Water Skiing Explains LUBRICATION - This CRAZY Engine Proves It!
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- เผยแพร่เมื่อ 7 ก.พ. 2025
- There are 3 stages of lubrication - Full Film, Mixed and Boundary. Just like in water skiing, when the boat is not moving the skier is down in the water, which is the boundary condition. As the boat begins to move, the skier begins rise up out of the water, which is the mixed film condition. Once the boat is up to speed the skier is fully out of the water, which is hydrodynamic lubrication.
Why does this matter? Because piston rings operate in all three stages of lubrication on every single cycle, and the piston rings are the number one source of friction and wear in your engine.
In lubrication engineering, the Stribeck Curve indicates that friction and wear are higher in the boundary condition.
By rotating the liner, this genius engine design not only proves the stribeck is correct but it also massively reduces friction.
For more information on the rotating liner engine, check out www.rotatingli...
Or, contact Dr. Dardalis directly at dardal@rotatingliner.com
To learn more about Tribology, check out www.stle.org
For more information about piston ring friction, check out: • How Much DIFFERENCE Ca...
To learn about used oil analysis, check out www.speediagno...
For a deeper dive into the science of lubrication, check out my good friend Rafe Britton's channel @LubricationExplained
To learn more about Tribology, check out www.stle.org
Who is the @themotoroilgeek ? I'm a Society of Tribologists and Lubrication Engineers Certified Lubrication Specialist and Oil Monitoring Analyst (I've maintained both of those for over a decade). I also worked for Joe Gibbs Racing for 12 years as their lubricant specialist. During that time, we worked with Wix Filters (one of our sponsors) to test and develop filters for our race engines. We also worked with Lubrizol and Chevron-Phillips Chemical to test and develop oils for our race cars. Following that, I was the head of R&D for Driven Racing Oil. During that time, I formulated and tested over 50 products. We also worked with Cummins, Comp Cams, Oak Ridge National Labs and General Motors on various R&D products. Those efforts are recorded in peer reviewed white papers published by SAE International and ACS Sustainable Chemistry journals. I also own and operate SPEEDiagnostix, which provides used oil analysis.
For more about my Dad, check out this great video from @Stapleton42 • Lake Speed Shows Us Hi...
#motoroil #friction #tribology #diesel
WOW! Thank you for watching this video!
Based on the comments so far, here are a few points of clarification.
1. The piston rings are pinned like in a 2 cycle engine, so they do not rotate.
2. The unique cylinder seal features oil passages to lubricate the backside of the liner.
3. Here's a great video that features some animations of the sleeve valve engine th-cam.com/video/xdkgcXnWoxY/w-d-xo.htmlsi=tWrYLUbq8OF4NDO_
4. Dr. D, Jim DeGroot (who did the machine work and built the prototype engine) and the rest of the team behind the Rotating Liner design are looking for funding to build a complete Cummins 4BT to continue the development of the concept.
5. The friction reduction noted in the video is net of the friction required to rotate the liner, which shows just how much friction there is between the piston rings and liner near top dead center and bottom dead center.
why not just have rotating gudgeon pins ,that have small bearing's fitted to each end and the c clips hold everything in place.🦘🦘👌👌✌✌
Also because you have added more moving parts there's more friction and wear to worry about in the end of all things? cheers at least thats my 2 bob worth 👌👌✌✌🦘🦘
Lake, I believe a large portion of the friction reduction would be from the pistons themselves, not just the rings. The rings have combustion pressure holding them in contact, but there are large side loads on the pistons at anything other than perfect 0 degrees TDC. A likely reason the rings cause more measurable wear is the contact pressure is much higher; piston loads are spread over a much larger area.
Also, the relative speed of the moving surfaces is lowest at idle (larger portion of stroke in mixed lube condition), which is probably one reason the idle efficiency gain is so high despite loads being very low.
@@superspeeder The piston skirts are also a source of friction, but many studies have shown the rings to have a larger percentage of the friction that the piston skirts. To your point, rotating the liner reduces the friction from both the rings and the pistons.
@@themotoroilgeek thanks for confirming! I don’t doubt your info, I was just surprised the pistons weren’t mentioned.
BTW you’ve got a GREAT channel going here! I did Tribo failure analysis in a previous life and I’ve directed my replacement here several times to check out your content.
@@superspeeder Thank you so much! As I'm always "teaching" on this channel, the emphasis on the piston rings was intentional. This sets up a future video where piston ring and liner friction/wear are critical.
