By on July 14, 2013

waissi1a

Though much of the attention paid to new automotive drivetrains recently has focused on hybrids and battery electric vehicles, the simple fact is that internal combustion engines are going to be around for a while. They’re still teaching the old dog a few tricks and even coming up with a new breed or two as can be seen every year at the Society of Automotive Engineers World Congress, in Detroit’s Cobo Hall. There is always at least a handful of inventors and promoters at the SAE confab showing off their new engine designs. Maybe it’s the romantic idea of a lone inventor trying to prove his concept in the face of a skeptical world, but after looking over the convention program, the booth that I most wanted to visit was that for the Waissi Engine, the invention of Gary Waissi, an engineering professor at Arizona State University.

waissiengine

Note: The SAE World Congress was in April. Publication was delayed while I corresponded with Professor Waissi and clarified some questions about his engine.

Waissi’s new engine is an opposed piston configuration that uses conventional head, valve and combustion chamber designs. What’s different is that the Waissi engine has no connecting rods between the pistons and the crankshaft. Instead, the pistons push directly on what Waissi calls a “crankdisk”. The engine’s output shaft has a large journal mounted eccentrically on the shaft, with a bearing ring that spins on the journal. The outside surface of the bearing ring fits into a landed grove at the bottom of the piston structure. When the piston is pushed down during the power stroke,  the downward motion of the piston causes the crank to spin because of the offset as the bearing ring rolls under the piston landing. Each piston has an opposed twin which then spins the crank disk another 180 degrees to complete a revolution. The two pistons are attached to each other via steel rods, which keeps them timed properly. In his latest design, Waissi has replaced the rods with solid plates.

Waissi's latest design, which will be the basis for the prototype that hopefully runs.

Waissi’s latest design, which will be the basis for the prototype that hopefully runs. Stiffer solid plates have replaced the steel rods that keep the pistons attached to each other and properly phased.

The advantage over a conventional connecting rod engine is reduced friction, reduced weight, and reduced complexity. For a four cylinder engine, Waissi’s piston/crank assembly has only five moving parts vs nine for a standard engine. Fewer parts means lower cost.

The proud inventor.

The proud inventor.

Many of today’s new engine designs are focused on reducing friction. The Waissi engine has nine bearing surfaces compared to 11 for a standard motor. Four of those nine surfaces, where the pistons meet the crankdisk bearing ring, are rolling surfaces which have significantly lower friction than the sliding surfaces in a conventional engine’s piston rod big end bearings. Because the two pistons are fixed to each other there is also reduced friction from pistons rocking and then scraping the cylinder walls. Waissi calculates that total friction will be 50% of that of a conventional engine.

The "crankdisc" that is at the heart of the Waissi engine design

The “crankdisc” that is at the heart of the Waissi engine design

Dynamic balancing is also simpler because there are no rocking connecting rods generating secondary forces. Waissi claims that because there are no connecting rods, the piston acceleration and force curves follow an ideal, perfectly sinusoidal path, something that would only be possible in a conventional engine if the connecting rods were infinitely long. That should result in a smoother running engine.

Fewer parts mean cheaper assembly.

Fewer parts mean cheaper assembly.

The concept is not fuel or cycle dependent so two-strokes and diesels are possible. Other than how energy is transferred from the pistons to the output shaft, everything else works the same. The concept is based on a two cylinder module, so 4, 6, and 8 cylinder (or more) versions are possible by just stacking modules with the correct phasing to maintain dynamic balance. The four cylinder’s two modules would be phased 180° apart, a six cylinder would have them 120° apart and an eight would have the modules phased 90°. As with Ecomotor’s similarly modular OPOC engine, or with Chrysler’s aborted Gemini engine developed by Roush, cylinder deactivation could  be effected by a clutch between the modules, allowing a module to be completely shut down, unlike in a conventional multi-displacement engine which still has frictional and pumping energy losses from the deactivated cylinders.

waissi2

The crankdisc actually rolls under the pistons. Rolling friction is reduced compared to the spinning friction of a conventional con rod’s big end bearing.

