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Thread: A work of pure genius! - Brilliant "Revetec" Engine

  1. #496
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    Quote Originally Posted by manolis
    PS1
    Revetec, without having finished even the parts of their first X4 prototype (Jan 8, 2007), will take more than one million dollars because their engine “will be” so good. This is what I call success. Congratulations to Revetec.
    Pattakon’s GRECO i3 www.pattakon.com/greco/Grecoi3.exe impatiently waits for the real success of Revetec X4.


    Thanks
    Manolis Pattakos
    The X4 parts are finished....We are just finalising parts like thermostat housing and dipstick etc... The first evaluation engine has only taken AUD$500k from start to finish. Further funds will be spent on production designing and fine tuning. So stop making uninformed silly comments!



    The above picture was taken a month ago before internals were fitted. Currently the internals are all fitted.
    CD carburettors and dual Magnetos/plugs are fitted for aircraft safety from power failure. 95% has been built inhouse.
    X4 aircraft engine setup mounted to the aircraft airframe, which has been mounted on our dynamomenter.
    Note: Intakes are calculated length to provide RAM induction at the desired operational speed.
    After initial testing, fuel injection will be added for other markets including GTM trikes.
    Last edited by revetec; 02-08-2007 at 04:26 PM.

  2. #497
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    Quote Originally Posted by manolis
    Felix Wankel was nothing but a “high school boy”, an insignificant and poor “self educated machinist”.
    He followed his dream and offered to the world more than many thousands of university professors and overqualified engineers.
    A beleif in that probably explains why you think you're approach might succeed.

    However, those aren't the facts.
    Yes he was in the main self-educated ... but by reading the works of many researchers in the university he worked.
    Yes he came from a poorer family - but so did most who lived in that time in Germany. 1000% inflation can do that to you
    The working DKM engine was a collaboration, directed by Wankel's efforts but not solely.
    Hoep you didnt' rely on WIKI for your background on Wankel !"!!!!!



    Jeez, Brad, that is looking sweet in the plane support frame. VERY short. How long do you think it will realistically take to get aviation certificatino for it ?
    "A woman without curves is like a road without bends, you might get to your destination quicker but the ride is boring as hell'

  3. #498
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    We are going into uncertified sport/recreational and military uses first. You need to fly 200 hours and inspect to give service schedules and life to overhaul.

    We will certify later as this is costly and time consuming. Uncertified aircraft is around a US$6 billion a year market.

  4. #499
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    Revetec: “So how much more power?
    It is now 5 years since the Patent was lodged on a camshaft design. The engine tacho shows it goes to 9,000rpm, so the engine is running. How about posting a dyno graph which is third party certified to show us the improvements over the standard engine. If it is better I'm even interested.”



    I am interesting too, in a few details of Revetec’s design, for the sake of Pattakon GRECO I3 at www.pattakon.com/greco/Grecoi3.exe (a true “thrust free” engine), but Revetec persistently keeps the precious secrets. Even the Bore and the Stroke.



    Checking US-PTO for Revetec’s patents, what I see is that the first basic design of their engine was longed on July 1995.

    If, after 11.5 years (i.e. 5.5 years before patent expiration) and millions of dollars from their share holders, Revetec’s best dyno graph is the one for RHL4 1400cc finishing at 4600 rpm (which actually is not good news for Pattakon’s GRECO engines future), Revetec should be more patient and less arrogant with Pattakon’s “delay”.



    As regards the power, I admit that Revetec’s RHL4 (1400cc) makes more power than the one cylinder of Pattakon’s prototypes, either with the light version Honda B16A (1600cc) at www.pattakon.com/vvar/VVAL.htm or with the full version Honda B16A www.pattakon.com/vvar/OnBoard/ . And I estimate that neither VTS www.pattakon.com/vts/ (1600 cc Citroen) with only one working cylinder (i.e. with the other three cylinders deactivated) and without supercharging would be able to win the RHL4. But with two cylinders deactivated and two working (of anyone of the above Pattakon prototype engines), the Revetec RHL4 has no chance at all.

    When the new 2400cc Revetec engine is ready, we’ll see how many cylinders to deactivate. Two or one?

    As for the Pattakon PRE single cylinder, 515cc, naturally aspirated, direct injection opposed piston Diesel engine ( www.pattakon.com/pre/PE14.exe and www.pattakon.com/pre/droplet.exe ) I dare say it will provide similar power to the Revetec RHL4.

    Thanks
    Manolis Pattakos

  5. #500
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    Quote Originally Posted by manolis
    Revetec : “Or do they hope to overcome problems at a later date?”