I have been building engines for over 45 years. Its amazing every time I see something totally different. Never to old for learning new things.
Thanks for another great video.
Thank you!
Only a true master knows what you just said. I’ve been in the business for 15y and have been shown over and over that you can learn something new from anybody - yes, even from the young guys. It baffles me how some people close their mind after certain time.
Just curious when are we going to start seeing your tests on Amsoil? In your Q&A video maybe 6 months ago you stated it was coming up soon. @@themotoroilgeek
i remember seeing this in 2015~ whenever i was researching ( friend's/coworker's and siblings idea and or them trying to get me to ditch the 8-71+mechanical+mag parts list/build i was doing for my 2-gen charger F8/green aka i had this before FF1-movie as a 4~yo/1995~ and or next door had a blue-car i liked-etc ) how to add modern-EFI/GDI/TT to a 1970~383 mopar, and yes my new build it's on my to do/add-list for my D8-hemi/re-pop-iron 540~ci ( with 4.3in-pistons liner's wonder if the bore sized vs piston's or high-dome/dish makes a difference and or block( i don't like aluminium casting's but this is my 2C and yes it's backed in testing like Canada hemi-shop/Indy-auto/TH-camr-channel 20~hp-gain-ect and also my time R&Ring Chevy's/vortec's/ford's mix'd-casting materials of the 80's-12-era and lifted head gaskets-ect aka milkshakes from daily/cold-starts-ect )/bearing materials and or liner's and or possibly to make the liner out of say T70-aluminium for heat-spreading/thermo-siphon/heat-sink and or anti-knocking+better-rings-sealing reason's, also from my understanding at least in bushings-piston's/rod's aluminium bearings are less likely to sease-up aka better materials and or additional DLC helpful but im not sure if that carries over to pistons+liner in full-film bearing-mode or a terrible idea ) combo but im not convinced that having it at the top and or split-head's is the best method as offies/bugotti's/dussenburges/aero-engine's sometime's doesn't have head-gasket's and or can run stupid amounts of boost and or knocking and the next fuse that fails is the injection cup's/aluminium in iron/steel-head or the piston's also aluminium fails before the steel/SS/titanium from heating or stress-crack-propagation or the exhaust valve/seal gets burnt if pushed way to hard more likely without being cooling like ( and add note that it helps if the valve head ect keep's the heating in the air/aka-power-pulse and or out the-pipes, instead of being put into the oil or water-loop )sodium-filled or barium/copper seat-materials combined combo
Your videos have taught me so much about how to care for my cars. Both are accords (I know, boring), but the way you present the information in a way that anyone can understand makes you an incredible asset to those wanting to learn more about how to get the most from a car.
THANK YOU!!!!!
Thanks for watching!
@themotoroilgeek i was always curious can you do an oil video on royal purple?
I'm a Brit and a WWII buff and I never knew the Napier Sabre had this engine technology.
I’m glad we could share something helpful!
Google Bristol Centaurus.
@rogerpearson9081 I'd like to see animation of how they were able to rotate the liners in a radial engine.
@@johngregory4801there are some TH-cam videos that show that
@themotoroilgeek Ty 😊
Science and common-sense feels like a guilty pleasure these days. Thanks!
My pleasure!
Yes. Now people put a DEI filter on reality.
@@themotoroilgeek That’s some serious dedication and engineering!
Probably not a good cost and weight trade for a car, but very probably a very useful efficiency boost in certain niche such as high duty cycle stationary engines such as a genset in remote area. I bet DARPa will love this.
@@richardkudrna7503Nicely put, sir. Think I may have to steal this...
Love your channel Lake. Love the history too. The sleeve valve engine was actually invented well over 100 years ago by american Charles Knight. His "Silent Knight" engines ostensibly eliminated valvetrain noise. The technology was licensed to many other manufacturers ie Napier which lead to the Centaurus and Sabre aircraft engines. The 24 cylinder Sabre eventually made 3500hp in the Hawker Typhoon and Tempest during WWII. I really believe lubrication technology of the time was this designs greatest downfall. My neighbor is currently restoring a Tempest V and has a couple of these Sabre engines. It would be great to get your input lubrication wise on bringing this monster back to life. I don't think anybody has actually heard one of these engines run in almost 70 years.
Awesome! Thanks for sharing!
