# PatRoVa Rotary Valve engine



## manolis

Hello all.

At http://www.pattakon.com/pattakonPatRoVa.htm it is presented a new and different rotary valve: it comprises a pair of oppositely acting fronts / disks firmly secured to each other by a robust hub; the fronts seal a pair of oppositely arranged ports / windows (chamber ports) of the combustion chamber.







Here is the youtube vid eo of the first PatRoVa Prototype:

[video]https://www.youtube.com/watch?v=6Q-EGdeS0ws[/video]
https://www.youtube.com/watch?v=6Q-EGdeS0ws

and here is a proto of the prototype and of the cylinder head exploaded:












This drawing:






explains a fundamental difference of the PatRoVa rotary valve relative to all the rest rotary valves: the total force acting on the bearings of the PatRoVa rotary valve is zero, no matter what the pressure into the combustion chamber is.



We are planning to put it on a Ducati Panigale (V-2 at 90 degrees as in the first animation of this thread) to show its advantages over one of the best poppet valve engine (like: simplicity, ability for way higher revs (actually there is no rev limit for the cylinder head), compactness, low friction, high flow capacity, smoothness etc, etc). 



On the other hand, a small RC / model engine with the PatRoVa rotary valve on the cylinder head would be an interesting start.

Think of an RC 4-stroke engine, say 16mm bore x 15mm stroke, with ringless piston and the PatRoVa on the cylinder head, running above 40,000rpm.

Does anybody in this thread have the tools, the will and the time to modify a high revving RC engine to PatRoVa?   
As a third party, I mean.
Any estimation of the cost and of the time required?


Thoughts?

Objections?

Questions?

More details at http://www.pattakon.com/pattakonPatRoVa.htm

Thanks
Manolis Pattakos


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## lohring

Sealing has always been the problem with all rotary valves.  In high pressure steam engines, only poppet valves can be made leak proof.  IC engines have had the same experience over a wide range of valve types..  

By the way, I'm a fan of your variable poppet valve mechanisms.

Lohring Miller


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## manolis

Hello Lohring

You write:
&#8220;Sealing has always been the problem with all rotary valves. In high pressure steam engines, only poppet valves can be made leak proof. IC engines have had the same experience over a wide range of valve types.. 

By the way, I'm a fan of your variable poppet valve mechanisms.&#8221;




POPPET VALVES

Thanks for being fan of pattakon&#8217;s VVA&#8217;s.
The top is the DVVA (Desmodromic Variable Valve Actuation). 
It is presented at http://www.pattakon.com/pattakonDesmo.htm .
It needs not valve springs. 
It is a fully variable VVA: the valve duration varies from zero to a maximum &#8220;on the fly&#8221;, the valve lift varies from zero to a maximum &#8220;on the fly&#8221;, too, and the valve duration and the valve lift vary independently from each other.
The DVVA provides valve lift profiles like:









ROTARY VALVES

Quote from http://www.douglas-self.com/MUSEUM/POWER/unusualICeng/RotaryValveIC/RotaryValveIC.htm
(Rotary Valve Internal Combustion Engines):

&#8220;. . . many inventors have been attracted by the apparent simplicity and the uniform motion of rotary valves of one kind or another. There is also the tempting prospect of being able to run on inferior fuels because there was no hot exhaust valve always present in the cylinder to trigger pre-ignition. However, as with both steam and IC rotary engines, the simplicity was more apparent than real, and the engineering problems were daunting. 

The basic problem, is that the pressures in the cylinder of an internal combustion engine are high, due to both the compression stroke and the explosion of the fuel-air mixture. This produces large forces on the valve system, however it is contrived; the beauty of the poppet valve is that such forces simply push it harder against its seat, and have no effect at all on the valve-actuating mechanism.

However, the geometry of rotary valve systems is inherently different; in the Aspin concept below, the vertical valve cone is pushed up axially against the cylinder head, while the horizontal Cross valve is pressed up against the top half of the bearing surfaces. In both cases this can cause excessive friction and seizure, the root of the problem being that enormous forces are acting on the valve while it is moving.&#8221;

. . .

****Another contemporary concept is the PatRoVa rotary valve. Like the Cross design it balances out the forces acting on the rotating valve.****

End of Quote

The last paragraph in the asterisks was added recently (May 1, 2016) and is as wrong as it gets..

I tried to explain it to the creator / owner of the above web site by emails, but it seems it is too difficult to convince somebody for the obvious.

What is the obvious? 

When the pressure into the combustion chamber is high, say 100 bars, the Cross rotary valve is pressed &#8220;upwards&#8221; by a force equal to the pressure into the combustion chamber times the area of the &#8220;window&#8221; through which the combustion chamber communicates with the Cross Rotary valve.

With a &#8220;window&#8221; area equal to 20cm2, the overall upwards force acting on the Cross rotary valve is (100Kp/cm2) * (20cm2) = 2tons (4,400lb).

Such a force causes a significant distortion on the cylinder head, on the bearings of the Cross rotary valve and on the Cross rotary valve itself (the Cross rotary valve is actually a pipe having an oblique separator in the middle between its intake side and its exhaust side).

With its two bearings away from each other, the bending of the Cross rotary valve gets significant. 

With the one side of the Cross rotary valve running cold (intake side), with the other side of the Cross rotary valve running red hot (exhaust side) and with the highly asymmetric shape of the Cross rotary valve, the thermal expansion and distortion is anything but negligible.


Despite all these, the Cross &#8211; Bishop rotary valve:







came so near to success (more at http://home.people.net.au/~mrbdesign/PDF/AutoTechBRV.pdf ) that FIA changed the rules in 2004 banning the rotary valves from F1.


In comparison to the Cross rotary valve, each disk of the PatRoVa rotary valve is pressed to the side by a force of 1,000Kp (2,200lb) (because, for the same total port area, each window (chamber port) of the PatRoVa cylinder head has an area of (20cm2) / 2=10cm2. 
Through a hub, the two disks of the PatRoVa rotary valve are connected to each other.
The pressure force acting on the one disk through the one window counterbalances the force cting on the other disk through the other window, leaving the bearings completely unloaded. 
The high stiffness of the hub that connects the two disks minimizes the elastic distortion when the two opposite forces act, through the &#8220;windows&#8221; onto the disks.

Quote from http://www.pattakon.com/pattakonPatRoVa.htm :

&#8220;From a practical viewpoint: 


Leaving free (i.e. without support bearings) the PatRoVa rotary valve on the cylinder head to seat in place and seal, by its oppositely arranged fronts, the two side chamber-ports, and applying a high pressure (like 100bar) in the combustion chamber, the PatRoVa rotary valve has no tendency to move upwards, or downwards, or to the side. 
In comparison, a force of a few tons is required to keep in place a state-of-the-art rotary valve when the same 100bar pressure is in the combustion chamber; the extreme upwards force loads its bearings and causes, among others, the flexing / deformation of the spherical valve, of the shaft of the rotary valve and of the cylinder head wherein the shaft is supported. 

The *cavity* of the PatRoVa architecture eliminates the radial forces acting on the rotary valve and on its bearings, which is a major (if not the worst) problem of the known rotary valve designs. 

The ceiling of the *PatRoVa cavity* receives the heavy radial forces and releases, this way, the rotary valve from them. 

The PatRoVa cavity is a buckler that protects the rotary valve from the radial forces.&#8221;

End of quote.



Quote from http://www.pattakon.com/pattakonPatRoVa.htm 

&#8220;*Sealing* 

. . . 

A more ambitious idea is to exploit the inherent characteristics of the PatRoVa rotary valve and seal the combustion chamber without using conventional sealing means. 

For the sealing between the pair of flat-fronts and their respective chamber-port-lips only the one of the three dimensions is significant: that one along the rotation axis of the rotary valve (i.e. the distance between the two disks and the width of the combustion chamber); the displacement of the rotary valve along the other two dimensions does not affect the sealing. And because the heavy forces applied on the flat fronts balance one another "internally", such a displacement is easy to be realized and to be controlled (Variable Valve Actuation). 
In comparison, the slightest displacement, at any direction, of a spherical rotary valve changes significantly the sealing quality. 

The sealing is tolerant to deformations of the cylinder head because, as before, only the one of the three dimensions really matters; significant deformations of the chamber along the other two dimensions do not affect the sealing. 
Between its chamber ports the chamber (i.e. the cavity into the cylinder head) is like an open ring (a thin open ring); if the diameter of the ring is for some reason increased (due to the high pressure into the chamber, for instance, or due to the temperature etc) it makes no harm to the sealing. The pressure in the chamber cannot essentially affect the dimension of the "ring" along the rotation axis of the rotary valve. 
Besides, the lower part of the chamber is "enclosed" and is strongly supported by the lower end of the cylinder head (which is stiff as being the roof of the cylinder). 

With the distance between the chamber-port-lips being small, proportionally small is the effect on the sealing quality of the temperature difference between the rotary valve and the chamber walls. 

The limit of the width of the combustion chamber (i.e. of the width of the cavity into the cylinder head) is set by the diameter of the spark plug (or of the injector). For instance, with a distance of 25.4mm (1 in) between the two disks, the estimated thermal (and stress) expansion/contraction is several times smaller as compared to the case wherein the two ports were arranged at the sides of the cylinder.&#8221;

End of quote


By the way, here is a PatRoVa rotary valve (not yet finished) on a PatRoVa cylinder head (353cc cylinder capacity: 80mm stroke, 75mm bore)).







The manufacturing accuracy is poor.
The surfaces are dry (not lubricated surfaces at the top).
With manual (i.e. by the hands) cranking, the compression is 12 bars at some 300rpm.

The leakage at 3,000rpm is ten times less than at the 300rpm of the cranking (note: the leakage in the PatRoVa is internally recycled during the next intake stroke).
At 6,000rpm the leakage is 20 times less than at the 300rpm of the cranking.
At 15,000rpm the leakage is 50 times less than at the 300rp of the cranking.

It is not difficult to repeat the above &#8220;leakage&#8221; test.



I hope they are now more clear the differences between the PatRoVa rotary valve and the conventional rotary valves.

Are they?

Thanks
[FONT=&quot]Manolis Pattakos[/FONT]


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## manolis

Hello all.:

Quote from my first post:

" On the other hand, a small RC / model engine with the PatRoVa rotary valve on the cylinder head would be an interesting start.

Think of an RC 4-stroke engine, say 16mm bore x 15mm stroke, with ringless piston and the PatRoVa on the cylinder head, running above 40,000rpm.

Does anybody in this thread have the tools, the will and the time to modify a high revving RC engine to PatRoVa?   
As a third party, I mean.
Any estimation of the cost and of the time required?


Thoughts?

Objections?

Questions?

More details at http://www.pattakon.com/pattakonPatRoVa.htm "

End of Quote.


I mean a model / RC engine like:






Here are the basic parts. 
Spot on the casing (dark green; it is a single-piece part) and think its manufacturing difficulties:






With 20mm bore and 20mm stroke it has 6.26cc capacity.

At 35,000rpm its mean piston speed is 23.3m/sec

Reasonably it will make some 3hp

 Thoughts?

Objections?

Questions?

Thanks
Manolis Pattakos


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## Charles Lamont

manolis said:


> Thoughts?




It won't work. It may run, but you are never going to get it to any useful durability.



> Questions?


When dozens, may be hundreds, of good engineers have spent thousands and thousands of hours and wasted millions on failing to get clever rotary valve ideas to work reliably, what makes you think you can do better?