    Revetec knows better than anyone else.
    Unless Revetec applied for a patent with all problems solved.
    For a start, we are an honest company and we have not and never get into the practice of modifying and taking out new patents of other peoples technology.

    Quote Originally Posted by manolis
    Revetec: “So how much more power?
    It is now 5 years since the Patent was lodged on a camshaft design. The engine tacho shows it goes to 9,000rpm, so the engine is running. How about posting a dyno graph which is third party certified to show us the improvements over the standard engine. If it is better I'm even interested.”

    I am interesting too, in a few details of Revetec’s design, for the sake of Pattakon GRECO I3 at www.pattakon.com/greco/Grecoi3.exe (a true “thrust free” engine), but Revetec persistently keeps the precious secrets. Even the Bore and the Stroke.
    After a huge amount of time performing analysis, as if I'm going to tell you details like that? Come on....be sensible...would you release that info to me if the situation was reversed? I bet not.

    Quote Originally Posted by manolis
    Checking US-PTO for Revetec’s patents, what I see is that the first basic design of their engine was longed on July 1995.

    If, after 11.5 years (i.e. 5.5 years before patent expiration) and millions of dollars from their share holders, Revetec’s best dyno graph is the one for RHL4 1400cc finishing at 4600 rpm (which actually is not good news for Pattakon’s GRECO engines future), Revetec should be more patient and less arrogant with Pattakon’s “delay”.
    Early history of our company was that we were under funded for the first 6 years.

    Let's look at Revetec Today. The X4 concept was designed on 10 July 2006. Patents were lodged in August 2006. X4 first evaluation/build design was completed November 2006. Engine completed in two weeks (fully dressed and running February 2006. We now have a fresh patent 20 years (not the 17 you stated because you probably don't know about the 36 month extension you can make for the PCT.

    Quote Originally Posted by manolis
    As regards the power, I admit that Revetec’s RHL4 (1400cc) makes more power than the one cylinder of Pattakon’s prototypes, either with the light version Honda B16A (1600cc) at www.pattakon.com/vvar/VVAL.htm or with the full version Honda B16A www.pattakon.com/vvar/OnBoard/ . And I estimate that neither VTS www.pattakon.com/vts/ (1600 cc Citroen) with only one working cylinder (i.e. with the other three cylinders deactivated) and without supercharging would be able to win the RHL4.
    Well to this date, everyone has been asking for figures from you and nothing has been posted.

    Let's look at your statement because we are going to be talking about power per litre at a certain RPM range. Higher the Revs the more power it is possible to produce. We are loking at efficiency not outright performance.

    If what you say is correct, then one cylinder of your 1600cc 4 cylinder engine is 400cc. This 400cc your quoting will have to make about 58kW at 4,200rpm normally aspirated to be equal to our old engine.

    By your statement are you saying that you can produce 145kw or about 200hp per litre at 4,200rpm?

    OK...BMW M6 produces 100hp per litre at 7,750rpm. If you look at the dyno graph of the M6, at 4,200rpm it is producing about 50Hp per litre.

    So your saying that you can produce 4 times the power per litre at the same speed as our tested engine and than the BMW M6 at the same RPM?


    You are the funniest person I have ever had contact with. At our tested peak power point of our old 1350cc engine we are producing about the same power per litre as the M6 at 4,200rpm but our fuel consumption is less.

    Just by having variable valve timing, you are not going to produce 4 times the power per litre.

    If the point you were making about your engine is able to rev to 9,000rpm then your fuel will at least double to do so. Anyways this still means you are saying that you can make twice the power (apples for apples) per litre than the BMW M6 with modifying a Citroen 1600cc with your VVT?

    Impossible and a stupid statement.

  6. #501
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    MISTAKE
    First I have to correct a mistake I made.
    I wrote that Revetec’s patent has 5.5 years before expiration (this was the law a couple of years before).
    The correct is that Revetec’s patent has 8.5 years before expiration.


    DESMO
    The desmo valves is a completely “correct” geometry.
    The “eye” like member is always in contact to both lobes: the internal (or conventional) lobe and the external lobe.
    The “eye” like member is actually the section of two cylinders.
    A simple way to made the Pattakon desmo camshaft ( www.pattakon.com/greco/Desmo2D.exe and www.pattakon.com/greco/Desmo3D.exe ) has been already described by another’s post.
    After the internal cams are grinded on a shaft (just like in normal camshafts) the external cams are secured properly to the basic camshaft.
    The assembly of the rest parts is much more easy than initially seems: through a side hole in the “external” cam, the “eye” like member is inserted in its working place.
    The valve stem passes through a hole on the “eye” like member (or cam follower if you prefer) and is secured and aligned by a pair of nuts.
    An elastic washer (i.e. a strong spring of very short stroke) inserted between the “eye” like member and the valve stem is used to take the lash and the thermal expansion.
    The system is much more light, compact and robust than the known desmo systems.
    If it fails to work in practice, nobody is going to get hurt.
    But think, if it works, why F1 engines need pneumatic valves any longer.