The sleeve valve engine did not have a downfall. The downfall was on the whole large aero piston engines that were replaced by the gas turbine. Sleeve valves were used in a commercial basis all the way in the 80's. If you meant the Sabre specifically, the Sabre was very expensive and loud, and had very limited advantages compared to the Bristol sleeve valves. But if it makes you feel better, Rolls Royce and copied the design in the RR Eagle, with saw very limited production. The Sabre had a difficult life mainly due to its sheer complexity, and the Brits managed to get the issues under control by 1944. Perhaps a bit too late. The main problem of the Sabre was that the Hawker fighters that was used on were too heavy and too ugly, so the Spitfire completely overshadowed them. Cheers.
@@dimitriosdardalis6658And , if I am correct , Sabre engines needed to be on temperature before starting . ..... Unlike normal piston engines.
The Knight sleeve was not the same as the sleeve used in the Napier Sabre and Bristol radials. Those engines used the Burt-McCollum single sleeve.
@@andyharman3022 Indeed, the knight was a twin sleeve with no rotation which had terrible friction characteristics. The single sleeve was co-invented by these two fellows, so they typically use both of their names simultaneously, I think one was in the USA the other in England.
There is a lot of controversy within the rotary community as to mineral oil and synthetic blends.
Could you please do a video explaining your take on this conundrum.
I personally am using full synthetic and haven't had an issue.
As a heavy duty mechanic for 40 years, I appreciate your videos.
Keep up the good work.
Thanks!
Would also like to know if this has any credibility. An old thought was that they didn't know if a synthetic oil would burn so they were being safe. But much 2stroke oil is ester oils sometimes from castor beans especially back in the old days. There are synthetic ester oils and ester based modern 2stroke oils. I don't know if a pao will burn easily and I do know that it's legal to call a mineral oil synthetic in USA if it's been hydrocracked or created through perhaps an even more involved lab process like the gas to oil base stocks. So a lot of this discussion may have a lot to do with if you're synthetic oil is or isn't mineral oil, because in America it very well may be that it is mineral oil with other base stocks added to it. But if a pao oil burns fine, could it be that the rotary guys are just being a little too cautious? And are there more important things to watch out for like additives known to cause detonations?
WOW!!!! The golden age of aerospace research is still teaching us youngins to this day! Thanks for that, always nice to learn something new.
This one was fun!
This guy is a brilliant chap, he is explaining many complex mechanics in little time. Which is very hard to do. 😊
Dr. D is super sharp!
Lake falling in love with all that tribo tech. Awesome engine for sure.
I’m a sucker for Tribology!
This idea really warms my engineer heart.
I’ve known for a long time about the extra wear near the top, and attributed it to the extra pressure. That it comes from the collapse of the oil film is a revelation. Great to learn that.
Thanks. Kudos to Dr. D and team!
Thanks! I've been waiting to make this video.It's foundational knowledge for understanding lubrication.
Same, well, kind of.
Noticed increased wear at the bottom as well and somehow always thought that it's a trait of offset crank/offset piston pin engines due to some strange inertia-physics deal kind of stuff.
It's so very obvious what happens though, astonishing nobody around me or myself noticed the right answer is right there and even extremely simple and outright intuitive.
Very cool! So many people are still working on IC engines, improving efficiency which improves fuel mileage and reduces emissions. Money better spent than on EV technology.
Agreed!
Fascinating. You've reduced the start-stop friction of the friction ring within the cylinder during each cycle. You've also reduced the static friction of the piston skirt under high load on the cylinder.
wall at the top of the cycle. Both of these are under load.
But you've increased the surface area for friction in each of the rotating cylinders, but they typically are not under load. At least not much load. But you do have drive losses in the gears. The gear train and the surfaces the bearing surfaces of the rotating cylinders.
I am surprised that the sustained losses due to internal friction can be reduced by 10%.
I'd really want to take a look at the experimental system design and the data.
Also, that rotating head gasket seal needs to last 200, 000 mi under varying loads with high reliability.
Static Head gasket took a long time to get there. And sometimes manufacturers blow it. Another place for development. Great work.
Hook em Horns.
The old sleeve valve designs solved the moving head seal issue by replacing the head with a "junk head" which was basically another piston (complete with rings) fixed in the top of the cylinder.
As a fan of sleeve valves, I love that this is being pursued. Bristol engines found out about the higher efficiency with their sleeve valve radial engines, but at the time it was put down to reduced pumping losses and more efficient airflow with the sleeve valve design.
I see this rotating sleeve technology as opening the path to metal composite liners finally- imagine the friction reductions and thermal stability improvements in an engine from say a ceramic/ metal rotating liner?
