The Scotch Yoke Engine is Alive! 8 Pistons, 4 Rods

[@d4a]

100 cars that changed the world: amzn.to/3DGXDf6 Become a Tuning Pro: hpcdmy.co/dr4a Stem engine model: amzn.to/3Y5iZLv 1-2-3 count with Car parts: amzn.to/3jxP7Z6 Patreon: www.patreon.com/d4a Motivation: kzbin.info/door/t3YSIPcvJsYbwGCDLNiIKA

[@thevoiceofcake]

Huge props to the company for posting their data.

[@nah9585]

Definitely.

[@Taliyon]

I've studied engine balance for over a decade. You consistently break it down in a way I've never been able to translate to others.

[@Mason-b2r]

What did you study? These engines are a balance nightmare. If you were that knowledgeable you would know how much bs this guy spits out

[@Wtfinc]

@@Mason-b2rhe just says he studied it, not went to school. U need to calm down. And dude explained it great, there was no BS. If you anything about anything you would not have latched onto that. Since you know everything, why does he keep clarifying the flat 4 as “non-boxer” when a boxer engine is just a Subaru flat 4, its not an engine type. If it is, what makes a boxer different from any other flat 4? Different ignition cycles? Idk

[@kadmow]

@@Wtfinc : Boxer engine - also typical of Porsche 911 (Boxter, Cayman, Spyder) flat engines (aero derived) - typified by offset cylinders with conrods on individual crankshaft journals - moving with with opposing directions (matched pairs moving out or inwards simultaneously - Apparently it is a very old design, from back in 1887 (Karl Benz), long before Ferdinand became chief automaker to Herr H. Commonly adopted in Aircraft applications - ie. Lycoming, Continental, etc.. Other flat 4's use common journals and evenly-opposed cylinders - both cylinders motion being constrained by the common crank journal.. (as per the graphics in this video) - the Flat "non-boxer" is commonly described as a 180 degree 'V' engine - any angle could be used for packaging needs (Ferrari flat 12 is an example (used in the Berlinetta Boxer, which funny enough didn't have a Boxer Engine).. - note; flat plane and cross plane cranks could be used in either v or flat engines - as well as individual or shared journals, there may not be a pet name for every variant, Boxer is just one which stuck. NB, all of this could well be wrong, do your own research, it is fairly easy these days, lol...

[@colinfitzsimons3409]

​@@Wtfinc is that comment for real? What a joke!

[@colinfitzsimons3409]

​@@Wtfinc the "dude" got it completely wrong yet again.

[@inertiaMS]

Some times people need to relax their expectation of every idea needing to become a commercial success to be considered anything but a failure or scam. Whether it becomes a relavant piece of technology going forward we should all just enjoy this process or seeing and working through this engineering challenges

[@d4a]

Thank you for that!

[@piccalillipit9211]

I completely agree

[@kricker8562]

@@d4a I was wondering, if the scotch yoke is allowed to tilt by using a wrist pin, how is it then any different to a normal engine with con-rods?

[@GCS88]

@@kricker8562 It's all about the pull, a traditional piston on conrods gets pulled on an angle so 'side thrusts' occurs when the rings glide on the cylinder walls, I can imagine that the scotch yoke would also have this but in a very miniscule amount as it moves in a vertical manner

[@geemy9675]

​​​​@@kricker8562hink the Conrod is guided and actually not supposed to rotate more than within the tolerances. the pin is just to spread the side load and friction of the piston on all the contact surface with the cylinder instead of just the edge. think a hundredth of a degree of rotation if the Conrod is free to rotate then you have one to many degree of freedom and no more direct relation between the pistons position and crank position. the crank could rotate without moving the piston! the engine won't spin predictably, you don't have accurate timing and an engine that wouldn't even start and would lock itself

[@myhandleurl]

Thank you. As someone who had to leave behind mechanical engineering to pursue IT, your amazing channel helps me stay up to date with the field I truly love.

[@shampoo4273]

Same lol

[@alphaforce6998]

What is it with people not being able to accept responsibility for the decisions they make. Who put a gun to your head or otherwise coerced you into choosing IT, where you will soon be replaced by an AI chatbot, instead of sticking with the thing you enjoyed?

[@myhandleurl]

@@alphaforce6998 No one put a gun to my head. I chose IT bcos it provides a good income and the demand for mechanical engineerings in auto industry is dropping (at least in my part of the world). Sometimes one can’t always follow their passion. I have to also say, IT is not as boring as I assumed it might be.

[@alphaforce6998]

@@myhandleurl If you are a decent mechanical engineer, what is stopping you from independently applying your skills to design and sell things OR plans for other people to build things?

[@artlewellan2294]

@@myhandleurl A flaw in the presentation of this engine type may be a lack of thorough analysis of its "extended range" plug-in hybrid (PHEV) applications. PHEV engines achieve highest fuel economy (100mpg -150mpg) when their modest battery packs (Prius 5kwh vs Chevy Volt 18kwh) drive the car while the ICEngine is off. The ICEngine of a PHEV drivetrain is designed for fuel economy, not maximum horsepower nor torque. There are many, many benefits PHEV tech offers that deserve mention more than how their ICEngines achieve fantastic fuel economy. Another benefit is public safety. PHEVs can be driven by reckless speeders but their fuel economy plummets from 100-150mpg to 40-50mpg. Keeping a light touch on the gas pedal can teach idiot motorists how to drive defensively while spending less on gas. While BEV & HFCEV tech emphasize maximum driving range (say 300 miles) the limited all-electric range PHEVs offer (20-50 miles) encourages shorter drives which supports local economies whereby more trips eventually become possible without having to drive.

[@fredericocorrea9814]

I love this guy's zeal and understanding of engines and engineering. He singlehandedly has caused me to look forward to new technology in the world of engines. The way he breaks down the science and evolution is incredible. Thank you so much for sharing your knowledge, I am in your debt. Another great video.

[@markm0000]

This guy has unlocked the ability to love engines more than most guys love women.