Waissi is building the first prototype now. He hopes to have it running by the end of the year and have test results to present at next year’s SAE convention. He was displaying what he has so far at the World Congress to drum up interest and possibly funding from larger companies. The SAE World Congress did name Waissi Engines an “Industry Innovator” so he’ll probably get some attention. There’s no reason why the engine shouldn’t run. With today’s design software, if it works in the digital domain, you can be pretty sure that the first prototype will run. How well it runs and how far Waissi goes with the idea is another question.

You can see Dr. Waissi demonstrate the basic mechanics of his new engine design in the video below.

YouTube Preview Image

Recently, Professor Waissi made a demonstration about his invention to an unnamed large corporation and he graciously made that presentation available to me. You can download the Powerpoint file here. Another Powerpoint presentation, showing the Waissi engine’s simplified (compared to regular motors) assembly procedure, can be found here.

Ronnie Schreiber edits Cars In Depth, a realistic perspective on cars & car culture and the original 3D car site. If you found this post worthwhile, you can dig deeper at Cars In Depth. If the 3D thing freaks you out, don’t worry, all the photo and video players in use at the site have mono options. Thanks for reading – RJS

Get the latest TTAC e-Newsletter!

76 Comments on “The New Waissi Engine, Pistons But No Connecting Rods...”


  • avatar
    kosmo

    Very interesting. Keep this kind of stuff coming!

    • 0 avatar
      NMGOM

      Kosmo – - –

      I fully agree! This is the sort of stuff that progress is made out of, whether this particular design succeeds commercially or not.
      Why? Because of spin-off thinking. Some aspects of this invention can easily encourage new ideas for designs within already-existing (or previously patented) engines.
      We certainly need more of these “out-of-the-box” efforts in the ICE world, especially since fuel mileage and CO2 emissions are now so greatly emphasized.

      ——————-

  • avatar
    mr.cranky

    So, where’s the benefit of using it?

    Reduced fuel consumption?

    • 0 avatar
      dolorean

      I would think so. With lower weight and lower amounts of frictional space, it should be rather efficient. Question I have is, would this engine be mated to an Air Cooled or Water Cooled System?

      • 0 avatar
        Quentin

        Either would work, IMO. You can still have water jackets around the piston bores in the block and you could still have cooling fins on the block. I am not super familiar with air cooled car engines, but I don’t think the piston, crank, conrod setup is any different in them versus a water cooled.

    • 0 avatar
      Quentin

      Less friction means that more power is transferred to your transmission. That is good for fuel economy and performance.

    • 0 avatar

      Lower friction should yield better fuel economy. Fewer parts and a simpler assembly mean lower costs than with a conventional engine.

      • 0 avatar
        Piston Slap Yo Mama

        Lower weight and less rotational mass also suggest an engine that’s willing to instantly rev, and perhaps rev to higher rpm’s.

        A decade+ ago I read about an engine that had articulated connecting rods, i.e. rods with a joint in their center and a mechanism that could vary the angle of the connecting rod so that piston speed could be kept at optimum efficiency irrespective of engine rpm. Then I never heard about it again. This looks a lot more practical.

    • 0 avatar
      davefromcalgary

      Boxer 4,6,8 motors are inherently balanced, like an I6, requiring no counter rotating balance shafts or weighted crankshafts or heavy flywheels to provide smooth operation. So, that would save weight and complexity (parts). Further more, boxer motors are wide and flat, which generally helps to lower the center of gravity but I have a hunch this motor would be narrower than a traditional crankshaft motor, improving packaging. Plus as everyone else mentioned, more efficient.

  • avatar
    Frownsworth

    Seems a lot like the Bourke engine:

    http://en.wikipedia.org/wiki/Bourke_engine
    http://bourke-engine.com/images/altbrk.GIF

  • avatar
    Feds

    It’s an interesting concept. Armchair critic says:

    1. That crankdisk is sliding under those pistons, not rolling. There might be an adantage via the relative sizes, but that is still sliding as far as I can see.

    2. It seems like the engine would want to yaw a whole bunch. The front bank is going left while the rear bank is going right. Wouldn’t there be a lot of twisting about the vertical axis between the two banks?