I have an old diesel engine in my tractor with dry liners that are a simple sliding fit in the block. They don't rotate but are sealed from combustion with some interesting tricks.
Part of the reason of the improved sleeve valve efficiency was the higher compression ratio. But friction was a big factor as well, probably greater. Ricardo and Bristol knew, but they did not want to emphasize that in order to reduce confusion when they were trying to sell the concept. At the end, it is the friction part that survived into the 21st century.
Lake, you never cease to amaze me with your content! That is game changing tech that seal on the top of the cylinder is really neat
Hope all is well your way!
Andy
Thanks!
This principal is not new, but certainly new to this application. Mechanical Hydraulic Control systems (fancy governors) used this decades ago to minimize sticking of the pistons and reducing "hunting" in the system. Truly brilliant application in this case!
Thanks for sharing!
The Greek is a genius!! Well done Demetris
Dr. D is awesome!
I learned something new. High Speed moving parts create full film lubrication which is the most efficient lubrication.
So lugging an engine around at near idle rpm to save fuel kills it faster.
10% increase in fuel economy is massive. An extra mile per gallon for a long haul diesel that gets 10 mpg cruising with a 500 gallon tank means that truck can now go 500 miles further before needing to refuel.
And save a lot of money in the process!
@@dimitriosdardalis6658 It's not just the distance, the logistics of it too. You can skip a state, fill up in a cheaper state, or one with better truck stops. Small quality of life improvements, means higher morale, higher profit margins, which ultimately lowers prices for consumers. It has knock on effects that we don't even consider.
Everything will be electric in 10 yrs. 🙄🙄🙄
@ Yes, including the generators.
@@hotrodray6802 Very doubt full. Within a city, maybe; out in the country, hell no. And definitely not OTR trucks, not unless quick swappable battery packs become a thing in the US.
The single-sleeve valve didn't purely rotate. It rotated and reciprocated in an elliptical path. The important thing about it was that the liner never stopped moving, so there was always relative motion between the ring and liner. But that was only a secondary benefit of the sleeve valve. It improved engine breathing and eliminated the hot-spot in the combustion chamber caused by the exhaust valve. Sleeve valve engines could have higher compression ratios and total freedom in combustion chamber design. Their lubrication requirements were not aggressive because piston thrust on the cylinder wall was borne by such a large surface area that unit loading was low. Manufacturing a good sleeve was very difficult, though. Early test engines had a problem with the sleeve going out of round and sticking in the cylinder. The problem was solved by improving the finish grind process to eliminate residual stresses.
Pause on the graph at 10:50 It's weird that the friction is slightly lower on the BSL (presumably Baseline engine) with the 15w40 oil vs the 10w30. The RLE (presumably Rotating Liner Engine) shows about 20% decrease in fmep.
Higher viscosity oils tend to have lower friction at low engine speeds and high load. The thinner oils have lower friction at higher engine speeds.
@@themotoroilgeek Thicker oil film to get out of boundary lubrication....
That engine modification was so cool.
Absolutely!
Always great to hear complex technology explained in terminology that can be understood by someone with average abilities.
I’m glad it was helpful.
This channel just keeps getting better... Science and facts!!
Thanks!
Another indirect discovery from WW2 helping us in 2025. The Napier sleeve valve engine was massive and an awesome engine design.
Agreed!
I worked on one a Willy's knight in a car
Also check out the Napier Deltec triangle motor ....
but at what point is micro jet-shafted power makes more sense as much as i like 440's the other in Chrysler 518?-engine ( 90-250 hp for recharging batteries using kerosene/diesel and letting gasoline pumps die-off eventually ) makes more sense in a hybrid version my 2C
as hoover/other's pointed out turbocharged or v8's have lot's of little details/parts and or emissions can be challenging and renki-cycling is simpler generally speaking it's the materials science that's harder and or marketing
If you mean using a gas turbine, to run a generator, it probably becomes viable if your intended output is more than 300 kW or so. Small gas turbines have poor efficiency for various reasons.
Mind blown!!!🤯
It's amazing what can be learned just by watching your videos!
I need more, I'm addicted to tribology.......🤪
More to come!
Simply amazing... I forwarded this to my brother. He has worked in MiT's Sloan Engine laboratory
Thank you!
That's impressive to gain efficiency while increasing the demand from the motor. As in turning the cylinders vs not.
It just shows how much friction is in the ring and liner interface near TDC and BDC.