    PORTABLE FLYER
    There is a great difference between the synchropter shown in the picture and the Portable Flying Machine ( www.pattakon.com/fly/Flyer4.exe ). In a helicopter you cannot change the position of the center of gravity compared to the rotors.
    In the portable flyer, the pilot/rider can displace his body compared to the engine/rotors.
    This is enough to give absolute control of the flight.
    Just think that the pilot can slightly change the revs of the engine to keep the Flyer hovering. A little more throttle and the Flyer moves slowly upwards, a little less throttle and the Flyer moves slowly downwards ( www.pattakon.com/fly/Flyer5.exe ) .
    As the pilot/rider pulls or pushes the “grips” (or handlebars), what he is actually doing is that he displaces his center of gravity relevant to the rotors. This is more than enough. No need for pitch control, no need for electronic sensors and servo mechanisms (the body is the best sensor ever).


    GRECO i3
    The Greco i3 ( www.pattakon.com/greco/Grecoi3.exe) has absolutely zero inertia forces, inertia moments and inertia torques (case of sinusoidal piston motion). There is no conventional engine better balanced than this 3 cylinder. Only the rotary Wankel has similar balance quality.
    To get the importance of the zero inertia torque of the Greco i3, compare it to an even firing four stroke, four cylinder engine like the X4.
    The X4 has a significant inertia torque: when the two pistons of X4 are at TDC, the other two are at BDC, which means that all pistons of X4 are immovable simultaneously, i.e. they have zero kinetic energy.
    At the middle of the stroke of a piston, all pistons of X4 have near their maximum velocity simultaneously, i.e. they all reach their maximum kinetic energy simultaneously. In other words, the kinetic energy of the four pistons of the X4 changes from zero to a maximum, two times per piston reciprocation. This, in turn, is translated into variable velocity of the output shaft : for instance when the engine operates at 5000 rpm, if you measure the instant angular velocity of the output shaft of the engine it will be lower (let say 4900 rpm) when the pistons pass through the middle of their stroke and higher (let say 5100 rpm) when the pistons are at their TDC and BDC. The less the flywheel moment of inertia, the more the change of the angular velocity during a cycle. Using elastic absorbers between the output shaft and the helix / rotor / load in order to rectify this irregularity, a part of the energy is lost.
    Each piston of X4 has two heavy rollers that move together with the piston. So, at TDC there are eight heavy rollers (heavy because they have to be of yoke type) and four pistons and two “plates” interconnecting each pair of pistons (and keeping the “shafts” of the roller), all immovable. “Half of a piston stroke” later, the eight heavy rollers and the four pistons and the two “interconnecting plates” have reach their maximum speed, i.e. their kinetic energy is at maximum. “Half a piston stroke” later, the pistons, rollers and plates are all immovable again. In other words, at high revs there is a tremendous energy oscillation (this is the meaning of the high inertia torque of the even firing four stroke four cylinder engine, as compared to the six in line or V8 etc).
    In the case of the Greco i3, the total kinetic energy of the three pistons is always constant. When a piston assembly losses kinetic energy (i.e. losses speed) the other two absorb exactly the same amount of energy. This means that when the engine operates at 5000 rpm without load, no matter at what specific angle of the main shaft the revs were instantly measured, they are always 5000 rpm. The helix / rotor take only combustion torque from the main shaft.
    The rollers of the Greco i3 can be similar to the light needle roller bearings shown at http://www.pattakon.com/greco/GrecoS...isassembly.exe and http://www.pattakon.com/greco/GrecoS...erCylinderWall . Instead of having the roller bearing rolling on the cam, you can have light “wheels” (like train wheels) rolling on the cams with the needle roller bearing “nested” into the aluminum of the piston.
    Having a unique cylinder head of the conventional type (DOHC, 4 valves per cylinder etc) is significant.
    The simple synchronizing gearing (including only two spur gears) between the two “shafts” is also significant.
    The absolute absence of thrust loads (truly “thrust free” engine) is also important.
    If necessary, the Greco i3 can easily change to an even firing six cylinder engine, like the Greco U6 shown at www.pattakon.com/greco/GrecoU6.exe . This engine has the length of the conventional three in line (and less height) and uses a unique cylinder head (like the VR6 of VW) etc etc.
    Both Greco i3 and Greco U6 are true alternatives of conventional, offering many more than just “improved” thermal efficiency.
    They can be used not only in airplane applications but in any application the conventional is currently used.