[@d4a]

😂😂😂

[@BloodyMobile]

Only a true engineer can properly admire engineering achievements. Most things aren't impressive unless you understand /why/ they /are/ impressive. The best example are CPUs. What our phones can do in the size and energy footprint today, would've been a borderline mini (not just in the literal sense) super-computer a quarter century ago. Back when CPU speeds were 3 digit *mega*hertz and some computers even had a "Turbo" key, which is basically the ancestor of on-demand overclocking. Today CPUs do that constantly on their own, because why run at 2.5 Ghz when there's nothing to do? Literal waste of power. Same goes for engines. The engineering to get them as efficient as they are today went equally far, but you need to understand how intricate the balance of all parts in relation to each other is, before it becomes truly impressive. An example here would by my '18 VW Polo vs an original VW Beetle: the Beetle needs 3x the fuel of my Polo to create 1/3 of the power. My Polo can go +180 km/h with the consumption that the Beetle had on *average*. If that progression over the decades isn't impressive, then nothing in the engineering world is. Probably. But it's not impressive unless one really builds an understanding for the "how" and "why" of these examples. Without that, it's just numbers.

[@VintageSG]

Cars don't get jealous if you look at another car. Cars don't stab you if you take another for a test drive. Cars don't care if you're polycarous ( polygamy with cars? ) Own two cars?, sleep well. Cars don't care if you replace them with a younger, slimmer model. Cars don't take your house and savings if you get another one. Cars don't gossip if you take a motorbike for a ride. Cars shut up when you turn them off and walk away. Cars are easy to turn on when you want. Cars don't care if you fart. Cars don't have psycho mothers.

[@toejamr1]

Yes. We call this autism

[@OldSchoolZ-wy2yx]

​@@toejamr1 wtf are you on

[@maccaberry1041]

The grin on your face shows how excited your are and is so fun to watch. The ICE is not dead, and your enthusiasm for it brings a smile to my face too. I bet when you discovered this, it even exceeded the joy of your first motorcycle ride.

[@johnburns4017]

The ICE is slowly dying. The end will be quick.

[@eTiMaGo]

Looks like it could drop into a Subaru :D

[@Athiril]

Yeah I think a scotch yoke boxer would be pretty cool. We might as well go all the way. Dimpled pistons. Some kind of freevalve for full timing control.

[@mikewallace8087]

@@Athiril the problem with all these I.C.E. is they are energy sinks that reject energy to the surrounding air . No ceramic engine revolution yet.

[@Vel1ar]

@@Athiril well, 4cyl seems to peak in power at 4500 rpm, which is disappointing. If 8cyl redlines in same rpm range, it'll be one boring-ass engine.

[@budthecyborg4575]

My first thought. I would cry tears of joy if this can revive the WRX STI.

[@2b134]

@@Vel1ar yeah, but I assume that might be due to the efficiency-oriented cam profile, maybe with a more aggressive profile it could be much better at higher rpm

[@ManChildMaineiac]

Dude your videos are LITERALLY the most detailed and informative videos on KZbin!! And you’re the only one who can keep me completely attentive even with A.D.D. 🤣😂

[@apparentlysmarterthanyou3446]

I hear you about the ADD, something makes me think that this guy suffers from a neurodivergence himself. Not always a bad thing,unlike what people think! Besides, having ADD, if we like a subject we will focus on it intensely, normally its only a hinderance if you're trying to focus on something you dont like but need to do XD

[@alfadanhighperformanceoutb8416]

At ALFADAN we looked at this same design given that the owner personally owned the only Bourke 400 ever built. The Bourke 400 was this same flat 4 design but in a two stroke, 400 cubic inch version. The ALFADAN outboard project required a 7.5 Liter displacement and the i4 was the best platform that gave us the smallest engine possible. Although our design ideas originated from the Scotch Yoke we had to take a completely different design approach due the weak lower end of the rod as described in this video. In summary, the ALFADAN design achieves large displacement in a small engine package operating under perfect primary and secondary balance without the added friction and complexity of balance shafts. Great video D4A!

[@rickcollins1825]

Why couldn't ALFADAN strengthen the bottom of the Scotch Yoke? It's only loaded on the intake stroke of the cycle.

[@FarhadB-og9js]

این پروژه هم شکست خورده هست. بیخود تلاش نکنید

[@horrorhotel46290]

This commercial brought to you by investor-money which was meant to go towards developing the final product, but goes to PR-salaries instead ❤

[@albertaraujo6358]

We have no affiliation or business with D4A. Nevertheless, D4A has done a great job at describing the SY engine. With regards to strengthening the bottom of the SY rod it does not solve the problem. As weight increases in trying to add strength, the reciprocating mass also increases which further increases the load on the rod and bearing. We worked on this design and decided to opt for a new design with no lower rod end and therefore solved this issue.

[@johncunningham4820]

@@rickcollins1825. Correction , the bottom side of the Yoke is loaded during COMPRESSION and Exhaust .

[@almostbutnotentirelyunreas166]

Been watching this channel for some time now, going from strength to strength, focusing on FACTS, rather than hype. There's an engineer in there somewhere, directing the excelelnce of the information and the video quality....Congratulations, keep this up! A credit to YT.

[@cerseonbrassmann5222]

I just love your expressions. you actually really glow up/ geek out over it. it's fascinating

[@wingnut2893]

The overwhelming enthusiasm is contagious.

[@max_power8510]

Seeing your happiness and enthusiasm is what makes the heart of this channel beat. We feel just as enthusiastic as you about seeing new engine technology become available and the exciting possibilities of adding more power! Your smile at the end of the video really summed up why I started watching this channel.

[@der_kanadier]

I think you might have missed an aspect of the cylinder wall forces @12:30. In the boxer configuration, the piston leaning force during the compression stroke is shared with the non-combustion cylinder through the single connecting rod. This should roughly half the twisting load between the cylinders and spread the wear from this friction to both sides of the cylinder. This could reduce overall wear due to these forces. Great video!

[@raptorjesus5488]

I don't know how the i4 will solve yoke lean all I can think of is guides in the block on either side of the big end of the yoke or a guide rod on the yoke sticking into the oil pan through a girdle or something

[@rickcollins1825]

Yes, the Scotch Yoke as show in the video would not only create friction on the piston skirt and cylinder walls, it creates a twisting motion on the piston, since there is nothing else to keep the piston straight. By adding a wrist pin, the twisting force is eliminated, leaving only the sideways push from the offset force of the crank bearing.