    3. Rotational inertia of the crankdisk. That’s a heavy crank to spin up relative to a conventional arrangement. The centre of mass is also likely further from the crank axis. That will eat into some of the efficiency gains for sure

    It’s cool, but I want to see a runner at 5500 rpm

    • 0 avatar
      tree88

      I completely agree, and add to that the issue of strength/ heat expansion. The connecting bolts/plates are going to be subject to enormous forces which I would particularly surprised if the current design could withstand. Another issue I can foresee is heat expansion. For this design to work quietly, the piston/ crankdisk clearance would undoubtedly have to be pretty tight- but as the engine warms up, the clearance will get looser due to the piston material being subject to more heat and the heat will make its way to the sideplates or connecting bolts- causing them to grow. If enough clearance is allowed at higher temperatures- there may be insufficient clearance for the engine to even rotate when cold, and on the flipside of that- if enough clearance is given for smooth low temperature operation- when warmed up, it mat lead to the pistons hammering against the crankdisk (which in turn opens up a whole new can of worms- harmonics). While it is a novel concept, I just don’t see a functioning engine lasting very long. I do hope he can prove me wrong though.

    • 0 avatar
      sportyaccordy

      IIRC you can’t see it but the piston assembly is in contact with the crankdisk by roller bearings.

      I don’t think the engine would yaw any more than a boxer (i.e. not at all).

      And they could use a hollow crankdisk with smartly placed reinforcement webs or holes to reduce the weight. In fact they could hollow out the center and put a phasing clutch in the middle of each disk.

      I think it’s a great idea. Then again many great ideas have been passed on. Pattakon has worked out how to do variable lift timing on pretty much any valvetrain- OHV, OHC, coil spring, air spring, oil spring, desmodronic actuation- cheaply + simply with working retrofitted demonstrations and no manufacturers have seemed to bite.

    • 0 avatar
      sirwired

      Looking at the picture, I don’t see that the new crank necessarily has any more weight than a traditional crank + connecting rods.

      • 0 avatar
        dolorean

        Perhaps its design can be raised to where its more diesel in its rotation; i.e., lower RPMs generating more torques. Seems to me, you could fit a rather large piston assembly into wide and flat for sports and stability or tall and lean for hauling and pulling.

  • avatar
    Dimwit

    It looks interesting but with those cranks being round I wonder how it will work at TDC. I can see it jamming or going backwards all too easily.

    • 0 avatar
      Quentin

      While there is usually some wristpin offset on a traditional piston engine, inertia of the crank will carry it past TDC.* It will actually act like a flywheel. If you are starting the engine with the pistons at TDC, the starter motor will turn you past TDC. Also, with this being a boxer configuration, you have and explosion on the right side that drives the compression or exhaust stroke on the opposite side. (I don’t remember the firing order of Subaru 4 cyls anymore.) Since the 4 pistons are connected by the crank, you’ll always have an explosion somewhere carrying on the inertia of the crank.

      *When I had the timing belt go on my 1993 Impreza (this was back in 2000), the revs shot higher than where I was cruising and then relatively slowly died off to 0 RPM. Basically, I got one good combustion as the belt was breaking and the cams were no longer being pulled by the crank via the now broken timing belt. That expansion stroke combined with the reduced drag meant that the crank speed shot up really quick but the inertia of the crank kept on pushing pistons for a few seconds before it ran out of energy.

      • 0 avatar

        Just to be pedantic, it’s not really a boxer engine. It’s a common mistake, I was going to call this a boxer but while I was researching this post I found out that not all horizontally opposed designs are boxers. The term boxer comes from the way that the pistons in each pair are timed/phased to each other. In a boxer both pistons move towards the crank at the same time, like boxers’ fists hitting each other. In the Waissi engine, as you can see from the animated GIF, when one piston is moving down, the other is moving up. Horizontally opposed but not a boxer.

        Compare the GIF above to this one of a boxer layout:
        http://upload.wikimedia.org/wikipedia/commons/8/8a/Boxerengineanimation.gif

  • avatar
    Lie2me

    I guess the two biggest questions are output and efficiency with a side of practicality. It seems so simple not to have been explored in some manner prior. I’m kind of surprised that there isn’t some kind of estimated projections as to the possible benefits

    • 0 avatar
      highdesertcat

      We really won’t know about results until he builds a running engine and can tweak whatever it is that will need tweaking.