@@themotoroilgeek Lake are these set up with ring tension closer to the old standard or new low tension ring standards ? Could the rotating sleeve allow a return to more ring tension and reduce blowby and oil burning ?
@@MathewPollard-vj4uq These are standard tension and size rings.
@@MathewPollard-vj4uq The only modification to the rings are reliefs at the end gaps to allow pinning them.
man, the boat and water thing clarified my mind, tks so much!!!!!
It is the analogy for lubrication.
I don't know if I agree with this as you don't see that much wear at the bottom of the stroke . I feel that there is more wear at the top because on the power stroke the pressure is the greats at the top which forces the rings out more . Buy rotating the cylinders helps to reduce oval wear which is common to see . Also spinning the rings in the piston would cause premature ring land wear ?
I'm also wondering about ring land wear. Not to mention maintaining reliable lubrication of sleeve to block and gear drive teeth. Lots of questions still to be answered.
@@davidg3944 The rings are pinned.
The rings are pinned, but you are correct, there is a lot more wear at the top of the stroke. The oil control rings wear the same on both ends though, and the oil control rings generate a lot of friction at both ends of the stroke.
I have been rebuilding truck and tractor engines since before you wear born . I always believed the cylinder top end wear was compression related ,
Today I learned SOME THING NEW , thank you chap much appreciated .
I'm glad it was helpful.
In a way it is if the crank was driven from the crank end with open valves. the oils viscosity would be high enough to maintain a boundry layer.
When combustion occures that creates a downward force and the crank resists that force due to the resistiance of the vehicle, this is a upward force. Due to the angle of the crank those 2 oppsing forces push the piston to the side and overcome the viscosity of the oil.
By rotating the liner you are reducing the ammount of time the force has on a given area of oil.
Without compression the engine could likly do the eqivalent of 1 million miles and have basically no wear.
@@jamessssssssssssssssssssssssss Close enough ... As far as the piston skirt is concerned. The rings are also a big factor, cylinder pressure gets behind the rings to push them against the cylinder in order to seal. This is also a major friction source that the rotating liner comes to the rescue. Cheers.
This technology should be of great interest to aege diesel engine users such as railroads and shipping lines. The savungs in fuel for a 50 MW 2 stroke diesel or NG 4 stroke engine would make this technology worthwhile.
That's so cool. But how does the outer portion of the liner (the part inside the engine not with the piston in it) and the sprockets that turn it get lubricated?
The seal at the top has oiling passages that provide oil supply to both.
@themotoroilgeek thank you for clarifying
What a great way to start the morning, awesome video!!
Glad you enjoyed it!
I'm not sure how I found this channel, but, Lake, I'm so thankful for you doing this. The human mind is so interesting, I've never thought about oil, it's just something I do when my car tells me to do it, but now with just a tiny bit of knowledge, I can't get enough information. I'm utterly fascinated, and am now considering going back to school to support a new career! Changing my entire life because of something that, just a week ago, I didn't think anything of. Thanks for doing what you do.
Have you considered reaching out to the guy from Project Farm? I think you'd both benefit from each other (TBH, he'd likely benefit more in terms of knowledge, but he has millions of subscribers, so you'd greatly benefit too).
Thank you so much! Tribology is an amazing field.
Remarkable!
Now…
-Will Automotive and other engine manufacturers adopt it?
-Might they not adopt it because it might interfere with existing parts suppliers or other pressure?
Great question!
Seems many great ideas cocerning ICE engines in the past have unfortunately been overlooked for many reasons. Mainly money ❤ great video.
Thanks!
Excellent Tec.
Adolf.
10%!! That gets the mind working. Thank you for sharing.
Hello from Indian Trail, NC! 👋🏻
Didn’t realize you were that close. Small world. Thanks for sharing this. Fascinating design. I’m blown away by the seal to the cylinder head. I have so many questions about the engineering of this design, but it’s really a monumental accomplishment they have managed to get a working prototype. The engineering that has gone into this is wild!
Howdy Neighbor!
Please visit the website for more information on the seal.
Very interesting to get real data on this effect vs theoretical .I have an idea/vague memory that governor shafts on old style diesel jerk pumps rotated to give a friction/stiction free operation of the rack to avoid erratic power fluctuations. Same thinking as this engine.
Awesome! Science and its practical implementation!
Thanks!
Dr. D Is a fascinating man
Indeed!
Thank you, Lewis/Gilbert, for another good vid.