[@alanbunder9068]

I love how excited you were scrolling through all the data on the website, great video!

[@originalni_popisovac]

no u dont

[@JeffreyClark-fp5up]

I am a private pilot that owns a single opposing piston engine airplane in a land configuration, My airplane is a 1949 North American, Ryan Navion which is powered by a Teledyne Continental E-225-4 over head valve opposing 6 cylinder engine with a 5in bore and a 4in stroke, which means that this engine is not a boxer. This engine has 470 cubic in displacement and gives 225 HP at 2,600 RPM. The engine in my airplane works well and is proven dependable after decades or application. The continental engine company has the only engine that has a 8 cylinder version of this design, which supply's an impressive 400 HP and to my knowledge is only in one airplane and that is a Piper Comanche 400. All that being said, this Scotch Yoke engine would be a great engine for the aviation industry. I would love to see this happen. So thank you for your video and update on a modern tech improvement in my opinion.

[@Mikexxx531]

Agreed. Also a pilot. Many have tried to make more reliable, efficient, and longer TBO engines and they've fallen by the wayside. I'd love to see this happen. Aircraft engines run at high power most of the time, unlike auto engines. I don't know what to think of the sliding bearing of the scotch yoke, though materials science and innovation can often minimize these considerations.

[@mrbrisvegas2]

Aircraft engines operate at low RPM and have very low specific outputs per litre. That is the real reason why they are reliable. They are only marginally more sophisticated than the engine of VW Beetle. Modern turbo automotive engines can reliably produce up to *10x* the power per litre as aircraft engines. Any modern car engine will run at *maximum* power output for up to 500 hours continuously on a test bench. That is equivalent to 100,000+ Km of high speed driving.

[@budthecyborg4575]

The flat non-boxer addresses basically all of the flaws mentioned in the first video. Bravo to the Sytech engineers. Let's hope Porsche and Subaru can adopt this configuration ASAP.

[@Wingnut353]

It absolutely does not address all the problems... that engine is obviously going to have high wear on that scotch yoke.... and probably need replacement every few tens of k of miles... while normal boxer engines last hundreds of thousands of miles with minimal maintenance.

[@Imagineering100]

@@Wingnut353 Yes it will it looks to me it has more surface area to wear out. I don't see the big car company use this they have too much invested in normal engine design and put this into production yes billion$ and 5 years and then if they have problems with it when they have sold 100000s of them well say goodbye. Not just that the car companies have known about this for decades if it was good, they would have done this decades ago.

[@CountChokcula]

@@Wingnut353 they can make it a roller bearing

[@michaelpielorz9283]

The internet is floodet with new engine designs that have one thing in common: even Wile E. Coyote wouldnt adopt them (:-)Dear boys, before praising them like a golden calf sit down and THINK for one miute (only if it is possible for you!!

[@michaelpielorz9283]

@@WaldemarPerezJr Please stop taking those colorful pills !!

[@AlexTrull]

Your honesty and interest always shine through, thank you.

[@brendonrenken6811]

Also YOU! YOU ARE THE BEST GUY ON THE INTERNET! I have learned more from your videos then any other source or any kinda experience! Keep doing your thing!

[@blackfrost273industries4]

I hope you also add in that I am also very, very satisfied that they shared so much information. That is awesome that they publish all of that on their website ! That made my whole month

[@AliusScitmelius]

But can you trust that information - are the curves in the graphs really measured or are they only sketched.

[@GL0BETREKKER]

the low center of gravity seems great for sports car applications, and so compact too. Cant wait to see more of this engine

[@JohnKickboxing]

This engine would get worn fast and badly, due to high friction. They need to add some rollers there to solve this problem.

[@howardking3601]

Really interesting and fun! You are a great presenter. You break things down very well and keep them simple. Thanks!

[@chir0pter]

D4A you really raise the bar with your videos. Thanks for all your hard work that I'm sure it takes to make such smooth and informative videos! 11:52 this is why ICEs will always be more interesting than EVs...designing, engineering & building parts that have to work in atom-space over millions of cycles is just inherently more aesthetic and fascinating

[@connorbingel7134]

Motors are cool but not that cool. They also aren’t at all intuitive. Engines are just way more interesting

[@incolink]

about 20+ years ago I had a job interview with CMC power systems and discussed the engine and its development don't think i got the job but the coolness of it has haunted me ever since I'm really glad to see it went a bit further I remember them saying they used Subaru heads for a few porotypes

[@Nafeels]

Between this, Mazda’s SkyActiv, Alfadan, and LiquidPiston, I’m psyched that ICE engineers won’t go down without a fight. I’m super hoping that the Flat-8 engine makes it into production, which would make them one of the first company in decades besides Porsche and Lycoming to pursue this ultra-rare layout. If they do, I’d buy a sports car just to fit one.

[@virtusetglorie]

And free valve

[@joshuasimmons2412]

Check out achetes opposed piston engine it's a awesome design.

[@tommynobaka]

Realistically ICE will not be phased out like everyone thinks. The market will shrink, but ICE will have its place. I think its great that as consumers, we will have the freedom to either buy electric or stay ICE. Gas and Diesel stations will not go anywhere

[@harrywalker968]

i have a 351 c ford v8.. its 50 yrs old, no issues.. why do we need this bs.. all engines will run on lpg & produce oxygen out the pipe..so why spend trillions on all this inovative bs, hybrids, solar, EV,s wind, . its all garbage..endless power comes from sodium reactors,, we only have nuke because of weapons.. fact..

[@NathanaelNaused]

All they need to do is use hydrogen

[@argledotorg]

The bearing surface is probably made of a relatively soft metal, since it appears to be made for "easy" replacement

[@wobblysauce]

Just a bearing material…

[@micgalovic]

Easy replacement is arguably more important than maximizing wear life. Doing an easy replacement job twice is better than doing a hard replacement job once.

[@IIGrayfoxII]

@@micgalovic Stripping down the engine is still costly for the customer

[@budthecyborg4575]

In high end pocket knives they like to use phosphor bronze washers to make a smooth pivot, not sure if those are up for the heat though.