Sorry to be brutal, but I hate to see someone pouring so much effort into flogging a dead horse. My sincerest advice is to stop wasting your time. Now.


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## canadianhorsepower

Charles Lamont said:


> It won't work. It may run, but you are never going to get it to any useful durability.
> 
> When dozens, may be hundreds, of good engineers have spent thousands and thousands of hours and wasted millions on failing to get clever rotary valve ideas to work reliably, what makes you think you can do better?
> 
> Sorry to be brutal, but I hate to see someone pouring so much effort into flogging a dead horse. My sincerest advice is to stop wasting your time. Now.



Not sure why you say this but 
Stihl has a four cycles engine running with ONE cam loab :fan:


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## manolis

Hello Charles Lamont.

   You write:
   When dozens, may be hundreds, of good engineers have spent thousands and thousands of hours and wasted millions on failing to get clever rotary valve ideas to work reliably, *what makes you think you can do better*?

   Nothing more and nothing less than the architecture and the technical characteristics of the PatRoVa rotary valve.

   The PatRoVa rotary valve addresses some crucial issues / problems of the previous rotary valves, without introducing significant drawbacks.

   Think for instance: Is there another rotary valve that covers and seals big ports of the combustion chamber receiving, during the combustion, a zero total force?
   Compare the loads on the bearings of the PatRoVa rotary valve with the loads (and the resulting distortion) on the big diameter needle roller bearings required for the Bishop rotary valve.


Or think what happens if the PatRoVa rotary valve is "lifted" by, say, 1mm (and compare it with what happens in a Cross rotary valve "lifted" by 1mm).

Or think why leaving free (i.e. without support bearings) the PatRoVa rotary valve on the cylinder head to seat in place and seal, by its oppositely arranged fronts, the two side chamber-ports, and applying a high pressure (like 100bar) in the combustion chamber, the PatRoVa remains in place without any tendency to move upwards, or downwards, or to the side. 





   You also write:
   It won't work. It may run, but you are never going to get it to any useful durability.

   The title of this forum is Home Model Engine Machinist.

   Forget the unconventional rotary valve of the model engine in my last post and let me know whether, with a conventional cylinder head, the same model engine would work and would be durable.

   Then compare the ring-less piston with the PatRoVa rotary valve:

   The one part (the piston) seals the lower end of the combustion chamber, the other part (the PatRoVa rotary valve) seals the top end of the combustion chamber.

   Unless I am wrong, and despite the heavy mechanical and thermal stresses it undergoes, the ringless piston proved in practice good in both: sealing and reliability, 

   Think the pressure load on the piston: with 20mm bore and, say, 50bar maximum pressure during the combustion, the downwards force on the tiny piston is some 157Kp / 350lb.

   Due to the leaning of the connecting rod, the skirt of the piston is heavily and unevenly loaded by the pressure loads and by the inertia loads; it thrusts / abuts heavily on the cylinder liner and needs good lubrication to avoid seizure.

 Think also the thermal load on the piston: during the combustion the piston top comprises some 40% of the total surface of the combustion chamber.

   The reciprocating piston needs to be lightweight (otherwise the inertia loads limit the red line), the same piston needs to be robust to receive the loads keeping the distortion minimum.

   In comparison to the piston of the model engine, the "life" of the PatRoVa rotary valve is by far easier and the sealing it achieves better.
   For instance, the hub between the two disks of the PatRoVa is as big in diameter and as heavy as necessary because it does not reciprocate: it rotates smoothly with half crankshaft speed.
   For instance, the clearance between the chamber windows (chamber ports) and the two disks of the PatRoVa can be substantially smaller than the clearance of the piston.



   By the way, the model engine in the last post has square design: 20mm bore x 20mm stroke. 
   For a high revving 4-stroke engine a substantially over-square design is preferable.
   For instance, with 24.8mm bore and 13mm stroke the capacity remains the same (6.28cc) while the bore to stroke ratio gets equal to the bore to stroke ratio of the famous Ducati Panigale 1299 (116mm bore, 60.8mm stroke).






   With only 13mm stroke, the PatRoVa model engine has, at 50,000rpm, a mean piston speed of only 21.7m/sec, and the expected peak power becomes more some 4.5hp (3.3kW ).


It is interesting the manufacturing simplicity. 
For instance, for the manufacturing of the casing (dark green part) all it takes is a conventional (not CNC) milling machine. 




   Instead of general purpose advises( like: the others failed, why not you? ), please try with strictly technical arguments / objections. This is what I am asking for.

   Thanks
   Manolis Pattakos


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## enfieldbullet

I have a few issues with some things you said. mind that my background is in mechanical engineering and that i`m not criticizing the overall design but rather some rather flimsy conclusions you arrived at.

first and foremost, thats a cool new rotary valve design, i`ve never seen it before and i think it could be really cool to build an engine using it. but your 40,000 rpm is just...too much. modern F1 engines arrive at 18.000 rpm. you could probably do a little faster on a reciprocating otto cycle but not much, not nearly 40.000 rpm.

that`s because your flame front has to consume the fuel in the combustion chamber at every powerstroke and at 40.000 there isn`t enough time for that to happen. your engine would do a full turn at almost every 1 millisecond and you would have 0.5 milliseconds for combustion to occur. combustion cannot happen that fast normally, i think i remember 3 milliseconds quoted in a book in high-turbulence designs. maybe you would just have a lot of combustion happening in the exhaust pipes, and that you make a pretty inefficient engine.

secondly, at 40.000 rpm in a reciprocating engine, the inertial forces on the piston would be a HUGE problem and you would need a super strong material or a super dimensioned part. but the more massive the part is the slower the engine`s top speed would be. which brings me to the third point

third: it`s not just because your valves are revolving that they don`t take force to turn. they do, just like poppet valves. and by the apparent size of the drawing their moment of inertia would be pretty big. you could make their diameter smaller, but then breathing would become an issue(must reach a compromise here).

also, a reciprocating engine with just 6cc reaching 4.5hp is just unrealistic. did you factor in the thermal problems? i mean, normally 2/3 of the power is lost as heat inside the engine and at the exhaust. and at just 6cc those small parts would have a hard time getting rid of the heat instead of melting. (also, parts weaken the hotter they are and reaching 40.000 rpm just gets more and more unrealistic)

lastly...you drawing shows a timing belt pulley. F1 engines use gears because timing belts simply lag too much at 18.000 rpm to give accurate valve timing, you wouldn`t be able to get away with that.


*but,

let me also say this:

*i disagree with `many other tried and they failed, why would you suceed?`. failure is very subjective in engineering, because we live mainly in trade-offs .

did the rotary engine fail? not really...it works...just has bad emissions and etc. but it does work and in SOME application it must be a good choice.

and most of all, i think experimentation is always valid. i say go for it, build it, measure it, improve it. just don`t expect to suddenly have the greatest engine of all time. all things in engineering start rough and then get refined. the 4 cycle reciprocating engine is SO GOOD because people invested a LOT of time in making it better.(it started out VERY bad). 

and even though ultimately there`s a limit in how good you can make something, that does not mean you are wasting time testing new things out.


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## manolis

Hello Enfieldbullet.

  Thanks for your technical arguments and the opportunity to explain a few things.


   You write:
   &#8220;first and foremost, thats a cool new rotary valve design, i`ve never seen it before and i think it could be really cool to build an engine using it. but your 40,000 rpm is just...too much. modern F1 engines arrive at 18.000 rpm. you could probably do a little faster on a reciprocating otto cycle but not much, not nearly 40.000 rpm.
   that`s because your flame front has to consume the fuel in the combustion chamber at every powerstroke and at 40.000 there isn`t enough time for that to happen. your engine would do a full turn at almost every 1 millisecond and you would have 0.5 milliseconds for combustion to occur. combustion cannot happen that fast normally, i think i remember 3 milliseconds quoted in a book in high-turbulence designs. maybe you would just have a lot of combustion happening in the exhaust pipes, and that you make a pretty inefficient engine&#8221;



   50,000rpm sounds as too much, but it is not too much.

   Let me explain it.

   The Ducati Panigale 1299 has 116mm bore, 60.8mm stroke and runs reliably till 11,500rpm of the rev limiter.

   In the 24.8mm bore x 13mm stroke PatRoVa model engine (same bore to stroke ratio with the Ducati), the flame has to travel a 116/24.8=4.7 times smaller distance.

   Provided the flame front propagates at the same rate (speed) in the Panigale 1299 and in the PatRoVa model engine, the second burns the mixture until at least 11,500*4.7=53,800rpm

   Actually, the flame in the Ducati Panigale extends slower than the flame in the PatRoVa model engine because the shape of the combustion chamber of the first is not good: it is a thin disk (116mm diameter, 5.24 mm average height for 12.6:1 compression ratio), with deep valve pockets on the piston crown and necessarily abnormal shape of combustion chamber walls. 
   In the one case the flame extends at the two only dimensions (thin disk), while in the second case, wherein almost all the mixture is concentrated into the chamber formed between the two disks of the rotary valve (the clearance between the flat piston crown and the cylinder head is quite small: the limitation is to avoid the piston-cylinder head collision at high revs), the flame extends in three dimensions and proceeds faster with lower thermal loss.

   So, as regards the combustion, 50,000rpm is OK for the oversquare PatRoVa model engine.


   From the practical viewpoint, take the OS.18TZ model engine ( http://www.pattakon.com/tempman/osmz2110-dynotest-rcnitro.pdf ).
   2-stroke with 16mm bore and 15mm stroke.

   The dyno test in the above PDF shows the peak power at 30,500rpm and the maximum rpm at 42,500.

   Here is the port timing (quote from http://www.pattakon.com/pattakonPatAT.htm ) : 






   Its is a tiny engine that provides 750bhp/lit. To achieve such high specific power it is required the efficient burning of a good quantity of fuel inside the cylinder.



   You also write:
   &#8220;secondly, at 40.000 rpm in a reciprocating engine, the inertial forces on the piston would be a HUGE problem and you would need a super strong material or a super dimensioned part. but the more massive the part is the slower the engine`s top speed would be. which brings me to the third point&#8221;


   The abovementioned OS.18TZ model engine revs reliably at 42.500 rpm wherein the mean piston speed is 21m/sec and the maximum acceleration of the piston (with, say, connecting rod to stroke ratio 2.0) is 19,000g (g=9.81m/sec^2).

   With 13mm stroke versus the 15mm stroke of OS.18TZ, the PatRoVa model engine has a mean piston speed of 21.7m.sec at 50,000rpm and a peak inertia acceleration of 23,000g. With longer connecting rod (say, 3*stroke=39mm from center to center) the maximum acceleration of the piston falls at 21,000g (only 10% higher than in the OS.18TZ).

   An advantage of the 4-stroke is that its piston is shorter than of a 2-stroke because it needs not to cover and uncover ports on the cylinder liner. It also runs colder (it burns every other reciprocation; and there is no side of its piston skirt thrusting over hot exhaust port).

   According the previous, when a 4-stroke model engine with 13mm piston stroke is operating at 50,000rpm, the inertia forces on the piston is not a problem (at least not a huge problem) and the existing materials used already in the model engines are OK.



   You also write:
   &#8220;third: it`s not just because your valves are revolving that they don`t take force to turn. they do, just like poppet valves. and by the apparent size of the drawing their moment of inertia would be pretty big. you could make their diameter smaller, but then breathing would become an issue(must reach a compromise here).&#8221;


   No. There is no comparison of the loads.