      To me it seems that the outer rim of the crank-disc needs to be a roller-bearing in order to “roll” behind the pistons. I can’t imagine direct contact between roller-bearing-less surfaces to be very efficient. But a roller-bearing surface?

      I see where Subaru may be very interested in the double twin-opposed design since that concept is their trademark engine, as was the early boxer-engine from VW/Porsche.

      The Waissi engine just refines the concept even more and takes it to a higher level.

      Then again, we all know what happened to the Wankel Rotary, not to mentioned the Miller-cycle engine, and let’s not forget the Sterling. I remember Honda’s concept of oval pistons. How did that work out?

      Each was a great concept but found little application in real life because the conventional engine is hard to beat.

      • 0 avatar
        JimC2

        Don’t forget Dyna Cam.

        Regardless, kudos are due to the professor for having the gumption to try this… and I hope his engine is commercially successful.

        • 0 avatar
          highdesertcat

          I agree! It takes a brilliant mind to deconstruct current engine designs in one’s mind and improve upon them in practicality.

          There’s no reason why this concept cannot be commercially successful. Only time will tell.

          I briefly owned a used Ro-80 while stationed in Europe with the US military, but the maintenance on that engine was demanding, like the life-expectancy of the Mazda Rotary was short before the seals had to be replaced at the factory.

      • 0 avatar
        Lie2me

        ” the conventional engine is hard to beat.” Exactly, so why even undertake such a task without knowing the potential outcome. There must be a theoretical benefit (MPG/HP/CI or a longevity factor of .5 million miles or better) without that you just have a different configuration producing the same thing

        • 0 avatar
          highdesertcat

          “so why even undertake such a task…?

          Because it is there!

          Nothing ventured, nothing gained. If no one had ventured to improve the current normally aspirated engines we use in our vehicles, we’d still be running on points and carburetors with chokes.

          The design I liked best was the old NSU 3=6 2-stroke design; it had the compactness of 3-cyl and the power of 6-cyl.

          It was immensely popular in motorcycles from Suzuki and Yamaha.

          Another design I loved was the smoothness of the Wankel Rotary. Only a well-balanced turbine would be smoother.

          Why did these designs ultimately fall out of favor? Because conventional contemporary 4-stroke engine design ruled the day.

          “Keep It Simple Stupid” is a slogan that has many applications, especially when it comes to mundane power plants.

          Yet I am intrigued to know what the harmonic resonant frequency of the Waissi design is and the highest piston velocity tolerated.

          I watched my dad blow a perfectly good 426 Hemi in his Nitro-Methane dragster when he exceeded the design limitations.

          Lower friction coefficient, higher spin rates, unless you put a governor on it.

        • 0 avatar
          noxioux

          If the actual friction reduction is even half what he’s claiming, I’d say it was worth it on that basis alone.

  • avatar
    FordRangerFTW

    I see this design finding a home in snowmobiles and ATVs; where weight, size, and complexity are a larger factor. Long-term durability is also less of a requirement in these applications.

    • 0 avatar
      highdesertcat

      I like to see the Flat-6 and Flat-8 versions of this Flat-4. My guess is that the 4 and the 6 will need counter-balance shafts because of the mass of the twin-pistons moving.

      With the boxer concept the weight of the pistons moves in and out to counteract the shift in weight, but with the weight of a twin-piston mass moving sideways all at once, I see a lot of yaw-torque even with reduced piston-mass.

      OTOH, this design would make one hell of an air/gas compressor.

      • 0 avatar

        I asked Dr. Waissi about balance issues and this is what he said:

        “the WAISSI engine does not need any additional balance shafts. If you compare the concept to a short block V-4 (or V-6) in which two piston rods are connected to the same crank. Then each adjacent piston pair moves “in tandem”. So, this would be a similar arrangement, but still very different, because the Waissi engine does not have piston rods.