[@flexairz]

I am sure the designers have thought of this too...

[@javabean215]

The single piston rod weakness issue, you spoke about in the first video. And my immediate thought was to add a piston to both sides. This is pretty cool, and I'm hoping to see it get some production time to see how it does in the real world.

[@pugnate666]

Thanks for the update! Great to see a more mature version with extensive documentation.

[@foolicooli]

A 3.0L puting out 335 is pretty good for what is essentially a experimental design.

[@didjterminator808]

ikr!? and with how small and light it is you could probably fit it into many cars that shouldn't be able to fit a 3L F8 engine. I honestly kinda wanna see someone tune that engine up for a semi-race endurance build in a super compact ultra light car and absolutely send it. Like Rob Dahm but with a scotch yoke.

[@rdallas81]

Only under very specific circumstances. The engine probably can not be directly connected to a typical transmission. The linkage looks weak and probably loses a lot of potential energy through that. I don't believe it will go anywhere. A range extension engine should be a diesel. Actually mazda did a rotor engine for a range extender and its hooked to a generator that charges its battery ONLY. Its not connected to the wheels at all. They did a pretty good job with it.

[@didjterminator808]

@@rdallas81 that do be true - but we can still dream

[@foolicooli]

@@rdallas81 rotary engines aren't used because their oil consumption fuel economy and poor emissions. Diesels are good work horses but generally heavy weight. The geometry of the 3.0l V8 on a light frame say 90s Miata would probably handle it fine. I don't see these engines going in anything trying to be a tow vehicle or similar work load. But a few years in the market they may redesign the pistols to be stouter etc. These have great race potential imo. Slap on some solenoids for the variable timing and other things becoming more common in the race scene like the newer F1s with the weight savings I could see these maybe being banned like the old road runners did from nascar being too aerodynamic

[@rdallas81]

@@didjterminator808 I do. So many ideas. I have ideas! Just crazy this world is dominated by substances, drugs, violence, media, etc etc. All revolves around government, money, lies. We need a new coalition. We need new people to provoke involvement like it used to be. Now, with media and "independence" people have grown apart. A great falling away it seems. Imagine a world where China, Russia, Japan, UK, can go work together and invent new technologies together. Imagine what problems we could all solve. Instead- people choose to make enemies out of their neighbors. And they expect their children to do "the right thing"? Sorry. Just venting. I like these engines and technologies because we can have 20 different people from 20 different countries and its like it doesn't even matter. We all speak the same language when it comes to technologies.

[@_miobrot_603]

That flat 8 engine looks legit! I sure hope the production run is successful for them so they can expand their market to USA and Canada etc. Truly exciting, and thanks for the update and continuation of the scotch yoke engines. I hope that the flat bearings are made to last, maybe a titanium alloy to withstand the heat and load?

[@MrChancebozey]

There was a radial four piston two stroke motorcycle using a similar concept to a Scotch Yoke design almost 20 years ago called the JJ2S X4 500. Great vids and content.

[@grrh77]

The reason for the wrist pin is simply assembly issues and size. A 1 piece piston and rod assembly would take the corresponding bore diameter in the crankcase. Doing so reduces the amount of structural fastener and bearing area that can be used in the case, whereas the wrist pin design only needs an opening the width of the rod. As a second, different pistons are easily used, in the documentation it is available with 11.5:1 and 13.5:1 configurations. With premanufactured complete bottom ends available for sale lowering maintenance cost, replacement of a single piston without complete disassembly of the crankcase etc. Great video!

[@chrisbaker2903]

I remember my dad telling me about scotch yoke engines at least 60 years ago and the biggest problem he told me about what the amount of instantaneous torque. He told me about a two cylinder version hooked to a car transmission and it would sheer the splines off the input shaft to the clutch. He also told me about a 4 cylinder version that they put a propeller on, 8 bolts around the hub and they ran it up to half power and when they put full power it sheered all 8 bolts. I hadn't heard anything else about them since then and this must have happened in the 1950s or late 40s. I look forward to learning more.

[@Mikexxx531]

A system with a torque converter should solve that problem.

[@nhand42]

This engine was developed by CMC Research Australia over two decades ago. There were plans to put it into a hybrid concept car back in the early 2000s but that never happened. I would wager good money in the past two decades they tried shopping it to the well known manufacturers - Ford, Toyota, VAG - who all looked at this and decided against it. Selling it into China means they've hit rock bottom.

[@andgate2000]

Just in time for the elec invasion.

[@68404]

Actually, the only game in town is China. It is now the biggest car market in the world. China has evolved. It seems your prejudices have not.

[@Pozi_Drive]

@@68404 You just don't understand things, do you?

[@mikescherrer4923]

@@68404China has evolved? Ok, Chinese bot. Tell Xi the propaganda isn't working. China is a doomed cesspool full of rats clawing at each other to stay above the rising water of the CCP's war on it's own people.

[@Idklol603]

I dont think you do, hes righ

[@matthewbeasley7765]

In your free body diagram at 13:30 - your missing the reaction force. You've caught that the piston is driven to one side, but you're missing that there is an equal and opposite force that's trying to push the yoke to the right. It would cause the yoke to pivot, and that's not good. It would turn the yoke effectively into a rod because it would come to rest with the yoke placing the pin / block in line with the wrist pin. In old steam engines, they resolved this one of two ways: - In single cylinders per throw, they put guides on the sides of the yoke that resisted lateral movement of the yoke. - In tandem opposed cylinders, the piston rods had guides. (Remember, old steam engines were double acting). In the modern equivalent, the opposed pistons are going to provide the bearing surface to resist the lateral force.

[@haphazard1342]

Thank you for pointing this out. It was a glaring omission from the explanation in the previous video as to how this force could be controlled. In the single-acting design, he has completely ignored the guide surfaces required for the yoke. This represents a second planar bearing surface that is subject to the same engineering constraints as the primary inside the yoke. It is admittedly easier to lubricate as one side is stationary, but represents a second wear surface and source of friction. As you point out, the double acting opposed piston design solves this problem by using the opposite piston to control the lateral forces. This introduces a potential torsion at the point where the pistons attach to the yoke "rod", which coupled with ease of manufacture makes a wrist pin sensible. I would not want to be the machine shop tasked with manufacturing the rod-yoke assembly if it were integral to the piston, and I would not want to be the mechanic who has to replace the entire rod-yoke assembly in the case of damage to the piston alone. Overall, the double acting design seems efficient in terms of reducing wear surfaces and efficient packaging. Whether the lateral forces on the piston can be managed effectively in practice is another matter.