   With a rotary valve rotating at constant angular speed, the only resistance is the friction between the valve and the cylinder head. But there is no force pushing the PatRoVa rotary valve onto the cylinder head. So the friction is quite small. The sprocket has to provide this small torque to the rotary valve, and this is all.

   Note: the rotary valve does not accelerate / decelerate during each crank rotation; it just rotates with half crankshaft speed.
   If necessary, the upper sprocket can be elastically connected to the rotary valve shaft (to allow the rotary valve to rotate at more-or-less constant angular velocity despite the slightly variable angular velocity of the crankshaft (think how the clutch disk is connected to the clutch hub)) 


   Parenthesis.

   The requirements seem initially &#8220;opposite&#8221; / &#8220;incompatible&#8221;: 

   On one hand the PatRoVa rotary valve needs a stiff structure (which means heavy weight) wherein the high pressure acting on the two disks through the windows of the combustion chamber will cause only a tiny change in the clearance between the disks and the respective window lips:













   On the other hand, the rotary valve should be capable for extreme revs without significant friction.

   The above rotary valve (88mm diameter) has been tested alone (i.e. without a piston in the cylinder) at 11,000 rpm (i.e. 22,000rpm of the crankshaft) for several minutes without significant temperature increase of the cylinder head. 
Are there any normal size reciprocating piston engines running at 22,000rpm? 

   End of parenthesis.


   As regards the inertia loads, comparing the PatRoVa rotary valve with the poppet valve is like comparing the day with the night. 

   As a piston, the poppet valve accelerates and decelerates in synchronization with the crankshaft. 

   During, say, 240 crank degrees the poppet valve opens and closes (frequency: *1.5* of the crankshaft frequency). 
   Its restoring spring has to be strong enough to accelerate the poppet valve to close following the ramp of the camshaft.

   In the Ducati Panigale 1299, the intake valve lift is 16mm for a piston stroke of 60.8mm. This means that the acceleration of the valve is (*1.5*^2)*(16/60.8 ) =0.59 or 59% of the acceleration of thepiston.

   Note: the opening and the closing of the valve is far from being pure sinusoidal; 
   the acceleration of the piston, due to the limited length of the connecting rod, is not sinusoidal , too.

   But in the lump sum the acceleration of the valve is more than half of the acceleration of the piston.

   With the intake valve weighing 46.8gr, the overall reciprocating &#8220;valve mass&#8221; is about 100gr (it is the valve mass plus half of the spring mass, plus a part of the mass of any linkage like, say, the cam follower).

   At 11,500rpm the acceleration of the piston of the Panigale is about 5,600g; according the previous, the acceleration of the inlet poppet valve of the Panigale is more than 2,800g. 

   This means that the spring has to be capable to apply a restoring force of at least 280Kp (about 600lb) to the valve (actually more, for safety), otherwise the valve cannot follow the cam lobe. This means that the camlobe has to apply to the valve / valve spring an even stronger force (necessary for the acceleration of the valve / valve spring and for the compression of the valve spring) in order the valve to move as it moves.

   For the motion of the conventional poppet valves they are required extreme forces (which means stress on the parts involves (including the timing chain or belt), friction, wear, cost etc.) 
   Ducati solved partially the problem by eliminating the restoring valve springs (Desmodromic cylinder heads: the valves not only open positively &#8211; as in the conventional valve trains &#8211; by they also close positively, without the need of restoring springs).
   The Panigale seems ideal for the application of the PatRoVa rotary valve in full size. 
   But Ducati refuses to sell a Panigale without its expensive cylinder heads (they reasonably cost a dozen of times more than the PatRoVa cylinder heads), so we are looking for a Ducati Panigale with destroyed cylinder heads to modify it to PatRoVa.


   I hope it is now clear: 

   There is no comparison. The load on the timing chain or belt of a conventional engine (say a sport single cylinder or a V-2) is dozens of times more than in the PatRoVa rotary valve.

   By the way, a broken timing chain or belt is &#8211; typically - a catastrophe in the case of poppet valve engines (valves / piston collision, destroyed pistons and cylinders and casing). In comparison, all it requires a broken belt or chain in a PatRoVa engine is the replacement of the broken belt or chain.



   You also write:
   &#8220;also, a reciprocating engine with just 6cc reaching 4.5hp is just unrealistic. did you factor in the thermal problems? i mean, normally 2/3 of the power is lost as heat inside the engine and at the exhaust. and at just 6cc those small parts would have a hard time getting rid of the heat instead of melting. (also, parts weaken the hotter they are and reaching 40.000 rpm just gets more and more unrealistic)&#8221;


   The OS.18TZ 2-stroke model engine with only 3cc capacity provides 2.28bhp at 30,500rpm (750bhp/lit).
   With 6.28cc capacity the 4-stroke oversquare PatRoVa model engine has an easier task: only 4.5bhp.
   As for the cooling of the parts, a 4-stroke is better / easier in this area than a 2-stroke.



   You also write:
   &#8220;lastly...you drawing shows a timing belt pulley. F1 engines use gears because timing belts simply lag too much at 18.000 rpm to give accurate valve timing, you wouldn`t be able to get away with that.&#8221;

   If necessary, gear wheels can replace the timing belt and the sprockets.
   On the other hand, as explained in the previous, the timing belt of the PatRoVa engine has a far easier job than the timing belts in the poppet valve engines.

   Thanks
   Manolis Pattakos


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## enfieldbullet

Mr. Pattakos,

thank you, that was a great response. you seem to have a pretty solid plan.

with that in mind, if you ran all of the calculations, i think its time to build a prototype to test it out as you pointed out. there certainly are some people on this forum which could help you with construction.

I`ll certainly take a closer look at your design once i get home today.

Best Regards,
Rodrigo.


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## manolis

Hello Rodrigo.

   You write:
   &#8220;Mr. Pattakos&#8221;

   Just Manolis, please.


   You also write:
   &#8221;there certainly are some people on this forum which could help you with construction.&#8221;

   For the case these people need some more details for the casing / cylinder head, these animations may help:











   (the cooling fins and the rotary valve became bigger).

   Thanks
   Manolis Pattakos


----------



## blighty

i have model helicopter standing by for the prototype.


----------



## manolis

Hello.

Here is one more animation showing the rotary valve and the cylinder-head-cover from various viewpoints:






The design is quite simple. 
However, if anybody needs the CAD drawing, here is an email for communication:  [email protected]

Thanks
Manolis Pattakos


----------



## manolis

Hello again.

In the previous animations no attention has been paid to the lower end of the engine (crankshaft support, easy manufacturing).

Here:






things get substantially better and simpler.

The replacement of the timing belt gets quite simple, too.

The relative dxf file has been upgraded.

Thanks
Manolis Pattakos


----------



## Mechanicboy

The big question: Will the engine be repairable if the leak is coming from the rotary valve? Probably not! That means it costs a lot to replace a complete cylinder head + rotary valve. 
Who would have interest to have such a motor that can not be overhauled by the owner when the engine lost compression caused by leaky rotary valve.

I have a Webra T4 with Aspin rotary valve, not problem getting sealed rotating Aspin valve in cylinder head after the rotary Aspin valve was lapped together with very fine lapping paste on the cylinder head.

Comparing between the engine with traditional valve system and rotary valve in power / weight ratio: The engine with rotary valve is much heavier due to the bigger cylinder head which means extra weight + rotary valve weighing more than valves in the cylinder head. I has SC 91 four stroke and Webra T4 to compare: The SC 91 four stroke engine is much lighter and powerful than Webra T4. 

Why invent a new engine that weighs so much and can not fix later again when there are already effective and repairable 4 stroke engine on the market?


----------



## manolis

Hello Mechanicboy.

   You write:
   &#8220;*The big question*: Will the engine be repairable if the leak is coming from the rotary valve? Probably not! That means it costs a lot to replace a complete cylinder head + rotary valve.
   I have a Webra T4 with Aspin rotary valve, not problem getting sealed rotating Aspin valve in cylinder head after the rotary Aspin valve was lapped together with very fine lapping paste on the cylinder head.&#8221;


   Quote from http://ralphwatson.scienceontheweb.net/rotary.html (for all: do read it; you will like it).

_&#8220;I first became interested in the rotary valve as applied to internal combustion engines around about 1939, after reading an article in a motor cycle magazine describing an Aspin rotary valve four stroke engine. This engine had a capacity of 250 c.c. and it was claimed to produce 29 h.p. at 14,000 r.p.m., using low octane petrol._
_At the time, I was living in Nelson and serving an engineering apprenticeship. On occasion I watched a group of engineers, led by the well-known aviator George Bolt, race one metre hydroplanes on the local model boat pond._
_These model boats were powered by 30 c.c. engines and ran tethered to a central pole in the pond to provide quite exciting action. Being an enthusiastic experimenter, the Aspin engine came to my mind and I decided that I should give them some competition._
_With great, but what turned out to be misguided enthusiasm, I built a model engine based on the Aspin design, which incorporated a cone type valve the same diameter as the cylinder bore, rotating in the cylinder head. The combustion chamber was contained within the rotary valve, which rotated to line up in turn with the spark plug, exhaust port and inlet port._
_Full combustion pressure was applied to the valve, forcing it into the taper of its conical seat with the object of ensuring a good seal, but this arrangement could result in the valve seizing in the head due to lack of clearance and lubrication. In order to counter this, the Aspin design incorporated a roller thrust bearing on the valve stem._
_I used the same arrangement but could not attain an adjustment whereby the bearing took the load and a satisfactory seal was achieved. When adjusted so that load was on the bearing, the seal leaked and the engine had poor compression and would not run. With load on the cone the valve would seize. After suffering much frustration with broken drive shafts and stripped gears, the engine was eventually run for short periods with load on the cone, thanks to a copious supply of castor oil. This was supplied under pressure to the valve face, by means of a hand pump. My goal of fitting the engine into a model hydroplane came to naught and George Bolt and company remained unopposed at the model pond._
_However I was able to test the engine running against a brake and it recorded 1/8 h.p. at 8,000 r.p.m., which was a disappointment when related to the figures quoted in the article which had inspired my efforts._
_Many years later the story came out that the Aspin engine was tested by the motorcycle manufacturers Velocette, who found that it produced only half the horsepower claimed, the suggestion being that the original testing had been carried out with a wrongly calibrated tachometer.&#8221;_
   Here are the drawing and some photos of the &#8220;Cross &#8211; Ralph Watson&#8221; Rotary Valve engine:






















   End of Quote.



   According your experience with your Aspin rotary valve engine (Webra T4), the first question coming in your mind is &#8220;Will the engine be repairable if the leak is coming from the rotary valve?&#8221;

   Let me ask: 
   what is the relation between the TBO (time between overhauls) for the lower end (including the piston and the cylinder liner) of your rotary Aspin Webra T4 or of your conventional poppet valve SC91 (I suppose they are more or less the same) and the TBO of your Aspin Webra T4 cylinder head ?

   I.e. how many times you make the regrinding of the Aspin rotary valve before you need to repair something in the area below the cylinder head.


   Quote from a previous post:

   &#8220;Forget the unconventional rotary valve of the model engine in my last post and let me know whether, with a conventional cylinder head, the same model engine would work and would be durable.

Then compare the ring-less piston with the PatRoVa rotary valve:

The one part (the piston) seals the &#8220;lower&#8221; end of the combustion chamber, the other part (the PatRoVa rotary valve) seals the &#8220;top&#8221; end of the combustion chamber.