        For example, in the 4-cylinder WAISSI engine the static balancing (when the engine does not turn) is achieved by phasing the the two cylinder pairs 180 degrees apart; the dynamic balancing in achieved by the counter weights attached to the drive shaft (“crankshaft”), as shown on the images I sent you. No additional balancing means are needed. In a 6 cylinder version the phasing would be 120 degrees; and in 8-cylinder version 90 degrees.

        The source for a balancing problem with a regular engine in terms of dynamic balancing are the piston rods.”

        He goes into more detail in the Powerpoint presentation linked to in the post: http://www.thetruthaboutcars.com/wp-content/uploads/2013/07/WaissiEngine05292013-001modified06102013.pptx

        • 0 avatar
          highdesertcat

          Thanks, Ronnie. I understand about phasing and off-setting masses.

          We’ll find out more when Dr. Waissi presents a running model to the world.

          I’m sure he’ll address the harmonics and yaw characteristics as he further develops his engine.

        • 0 avatar
          porschespeed

          Looked at that “presentation” and saw in about 10 seconds that he didn’t even FEA the thing, let alone actually run it on a decent simulation.

          This has all the reality of ‘Better Place’ and DeLorean.

          Over the last 40 years I’ve seen hundreds of different junk proposals like this. None ever went anywhere.

  • avatar
    frozenman

    Correct me if I’m wrong, but would this produce any reasonable amount of torque?

    • 0 avatar
      sirwired

      I don’t see that it would produce different torque values vs. a conventional design. The fundamentals of the engine remain the same, just the way power is transferred to the crank is different.

  • avatar
    koshchei

    Interesting idea.

    I’m surprised that he went with a conventional spring-loaded valve-train though, since spring compression incurs an enormous parasitic loss. A desmodromic setup (http://en.wikipedia.org/wiki/Desmodromic_valve) or similar dual-actuated system, while slightly more complex, would overcome this problem, and would also allow a much higher redline.

    Of course, CAD renderings do not a viable alternative to an ICE make. Time to prototype up and see how it runs.

    • 0 avatar
      JimC2

      “I’m surprised that he went with a conventional spring-loaded valve-train”

      Probably because a conventional valve train is less risk (simply because it works and every detail about how it works is common knowledge). He’s trying to validate his crankdisc concept. Also, by using conventional design for everything else in the concept engine, it’s an apples-to-apples comparison.

      There’s no question that radical valve trains have their advantages (and disadvantages), but that’s beside the point for the time being.

  • avatar

    Well, it seems obviously that while the SURFACE of friction is reduced, the ARM of the friction is much enhanced near the top dead point. Is this the right trade-off?

    The correct answer is: nobody cares. All sorts of alternative kinematics were tried before, and they may offer a bit of savings here or there, but in reality is completely unimportant. Only sizeable gains can ever come from increased thermodynamic efficiency, not from mechanical wizardry.

    For an example of what I’m talking about, look at the so-called “5-stroke” engine, which offers an additional expansion cycle. Now that’s a real deal, which basically works on the same principle as a turbocompound engine, but packaged so it’s feasible in a car.

  • avatar
    Beerboy12

    Interesting idea indeed. I could see this in smaller (at first) applications.
    One of the challenges with pistons lying on their side is uneven piston wear. As lubricating oil has a tendency to collect at the bottom (lower side) of the piston wall, the top side, especially the rings, wears more leading to out of round pistons and all the issues that creates.
    Much work had been done to resolve this though so I wish this engine luck. It will vastly improve fuel efficiency though reduced friction.
    Also this might be a surprisingly good contender for diesel…

  • avatar
    Scoutdude

    I’m seeing this a much harder to assemble engine with the way those pistons are connected to each other unless the bolts are accessible at the top of the piston which would be a very bad location for them. Personally I’m not seeing any significant reduction in friction from this design. You are really only eliminating the friction of the wrist pin and there isn’t that much there since the range of motion is very limited. There will still be thrust forces on the piston skirts as the position on the crank wheel changes the piston will want to deflect.

    Still I would like to see a functioning prototype built.

    • 0 avatar

      The second Powerpoint slideshow shows the assembly procedure. You can watch it and decide for yourself if it’s simpler than a conventional engine.