[@cannaroe1213]

What a fantastic video, you were the perfect chap to document this engine, good job :) Your excitement reminds me of how excited I got when i first learned about sleeve valves, or the PatCam system, rabbit holes rabbit holes rabbit holes

[@thomaswomack3888]

I really appreciate how well you have presented all of this information in a way that is understandable and digestible. And props to Sytech for making this engine design work. I'd love to try one of their 8 cylinder engines in my old subaru and see what kind of lovely monster it would be. :)

[@TheDryOneGaming]

This is awesome. I just made a scotch yoke reciprocating saw for my senior project. Definitely didn't know that mechanism was being used for engines, super cool.

[@RobertDerusha]

I think your explanation of the wrist pin might be negated by the opposed piston resisting any tilting of the scotch yoke. My guess for including the wrist pin is just to aid in maintenance and parts commonality. Love the vids bud 👍

[@Chris-oj7ro]

This engine is completely new to me also and I thank you for going over it in detail! Maybe you could make a video on other promising engine designs that still have potential, whether or not we can expect some commercial release in the near future.

[@armandtdupreez1026]

Awesome video. This is the nerd-out content that I enjoy the most, I'm so excited that there are still new combustion engine innovations that are being developed and proof tested. Thank you for the information and explaining it so thoroughly and passionately 👍

[@imax.art86]

Thank you for the great video. I'm really surprised about this non conventional engine existing as a production ready prototype for a while and you're the first man who told me about. I'm so excited that I'm wanna to send this video to all of my friends who's cares just a bit about cars.

[@kylesharp9771]

God dammit this guy has to be the best engineheads from a physics standpoint and design analysis standpoint nobody does it better. Hats off

[@jonskid8929]

You are an engineer. Loved the design and your concise description, knowing the plethora of information you sifted through.

[@phantomforester9337]

Thank you for extensively researching and pulling out the key factors that make the concept work. You have saved a lot of time for a Web explorer.

[@shimy333]

Please do a video on Radial motion from Australia... I have been obsessed with their three piston radial engine ever since I saw a few days ago on Jay Leno with the new Myers Manx buggy... It sounds more amazing than anything I've heard in many years

[@paulw8356]

My dad knew Mr. Bourke, and after pondering for years, in the early 70s, he and I built a modified scotch yoke engine, one that used particular geometry that cured the scotch yokes inherent dwell problem that is virtually identical to that of a regular reciprocating engine. We tried for years to get funding for it never could.

[@thatotherguy4245]

An amazingly insightful and well researched video as always. Thank you for making this.

[@zaccheus]

If the engine is designed from the start as a range extender, it would certainly be possible that it could have an oil priming system that developed oil pressure before a start. Engine start is where a lot of bearing wear comes from because there is only an oil film, at best, to lubricate the journal bearings.

[@Eikenhorst]

You could solve that by starting an oil pump for this oil a few seconds before starting the main engine. Startup goes from 1 second to a second or 5, but that is not critical if that is what is needed to use an engine with plenty of advantages. But I agree that a range extender application makes more sense

[@zaccheus]

@Eikenhorst A delayed start doesn't seem critical. But we live in a world where CVT transmissions still shift through fixed ratios because customers don't like it when the can't feel the car shift 🤷‍♂️

[@whitefink7090]

That'd be wise since I recall Subaru engines being oil sensitive and prone to rapid wear.

[@felixbaum48]

Holy cow! Three Liter 8 Cylinder Engine at 130KG is amazing! Lighter than the lightest 8cyl mass produced, the Buick 215, by a huge margin!

[@BuzzLOLOL]

A properly designed aluminum V6 would have been even lighter... as typical of Buick, they did it wrong...

[@phugwad]

I am quite familiar with the Buick, Olds, Pontiac, Rover, 215, 3500-4600cc engine, having swapped one into a Datsun 510 back in the late 70s. That engine weighed less than 144kg, fully dressed, not more.

[@phugwad]

If the point of this engine was to make electricity for range extender use, why use a crankshaft at all. Linear engines, no crankshaft, just a piston connected to rods with magnets, driving a linear generator, get rid of a huge amount of complexity and weight.

[@BuzzLOLOL]

@@stevel6660 - The Buick V6 was a shiiite engine for it's first 25 years... ran like a V8 with 2 bad sparkplugs... shook back and forth 6 inches at idle... until 1988 when it got balance shafts to help smooth it out some... better idea would have been a crankshaft with 120 degree throws... then natural balance with no extra shafts or weak split rod journals needed... except it would have been so smooth would make it difficult to sell most people a V8 upgrade...

[@BuzzLOLOL]

@@stevel6660 - Millions of aluminum engines were made for WWII aircraft... there should have been someone around to consult with... Britain found them... and the Buick 215" aluminum V8 started in 1950 for use in concept cars... hence why they had rocker shafts instead of individual rocker arms on studs...

[@chrismckay3868]

To overcome the rocking of the pistons during a power pulse it might be easier to create a double scotch design with guides to locate the rod and prevent it from rocking.

[@PetarMakTeacher]

Some years ago I worked with CMC research where the SyTech engine was designed and built, in conjunction with Melbourne University. The engine was incredibly smooth running and it was very compact due to the short conrods. Side forces on the pistons is negligible due to the solid connection on the conrod. Our test vehicle was a Subaru as it used Subaru heads and bolted directly into it. We fitted a test engine into a passenger vehicle (Passat) as VW were interested in the concept. Unfortunately, like so many other research groups, the funding dried up and it was shelved. It's great to see it appear again, as I know there was an enormous amount of work done by very dedicated engineers to make it run so smoothly and reliably.

[@kevinmurimi2176]

Trying to imagine the sound of a flat 8 cylinder engine makes me smile. Great video

[@S.ASmith]

I think that bearing plate being made from Incoly or Inconel would work fine. Hard wearing, good temperature properties and they don't expand much when heated either.