Unless I am wrong, and despite the heavy mechanical and thermal stresses it undergoes, the ringless piston proved in practice good in both: sealing and reliability, 

Think the pressure load on the piston: with 20mm bore and, say, 50bar maximum pressure during the combustion, the downwards force on the tiny piston is some 157Kp / 350lb.

Due to the leaning of the connecting rod, the skirt of the piston is heavily and unevenly loaded by the pressure loads and by the inertia loads; it thrusts / abuts heavily on the cylinder liner and needs good lubrication to avoid seizure.

Think also the &#8220;thermal load&#8221; on the piston: during the combustion the piston top comprises some 40% of the total surface of the combustion chamber.

The reciprocating piston needs to be lightweight (otherwise the inertia loads limit the red line), the same piston needs to be robust to receive the loads keeping the distortion minimum.

In comparison to the piston of the model engine, the "life" of the PatRoVa rotary valve is by far easier and the sealing it achieves better.
For instance, the hub between the two disks of the PatRoVa is as big in diameter and as heavy as necessary because it does not reciprocate: it rotates smoothly with half crankshaft speed.
For instance, the clearance between the chamber windows (chamber ports) and the two disks of the PatRoVa can be substantially smaller than the clearance of the piston.&#8221;

   End of Quote.


   According the previous, the PatRoVa Rotary Valve model engine will need service in its cylinder head every, say, 5 repairs of the bottom mechanism.

   Even then, you can polish (in a milling machine) the working flat surfaces in the cylinder head / cylinder cover, and replace the PatRoVa rotary valve by an oversized one (as happens in the normal engines wherein after the re-grinding of the cylinder liners, the piston rings are replaced by the next size piston rings).



   You also write:
   &#8220;Comparing between the engine with traditional valve system and rotary valve in power / weight ratio: The engine with rotary valve is much heavier due to the bigger cylinder head which means extra weight + rotary valve weighing more than valves in the cylinder head. I has SC 91 four stroke and Webra T4 to compare: The SC 91 four stroke engine is much lighter and powerful than Webra T4.&#8221;


   Here is a photo of the Webra T4 cylinder head / rotary valve (from the AVION MAGAZINE ) :






   Look at the intake and exhaust ports on the cylinder head.
   Due to the Aspin architecture (wherein the size of the ports is limited by the necessarily big hole (in the center) though which the shaft of the Aspin Rotary Valve passes through to find, at the other end, the bevel gear) the intake port area is small.

   The diameter of the cylinder seems some 3.5 times bigger than the diameter of the intake port.

   The intake valve port area in the SC91 (27.7mm bore, 11.5mm intake valve diameter) seems about 50% bigger than the intake port area in the Webra T4. 

   This agrees with the only 1.1bhp at 11,200rpm of the Webra and the 1.5bhp of the SC91 at some 10,000rpm.


   Please do a calculation about the force onto the bearing of the Aspin rotary valve of your Webra T4 during combustion (suppose 50bar maximum pressure).
   A rough estimation says some 150Kp. 
   The worst is the affect of the above load and bearing on the clearance between the Aspin rotary valve and the cylinder head.
   As the revs increase, things get tough for the bearing.

   Do the same calculation for the PatRoVa rotary valve. If you calculate anything else than zero, do the calculations again.



   You also write:
   &#8220;Why invent a new engine that weighs so much and can not fix later again when there are already effective and repairable 4 stroke engine on the market?&#8221;

   As compared to the Webra T4 Aspin rotary valve engine, your conventional 4-stroke engine (SC91) is lightweight and strong.

   But is it? In absolute numbers, I mean.

*For instance, the Honda VTEC B16A2 1600cc 4-cylinder 16-valve engine used as the basis for the VVA-roller prototype at http://www.pattakon.com/pattakonRoller.htm has from the factory  (and it is a normal size engine, not a tiny one) the same specific power withe the SC91. *

   With only 2 valves per cylinder and &#8220;push rods&#8221; for their actuation, its rev limit is very low (at 10,000rpm of its peak power, 24.8mm piston stroke means only 8.3m/sec).

   It is too risky to increase the revs (and you gain nothing in power because of the limited valve area): the valves will hit the piston crown (as in the normal size poppet valve engines).

   The intake valve area is too small. 
   With 15cc cylinder capacity, your single intake valve port area is less than half than the total intake port area of the PatRoVa model presented in this forum (worse even for the exhaust).
   Besides, the capacity of your SC91 is 2.4 times bigger than the capacity of the PatRoVa model engine.
   2*2.4=4.8, and 4.8*10,000rpm=48,000rpm
   This is why I estimate 50,000rpm for the peak power of the PatRoVa 6.28cc (24.8mm bore, 13mm stroke) model engine.
   With same specific torque (mN per liter) with the SC91, the PatRoVa rotary valve (which is 2.4 times smaller in capacity) will make two times the power of the SC91. 

   As for the weight, I don&#8217;t think all these parts (covers, camshaft, pushrods, rocker arms, valves, valve springs) in the SC91 valve train weigh less than the PatRoVa rotary valve.

   And don&#8217;t forget the almost half piston stroke of the PatRoVa (think what this means for the weight of the crankshaft and of the con-rod, for the vibrations etc).

   In total, the expected specific power (bhp per liter of capacity) of the PatRoVa seems some five times higher than the SC91.


   Do I miss something?


   If anything is confusing, please let me know to further explain.

   Thanks
   Manolis Pattakos


----------



## Mechanicboy

Seeing that you downloaded my photo of Webra T4 who is located in RC Universe where my nickname is Motorboy in RC Universe.. 

SC 91 FS weight 0,64 kg, approximately 1,4-1,5 hp versus Webra T4 weight 1 kg, 1 hp. Also i will select low weight and high power to use in the model aircraft.


----------



## manolis

Hello mechanicboy.

   You write:
   Seeing that you downloaded my photo of Webra T4 who is located in RC Universe where my nickname is Motorboy in RC Universe..

   The photo has been replaced.


   For the rest, is it now clear the limitations the Aspin architecture introduces?

   For instance, think what happens if you lift for 0.5mm the Aspin rotary valve of your Webra T4: no compression at all.

   Then think what happens if you lift for the same 0.5mm the PatRoVa Rotary Valve. Nothing. 
   The PatRoVa Rotary Valve is so insensitive in this kind of displacement that this characteristic can be used to control the timing and overlap:






   For more: http://www.pattakon.com/pattakonPatRoVa.htm

   Thanks
   Manolis Pattakos


----------



## Hopper

As someone who has spent some time trying to get conventionally valved engines to flow more intake charge into the cylinder and get the exhaust gasses out as quickly as possible, when I look at this rotary valve, the first thing I see is a very tortuous path for the gasses to flow through. Basically in the intake charge enters the combustion chamber sideways and then hits a brick wall and then has to turn 90 degrees to go down into the cylinder. Allthis immediately after the intake charge has already made one rightangle turn to get through the disc valve.
It is comparable with the intake path of an old sidevalve engine, (but inverted) which is very inefficient compared to today's overhead cam engines where the intake port is an almost straight, vertical shot from intake down to the bottom of the cylinder. 
I have difficulty seeing how this cylinder head will flow at anything other than lowish rpm. 

Also, the exhaust gas heating the one-piece combined rotary valve, which then heats the incoming intake charge seems less than ideal. 

Looks like an interesting machining project for someone though, to make your prototype. Good luck with the project!


----------



## manolis

Hello Hopper.

   You write:
 &#8220;As someone who has spent some time trying to get conventionally valved engines to flow more intake charge into the cylinder and get the exhaust gasses out as quickly as possible, when I look at this rotary valve, the first thing I see is a very tortuous path for the gasses to flow through. *Basically in the intake charge enters the combustion chamber sideways and then hits a brick wall and then has to turn 90 degrees to go down into the cylinder*. Allthis immediately after the intake charge has already made one rightangle turn to get through the disc valve.&#8221;

   I think you mean like this:






   The two symmetrical incoming gas streams find each other and proceed downwards to the cylinder. 
   The one gas stream constitutes what you call &#8220;brick wall&#8221; for the other gas stream, and vice versa.
On the symmetry plane (it is parallel to the rotary valve disks, it also &#8220;bisects&#8221; the combustion chamber) the speeds of the two gas streams are identical / compatible; this &#8220;imaginary brick wall&#8221; (i.e. the above symmetry plane) is quite different than a true &#8220;brick wall&#8221; on the surface of which the speed of the gas stream is necessarily zero spoiling the gas flow.


   If something fits with the term &#8220;brick wall&#8221;, this is the head of the conventional poppet valve: 






wherein the incoming gas stream finds a real &#8220;brick wall&#8221; (the poppet valve head) and changes direction, with the average turn angle being some 90 degrees. Then the incoming gas stream changes direction again &#8220;downwards&#8221; along the cylinder axis.


Talking for &#8220;brick walls&#8221; and flow restrictions, in a photo from the CycleWorld magazine they have been marked by circles / ellipses some restriction of the flow in the Desmodromic Ducati Panigale 1299 (one of the most technologically advanced engines today):






The intake valves at a part of their periphery (green circles) are so close to the cylinder liner that the flow is substantially restricted.

At their neighboring area (cyan ellipse), the one intake valve becomes an obstacle (a &#8220;brick wall&#8221 for the gas entering through the other intake valve, and vice versa.

The exhaust valves at a part of their periphery (red circles) are so close to the cylinder liner that the flow is substantially restricted.

During overlap, the close neighboring of intake and exhaust valves (yellow ellipses) causes the short-circuiting of intake and exhaust spoiling the scavenge of the combustion chamber and allowing in a part of the incoming through the intake valves charge to escape to the exhaust.

*See how the cooling liquid holes are arranged on the Panigale cylinder head bottom: all but one are at the exhaust valve side.*


Think why the Ducati Panigalle 1299 has such extreme-over-square design (116mm bore for 60.8mm stroke for 643cc cylinder capacity):

   More specific power (PS/cc) requires higher revs. 
   Higher revs require shorter stroke and larger bore.
   Larger bore allows bigger poppet valve which go together with higher valve lift.

As the revs increase the piston acceleration increases proportionally with the revs square and decreases proportionally with the stroke. The reduced stroke limits the acceleration of the piston.

As the revs increase the acceleration of the poppet valves increases with the revs square, it also increases with the valve lift.

At the end, the ratio of the increase of the valve acceleration relative to the increase of the piston acceleration is about 3 (for an 20% increase of the piston acceleration, the increase of the valve acceleration is 60%).

At extreme revs the required forces in the valve train get so strong that a good part of the power provided by the piston on the crankshaft is consumed into the valve train.

   You can find a more detailed analysis for the previous at http://www.f1technical.net/forum/viewtopic.php?f=4&t=10966&start=975



   You also write:
&#8220;Also, the exhaust gas heating the one-piece combined rotary valve, which then heats the incoming intake charge seems less than ideal.&#8221;

Follow the exhaust gas and see how quickly and directly it passes through the exhaust ports of the rotary valve. This fast pass cannot heat substantially the rotary valve. 

In comparison, the head of the exhaust poppet valve and the lower half of its stem are into the &#8220;hell&#8221;. If you wanted to heat the exhaust poppet valve by a hot gas stream, this is the most efficient way. In order to protect the exhaust valves from overheating, you need a lot of cooling around their valve seats. A good part of the incoming fresh charge falls onto the hot exhaust valves and is heated reducing the volumetric efficiency of the engine. And later, during combustion, the compressed hot charge is in touch with the red-hot exhaust valve, reducing the compression ratio and the thermal efficiency of the engine.