Glad you enjoyed it
So - fully rotating Sleeve valve improves all wear properties, - model Aircraft engines of this type exist - the engine rotates at half piston speed - facilitating larger props on a small nitro engine. Those aero type engines - sleeves are a total upper cylinder cap needing no annular seal in the head ("just" a set of port seals)
- 10% paracytic losses reduced, sounds great (knowing that Otto cycle can only be ?? say 45% efficient thermodynamically (using "pump gas")... sad part about many "revolutionary" systems, they introduce complexity and further losses - usually negating - incremental gains - additives on the other hand (environmental issues rise).
Thanks for sharing!
Back in those days they were truely the innovators and creators of what we have today. They also made and used a (Rotating Radial Engine) that the cylinders spun around a stationary crankshaft, essentially acting like a spinning wheel with the cylinders radiating outwards, unlike a "stationary" radial engine where only the crankshaft rotates within a fixed cylinder block
For those of you wondering why any of this matters, realize that engines today are obsessed with ring friction. That’s why all these modern engines are burning tons of oil at 150k, they have all moved to very thin, low tension rings, resulting in big problems with carbon buildup causing blow-by later in life. We’re at the point where cutting ring thickness in half matters significantly.
Same reason 0W-7 oil is now a thing, designers are chasing fractions of improvement, typically to the detriment of long term durability.
If they can get a net reduction of friction with this design this is not just for longevity, it’s for overall efficiency.
As will all new designs, the biggest hurdle will be overcoming 125 years of previous development. Still, it never ceases to amaze me the creative variations people are constantly coming up with on engines. Wild!
You are spot on!
I love the concept that can make engines run much more efficiently, if this evolves into a production engine with a revolving cylinder they could expect higher mileage engines and less fuel consumption; nevertheless, more parts equals more failure points. I hope to see this design take off.
I hope they get to build a full size prototype to test.
Best yet, Lake! Many thanks!! And thanks for the links!!!
Glad you liked it!
I’ve been watching since tik tok got deleted this is amazing please never change
Thanks!
Oil pressure/fluid bearings/hydrodynamic friction illustrated… I always remember being a little kid and my grandmother boiling something in a pot with the cover on. I believe it was revereware and the fit was just right you could grab the handle of the pot top and spin it and it would keep spinning completely frictionless, it was suspended on a cushion of steam. Also air hockey is a fluid bearing of sorts.
Thanks for sharing!
Dmitri, long time no see! From a former classmate and SAE buddy! Hook 'em. .
Every time Total Seal is brought up, it reminds me of how it all started in this little warehouse off of W. Mountain View Rd and 22nd Ave behind a electrical utility yard. Bob, their manager helped me build my first V8. If only Joe Sr could see it now.
I love this,very technical/scientific information and very cool technology
Thanks!
Love it! Silly idea that'll break down @ head gasket & seals long before prolonging engine life. Trying to limit wear instead of re honing every 300K miles....
Very cool idea. Great video. Thank you as usual!
Thanks!
Very cool concept!
What a game changer! Awesome idea Lake! Three things interested me: how is the liner motion lubricated with regards to the block; how much power is consumed by the liner drive system and how liner cooling is achieved (oil cooled or a combo of oil and liquid). Loving these videos! 👍👍
Thanks! There are oil passages in the seal that direct oil to the backside of the liner, so the liner is both lubricated and cooled by the oil flow.
The 10% gain is net of the friction to rotate the liner, which shows how much ring friction there is at TDC and BDC in a normal engine.
@@themotoroilgeek Thank you Lake. I thought that might be the case for cooling. That net loss of friction makes a huge difference!!
The rotating liner may also be an advantage for diesels too in helping prevent liner attrition from coolant cavitation.
I'm looking forward to your next video.
@@steveross2797I don't think this liner contacts coolant in any way. It's more of a sleeve in an existing bore.
@@rotorhead5826 It's cooled by oil flow around the sleeve rather than liquid coolant as a conventional fixed sleeve would be.
Thanks for your videos! You have some great content, and I have found your science and chemistry-based approach extremely helpful. Would you ever consider doing a video or series on two-stroke oils for powersports, which ones are better, and how to tell the difference? I know many of us would find that very beneficial, as there are not many quality videos on this topic around. Thanks in advance!
2 stroke oils are on the agenda for this year.
@@themotoroilgeek Fantastic, I will be on the lookout for that video! Thank you!