    Think the case Revetec adopted the Greco i3 and Greco U6 engines and imagine what arguments they could use to “beat” the conventional engines in every application. Compare the case to the present position of Revetec in engine market.

    If the only real problem of the Greco i3 is the difficult finishing of its “cams”, this is nothing.
    Revetec knows the reliability of such a design. Pattakon does not, yet.
    If there is no such reliability “problem”, the benefits the Greco i3 design brings about are great.

    Greco i3 can be a WIN – WIN case (business is business and Australia is Australia). Doesn’t it, Revetec?


    Thanks
    Manolis Pattakos

  7. #502
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    DO NOT POST THE SAME THING IN TWO THREADS.

    Just makes the effort look silly
    "A woman without curves is like a road without bends, you might get to your destination quicker but the ride is boring as hell'

  8. #503
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    Yes manolis: Paste your silly replies under your own engine thread only...I responded to you there...if anyone wants to see my response go to the thread on: Pattakon engine.....legitimate alternative or just another fly-by-night.

    BTW: You still haven't answered any questions asked on your thread. I think this is because you can't answer them.
    Last edited by revetec; 02-15-2007 at 12:10 AM.

  9. #504
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    UGS who make Solid Edge (CAD) and FEMAP Analysis (Nastran FEA, Flow Solver, Thermal Solver) has featured Revetec's X4 on the front of Solid Edge's new Version 20 box. Link: X4 on Solid Edge Ver.20



    I supplied an internal design as well to UGS which I told them to keep confidential. They were amazed at the complexity of the design work versus the 3 and a 1/2 months I took to complete the design and analysis. I didn't expect them to put it on the box, so I'm pretty stoked. We are also the current featured image on their website.

    Revetec uses and recommends UGS's Solid Edge and Femap.

    We have now fired up our X4 engine (Pictures below: Sitting on our dynamometer). We are currently tuning and "running in" the engine. Performance and fuel usage figures in about 3-4 weeks. The X4 only took 7 months from conception to completion. This involved first concept, conceptual designs, international patent application (PCT), engine specs and research of engine dynamics, main design and stress analysis, machining of parts including block, barrels and liquid cooled cylinder heads (90% in-house), Custom building of parts like manifolds etc, Selection of ancillaries such as water pump and starter motor etc, Mounting on the aircraft frame and dyno, All plumbing, and Design electrical circuits and ignition systems. All in all about 2,500 man hours.





    Some of the X4 Engine Features:
    2.4 litre 4 cylinder "X" engine;
    Avgas fueled Aircraft engine (JP8 fueled version late 2007);
    Twin counter-rotating Trilobe drive cams (No Crankshaft);
    9:1 compression ratio (1.6mm head gskt) Current;
    9.5:1 compression ratio (1.2mm head gskt);
    Liquid cooled billet Barrels and Cylinder heads (Totally CNC Machined);
    Total Seal Piston rings (Gapless);
    Twin plugs and staggered timing electronic ignition systems (TSEIS);
    Extended piston dwell with mid-high RPM lean burn;
    Near constant torque lever through 90% of stroke;
    Ram induction intake.

    Hey Shanetrike....It'll look pretty good in the GTM trikes eh?
    Last edited by revetec; 03-01-2007 at 01:42 AM.

  10. #505
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    AWESOME RESULT BRAD!!!

    Making the Box Cover of SOLID EDGE is simply amazing!
    The X4 looks awesome and is an incredible result. I can't wait to get it in the trike.

    Brad is taking internal combustion engine theory and design to the next level. Maybe the comment Charles made about you in 2005 was in fact closer to the truth then I thought...

    Brad you are a GENIUS.

  11. #506
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    At last I found out Revetec’s Bore and Stroke (thanks to the second head gasket).

    I copy from Revetec:

    “Some of the X4 Engine Features:
    2.4 litre 4 cylinder "X" engine;
    Avgas fueled Aircraft engine (JP8 fueled version late 2007);
    Twin counter-rotating Trilobe drive cams (No Crankshaft);
    9:1 compression ratio (1.6mm head gskt) Current;
    9.5:1 compression ratio (1.2mm head gskt);
    Liquid cooled billet Barrels and Cylinder heads (Totally CNC Machined);
    Total Seal Piston rings (Gapless);
    Twin plugs and staggered timing electronic ignition systems (TSEIS);
    Extended piston dwell with mid-high RPM lean burn;
    Near constant torque lever through 90% of stroke;
    Ram induction intake.”