If I was asked to point at the worst thing in a conventional reciprocating piston engine, I would point at the exhaust poppet valves. And if I was asked for the second worst thing, I would point at the intake poppet valves.



   You also write:
   &#8220;I have difficulty seeing how this cylinder head will flow at anything other than lowish rpm.&#8221;

In  previous post I was explaining to Mechanicboy that the specific intake port area (cm2 / cc) of his SC91 4-stroke model engine is five times less than the specific port area of the short-stroke PatRoVa (6.28cc) model engine (double port area for 2.5 times lower capacity).

Things get even worse for the exhaust port area of the SC91(which is some 6 times smaller than in the PatRoVa model engine).

Do I need to say more? Five times higher specific port area, and you talk for lowish rpm!



   You also write:
   &#8220;Looks like an interesting machining project for someone though, to make your prototype. Good luck with the project!&#8221;

   It is also an easy machining.
   Some simple (but precise) milling and lath work and the PatRoVa model engine is ready to run.
   In comparison, the manufacturing of the cylinder head  / valve train of the ringless OS 4-troke FL70 :


























   seems as a nightmare.  

   Thanks
   [FONT=&quot]Manolis Pattakos[/FONT]


----------



## manolis

Hello.

    The two lips of the combustion chamber ports (or windows) in cooperation with less than half of the &#8220;inner&#8221; surface of the two disks do the high pressure sealing as shows the following animation:







   (the same animation in slower motion is at http://www.pattakon.com/PatRoVa/PatRoVa_sealing_slow.gif 

   The red color on the window lips indicates sealing of a high pressure in the combustion chamber, the orange color is for the medium pressure period and the yellow color on the window lips is for the low pressure difference period.

   Around the PatRoVa rotary valve, only the, about, one quarter (some 90 degrees) of the flat surface seals high pressure differences. At this quarter the section of the rotary valve is uniform and its shape is extremely robust, as an open spanner / wrench:














   Worth to mention: 


The hub (the robust fat and short shaft at the ends of which the two disks are secured) has about uniform temperature.

   Only around the exhaust ports of the PatRoVa rotary valve the temperature is substantially higher than the rest valve. But this part of the rotary valve surface is not related with the sealing of significant pressure differences. So it is not a problem: if necessary, by grinding slightly the flat surface around the exhaust ports periphery, the local thermal expansion cannot cause seizure between the disks and the window lips.


   Worth, also, to mention: 

In the case of the PatRoVa rotary valve only the one dimension is important for the sealing. 
   The displacement of the valve at the other two dimensions doesn&#8217;t affect the sealing quality. 
   And, as regards the sealing quality, the significant dimension (in simple words: the distance between the two disks) is small enough to keep the thermal expansion at this direction / dimension low. 

   The recycling during the next suction cycle of any leakage during the high pressure period is another significant characteristic of the PatRoVa architecture.

   The eliminated friction loss is another significant characteristic of the PatRoVa architecture.

   Thoughts?
   Objections?

   Thanks
   Manolis Pattakos


----------



## manolis

Hello.

The following animations show several design details of the PatRoVa rotary valve / head / cylinder for normal size engines:
















Most of these details are applicable to model engines, too.

Thanks
Manolis Pattakos


----------



## Hopper

Manolis, thanks for your interesting comments on the proposed gas flow vs traditional poppet valves. You make some very good points about the shortcomings of poppet valves. I look forward with interest to seeing how the rotary valve project goes when you get it up and running.

I may have missed in your other posts, but how will the rotary valve be lubricated to stand up to 40,000rpm  while coping with exhaust temperatures, which even with a short straight path for the exhaust, which will make the valve quite hot, I should think? Are you looking at hi-tech coatings or different materials for head and valve disc?


----------



## manolis

Hello Hopper.

   You write:
 &#8220;I may have missed in your other posts, but how will the rotary valve be lubricated to stand up to 40,000rpm while coping with exhaust temperatures, which even with a short straight path for the exhaust, which will make the valve quite hot, I should think? Are you looking at hi-tech coatings or different materials for head and valve disc?&#8221;


In case of normal size engines (say a CFR250 modified to PatRoVa or a Ducati Panigale modified to PatRoVa, or a Yamaha R1 modified to PatRoVa P1 as at http://www.pattakon.com/PatRoVa/PatRoVa_I4_90.gif (it needs different crankshaft, too)) the rotary valve will run dry, with the small roller bearings sealed (or ceramic). 
With a DLC coating (Diamond Like Carbon Coating) on the working flat surfaces, the PatRoVa rotary valve will run wear-free (reliability) and at low friction in case of surface contact.



In the case of small engines (model / RC engines) the lubricant used for the lubrication of the piston and of the crankshaft bearings will also lubricate the flat working surfaces of the PatRoVa rotary valve and its bearings.

   With the short stroke PatRoVa model engine (animations at http://www.pattakon.com/PatRoVa/PatRoVa_model_short_stroke_crankshaft_support.gif  and http://www.pattakon.com/PatRoVa/PatRoVa_model_short_stroke.gif ) running at 50,000rpm, the PatRoVa rotary valve in the cylinder head is rotating with only 25,000rpm (half crankshaft speed) and is completely rid of loads (if it is not yet clear &#8220;how&#8221;, please let me know to further explain). 

 In comparison, the crankshaft of the OS.18Z 2-stroke (15mm stroke) runs reliably till 42,500rpm (i.e. at almost double rpm than the PatRoVa rotary valve) and, note, it runs &#8220;heavily loaded&#8221; (combustion and inertia loads).

   So, I can&#8217;t see a problem.



Regarding the &#8220;high temperature&#8221; of the PatRoVa rotary valve, the PatRoVa rotary valve has a mean temperature lower than the temperature of the top cylinder walls and of the head bottom surface and of the piston crown.

The &#8220;red hot&#8221; exhaust gas does pass through the two exhaust ports of the PatRoVa and inevitably heats it. But it passes freely and quickly (just see the length (it is the width of the disk) and the shape of its path into the PatRoVa).
   Most of the rest valve surface is in contact with cold (or, at least, not too hot) gas. 
   The rotary valve actually lives &#8220;into&#8221; the fresh cold charge. 
   During the intake, the fresh / cold charge passes through the intake ports and cools down the rotary valve. 
During the final part of the compression and during the combustion and during the expansion, the hot compressed gas &#8220;sees&#8221; through the two windows only a small part of the inner flat surfaces of the two disks.

In comparison think what happens on the surface of the piston crown and of the bottom of the cylinder head and of the upper cylinder liner:
   During the compression &#8211; combustion &#8211; expansion &#8211; exhaust this surface is heated by the hot and extremely hot gas.
   The complete above surface is permanently in contact with the hot gas in the cylinder.  
   Only during the intake ( suction cycle ) the above surface comes in contact with cold gas and is cooled internally.
   Without additional cooling (cooling fins, cooling liquid) the engine will melt.


Or compare the temperature of the PatRoVa rotary valve with that of the Cross or Cross-Bishop or Aspin rotary valves. In the Bishop &#8211; Cross design, half of the rotary valve is &#8220;in the hell&#8221;; it actually is an extension of the red-hot exhaust pipe; it never sees cold (or not too hot) gas. The Aspin rotary valve comprises the &#8220;top&#8221; of the combustion chamber and is difficult to be cooled.


   Do I miss something?

   Thanks
   [FONT=&quot]Manolis Pattakos

[/FONT]


----------



## Goldflash

One of the main reasons for the success of the 4 valve head is the combustion chamber shape and the central location of the spark plug. 
I have problems with your design as I cant see where you put the spark plug and how do you achieve good flame propagation


----------



## Hopper

Manolis, no I don't think you have missed something! Very thorough explanation of the theory behind your design. I'm very interested to see it in practice. The full-size  motorbike engine in your pictures in earlier posts, has it been made to run? Might it be easier to make a full sized prototype head like the motorbike engine than to do it in miniature on a model engine?


----------



## manolis

Hello Goldflash

   You write:
   &#8220;One of the main reasons for the success of the 4 valve head is the combustion chamber shape and the central location of the spark plug. 
I have problems with your design as I cant see where you put the spark plug and how do you achieve good flame propagation&#8221;


   The Dexmodromic Ducati Panigale is regarded as one of the most technologically advanced engines today.

   Here is the &#8220;bottom&#8221; of its cylinder head (the circles / ellipses are explaines at post #20):






   And here it is shown the piston crown of the Panigale 1299, at left, and of the Panigale 1199 at right:






   The combustion chamber is formed between the cylinder head bottom and the piston crown.

   With 12.6:1 compression ratio and 60.8mm stroke, the mean height of the combustion chamber when the piston is at TDC is 5.24mm.

   Imagine a 116mm diameter disk with an average height of only 5.24mm.

   The space in the valve pockets on the piston crown comprises a significant part of the combustion chamber. A good part of the combustion happens into the valve pockets.

   The spark plug is centrally located, however the flame has to travel all the 116/2=58mm to reach to the ends of the combustion chamber.

   The combustion chamber (the space between the bottom cylinder head and the piston crown) is designed around the poppet valves, their motion and their limitations.

   If the pent-roof combustion chamber were so good, the 2-strokes would use the pent-roof, too.

   Here is the PatRoVa V-2 for comparison with the abovementioned Panigale:






   The cylinders / cylinder heads are sliced in half; the animation shows the shape of the half combustion chamber. The width of the complete combustion chamber is double.

   At TDC the clearance between the flat piston crown and the flat bottom of the cylinder head is as small as possible (it is required a safety clearance to not allow piston / cylinder head collision at high revs) so that almost all the compressed gas is in the chamber between the two disks of the PatRoVa rotary valve.
   See the size of the squeeze area.
   See the shape of the combustion chamber (its width is some 30mm) and how close to the spark plug is concentrated the mixture to be burned.

   The travel of the flame is about half than in the Panigale (for same bore).
   And while in the Panigale the flame actually propagates along only two dimensions (as explained, the combustion chamber is like a thin disk), in the case of the PatRoVa the flame propagates along all three dimensions and its speed is substantially faster, enabling most of the combustion to end in a narrow area of angle around the TDC.

   Unless I am wrong, in the Ducati Panigale they use, at specific conditions,  even 60 degrees spark advance. Think what this means.

   With substantially faster combustion and with substantially more compact combustion chamber, things improve a lot (fuel efficiency, clean exhaust, less cooling, etc). 

   While the 4-stroke poppet valve engines are the best engines today, they have several issues. These issues get apparent when alternative designs come to challenge the existing solutions .


   Thoughts?

   Objections?

   Questions?

   Thanks
   Manolis Pattakos

 .


----------



## manolis

Hello Hopper.

   You write:
   &#8220;I'm very interested to see it in practice. 
   The full-size motorbike engine in your pictures in earlier posts, has it been made to run? Might it be easier to make a full sized prototype head like the motorbike engine than to do it in miniature on a model engine?&#8221;


   So far we have made a &#8220;proof of concept&#8221; &#8220;full size&#8221; running PatRoVa prototype:











   Youtube video at [ame]https://www.youtube.com/watch?v=6Q-EGdeS0ws[/ame] 

   [youtube]https://www.youtube.com/watch?v=6Q-EGdeS0ws[/youtube]

   Its manufacturing quality is less than poor, however it shows that the basic idea is right, functional and promising.



   So, why a model / miniature PatRoVa?

   Because it is too simple and cheap and easy to be made. 
   And because it will be a unique model / miniature engine: it will be the only 4-stroke model engine running at higher revs than the similar size 2-stroke model engines. Etc. Etc.