      Until a prototype runs, he hasn’t gotten as far as Lonny Doyle with his split cycle rotary engine.

      • 0 avatar
        Scoutdude

        That shows how the crank and pistons assemble in one version, which is not the same as some of the other versions shown and that definitely is more steps than a conventional set up. However the real question is actually assembling that inside of a crank case.

  • avatar
    Juniper

    Many have tried the double ended piston route. The problem is alway the interface between the crank and piston is always some sort of line contact. By the time you get something that gets the loads down all the simplicity is gone. You can see this happening between the first and second generation already. And he doesn’t have a running prototype yet. I wish him luck and keep on inventing.

  • avatar
    fishiftstick

    It seems to me that in terms of number of components and complexity, the plates connecting the pistons in this engine are no different from connecting rods in a conventional engine. Plus, the horizontally-opposed layout requires separate valvetrains and heads.

    • 0 avatar
      niky

      Valvetrains, no different from a typical boxer/horizontally opposed engine… but for six cylinder motors, that’s not a big deal.

      While it still uses a lot of parts, the whole point is that it eliminates the side loads on the pistons and the bores by eliminating the moving con-rod. Those side loads are a real limiting factor in how high a piston engine can rev and how long it will last.

  • avatar
    RobertRyan

    Hate to be a Killjoy but there are numerous “cutting edge new technology” designs out there. especially ones with either “Free Piston” or “crankless designs”
    OEMS are not really interested. There only interest is in Hybrids, hybrid electrics or diesel.

  • avatar
    3Deuce27

    Interesting, but still has the old cumbersome intake and exhaust system using cam action valve control. While I love cam actions, and am about to file for a patent that employs cam action, the use of one in the typical fashion of ICE’s, is quite antiquated.

    I designed a new induction system some fifty years ago, that would have eliminated all the inherent issues with the cam actuated valve system, mainly reduced friction and valve train loads due to spring loading. That idea coupled with today’s variable timing and metallurgical advances, would probably make it feasible. As it stood, originally, I saw issues with sealing, similar to what rotary ICE’s have, so I filed it in a dark place.

    Lets see more of these types of posts.

    Thanks Von Schreiber …Tre

  • avatar
    Theophilus138

    What is this Chrysler/Roush Gemini engine of which you speak, Ronnie? Allpar and Google have both let me down.

    • 0 avatar

      A project that never saw the light of day because “Ve have a development team in Germany”. I never wrote up the story because my source asked me to leave out some of the best parts of the story, as well as his name, which I got off of tag on the palleted engine in the back of the Roush museum, and how I found out the story in the first place.

      Short version: For Chrysler, Roush developed a modular V4 made of two V twin banks connected by a clutch so that a module could be shut off but it would be completely shut off (but with a shared cooling system so the shut down module would still be at operating temp) and not have the frictional and pumping losses of a conventional variable displacement engine. Sort of but not really related to the Harley Davidson VR1000 project, also worked on at Roush. Killed by Daimler. Happened late ’90s, early ’00s.

      Like inventors with new engines, there are many many stories of failed, aborted, killed, bungled and other projects that never saw the light of day in Detroit (and Tokyo and Stuttgart and other automotive cities as well).

      I just was asked permission by a college kid making a documentary about the AMC Pacer (great idea, don’t you think?) who wanted to use my photos of the GM Rotary Engine which was about as close to production as an engine can get.

      I’ll ask Jack and Derek if they want me to write up what I can.

      • 0 avatar
        andreroy55

        Jack and Derek be damned! (kidding!) :)

        Yes! Write it up!

        There are tons of different experimental engines that have seen the light of day over the years. In the late 1960s and early 1970s Popular Science would have several of them every year. Fascinating stuff.

        Here’s one Pontiac was playing with in the late sixties. Looks like the basic idea sort of made it into production, even! http://www.popsci.com/archive-viewer?id=EyoDAAAAMBAJ&pg=64&query=pontiac%20experimental

        or http://tinyurl.com/q9eg8lz for a shorter link.

