MORE Strength and MORE Balance - BETTER IN EVERY WAY Scotch Yoke Engine Technology

[@AquaMarine1000]

The piston offset force is still present with the scotch yoke. As the yoke slide oscillates from side to side with the downnward force of the piston, the force moves off centre with each oscillation as with the connecting rod design. Some large marine engines use va linear slide between the piston and the lower conecting rod to control uneven cylinder wear.

[@linuxman0]

It seems that the advantages and disadvantages sort of cancel each other out. However, I think the block that slides back and forth should be circular and that the ends of the slide should be rounded off. This would make a roller and would reduce friction.

[@mcanderson0]

@9:17 conventional engines have sliding friction EVERYWHERE... crank journals, wrist pins, cylinder bore, non-roller cam shafts and associated valve components, pushrods etc.

[@FairladyS130]

If the piston is fixed to the yoke then it will bear side forces generated by the sliding yoke, something not mentioned. If the piston is connected conventionally there will still be some side force and of course the advantage of simplicity is reduced.

[@cromo7743]

Scotch Yoke engine have side-thrust, similar do convencional engine (no difficult do see).The Scotch Yoke engine cannot be as shown at the beginning of this video, the conrod would tend to rotate, it needs something to limit this rotation to keep conrod in its linear movement. Offset is also interesting to use for the same reasons. From the images in this video, the Alfadan engine is not a Scotch Yoke, but both have sinusoidal movement and consequently there are no second-order vibrations.

[@zachthelen6049]

You still have the offset forces on the downstroke, and now it's producing sliding forces while doing it.

[@Mr986Willis]

The wear and stresses experienced by the sliding mechanism must be immense. At max revs you are looking at around 7 tonnes of acceleration forces acting on a traditional crankshaft, the components of this design looks much heavier and I expect the lower bearing surface of the slider to fail by fatigue.

[@v4skunk739]

There is a reason why it never went mainstream.

[@pazsion]

Yea, they just never built it

[@bdkw1]

Scotch yokes have been around since steam engines were high tech. There's a reason you don't see more of them. Except maybe alfadan, but I've yet to see anything more than marketing hype out of them.

[@Obamaistoast2012]

This design doesn't last long, we see it used in industrial machinery, it's only good for slow speeds.

[@peterklein4349]

@obamaistoast2012. Scotch yokes were much used in steam locomotives. Were the experiences that bad? Or were the RPMs still very low?

[@jlsracing997]

That rod would seriously increase the weight of the rotating assy. and the sliding friction would increase and there couldn't be any pressurized lubrication, just splash. The crank would have to be a built up unit also. Way too many negatives for my liking.

[@bbpetrov]

what a great invention that was found decades ago and never will go into production ...

[@leensteed7861]

why not try linear roller guides for the block? Can also make the rod strong by making it double ended for a twin piston

[@JohnPittaway]

I'm not convinced that there would be any real gain in using a Sotch Yoke. Aside from the drawbacks pointed out, much of the friction generated during compression & combustion will be translated into side thrust on the piston. This could be compensated for with a longer piston skirt, but this would generate more friction & likely require a longer cylinder to accommodate it.

[@sproutpits]

Would be curious to see this compared with offset cylinders.

[@asharma9345]

Rightly Said, I have heard that they are smooth but have some problem with the Balancing.

[@demoryross-vq6vo]

Hi good morning I'm from Trinidad and Tobago instead of the sliding y do u in put a Bering in side that square area

[@demoryross-vq6vo]

And make it lighter

[@Alrich-uo4rc]

I think they can add linear bearings on the sliding block.

[@redandgearhead]

Another factor is the thrust through the piston rod is maximized only when the angle between the piston rod and the crank throw is 90 degrees.

[@syndeko1632]

I have a question, what if you used a double crankshaft?

[@bentaxelrod]

I suspect all mechanical engineers have dismissed this design for 130 years. I’ll bet we all thought of it at some time or other.

[@dennisford2000]

A boxer with forged rods. Drive a prop , low revs . Run high compression and throttle it, tailor the ratio for 9000-11000 ‘ . Really high compression and use diesel. But boxer . Rods can be more stable and lighter webs or even a hollow triangle. Porsche has printed pistons much lighter than standard ones and P has lighter parts than most. Definitely either a forged or billet

[@reedsilvesan2197]

It looks heavy to me, which is still going to limit RPMs as with any engine. You can only build a crank just so strong and still be affordable.

[@jonathanparle8429]

ICE makers these days have certain "tweaks" that mitigate the reciprocating mechanism shortcomings such as offset connecting rods, etc. I remain amazed at the progress that ICE engines have made over time. When I learned to drive in the early 1980s, you could buy a brand new 4 cylinder medium sized sedan that might have produced perhaps mid 30 kilowatt power output per litre capacity and used around 10 litres of fuel per 100 km if you were going steady on the freeway. Today you can buy an inexpensive normally aspirated Korean medium sized sedan (for a fraction of the cost in relative terms taking into account inflation) that will produce around 56 kilowatt power output per litre capacity and use around 6 litres of fuel per 100 km on the freeway. Whilst there have obviously been significant improvements in ignition systems, fuel and induction systems and cylinder head technology, a lot of the credit for massively improved efficiency is down to better design, better materials and more precise manufacture.