   If you study the CAD drawing ( email me; contact info at http://www.pattakon.com/pattakonContact.htm ) you will be surprised by its simplicity. Most of it is easy, but accurate, conventional milling work.

   If it is made by an independent third party (like one or more members of the Home Model Engine Machinist forum) and is evaluated by a third party, the evaluation would have a different value.
   .
   Thanks
   Manolis Pattakos


----------



## Hopper

Sadly, I don't have a mill or rotary table at this stage so can't help out. Hopefully someone will step up and make you a piece, just to see if it works as well as described or not! Come on guys, not a big job and enquiring minds want to know!


----------



## manolis

Thank you Hopper.

   Here is another version of the PatRoVa short stroke model engine:






   There are two differences as compared to the previous animations.

   It has funnel exhaust ports (the port area at the outer side of each disk is substantially bigger than at the inner side of the disk).

   It exploits the exhaust gas inertia to accelerate a fresh air stream and cool internally by it the exhaust port of the rotary valve as well as the exhaust passageways in the cylinder head.


   In the animation the engine is shown at the overlap. 


   The exhaust is near to finish. 

   The exhaust port in the PatRoVa rotary valve has just started to  bridge the exhaust passageways in the cylinder head with a port cut on the head cover (the blue part) providing fresh / ambient air (not air-fuel, just air).

   The inertia of the exiting exhaust gas into the exhaust gas piping (not shown) creates a vacuum and suctions fresh air (through the exhaust port of the rotary valve) from the port on the cylinder head cover, *scavenging* the hot gas and cooling internally the exhaust port of the rotary valve, the exhaust passageways in the cylinder head and the rest exhaust piping.

   In the specific design, the exhaust port of the rotary valve continues to bridge the fresh air port on the head cover with the exhaust for some 120 crank degrees after the overlap.


   Note:
   In the animation they are not shown the two side covers of the exhaust passageways. Without them, the exhaust gas exits from the sides of the cylinder head. With them, the exhaust gas exits from the two orthogonal holes at the front (shown at right) side of the engine (these orthogonal holes are arranged oppositely to the inlet port).


   Thoughts?

   Objections?

   Thanks
   [FONT=&quot]Manolis Pattakos [/FONT]


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## manolis

Hello all.

This stereoscopic animation of the short stroke PatRoVa model engine:






(more on how to see stereoscopically at http://www.pattakon.com/pattakonStereoscopy.htm )

is complimentary to the animation in the previous post.

Thanks
Manolis Pattakos
.


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## IceFyre13th

just cross your eyes and look at the middle image......love it!!!!


----------



## manolis

Hello IceFyre13th.

Here is the same engine stopped, shown stereoscopically  from various viewpoints






Try to explain to the rest forum members how much more info you get by combining with your crossed-eyes the two images, than you can get from each image alone.

You can also try this:






or






or






or






Thanks
Manolis Pattakos


----------



## IceFyre13th

How, what did you use to create the stereo images.........Only way I know of is with a dual lens "stereo" camera, is there an app or program that can be used?


----------



## manolis

Hello IcwFyre13th

   You write:
   &#8220;How, what did you use to create the stereo images.........Only way I know of is with a dual lens "stereo" camera, is there an app or program that can be used?&#8221;



   This animation (stereo diamonds):






   was made by a small program written in Quick-Basic long ago. 

If you hide by your palms the side images, it gets even better.



   This:






   stereo-photo is nice by its own. 

   But what if you could focus on any particular point you like?

   This is what the http://www.pattakon.com/educ/StereoFlowers.exe program, written in Visual Basic, does. The result is more impressive and useful than the &#8220;static&#8221; stereo photo. 
   Provided you run windows, you open the above exe program and look at the image with crossed eyes; then you move the mouse smoothly around the screen and look; you can spend several minutes &#8220;exploring&#8221; this photo, and each time you re-open it you discover new details in it..
   You can do the same with the http://www.pattakon.com/educ/StereoAgiaKyriaki.exe and http://www.pattakon.com/educ/StereoPatsosMilos.exe (they also need windows).



   And you don&#8217;t need a &#8220;dual lens stereo camera&#8221;. 
   For instance, this stereo image:






   was created by combining two independent slides (from a series of slides given to the public) taken with a high tech GE&#8217;s computed tomography device.
   I.e., all you need is a pair of &#8220;compatible&#8221; photos (of an object or scene) taken from the proper direction and distance. 

   For instance, to create the last stereo-photo of the previous post you pick a central point in the scene to focus on, you also choose the &#8220;horizontal direction&#8221; you like. Take the first photo, then rotate for some degrees (say 5, 7, 10 etc) the camera about the central point keeping the distance from the central point unchanged and the &#8220;horizontal&#8221; direction unchanged, too. Finally put the two photos side by side and look at them by &#8220;crossed eyes&#8221;.

   In case you want to make stereo videos with a simple camera, you can do it, but it is a little complicated because you need a set of four small mirrors properly arranged in front of your camera. But this is another story.



   And what about creating stereoscopic drawings?

   Things are not too complicated.

   Think simply: 
   What you need is not necessarily a pair of photos of the same object from two different viewpoints. 
   If you put properly two &#8220;identical&#8221; objects side by side and take a single photo of them, you have what you need. 
   This is what you can easily do with a CAD program.

   Suppose you have the CAD design of a mechanism and you want to see it stereoscopically on the screen.

   Orbit the mechanism to come to your desired &#8220;view direction&#8221; and set the UCS (user coordinate system) according the current view (i.e. so that the X axis is horizontal on the screen, the Y axis is normal to the X on the screen too, and the Z axis is normal to the screen towards the viewer).
   Copy the complete mechanism at the one side of the original mechanism, at some distance from each other. 
   Then &#8220;center&#8221; the screen (pan command) to show both mechanisms (the one at the left side of the screen, the other at the right side of the screen, with an empty space between them).
   Now choose the &#8220;perspective view&#8221;:
   In AutoCAD there is the command &#8220;Dview&#8221; wherein you can choose the distance of the camera and the zoom/lens used.
   In Autocad there is also the &#8220;Orbit&#8221; command in the sub-menu of which you can choose the &#8220;perspective view&#8221; instead of the standard &#8220;parallel view&#8221;. If necessary change the lens characteristics (by, say, the Dview command).

   Now you have on your screen the mechanism stereoscopic.     

   If you like, you can orbit the set about the horizontal axis (orbit command) to view it stereoscopically from various viewpoints.



   The important with the stereoscopic view is that looking with &#8220;crossed eyes&#8221; at the two flat images / photos of the object / mechanism / scene, the object / mechanism / scene leaves the screen or the paper and is formed in front of the viewer &#8220;alive&#8221;. The viewer thinks that he can touch by his fingers the flowers, or the nose of a person, or the piston, or the cooling fins etc of a prototype engine etc.

   In complicated drawings the stereoscopic viewing proved in practice a useful and fast way to check for errors.

   Talking for errors:
   there is a &#8220;game&#8221; wherein they are provided two slides / scenes having a few small differences / errors between them, with the question being to find the differences / errors.
   Don&#8217;t try to compete / to win in this game someone who can see &#8220;stereoscopically&#8221;, because by a glance he can spot on all differences.  



   It is sad that only few people insist and finally achieve to see this way. Then it is like the bicycle: you can&#8217;t forget it.


   If something of the previous is confusing, please let me know to further explain.

   Thanks
   Manolis Pattakos
   .


----------



## IceFyre13th

Great explanation, thank you........gives me another tool for work. I am a mechanical engineer and use SolidWorks.......its always been a problem with 2D renderings to get the full effect of the look across to others who "don't _see_ as I do". This technique may just be what others need to "see the vision" of the product (s) I am.


----------



## manolis

Hello all.


   IceFyre13th, it is nice to see you understood the worthiness of the &#8220;stereoscopic viewing&#8221; as a tool for all those designing with CAD programs.


   I see many &#8220;likes&#8221; for the last post. 
   So let me further explain a few things for those interested.


   Here is the application in practice of my last post.

   What you see in the following stereoscopic gif slide:






   is what you will see opening the OOhttp://www.pattakon.com/PatRoVa/PatRoVa_model_engine_3_STE.dxfOO
   drawing with a CAD program. 

   How to open it?
   Copy the above link (omit the four O's at the sides of the text) and paste it in the &#8220;File name&#8221; box of the &#8220;Open&#8221; dialog box of your CAD.

   If after opening the above dxf file:

   1. you look normally at the left or at the right image, what you see is &#8220;flat&#8221; and confusing; for instance, you cannot say which part or line is over the other,

   2. you look &#8220;crossed eyes&#8221; both images, what you see in the middle is the engine formed in the space in front of you and not on the screen; now things have clear out: each line and each part has a specific location relative to the rest; now you can say for sure if this or that part is closer to you (and if you like, you can &#8220;orbit&#8221; the two images in order to see the stereo engine from various viewpoints; important: the orbit should be exclusively about a horizontal axis) ,

   3. you turn from perspective-view to parallel-view (for instance, using the submenu of the &#8220;Orbit&#8221; command in the case of AutoCAD) 
   (as you can check, you cannot see, any longer, the object stereoscopically, no matter how much you cross your eyes,
   as you can also check, the right image is a copy of the left image with the displacement being exclusively along the horizontal axis),

   4. you delete the right image,

   then what you get is the following conventional 3D (but non-stereoscopic) dxf drawing:

  OOhttp://www.pattakon.com/PatRoVa/PatRoVa_model_engine_3.dxfOO

   of the last version of the PatRoVa short-stroke model engine from which the transparent animations were made (note: as expected, the size of the last dxf file is about half than the size of the &#8220;stereoscopic version&#8221.


   As you see, going from the conventional drawing to the stereoscopic and vice versa, is a simple and fast procedure. 


   Opening with your CAD program the last dxf file (How? Copy the above link (omit the four O's at the sides of the text) and paste it in the &#8220;File name&#8221; box of the &#8220;Open&#8221; dialog box of your CAD), you have what you need in order to examine the details and the easiness of manufacturing of a prototype.


   Note: the O's at the beggining and at the end of the links were used to avoid the abreviation the system applies to the long links. If there is a better way, please let me know.

   Thanks
   Manolis Pattakos
. 
  [FONT=&quot][/FONT]


----------



## manolis

Hello all.

   Here is a V-2 model (RC) engine:






   The animation is stereoscopic (for instructions on how to look at it: http://www.pattakon.com/pattakonStereoscopy.htm )

   Bore 24.8mm, 
   stroke 13mm (i.e. same bore to stroke ratio with the Ducati Panigale 1299 which has 116mm bore and 60.8mm stroke), 
   total capacity 12.5cc, 
   rev limit at 50,000rpm (21.7m/sec mean piston speed).

With the secondary balance web (orange) at the free end of the crankshaft, the &#8220;vibration free quality&#8221; of this engine is the same with the vibration free quality of the big Ducati Panigale.

   The one connecting rod is red, the other is blue. They share the same crankpin.

   There is one only, common for both cylinders, timing belt.

There is one only crankpin (it is of bigger diameter than in the single cylinder).

The crankshaft is rotatably mounted on the casing (the green part) by two roller bearings. The roller bearing beside the main balance web (orange, with the crankpin on it)  is the strong one. 

   The casing (the green part with the cooling fins) is a single piece part. See how compact and simple and robust it is.

   Thoughts?

   Objections?