From a consumer standpoint, with well-maintained good-quality engines lasting 300k miles, which is basically the life of the rest of the car, what benefit is there? I see a future of endlessly replacing the seals, which will require a full engine teardown. Remember that this thing has to be 100% watertight, too, so it can be cooled while submerged and spinning. I think there will be too much to overcome for it to be viable for the consumer market. Super cool idea, though.
Application is heavy duty engines where fuel economy is critical. No need to be watertight.
Really interesting project. Sealing the combustion and coolant long term seems like the real challenge. I find it hard to believe there is that much friction in the ring pack hitting tdc and bdc stationary to counter the energy required to drive the liner. Seems like you would pick up enough extra friction just from constantly rotating the rings in the piston at liner speed to contradict any friction losses from the rings starting and stopping. Also I noticed they were only testing this at barely off idle speeds. Can’t wait to see data at 2500rpm and full load.
It just goes to show how much friction there is in the ring package!
This is so cool, thanks for sharing. I have considered this process before as a thought experiment but had no idea how to actually implement and test it. 10% fuel savings is huge.
Thanks for watching!
Awesome idea! Human creation has no bounds!
Absolutely!
Do we need to pin the rings? As they might stick to the bore and spin in the ring groove at some wear point of this system.
Good point. The rings are pinned in order to keep the endgaps at the optimum location. But they may not have to be pinned. The gas pressure forcing them down will prevail over the rotating force. However, the oil control ring would have to be pinned. At any rate, pinning the rings will reduce oil consumption, so no reason not to do it.
Question: what about the created friction between the liner and the cylinder block? How is that being managed? Additionally, I would assume there is a parasitic power loss to create the rotation of the liner...how does this affect the 10% savings? Is the net still the same? In other words...is the juice worth the squeeze?
The results reported are the net friction gains, so the amount of friction reduced in the ring to liner contact more than makes up for the added friction to rotate the liner.
Missing engine oil being at its designed operating temperature. Running at the right oil temperature is very important to wear and hydrodynamic lubrication . Must be formulated into equation... I Like this video and presentation. Very interesting.
We are using standard 15w40 oil for diesels.
Really awesome video. I learn something new every video. It's probably in the works, but could you do a video on oil filtration comparing OE to a few aftermarket filters like WIXs, Purolator Boss, Amsoil....ect. Im sure with all the oil sampling data you have, there has to be some sort of trend to best filter.
Oil filter videos are on the way
Interesting, 10% (ish) fuel savings is no joke. Are the big auto manufacturers looking at this or is it just something for a fleet/trucking market? How is the reliability and maintainability of the rotating cylinder engine? Adding more moving parts is always a tradeoff. BTW, adding the screen graphics text was a big help, Dr D spoke very quick for my ears to pick up everything he was saying.
I suspect stationary power generation and trucking would be the early adopters of this technology.
i find his numbers unbelievable but it is super cool
Remember, this is science, not speculation.
How much frictin and wear does the liner create to spin plus the drive power and gear to turn it?
The Three Stages of Lubrication: Dinner, Wine, Jewelry
The sleeve valve as it existed in the Napier Sabre most likely caused more friction problems along with other problems. If I remember because the sleeves moved partially with the piston it cause uneven wear in the sleeve and there is obviously the problem of lubricating both sides of the sleeve. This other design overcomes it in some aspects by having the sleeve move multiple times the speed of the piston, but the complexity might not be worth it.
The origins of the sleeve valve are to overcome the problems of valve float at high rpm, and deal with the inherent restrictions of engine valves such as the change in air flow direction. As technologies such as the liquid filled valves emerged the need for sleeve valves declined, although I would like to see them used in a modern vehicle.
Thank you Lake
I had never thought of a rotating cylinder - something from the aviation world? Very cool - tolerances have to be something like a plunger in a lifter? Sounds like a very specialized lubrication setup.
I had that same ski when I was young.
Too cool!
I am having a hard time understanding how the friction losses gained from this system overcome the losses of driving/rotating these sleeves. The additional parts and complexities added will increase weight and cost. So how much net benefit is there to the actual consumer?
I was wondering something similar but as I watched the video I thought this was at the university of Texas. If they are studying Tribology I think it was just being used to test and prove theory and not something that would ever be put into production.
It would have a greater benefit In something like commercial generators, pumps etc. Anything that is stationary where weight wouldn't be an issue. If they are seeing an approximate 10° gain on the test engine with all the new rotating parts then you should see the same gain on any equipment that has this design. The initial cost could be a major factor though.