    Provided the above data of Revetec are correct, with S the stroke of the X4 and D the equivalent height of the dead volume and 9:1 compression ratio, we have:

    (S+D)/D=9.0, i.e. S=8.0*D

    When the D is decreased for 0.4 mm (1.2 mm head gasket instead of the 1.6 mm head gasket), the compression ratio becomes 9.5 which means that:

    (S+D-0.4)/(D-0.4)=9.5 or equivalently (8*D+D-0.4)=9.5*D-9.5*0.4 or equivalently 0.5*D=8.5*0.4 or equivalently D=6.8 mm (and so S=8*6.8mm=54.4mm)

    So, the X4 (four cylinder, 2,400 cc) has 54.4mm stroke.

    If each cylinder of X4 is 600cc and B is its Bore, we have :

    600=pi*S*B*B/4, i.e. B=118.5mm

    I.e. Revetec X4 has 118.5 Bore and 54.4 Stroke (both in mm)

    This means the Stroke is 46% of the Bore (just about the Stroke to Bore ratio used in Formula 1, GP and in the short stroke GRECO animation at www.pattakon.com/greco/GrecoShortStrokeDis.exe and www.pattakon.com/greco/GrecoShortStroke ).

    With 50 bar combustion pressure (and piston area=pi*B*B/4, i.e. 110 square centimetres), the force on the two rollers is 5.5 tons. If I knew the offset of the two rollers, I could compute the torsional (twist) thrust loads.

    If Revetec gave the correct data, the surface to volume ratio of the combustion chamber compares, if not exceeds, that of Wankel rotary ( like Mazda RX8 ).

    Either it is a super-over-square cylinder with 118.5mm Bore for 54.4mm Stroke, or the data given about the gaskets and the compression ratios are wrong.

    Mathematics cannot lie.

    Thanks
    Manolis Pattakos

  12. #507
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    Perhaps you should stick to posting "facts" about your own engine? Except that so far we've seen no evidence that you actually have one...

  13. #508
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    Manolis: you are wrong. You are assuming I have a flat piston... Without head/piston volume ratio and design you are guessing.

    Maths doesn't lie.....it depends on if the person actually using it, whether they understand what they're doing or not.

    So you're not so smart with your spreadsheets and formulas are you?
    From your understanding, I know you have never built or modified a real engine ever!

    To properly calculate the compression ratio you need to know:
    Displacement;
    Number of cylinders;
    Non-zero deck volume;
    Piston dome/Valve relief volume;
    Head gasket volume;
    Head Flycut volume;
    and
    Combustion chamber volume.

    UGS Article on the X4
    Last edited by revetec; 03-01-2007 at 09:06 PM.

  14. #509
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    Revetec wrote:
    “Manolis: you are wrong. You are assuming I have a flat piston... Without head/piston volume ratio and design you are guessing.
    Maths doesn't lie.....it depends on if the person actually using it, whether they understand what they're doing or not.
    So you're not so smart with your spreadsheets and formulas are you?
    From your understanding, I know you have never built or modified a real engine ever!
    To properly calculate the compression ratio you need to know:
    Displacement;
    Number of cylinders;
    Non-zero deck volume;
    Piston dome/Valve relief volume;
    Head gasket volume;
    Head Flycut volume;
    and
    Combustion chamber volume.”


    As long as you follow the conventional definitions for the compression ratio, I do not need (for the calculations of my previous post) to know neither the shape of the piston head nor the shape of the combustion chamber.
    And it does not matter if the piston is flat or not.

    If the dead volume is Vd and the Bore B, the equivalent height is defined as D=Vd/(pi*B*B/4).
    The only assumption I did is that the gasket hole has diameter equal to the cylinder bore. As long as this is true (as in every other engine) what I wrote:

    “Either it is a super-over-square cylinder with 118.5mm Bore for 54.4mm Stroke, or the data given about the gaskets and the compression ratios are wrong.
    Mathematics cannot lie.”

    is the case.

    Recheck your data.

    Thanks
    Manolis Pattakos

  15. #510
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    You're wrong again.

    I'll give you an example:

    If I had an engine with 9:1 compression ratio, and put a high top piston in it and changed the compression ratio to 10:1. The engine capacity is the same, the head gasket is the same thickness. So you cant work it out.

    The only way is to know the requirements for working it out that I posted.

    Go back to engine school.

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