  • avatar
    sirwired

    How much power is lost to the sort friction this reduces? I can see that there would be benefits to reducing friction, but would those benefits be worth the (expensive) development program to bring such a design into production?

    • 0 avatar
      JimC2

      Try looking at this in the sense of reducing friction at part throttle operation.

      Horsepower and torque curves are usually given out for full throttle operation because that makes for neat publicity. That’s useful information for all-out acceleration on a freeway onramp or towing an 8,000 pound boat up Pike’s Peak and passing the slower traffic…

      Internal friction makes an appreciable difference when an engine is loafing along when you drive at a steady speed, making about one third of its rated torque and spinning at about one third of its max rpm- known as driving “normally.”

      Consider that typical passenger car engines don’t have deep skirt pistons anymore (those make just a touch more friction and they weigh more), main and rod bearing design is analyzed at the microscopic level so that they can be made a small as possible but still last predictably in service, and piston rings are usually 2 compression rings + 1 oil control ring (3 or more compression rings + 1 oil control used to be the norm). That stuff makes for neat publicity too- usually in press releases about the latest high tech fuel economy features.

      The savings are in the ballpark of (perhaps) one horsepower here, a fraction of a horsepower there… not a big deal at max power but they make an appreciable difference when you’re just cruising along a flat road and the car only requires 15-20hp.

      Hope that all makes sense.

      • 0 avatar
        porschespeed

        All of which is easily addressed by cryo-treating and appropriate coatings.

        Next…

        • 0 avatar
          mik101

          Yes… because coating and treatments reduce costs… right…

          • 0 avatar
            porschespeed

            They do in the world of something that you are going to use/keep/warranty.

            In the fantasy land of beancounters, they may not be short-term profitable.

            Thankfully, the racing world (the one that finishes at or near the top) knows a bit better…

  • avatar
    nickoo

    This seems like a brilliant idea. I take it the pistons have rollers on the end where they contact the disc. I think it’s a great idea, but I also think it will need some tweaks for an actual automotive engine: make this a small inline 6 instead of horizontally opposed configuration, as horizontally opposed has all sorts of uneven wear issues. Use the same roller friction method between the cam and the crank or even a geared connection between the crank and a SOHC, the cam should directly actuate roller rockers. It would be relatively easy to add a phaser to the cam drive lobe using the roller friction method for VCT.

    • 0 avatar

      No rollers, the bearing spins on the crankdisc while it rolls under the piston. I suppose a roller bearing could be substituted for the bushing type bearing he’s now using but then bushing type main and big end bearings (and cam bearings as well) are used in just about every production car engine. I’m sure some bikes have roller cranks but if you know of a street car with a roller crank, let me know.

      As for an inline six you would need twice as many crankdiscs, because each piston would need it’s own crankdisc. Also, you don’t have the benefits of reducing piston rocking. On the other hand, an inline engine only needs a single head and related valve train components.

      • 0 avatar
        porschespeed

        There’s ZERO effective lube cushion on his fantasy crank bearings.

        The only thing more pathetic than the guy who “designed” this joke is anyone who thinks it would last more than 5K miles (and that’s in dreamland).

        • 0 avatar
          The Soul of Wit

          Why ya gotta be a hater, mate? YOU design a better engine lately?

          • 0 avatar
            mik101

            All of his posts in this article indicate he’s just here to troll, rather than have a constructive conversation about the design.

            There are parts of it that will and won’t work, but I’d still like to see the designer try to make a running model. I suspect this could work for smaller things, but not effectively scale up to higher horsepower numbers without exotic materials.

          • 0 avatar
            porschespeed

            Thanks, I do actually build better engines, as they actually run in the real world.

            I guess I’m a “troll” because I really do build engines that actually work, and unlike you, can see what *won’t* work by just looking at the design. It isn’t really hard, if of course, you actually understand how an engine works.

            Sadly, you show that you know nothing about actually building an engine, so you are left with attempting to ridicule those who actually do.

      • 0 avatar
        NMGOM

        Ronnie – - -

        Despite my enthusiasm for this engine, and my wanting Dr Waissi to succeed, there is one ameliorating fact we cannot ignore: the Germans.

