clearly explained to us with his beautiful lecture on the subject of balanced motors is really great. Thanks for your class!!!, Greetings from S.L. Arg.!!!
WOW! Excellent! Just simply excellent! Thanks a whole lot. I love the series of videos you’re putting out. This off set engine was really interesting. I had no idea the engineers were doing this. Don’t stop! Keep going!
Each and every time I watch your excellent videos I am hugely impressed by two things: How absolutely brilliant engineers who design these mechanisms are, and by how very well you explain these complex topics in a way that I can easily understand them. Keeps the great work up, please. Very much appreciated.
I love your videos brother, I've learned so much this past year. Thank you!
Dude! I really admire what you do here. IDK how you do such a good job explaining things but it works.
For 2 stroke engines the offset is towards the exhaust with the cranck that spins in the same direction. This allow for a longer time for the first blowdown to be longer than the second allowing the engine to run slightly higher
probably, the only non-bot comment. thanks for this comment.. I was thinking this would only be beneficial for a 2-stroke engine. The compression stage of a 4-stroke would completely destroy the presenter's efficiency paradigm.
@@derrikarenal3308 Think about how much greater the forces are in the power stroke. After all, that one stroke produces enough energy to get the engine through the other 3 strokes and on top of that produce a huge amount of energy to accelerate the car. So making the geometry better for the power stroke, easily offsets the penalty of making the geometry worse in the compression stroke. (Where the downward & thus sideways forces on the piston are maybe in the order of ten times lower).
It's in the smallest of details where great ideas can form. Knowing what each part does by itself and in relation to its neighbor helps to create an instinctive understanding of the whole system. Some relationships have flexibility while others don't, and your videos explore those relationships.
Dude, just amazing explanation! I just can't find anything like this here in Brazil. I just need to watch your video another 2 times to completely understand, just amazing!
As a mechanic, I very much appreciate the technical detail & vernacular you used throughout this video. It was well-explained, and thoroughly detailed. What i don't appreciate is the manner in which you did it. I was not able to sit through 23 minutes of you whispering it all. Like you're doing this presentation while trying to not wake your grandmother up, while she sleeps behind the camera.
The one thing I noticed about the offset that wasn't mentioned was that the most extreme angle the con-rod makes is greater than that of the non-offset engine. This happens on the compression and exhaust strokes and would cause friction to increase with RPM, so I had been under the impression that offset engines generally produce more low end torque and have better efficiency, but the sacrifice is how high the engine can rev before it starts to lose power.
However, the compression and exhaust strokes are relatively low-stress periods in which the force on the piston is small, compared to the power stroke which has a very high force on the piston. Thus it gains more to reduce the friction coefficient on the power stroke than it loses to increase it on the others.
I'm not an engine nerd, but that aspect bothered me.
Yes, and no... at low RPM the friction from the power stroke goes way beyond the friction generated by inertial forces. But as the engine RPM rises the inertial-induced friction increases while the power-induced friction stays relatively the same.
@@saskprotogencyus2788 What you described happens to nearly the same extent in a non offset crank arrangement
@saskprotogencyus2788 exhaust is no problem as the force on the piston is relativ small. Compression is more annoying. What is a problem is bottom dead center. Once the crankshaft get's past 180° and starts moving up, but the piston still moves to his buttom dead center the pressure on the piston works against the engine. You can compensate this with valve timing but it will remain more prone then a no offset engine.
Crankshaft: 🔄 Piston: ↕ Connecting Rod:💃
😂
this was a beautiful way to explain it, and the way you go another level deeper is exactly how my mind works! this will be a game-changing thing in my life of learning
Your "challenge" at the beginning already told me that you're going to give a great presentation....Wasn't disappointed at all...Thank you sir
This was absolutely mind blowing. Thank you so much for your incredibly detailed research and explanation. This is knowledge gold ☝
Yet another great video. You're doing a really good job at explaining and showing highly complex topics in a way that can be understood by almost everyone. In my opinion this is significantly due to your very recognisable enthusiasm for the topics. Please keep it up and may the channel grow even more (three quarters of a million subscribers already seems massive, though. congratulations!)
Facinating explanation. I really enjoy how you take a complex topic and make it understandable to the lay person. Thanks 😃
Didn't look to see how long the video was, turned on just before bed. Lasted to "let's see..." Will finish in the morning.❤
This engine design is a game changer.
This is the best educational content on KZhead. Thank you very much!
Great videos. When I wrote my books on the Yamaha KT100 two-stroke kart engine, I became fascinated by piston pin offset and rod angle because these have a marked effect on the timing of the ports. As I commented on the prior video on rod/stroke ratio, I believe that piston pin offset, and cylinder offset (those having the same geometric relationships) affect camshaft events. All this prompted me, with a Cosworth engineer friend, to produce a piece of software that calculates stroke/rod ratios, the location of the piston in the bore, the piston location at TDC and BDC, and everything in between.
the effort that went into this video... Hats off.
excellent explanation with clear and nice looking animation. great job in educating engine geometry and operation. 👍👍👍
This was an interesting topic and great explanation of the benefits and issues. I had no idea these sorts of engines existed!
I watch every second of your videos! Thank you for all the time and effort that you put into these awesome videos. 😎
🤯 LOVE THIS ONE!!! You have an amazing gift of explaining complicated stuff.