[@EspenMyklebust-u1o]

Thank you @d4a for another great and educting video! I don't know if you are a contributer to wikipedia, but as you note there is no article on this engine, and I think it would be awesome if you would improve that marvelous encyclopedia with such an article. With your knowledge and talent in explaining complex topics, you could probably contribute to a heap of other existing and not-yet-existing articles as well. The wiki will only be as good as its users make it, you know😉 Keep up the good work!

[@padders1068]

Great video and as ever very well explained! Keep up the good work! 🙂

[@paulcooper9011]

I'm glad you acknowledged the off-centred crank position in the scotch yoke engine. I had thought that after a while and it bothered me with no way to see how this could be eliminated. The flat arrangement in this engine might help it a little by putting that friction across two cylinders but probably not by much.

[@catatonia1]

@driving 4 answers ....I worked for a engine machine shop in Melbourne Australia around 20 years ago and we worked on this scotch yoke engine over a number of years. It was based on a Subaru boxer engine using Subaru engine cases.We honed the slider blocks to finished size, bored and honed cases to suit the skirt less pistons, and balancing of crankshafts? Melbourne University was heavily involved in this project if memory serves . They had several working prototypes 20 years ago so it seems unlikely that it will ever be put into production if it hasn't by now!

[@koborkutya7338]

I read about those development efforts way back. When I looked up the principles I found that basic textbooks of internal combustion engines from the 1950s already contain the various scott yoke configs that were discussed here. That book stated "the key of these configurations is to find some ingenious solution to handle lubrication and friction at the yokes, everything else supports its success" so when I see all these animations I always think what is the actual trick they are deploying now - and that part is not really shown, just that "it's a flat piece of something" - that something is probably the factor deciding if it works or not. My expectation is they may deploy some material recently developed or recently used like some ceramics containing graphite or the like, which one could not easily reverse-engineer even with your hands on it.

[@juliocesarsangamatang8761]

@@koborkutya7338 To reduce friction they should use DLC coating

[@DJAizakku]

The flat 8 is giving me massive 60s prototype racecar vibes. Im intrigued to see what it could do in a performance application.

[@reisman44]

Please look into the Taurozzi engine.The Petronas University of Malasya conducted tests to confirm its efficiency.Would really love a video from you on that engine.Great job as always.

[@MadRat70]

Yes, these engines are much better than a scottish yoke. The concept hasn't even been given a real chance to strut its stuff. So simple yet ignored.

[@ryndrssn]

Malaysia*

[@bardocz]

I think one of the main reason, that the rod and piston is not a one piece unit is simply assembly. With the piston rings, it would be pretty hard (maybe kinda impossible) to assembly the piston into the cylinders.

[@miguelperaza6615]

Its totally awesome that somebody came up with a new technique of direct torque engines , LET'S also remember the flat type 12 cyl. Porsche 917 engine in 1968 it went thru very few changes and beat Ferrari , Matra Simca, Alfa Romeo , Corvette , Maserati , Ford Mustang , Jaguar , with it's 580 horse power and when it kept winning? The Le- Mans association mandated Porsches to ommit and block first gear with a metal plate on the gearshift to start races on second gear , thus giving a chance for other cars to win . The CanAm version of Porsche had only 350 horse power and won many races against McClaren Chevrolet. And Audi . The Porsche 917 is still today the fastest of all 24 hour race cars. Imagine a car that races 24 straight hours with 2 drivers one for day driving , and one for night driving , without rest , only pit stops to refuel and change plugs and tires .

[@thebeardyyc]

@7:32 dude with a decently rough accent corrects mostly proper english, its an amazing site to see. this dude is smart, i'm subscribing just for that

[@redshift6170]

The engine was used as a range extender engine back in… 2000. I thought it looked familiar, it was a concept car called the “aXcessaustralia II”. Not sure it has come very far in the last nearly 25 years since then unfortunately.

[@DrTheRich]

Could also be other issues, battery technology might not have been good enough for it to make a sellable car

[@jimmydesouza4375]

@@DrTheRich Battery tech hasn't improved since the 90's.

[@DrTheRich]

@@jimmydesouza4375 ah yes, how could I have missed all hose lithium ion battery cars driving everywhere 30 years ago...

[@jimmydesouza4375]

@@DrTheRich No idea, but you did. The original ranger EV which started selling in 97 had Lead acid (obviously), NiMH and Li-Ion options (though I beleive due to a lack of sales the Li-Ion option never went in to production). GM EV-1 (96) also had the same, was originally released with lead acid but was sold to buyers with the idea that they'd be able to replace the lead acid with NiMH after gen 2 (1999) came in to production (which happened) and then to Li-Ion when gen 3 (planned 2002) came in to production (once again due to a lack of sales never happened). Again, the technology hasn't changed, all that has changed is the marketing. Even the purported range increases only come about due to massive increases to the physical size and weight of the battery packs in newer EVs, because once again it's the same tech.

[@DrTheRich]

@@jimmydesouza4375 i never said liithium ion battery didn't exist back then. The technology back then to produce them at a viable scale, reliability and prive wasn't good enough to make it a sellable car... You point out yourself that all these cars that were promised to drive on lithium ion cars didn't actually go into production. So somehow it's weird for me to miss cars that weren't actually driving around. Probably because the technology to make those batteries back the wasn't good enough. Battery technology doesn't just include only the technology of the battery itself. It also means the means to maken them. Example: we know how to make graphite Right now. What we don't know is how to make it on a scale that's useful for any practical application. Aka the technology isn't good enough yet.

[@bondisteve3617]

Thanks King. Really enjoyed this. Well done!

[@MikeP59DE]

I totally agree. That's really very interesting stuff you've dug up for as. Your unique way to explain really adds to it. Maybe SYTECH is even the reason why ALFADAN hasn't come forward with anything about their approach to a scotch-joke-engine. Maybe they have come across patent issues. It's all too obvious that SYTECH is much, much closer to market on the technological part. It's only logical to assume, that they have done their homework on the legal issues just as good. I've learned so much from you already. Thank you very much for you work. I highly appreciate it.