        Engineers in German car companies are well known for practical, robust innovation. They were certainly aware of the Wankel engine, but chose not to go that route, and they were right. They have certainly been aware of the Bourke engine as well. And others had been working on the opposed-piston engine similar to this idea, but with connections to a more conventional crankshaft:
        http://en.wikipedia.org/wiki/Opposed-piston_engine

        So far, no BMW, Mercedes, or VW has jumped into the water on anything except more advanced technologies within the conventional ICE designs or electric motors. Could it be that robustness, low emissions, and endurance are just as important to them, versus just fuel mileage and ultimate efficiency, — as far as ICE is concerned? It seems that the hybrid route using electric motors, alternative fuels (like CH4), and hydrogen (H2) fuel cells, dominate their future spotlight right now.

        ———————-

      • 0 avatar
        TR4

        “if you know of a street car with a roller crank, let me know.”

        SAAB (and likely other) two-strokes had roller big ends, ball mains, and needle small ends.

  • avatar
    Big Al from Oz

    I love stuff like this, but also to be critical, either positive or negative. Go on the man for this.

    This engine will have to operate at very high speeds to produce enough torque by the use of gearing, similar to a turbine (but much slower).

    With the low friction concept the engine can run hotter, which will equal efficiency.

    If you look at the way that the base of the piston skirt contacts the cam there will be a loss of usable torque.

    In a conventional engine most torque is developed when the crank angle is at 90 degrees. This engine will lose torque efficiency when the ‘crank angle’ is at 90 degrees, ie, there isn’t much leverage. Look at the cam angle (crank) when the piston is half way through a single stroke.

    Also, excessive wear of the piston and walls will occur because the energy isn’t transferred concentric or as close to concentric to the piston. The load moves off to the side as the cam/crank rotates, which in turn will load the extreme top and extreme bottom of the piston. This will affect friction.

    I don’t want to spoil the concept, but if this can be developed to rev out to 10-12 thousand rpm and gear it down, it might work.

    • 0 avatar
      porschespeed

      It wouldn’t last 500 miles. Where’s the crank lube cushion? Oh right, there isn’t any…

      • 0 avatar
        Big Al from Oz

        Use gear oil.

        Gearboxes run for years.

        • 0 avatar
          porschespeed

          Use “gear oil”? For what exactly?

          Do tell how this imaginary substance is going to resist the pressure of engine compression friction without any containment? Unicorn quim and quadricorn farts?

          Do tell how long the molecular chain will last?

          No wonder we’re 50th-ish in the world when they do science rankings in the US….

          • 0 avatar
            Big Al from Oz

            Who said it was for the cylinders. I also build engines and have actually run a line punching out modules for jet engines.

            I have also built rally car engines and drag engines. But these engines were only a hobby.

            Do you understand lubricity, viscosity etc?

            If you look at the engine where would you use gear oil?

            Maybe between the platforms at the base of the piston skirts? So, inbetween the platform and the cam.

            Then work out what kind of load is being placed between those two surfaces. Understand?

            This engine is not viable as it will be inefficient.

          • 0 avatar
            porschespeed

            Thanks, I understand it quite well. Which is why I knew it would never work IRL.

            I also am old enough to have seen nonsense like this about a gazillion times. Which is why I can dismiss it readily out of hand. Anybody with a vague clue about how an engine works knows this is a sucker-ploy looking for chumps to “invest”.

  • avatar

    I don’t see much advantage in this engine, but I’m no ME. I’d like to see a running prototype, but I’m not seeing any advantage to this design, other than depending on how heavy those discs are, how low the red-line is.


Back to TopLeave a Reply

You must be logged in to post a comment.

Subscribe without commenting

Recent Comments

New Car Research

Get a Free Dealer Quote

Staff

  • Authors

  • Brendan McAleer, Canada
  • Marcelo De Vasconcellos, Brazil
  • Matthias Gasnier, Australia
  • J & J Sutherland, Canada
  • Tycho de Feyter, China
  • W. Christian 'Mental' Ward, Abu Dhabi
  • Mark Stevenson, Canada
  • Faisal Ali Khan, India