[@jts4233]

I see it's marketshare in weightcritical applications like drones and aviation when the sliding parts are made from carbonfibres and bearings instead of square blocks.

[@nairettan]

I don't see a marginal difference for this to be actually replace regular ICEs. The cylinder wear is close to nothing and most of the modern engines are pretty refined, even single pots. Edit: The disadvantages really makes sense why it was never used widely.

[@hasimhodzic9649]

A roller instead of a square block, three roller set up with two separate bottom rails for strength

[@kurtminges647]

Someone needs to invent rolling piston rings and with graphene rapidly coming onto the scene as the new Ultimate cooler better than anything we've ever dreamed exponentially will make our world seem like a cream dream

[@TheDeadMan3848]

How about making the block move up and down, while the rod and piston are stationary. 🤔 😆

[@gregarakelian2257]

Yeah I’m an old rotary motor guy and I love the way that motor looks I think it’s gonna be something real special oh my by one so I can test drive it

[@andrerousseau5730]

The Ross Yoke crank mechanism is far superior with much the same benefits and having none of the disadvantages.

[@burtvincent1278]

I don't agree. At 90 degrees of the crank shaft angle there is still a side load on the piston and likely more severe than with a rod on a wrist pin. There may be an advantage if the scotch yoke was also connected to an opposed piston in a boxer arrangement or a piloting rod. Then you would have to deal with an alignment problem inducing more wear.

[@knickebien1966]

1:00 Porsche 944 head?

[@Rose-f2t]

It looks like the video creator has his/hers biases against the Scotch Yoke design. There is no reason that the "connecting rod" part of the Scotch Yoke piston has to e so thick. I does not need to be any heavier than the conventional connecting rod. Further, the lower horizontal part of the Scotch Yoke can be easily reinforced is it is an issue, because it doesn't seen to have any load. One have to understand that the conventional piston engine has been in continues development for more than 100 years, as the Scotch Yoke has been in use so few times. As far as the internal combustion engine goes, the 500cc opposed piston engine being tested in a Japanese car appears to have a good future 🙂

[@TheBlibo]

The main reason why scotch yoke engined are not in production today is there are no benefits. So you have lost the wrist pin but now you have made the piston rod assembly 5 times more expensive to make and you have failed to mention that the bottom of the rod will need to slide in a crosshead like large marine engines also increasing the cost. And just look at the beg end end of the rod in order for it to be rigid enough to work it will need a lot mor metal than in the rendering shown and that will reduce operating speed It's a non starter it won't happen It has been tried before and failed. And as for thermal efficiency the big end arrangement has little to no effect

[@jimmydcricket5893]

Good luck with that...

[@razvanjean]

No oil pressure.

[@charlesspringer4709]

This is a BS description. The cylinder wear is the same. Both systems experience a torque about the crank. Just draw a line between the center of the piston and the point the force is applied to the crank. The rest is OK but somebody made of that piston wear part.

[@sgottoboni]

The newer design may have more noise.

[@cikgu_tadika]

Bore x stroke overbore hirev hp speed overstock hi torgue

[@bramweinreder2346]

*brief pause

[@buildingracingvideos4714]

So they took piston to cylinder friction and moved it to a scotch yoke then multiplied it. The yoke is sliding friction with the added 1000lbs weight from combustion. Alfadan is not using a scotch yoke. They are crooks and don't have an engine

[@johnburns4017]

When he said at the beginning, _"reliable technology [ICE] compared to electric",_ I stopped looking.

[@michaeldemetriou1399]

The Bourke engine is a scotch yoke engine and it shakes like a shitting dog to quote the Dirty Garage Guy.

[@martin-vv9lf]

A flat 12 scotch yoke engine would be balanced. i doubt anyone would be dumb enough to fund one though.

[@claudio8955]

This works good on paper... It's false the piston has no side force

[@jhndijkman]

Its a non runner. Pun intended

[@leebonney2773]

Nothing more than clickbait. As others noted, this is a flawed (side forces, sliding friction) description of a very flawed concept. Curiously the Alfadan patent drawing is completely different to the CAD rendering. The crankshaft in CAD rendering would be production nightmare, (multi part assembly vs one piece for conventional), and no high pressure oil lubrication. Good luck to those who got suckered into investing in Alfadan.

[@georgedvorak9481]

This is no innovation, no "modern" design. The idea of the sliding rod is as old as the idea of the combustion engine itself. And that's the proof that it can never be better than the conventional design of the connecting rod, simply because after 150 years of the engine development it would already be in use for ages.

[@yzhao5873]

This is the one already dead of low efficiency for many year!

[@lennyelter1662]

Are you an engine manufacturer.? Why are you trying to get our opinion.? Why are you sure the bottom journal? So thin when it could be easily a lot thinker so let's chance of breaking question. Markten 10 x, Are you trying to kill this idea or is this an actual question? Who? To read more later. It's not what I said but close enough..

[@yuanpingzhao1323]

Already dead by lower efficiency. A bad design in the industry.😤

[@r1madbrit]

I like the concept but fine adjustments to avoid wear and tear may be necessary .