[@johnburns4017]

One of these engines was built and inserted into a Ford Granada in England - about 25-30 years ago. It gave far more torque, especially at the low rev range, reducing the size of the transmission, or if designed right for a particular car, and body designed for the engine, no transmission at all. The flat boxer-type arrangement also gave a lower centre of gravity. It was pretty smooth going by reports, which was encouraging.

[@Grateful.For.Everything]

I feel like this Range Extender term is like a marketing pitch that paints a new picture of combustion engines, instead of being this thing people are rebelling against it gets hidden away in the back somewhere as this backup servant within an “electric vehicle” like it’s just some other component rather than the electric vehicle actually being ran by combustion. It will be exciting to see how this progresses.

[@jebise1126]

and i said 8 piston flat one would be perfect sense for it in that previous video

[@asdf8asdf8asdf8asdf]

Great find. Shows you how much information could be hiding out there in the open despite having easy access to "everything" -- sometimes it takes awhile to find "everything" 😊 .... really appreciate the in-depth discussion But also curious how this relates to the more conventional "liquid piston" engine design.

[@connorruss5976]

Another reason for the the wrist pin you may have overlooked is for modularity reasons, allowing different pistons for different bore size or different piston crown design

[@pizzablender]

Also manufacturing is a lot easier with wrist pins.

[@Bobdibob]

My narrator - you're an absolute scholar, thanks for the vids!

[@paulfuller5646]

Great explanation and detail, well done. thank you. The boxer engine name was coined for the pistons moving in the same manner as a boxer does when punching. The scotch yoke design, while innovative, operates in same manner improving upon the original boxer design, hence, “scotch yoke boxer”.

[@bigblue729]

I don’t think they necessarily need the wrist pin in this case. Since the engine now has two opposing cylinders, the rod flex or twist is now supported by two cylinders. That being said I’m glad you mentioned it because it was my first thought in your first video and absolutely would be a bigger factor on an in-line engine. The wrist pin could still be useful in assembly/disassembly as well as servicing the engine. A piston/rod assembly would be an expensive part to have to replace due to the complexity of it. The ability to use different materials from the piston to rod may also be a reason to split the two. You could also use commercially available pistons, reducing machining and repair costs. I’m curious to see the long term reliability of the sliding bearing since that seems to be the biggest question for whether or not this is really commercially viable. 500hrs of run time really isn’t that much and if it needs rebuilt soon after that time frame then maintenance costs will likely kill the engine design for most applications.

[@MrJamesBanana]

Yeah, 500hrs is nothing for an engine. Especially if that is in multiple different test cycles. Also, the two cylinder version will probably vibrate a lot since there is no way to get even firing intervalls for it. At least without making a two stroke engine of it. Also highly doubt an engine like this will be able to handle euro 7, those rules seems kind of strict.

[@blinkybagger8342]

Though the double ended scotch yoke rod has another piston attached (presumably )at an opposite point of the combustion cycle, the forces may be less even momentarily as the combustion forces do their thing. Wrist pins may reduce friction and improve assembly & servicing.

[@FallsGaming]

Wow cant wait to see what Car manufacturer would implement this into their lineup!

[@krisztiantkacs]

Only Mazda is stupid enough for something like this 😅

[@danhammond8406]

It's been over 20 years since it was made. I'm betting it has been turned down by all of the manufacturers

[@idrifted1]

You could probable model these 3 engines in the Engine Sound Simulator to find out how they'll sound.

[@haphazard1342]

Somebody page @AngeTheGreat!

[@gregstandish6439]

I am as excited as you are Mr. Driving 4 Answers. Very cool information.

[@garniful]

12:08 ~ 13:30 I got it, you have a nice explanation of the topic in both videos... Many thanks sir

[@garniful]

15:47 ~ 16:50 a beautiful futuristic topic explained here

[@torque350hp]

I can't help think having a wrist pin at this stage is just the easiest step in development to connect them.

[@AliusScitmelius]

yes, are the piston and crankshaft different material - at least they might be easier manufacture as separate parts and then should be connected in some way.

[@Ικαρος]

Amazing video and very interesting as always! Id like to know why the teeth of the gear box gears are in angle. Just a video idea. Again great video!!!

[@d4a]

Mostly to reduce noise. This is why you get that sound when you drive in reverse. The reverse gear teeth are usually straight.

[@patturk7408]

Yup. Straight cut gears do get noisy. I have fond memories of a straight cut M22 from the old days.

[@DanielFrost79]

​@@d4a Hence the sound of many racing gearboxes. No idea about you, but i love that sound. 😍

[@DrTheRich]

@@d4a Also reduced wear, constant contact means less vibrations to cause wear on the teeth.

[@CyberChrist]

@@DrTheRich Don't they also offer better strength?

[@klausbrinck2137]

If the SyTech-engine is used as a range-extender of an E-car, then its eventual vibrations are of almost no-importance at all, since they happen for a fraction of the driving-time, or even when the car is mainly parked...

[@flexairz]

With this you can use less toxic and easy exploding batteries.

[@flat6croc]

Not true, I wouldn't say. If you've driven a range extender car, the engine buzzing away can be quite intrusive, especially at town speeds. And as far as I am aware, the engine doesn't operate unless you're onboard / driving. Lots of reasons why you probably wouldn't allow the engine to run when the car isn't being fully supervised. Long story short, you'll be on board when the range extender is running.

[@klausbrinck2137]

@@flat6croc In Germany there´s a law, that you really cannot use the range-extender when parked, Cause the plague of all the exhaust gathering at one single place, wouldn´t be acceptable for all the people around it, walking the street... But the concern you expressed can be dealt with, an if the extender should burn hydrogen, exhausting anly water-vapor (I know, very unlikely, and I hate the odds of that trully happening, I hate the hydrogen hype), this concentrated-exhausts-concern of the german law wouldn´t be valid anymore...

[@jimmyc7269]

And if it runs at a fixed rpm and generate vibrations of the same frequency, then it would probably be much easier to deal with the vibrations.

[@klausbrinck2137]

@@jimmyc7269 ...the chance, that it then matches with the resonating frequency of ANYTHING else in the car, is virtually zero, u r right there !!!