   Thanks
   [FONT=&quot]Manolis Pattakos
.
[/FONT]


----------



## manolis

Hello.

Thiis transparent animation of the last V-2 PatRoVa model engine (last post) may  be helpful.






Thanks
Manolis Pattakos


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## Nick Hulme

Censored 

..............


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## Nick Hulme

Censored 

,,,,,,,,,,,,,,,,,,,,


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## manolis

Hello Nick Hulme.

   You write:
   what makes this seal as well as or better than previous rotary valve systems?
   . . .
*the gasses leak* around the valve faces and this *is dependent only on clearances* and the pressure difference between cylinder and atmospheric.


   PatRoVas sealing is better than previous rotary valve systems because its architecture allows several times smaller clearances to be used and to be maintained. 


   The above is analytically explained at http://www.pattakon.com/pattakonPatRoVa.htm 


   In a few words:


   With the permanently zero total force on the PatRoVa rotary valve (no matter what the pressure inside the cylinder is) the sealing is independent from the bearings that support the rotary valve. 

   In comparison the sealing clearances in a Cross rotary valve (or in an Aspin rotary valve, or in any other rotary valve of the prior art) is the sum of the basic sealing clearance (when the force on the rotary valve is zero, i.e. without pressure into the cylinder), plus the clearance of the bearings whereon the rotary valve is supported. And because these bearings are heavily loaded, and because these bearings are of big diameter (for instance, in the case of the Cross rotary valve or of the Bishop-Cross rotary valve the mixture and the exhaust gas pass necessarily through the bearings that support the rotary valve), and because some of this bearings run too hot, the bearing clearance (which is added to the basic clearance) cannot be small enough to allow sealing without additional sealing means.    


   With a structure which is by far stiffer (for the specific loads applied) than the conventional rotary valves, the clearances can be maintained several times smaller.

   Take the Bishop rotary valve (if the F1 rules had not been changed on 2004 to ban the rotary valves from F1, today all F1 cars would have rotary valve engines) and examine its structure and how flimsy it is for the loads it takes as compared to the PatRoVa rotary valve. 
   The Bishop rotary valve (the most advanced rotary valve, so far) is a thin tube with an oblique separator at the middle and two long axial ports, one on the cold side and another on the red hot side of the tube (i.e. it is a highly asymmetrical design which undergoes a highly uneven thermal expansion: half of the periphery of the tube (around the oblique separator) runs at, say, 900 degrees Celsius, while the other half of the periphery of the tube (around the oblique separator) runs at 50 degrees Celsius), with two big diameter needle roller bearings at the sides of the cylinder (i.e. at a long distance from each other, say at 130mm distance for a 100 bore cylinder) supporting it.
   Think what the thermal expansion can do in such a tube.
   Then think how much the sealing clearance is affected by a force of, say, 2 tons (20cm2 window area, 100bar cylinder peak pressure) acting through the window on the Bishop rotary valve.
   Make a calculation or better make a test / experiment: put a 65mm (outer diameter) x 55mm (inner diameter) x 150mm (length) tube on two supports 130mm from each other, apply a force of 2tons at the middle of the tube and measure the bending of the tube (i.e. the displacement of the middle of the tube relative to its position without the 2 tons force) by a micrometer). Then cut two long ports on the tube and do the same measurement. 
   In practice (on the running engine) in the basic clearance of the Bishop rotary valve it has to be added the displacement of the center of the tube due to the force applied on it, it has also to be added the clearance of the big diameter / high speed needle roller bearings at the ends of the valve. 
   Important: the previous are for uniform temperature of the Bishop valve (say, for cold engine). But the temperature of the Bishop rotary valve during operation is highly uneven along and around it, which causes bending / distortion of it and increases substantially the required clearances.
   Are we talking for hundredths of a mm, or for tenths of a mm?

   I hope you understand now the difference. 

   A Cross or a Bishop-Cross rotary valve or an Aspin rotary valve, or a Coates spherical rotary valve cannot function without additional sealing means because of the several times bigger (than PatRoVas) clearances its architecture requires.  

   With the same total port area (10+10=20cm2) and the same cylinder pressure (100bar) the force onto each disk of the rotary valve is 1 ton.
   Calculate the increase of the distance between the two discs of the PatRoVa. Take the diameter of the hub of the PatRoVa (at the ends of which they are secured the two disks) as 40mm (12.5cm2 of steel) for a normal size (like, say, 400cc) cylinder capacity .
   Are we talking for more than 0.01mm? 


   I could stop here the explanation. 
   But there is a lot more.


   Things further improve because the sealing in the PatRoVa is independent from the distortion / displacement at the two, of the three, dimensions.
   Only the dimension along the rotation axis of the PatRoVa is significant for the sealing / clearances.
   The sealing is so much independent from the radial clearances of the PatRoVa rotary valve that the valve can be displaced radially for a couple of millimeters (2.0 mm) without spoiling the working clearances.


   Things are further improved with the significant reduction of the working length of the valve (thermal expansion effect). The working length is the distance between the inner flat surfaces of the two disks. This length is typically less than, say, 1/3 of the cylinder bore. For the Panigale 1299 (116mm bore) it would be some 35mm.


   Things are further improved with the proper materials for the cylinder head and for the rotary valve. The basic requirements are small thermal expansion coefficient and high modulus of elasticity. Like, say, steel, spheroidal graphite iron, INVAR etc.


   Things are more improved by keeping the PatRoVa rotary valve actually outside the combustion chamber (compare it to the Aspin rotary valve that lives inside the combustion chamber and comprises half of the combustion chamber wall surfaces).


   The quick (and free, i.e. without obstacles) passing of the exhaust gas from the short exhaust port of the PatRoVa protects the valve from overheating (compare to the exhaust side of the Bishop rotary valve), further improves things.


   The easy manufacturing (all the working surfaces are flat / plain surfaces) is another advantage. To cut and grind the two parallel flat surfaces (at the ends of the thick / robust shaft) at a specific distance from each other (equal to the width of the combustion chamber plus the basic clearance) is one of the simplest machining works. So it is not only that the PatRoVa needs several times smaller clearances than the other rotary valves of the art, it is also that the machining of the working surfaces is simple and requires no special cutting tools.


   With proper surface hardening on the flat working surfaces (say, DLC) it is allowed the dry operation of the cylinder head (full absence of lubricant from the cylinder head), and it is enabled the reliable operation for a long-long time and the slower degradation of the lubricant (oil changes at substantially longer time intervals, read at Coates CSRV). 


   Things are further improved by PatRoVas symmetrical design and PatRoVas symmetrical temperature distribution (compare it to the Cross / Bishop rotary valve wherein a highly asymmetrical design (oblique separator in the middle of the valve) is combined with one cold side and one red hot side.


   The free support of the PatRoVa on the cylinder head is another important characteristic that minimizes the required clearances and improves the sealing quality, especially for the multicylinder arrangements. See in the animations of the four-in-line how freely and independently from the others is supported each PatRoVa rotary valve and how it can find its perfect position above and around its own combustion chamber / cavity.

   Etc, etc, etc.

   Objections ?



   You also write :
   If you rely upon an oil film you will hit the usual oil consumption issue associated with many rotary valves


   As explained in the previous, there is no need for an oil film between the sealing surfaces of the PatRoVa.
   On the other hand, in a high revving model engine (this is the Home Model Engine Machinist forum) an oil film is used to improve the sealing between the piston and the cylinder liner (total loss lubrication). Even if you try to keep the flat working surfaces of the PatRoVa dry, this cannot be done because the exhaust gas has oil droplets in it. So, in such a case (high revving model engine) the PatRoVa will operate with an oil film between its flat working surfaces (which, in turn, allows bigger clearances and lower construction accuracy, i.e. easier and cheaper construction).



   You also write :
   there's nothing in any of *the fancy animations* which shows an innovative sealing solution, without which you have a nice lawnmower engine


   You cant see sealing means in the animations (or in the photos of the prototype running engine; did you see the youtube video at [ame]https://www.youtube.com/watch?v=6Q-EGdeS0ws[/ame] ? ) because there are no sealing means to be shown.

   Sealing means like those used in the Bishop rotary valve or in the Coates rotary valves can be used in the PatRoVa and they will be simpler due to the flat surfaces they abut on.

   However, and as explained analytically in the previous, the PatRoVa has, and maintains during operation, tiny clearances which make the conventional additional sealing means unnecessary.

   Think how much everything will change in the internal combustion engines if the PatRoVa is as claimed. The conventional; poppet valve cylinder heads will be replaced by zero friction, high flow capacity, no-rev-limit PatRoVa cylinder heads.



   By the way, did you achieve to see stereoscopically?
   I think not, because you wouldnt call these animations fancy.
   Most of those who failed (actually they stop trying) to see stereoscopically use to say: it cant be done.

   My advice: try harder; it is worthy; it is more than fancy; the software is in your brain, all it takes is activation.



   If I had to say in one sentence the previous:

   The PatRoVa does what the other rotary valves fail to do: it keep the rotary valve at its place, it has and maintain tiny clearances, it is robust and stiff where it is required to be.

   Thanks
   [FONT=&quot]Manolis Pattakos
. 
[/FONT]


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## Nick Hulme

Censored 

.......................


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## Charles Lamont

Nick Hulme said:


> You're just doing the same here as you did on the other engine sites you have spammed and finally given up on once discovered.


If we just ignore him he will probably give up here eventually.


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## manolis

Hello.

   Unless I am wrong, the HMEM is an Open Technical Forum.

   Some members (like Nick Hulme) try the &#8220;conspiracy theories&#8221; instead of the technical arguments. 


   To make it clear, you cannot buy pattakon stocks even if you want to. It is impossible. 

   Is it clear?

   What I want is not your money. 
   What I want from you is your background and experience and manufacturing capabilities.


   The funny think is that the guy who bankrupted several hundreds of innocent / naive investors worldwide (the founder of the Australian Revetec Company) was accusing others, writing:
   &#8220;Companies like this (he meant &#8220;pattakon&#8221 just burn investors money without having any prospect of getting an engine to perform or get to production.

   If you want to read my reply to Brad Howell-Smith (who accused others (!!!) for burning investors money), go to http://www.ultimatecarpage.com/forum/showthread.php?t=2958&page=9 and read the post 125.



   Here is the last sentence of the last post (by Spiderman, October 2015) in the original discussion for the Revetec engine at the Ultimatecarpage forum ( http://www.ultimatecarpage.com/forum/showthread.php?t=2958&page=98 ) :

   &#8220;Any claim that an altenative mechanism for pushing the pistons up and down can increase thermal efficiency by more than one or two percent are just rubbish (as pointed out by Manolis and others long ago, only to be shouted down by *all the experts here*).&#8221;


   In the hindsight, it is obvious that Revetec had a supporting / applauding team in the discussion in UltimateCarPage Forum (&#8220;all the experts here&#8221. Nobody was allowed to argue about Brad&#8217;s cranksless engine design, no matter how problematic it was. However, at the end it came the reality to put each one in his right place.  

   If you read all the posts, and have some basic technical background, you will understand who is right and who is wrong. 

   In the hindsight I was right (Revetec bankrupted, their investors lost their money, and, unless I am wrong, some of them have sued Brad Howell-Smith (who is out of Revetec for some years now).


   Have you seen the videos of the Opposed Piston Diesel prototype engines of pattakon? 