Once it's in production it's probably not that much more money, and weight is probably not much either. As this is mainly for comersial engines they'll make back cost quickly, and reduced friction usually means less heat so the whole package with radiator might actually be lighter.
I too do not see how rotating the cylinder makes any difference in the friction. How does the oil stay on the cylinder wall any longer when the piston is still moving up and down and the pressures are still while the cylinder is at the top end of the bore.
It seems like a cool idea in concept. Helping to reduce wear in a critical area. The question being, will this new system's reliability out last the common failure mode which is the cylinder seal.
I suspect, especially looking at how complicated it is to seal it. No. But I do enjoy a good engineering experiment!
Fascinating. Thanks!
Glad you enjoyed it!
Interesting design
I think so too!
Don't forget that Napier also made the Deltic engines - triangular orientation of cylinders with opposing pistons in the cylinders.
Napier made some cool stuff!
I love this kind of science……schools missed the boat on this fun stuff
Thanks!
Do gas vented pistons increase your seal and or lubricant protection at top dead center.
Gas ported pistons due increase seal, but they also tend to increase wear.
That's very impressive.
That's super cool. Something that should be adopted for sure!
Thanks for watching!
this is so cool! I wonder when it will be available in natural gas generators
That would be a great application!
I wore out the outside of my lines at 20K miles but the inside of my liners looked great!
Heat transfer to block ...One overheat and its a wrap. How does the fire ring in head gasket seal ?
How is rotating sleeves lubricated?
Sleeve valve were made long ago because advanced metallurgy for exhaust valves and seats were an issue.
Also sleeves had oil consumption and carbon clogging issues .
I fixed a willys knight motor in a 1920s Brewster car made in NYS.
Good idea 💡
Lot of information.
But, like the way it was explained
Thanks!
The concept is inspired by historical sleeve valve engines from WWII
Im not a mechanic or engineer, but wouldn't the "sleeve" rotating as the piston moves against it increase pressures/friction or temperatures? Fascinating video.
Thanks for watching. The rotation creates relative motion between the rings and the liner, which creates a lower friction oil film. Think about the water skiing analogy.
This is very good and I paused the video to study the data and chart, but it might have been helpful to do your own follow-up at the end to translate Dr. Dardalis' technical explanation into something slower and easier to understand.
I'd also like to understand why the RLE test ended at 7 bar IMEP and why the data shows the weird FMEP drop and spike at the end.
The spike at the end is due to temperature variations of the tests. The IMEP limitations are not related to the rotating liner concept but to the fuel injection system and the lack of a turbocharger. We will run the engine under higher IMEP in the future.
Steve-O’s super smart brother.😊
LOL
What an awesome idea. Lower friction, more power and less wear. I wonder if it changes the exhaust note?
Good question!
Maybe you can do a segment on break in oil. I have a flat tappet cam engine that I need to break in.
Check out the Total Seal channel for that video.
Great content. Thank you
Glad you liked it!
This is Awesome stuff!!!
Thanks!
I'm guessing that he had the sleeves geared to the crankshaft, but did he estimate whether there was an "optimal" rotation speed of the sleeves, relative to engine speed and load?
That’s something they are still investigating.
The Bristol Hercules radial engine was the most successful of the sleeve valve engines. There are a number of them still in use in restored warbirds.
Reducing friction by adding more friction?
Yep. In this case it is a net 10% gain.
@themotoroilgeek %10 gain for how long?
@@AnubisSolvangcontinuously
@themotoroilgeek obviously you missed the point of my question. Yes continuously. For how long?
@@AnubisSolvang It should be for the working life of the engine, but long term testing would need to be done to validate that.
Really interesting engine, it will be fascinating to see the difference in friction. But the complexity and the power loss from the rotating liners I think it will make hard to justify this system.
Interesting concept. Is there anything lubricating the back of the liner against the block? Does the 10% advantage factor in the energy needed to rotate the liners?
Seems like more oil shearing also , but I'm ignorant lol
The 10% friction reduction is net friction, so that includes the friction loss of rotating the liner. If you look at the stribeck curve, the continuous rotation would not add much friction (hydrodynamic and low speed).
There is pressurized oil lubricating the exterior journal bearings of the rotating liner. Lake answered the second question.
@themotoroilgeek Thanks, Lake. Appreciate the clarification.
Those top liner seals would probably come in handy in a rotary engine or pumps. A big problem for those engines is how to seal the rotor against the sidewall.