[@petefluffy7420]

Nothing can excite more that an engine released just in time to be made obsolete.

[@c.a.r.s.carsandrelevantspecs]

Thanks for this fantastic video! This is the kind of engine technology that gets me excited for the future! Keep up the awesome work! 😃🚗🚙

[@haico1992]

Look interesting as a motorcycle engine at 2 cylinder coniguration. Short enough to be put in a maxiscooter

[@battshytkrazy156]

🆒️⚠️

[@ryukisai99]

I wonder if SY in SYTECH stands for scotch yoke? Also, after your previous video, it was already clear to me that opposing pistons would solve a lot of the rod design constraints.

[@MrRandomcommentguy]

I don't know, 700 x 518 x434 doesn't seem very compact to me... Compared to a rotary for example it is immense.

[@AntonioBarba_TheKaneB]

it's probably easier to make than a rotary and probably burns less oil, but we will see in a few years

[@d4a]

Everything is immense compared to a rotary? But s rotary can be immensely problematic? 😁

[@MrRandomcommentguy]

@@AntonioBarba_TheKaneB I think a Rotary would be ideal for a range extender because the inherent lack of torque isn't an issue when you only need the engine to spin a generator to charge the battery.

[@DrTheRich]

@@MrRandomcommentguy If you include overhauling your engine after every trip into account in the extended range calculations 🤣

[@TOONMAN200]

I'm concerned about max RPM on the Scotch Yoke Engine. As 35 year mechanic, I have seen many new engine types. Correct me if I'm wrong, I can see some future problems with this design. Remember the good old piston engine, we have now, is dependable, long life, and much more. People are trying to improve on a good thing like the receipting piston engine, witch has proven itself over 100 years. I just purchased 2 cars with 4 cylinder turbo charged engines, they are smooth running, 34 MPG. Call me old fashioned but I know a good thing .

[@concoat]

I believe Commer commercial vehicles made a similar diesel truck engine back in the seventies, sounded amazing.

[@gavinmcmillan6222]

The rod will be restrained from pivoting in a boxer configuration.

[@DrTheRich]

In a boxer configuration you loose most of the benefits: the rods now have a thin flat side again. and you have to offset the pistons

[@NotAnonymousNo80014]

@@DrTheRich Pistons are not offset in this Scotch joke engine type, but the rod also won't be restrained I think, it needs to stay light and will flex slightly in the middle part under one sided load.

[@DrTheRich]

​@@NotAnonymousNo80014 But his engine is not a boxer configuration. If you want this as boxer, you need to give every piston it's own yoke, giving it the same downsides as the inline 4 engine

[@hybridstoatdragon]

13:32 theres a major flaw in your model. If theres weight. There is inertia. If the rod swings. It will slide along the bearing.. hitting the wall.... and or the sliding piece in that model will SLAM either end and shatter the rod out a side. The single piston model you had before was stable. You destabilized it by doing this. The non boxer design or whatever litterally ballances itself horizontally so the rod pin to the piston head in their model works out to remain stable from what i can see. A vertical setup cannot handle that pivot point in the engine being there under certain frequencies. Itd explode into pieces and destroy itself at this point in your diagram

[@hybridstoatdragon]

I know from experience just goofing around with robotics and legos..... the yoke engine would be a pretty powerful electric water pump

[@aoyuki1409]

so an inline scotch yoke should use a solid piston-rod but a flat scotch yoke should use fluid piston-rod configuration

[@hybridstoatdragon]

@@aoyuki1409 BINGOOOOO

[@hybridstoatdragon]

I just realized why they added the pin. So piston HEADS can be removed way easier? Like if one goes bad you dont have to unbolt the entire assembly and go all the way down to the crank and remove the entire darn thing from the shaft

[@Dirtyharry70585]

@@hybridstoatdragon like the Subaru flat4, it’s a multi section block and heads. It still has heat problems if exhausts under the pistons just like Subaru’s failures.

[@halsnyder296]

I thought an opposed engine would be tailor made for this

[@illinoisstatetrooper2359]

How did you comment this 2 days ago the video has been out for 5 minutes

[@drift4yourself]

@@illinoisstatetrooper2359 i was also looking at this weird thing 😂😂

[@mattd1188]

I want to love anything half as much as this guy loves engines.

[@PikemanLures]

I never knew I needed it, but I really need a 2-Stroke, Diesel, Scotch-Yoke engine.

[@Lordosvk]

i would like to see two oposit pistons in one chamber. that would be amazing o---lll lll---o

[@oliviervanespen5047]

Napier deltic, look it up real nice, and big

[@IIGrayfoxII]

That does exist opposed-piston engines. One cylinder bore has 2 pistons that come together. It is just quite complex to make due to the moving parts required to have 2 pistons move together and apart at the same rate.

[@Lordosvk]

@@IIGrayfoxII its exist... Search more.

[@IIGrayfoxII]

@@Lordosvk I know it exists. Just pointed out the issues with it. It is complex as you have to some how transfer the power from multiple pistons which will have linkages or multiple crankshafts to one crankshaft

[@Lordosvk]

@@IIGrayfoxII gears mate :D

[@288gto7]

This is not an opposed piston

[@billh308]

Would you be able to speak if you were handcuffed?

[@Cugy_2345]

What?

[@zAvAvAz]

Wrong. Alfa dan was at this stage years ago and has statement of work and have tested big block 4 cylinder engines tested for extended periods of time. And also prove exactly what we all knew, great power increase potential from less cylinders of engines of equal size. Why then say " i don't think . . ." You have to know to say something like that. However it is very understood that you prefer the opposed 8 engine and why as shown in your analysis. Thank you tons for this video and your insight on the development of cool and amazing engines and technologies and science.

[@doo0T]

The other reason for a wrist pin may be that conventionally sourced pistons can then be used. Even if they are not an off the shelf piston, there's still plenty of piston manufacturers that can deal with customization. It will be a hell of a lot easier and more sensible than trying to forge the piston in with the connecting rod assembly.

[@danbenson7587]

It’s nearly impossible to align the two block halves unless they are assembled and cylinders bored as a unit...then disassembled. Second it is unlikely the engine expands evenly when col started. The piston pin allows more slop. Cheers