   Here is the PatOP Opposed Piston single cylinder Diesel engine free on a desk:

   [ame]https://www.youtube.com/watch?v=2ByEgfTTq1I[/ame]

   more at http://www.pattakon.com/pattakonPatOP.htm 


   Have you seen the video of the Honda VTEC 1,600cc modified to pattakon VVA roller? It is the only fully variable VVA that can do such things:

   [ame]https://www.youtube.com/watch?v=-zzW8YkReLU[/ame]

   more at http://www.pattakon.com/pattakonRoller.htm and http://www.pattakon.com/pattakonVtec.htm


   There are several other patented projects in the www.pattakon.com web site.


   Compare them to the last video published by Revetec (some three years ago) showing their Diesel engine &#8220;running&#8221; at &#8220;Atalan Makine&#8221; Turkey. 
   It was sad, but it was predicted. You can&#8217;t argue with reality.
   Now they (Revetec) cannot even pay the maintenance fees of their patents and one by one lapses.


   Allow me to declare once more that Pattakon never took a penny of any investor. 
   Nick Hulme, you should respect it and you should apologize for what you wrote. But it is your choice.



   Back to the strictly technical discussion:

   Are there, form the rest forum members, any technical arguments / objections for what  I wrote in the last technical analysis for the PatRoVa rotary valve in my last post?

   Thank you
   [FONT=&quot]Manolis Pattakos
.

[/FONT]


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## Nick Hulme

Censored 

...................


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## manolis

Hello Nick Hulme.

   Let me remind you: You can ignore this thread and proceed to the other ones; there are many. 

   Simple question: 
   Did you achieve to see stereoscopically? Honestly, did you?  
   Many people can&#8217;t and give in. 
   If and when you achieve it, you will like even more stereoscopic animations and &#8220;CAD diarrhoea&#8221;.

   Judging from the &#8220;22 new likes&#8221; in the last few days, it seems that several forum members disagree with you and enjoy this technical discussion and what you characterize as CAD &#8220;diarrhoea&#8221;.

   Thanks
   Manolis Pattakos


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## Nick Hulme

Censored 

....................


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## t.l.a.r. eng

Overheard a smart fellow once say, "If you cannot explain it simply, then you probably don't understand it yourself"  :wall: :fan: :hDe:


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## IceFyre13th

What is wrong with you guys......something comes along and you don't understand how it works so you bash a guy................If you don't like it shut up and let the rest of us who "get it" keep reading.

I have found this informative, and guess what.....I do "get it".... 

How does it seal.....guess you could ask "how a Wankel engine seals" too.

If you have nothing constructive too add then you can just move along and let the rest of us who find this interesting enjoy his postings. Too many "elite" builders here who think they know it all when they fail to see whats right in front of them........


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## manolis

Hello all.

   Thank you IceFyre13th for your idea with the Wankel.








*PatRoVa sealing versus Wankel sealing*


   Let me compare the sealing (and so the gas leakage) of a Wankel Rotary RC engine (say, the 49PI of the OS) with the single cylinder short stroke PatRoVa:

   According OS, their 49PI Wankel rotary has:
   4.97cc capacity (per chamber),
   1.1hp/17,000rpm,
   practical range: 2,500-18,000rpm,
   (weight: 450gr).

   According OS manuals / drawings, the height of the rotor (piston) along the axis of the power shaft is estimated at 15mm, while the total periphery of the triangular rotor is estimated at 120mm (40mm between each pair of apexes).

   So, each chamber of the model Wankel rotary uses for its sealing two apex seals and two pairs of flat surfaces (the one on the side of the rotor, the other on the casing) each having 40mm length. So, besides the two apex seals, each chamber of the above Wankel model engine leaks from a periphery of 40+40=80mm. The leakage through these two long slits (80mm total length) is limited using a small clearance between the sides of the rotor and the flat surface of the &#8220;side covers&#8221; of the combustion chamber. 


   The PatRoVa short stroke model engine has:
   6.28cc capacity,
   13mm stroke,
   and 24.8mm bore.
   The periphery of each window of the PatRoVa model engine is 30mm, which means the total &#8220;sealing&#8221; periphery is 30+30=60mm for a 6.28cc capacity. 


   At the same revs, say 15,000rpm of the crankshaft and of the power shaft, the time interval for leakage is 50% longer in the case of the Wankel: while the reciprocating piston of the PatRoVa needs 180 crank degrees to go from the maximum volume in the combustion chamber to the minimum volume in the combustion chamber (actually from the BDC to the TDC), the power shaft of the Wankel needs to rotate for 270 degrees in order the volume in the combustion chamber to go from its maximum to its minimum.


   The PatRoVa can feature a several times smaller clearance between the inner flat surfaces of the two disks and the lips of the chamber ports as compared to the required / necessary clearance between the flat sides of the rotor and the flat side covers of the casing. 
   Think why. 
   For the sake of the calculations let&#8217;s suppose the PatRoVa uses the same clearance with the Wankel rotary. 

   The absolute leakage in the Wankel model engine through the side slits is (80mm/60mm)*1.5=2 , i.e. it is double than in the PatRoVa model engine (the 1.5 is due to the 50% longer time the high pressure is maintained into the Wankel&#8217;s combustion chamber).

   The relative leakage is even worse: 2*(6.28cc/4.97cc)=2.5. This means that if a percentage of 25% of the charge in a combustion chamber of the Wankel model engine leaks from the sides of the rotor, this percentage drops to 10% in the case of the PatRoVa.

   (From another viewpoint: for the same percentage of leaked gas, the PatRoVa can run 2.5 times slower than the Wankel model. For instance, the PatRoVa running at 1,000rpm has the same leakage with the Wankel running at 2,500rpm (the lower practical rpm according OS)).



   But there is more:

   The PatRoVa has the same bore to stroke ratio with the Ducati Panigale 1299 and even freer breathing (the ratio of the total chamber port area to the piston area is bigger than in the Panigale). 
   The Panigale (1300cc, two cylinders in Vee 90 degrees) makes its peak power at 10,500rpm (21,3m/sec mean piston speed). Reasonably the PatRoVa model engine will make some 4.7hp at 50,000rpm (21.7m/sec mean piston speed).

   At 50,000rpm the time for leakage is 50,000/17,000 = 2.94 times less than at 17,000rp (where the Wankel model engine makes its peak power).

   And because 2.94*2.5=7.35, if at 17,000rpm the 15% of the charge in a combustion chamber of the Wankel model engine leaks from the side &#8220;slits&#8221;, this percentage will drop to only 2% in the case of the PatRoVa model engine. 


   And there is more:

   While the width of the combustion chamber of the PatRoVa (i.e. the distance between the two disks of the rotary valve) is less than 9mm, the rotor height (along the rotation axis of the power shaft of the Wankel) is 15mm, i.e. the one width is 60% bigger than the other.

   This means that the necessary clearances in the Wankel need to be some 60% bigger than the clearances in the cylinder head of the PatRoVa.
   Actually they are way bigger because of the architecture of the Wankel (see how the two side plates are secured to each other) and of the big temperature differences along the parts / surfaces that participate in the side sealing of the Wankel.

   To be noted: a double clearance allows a way more than double leakage.



   According the previous analysis:

   The sealing quality in the PatRoVa model engine is many times better than in the existing Wankel model engines.


   Objections?

   Thanks
   Manolis Pattakos

   .


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## Nick Hulme

Censored 

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## Nick Hulme

Censored 

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## manolis

Hello Nick Hulme.

   You write: 
   &#8220;It doesn't seal very well, to meet emissions&#8221;

   This is a progress!
   Now it seals, but not &#8220;very well&#8221;!



   Quote from http://www.pattakon.com/pattakonPatRoVa.htm :

*&#8220;Leakage internally recycled* 

Without having a pathway to the exhaust, any gas leakage from the combustion chamber during the compression / combustion is recycled: it returns into the cylinder at the next suction cycle. 

This built-in "recycling" of the unburned gas leakage is even more important at the warming-up period wherein the clearance between the valve fronts and the chamber ports is not yet minimized.&#8221;

   End of Quote.


   I.e. the PatRoVa rotary valve automatically recycles any leakage from the top end of the combustion chamber.

   If you look carefully at the CAD drawings and at the photos of the parts of the working prototype, you may understand how. 
   If not, let me know to make a few more CAD drawings.


   The conventional poppet valve engine besides leaking from the piston rings towards the crankcase, it also leaks (slightly, but leaks) from the poppet valves before the pressure gets high enough to make the valves seat tightly on their seats.
   Think: where the leaked, through the not perfectly seated exhaust valves, goes?
   Did you ever think the effect of the uneven thermal expansion in the cylinder head of a poppet valve engine?






   Look at the one exhaust valve (say the one at right top, it is 38.2mm diameter) of the Panigale: its valve seat neighbors at left with the cold intake valve, at right with the hot exhaust and at its lower part with the other red-hot exhaust valve. When cold the valve seat is circular. At operation (i.e. hot) is cannot help being oval. 

   Are you sure that during the initial part of the compression there is no escape of charge towards the exhaust?

   As you see, the thermal expansion has to do with the poppet valve engines, too.. 



   In the Wankel rotary a good part of the leakage is from the two apex seals of each chamber. 
   During the high pressure period in a combustion chamber, the leakage to the (following) chamber wherein intake and compression take place is &#8220;automatically&#8221; recycled during the next combustion. 
   However the leakage to the other (leading) chamber wherein the exhausted gas is expelled by the rotor, goes inevitably to the exhaust and this is a significant problem (emissions).
   By the way, near the apex seals of the Wankel is where significant quantities of unburned mixture are found at the end of the combustion, i.e. what leaks from the apex seals is, mostly, unburned mixture.



   The recycling of the leakage is a significant problem for the Coates spherical rotary valves, too.
   Any leakage from the exhaust spherical valve goes directly to the exhaust and spoils the emissions.



   You also write:
   &#8220;The sealing quality in the PatRoVa model engine is still a bit Wankel compared to poppet valves!&#8221;

   The 5cc OS model Wankel engine runs well (as a model engine) without side seals. Its side &#8220;slits&#8221; through which a part of the leakage occurs have an 80mm total length and the height of the rotor (along the rotation axis) is 15mm.

   As shown, the leakage in the PatRoVa short stroke 6.28cc model engine is several times smaller.

   Consider now the PatRoVa Panigale 1299 (116mm bore, 60.8mm stroke). All its dimensions are 4.7 times bigger (so the length of the &#8220;leaking&#8221;slits increases 4.7 times), while the capacity of the cylinder is 4.7^3, i.e. more than 100 times larger than the model PatRoVa engine.

   Think: while the length of the periphery wherein leakage happens has been increased 4.7 times, the capacity of the cylinder has increased more than 100 times.

   Try to think the rest by yourself, or let me know to continue..



   You also write:
   &#8220;Coates also loves people like you, and their money&#8221;

   As Brad Howell-Smith (the founder of the Australian Revetec), similarly Coates (the founder of the US CSRV) has spent millions of  dollars of his investors for nothing. 
   Unless it is not fact that:
   almost all his patents are lapsed, 
   there is nothing in production,
   and many of his investors are penniless (it is really sad for the non-technically oriented ones). 

   On this basis, a fair guy should respect those who spend their own money to develop new ideas / inventions / solutions, even if they look crap.

   Thanks
   [FONT=&quot]Manolis Pattakos
.
[/FONT]


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## Nick Hulme

Censored 

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## manolis

Hello Nick Hulme.

   You write:
   It leaks
Thank You. 
It Leaks Back Into It's Own Induction Tract. 
So it burns oil and has reduced performance from contaminated inlet gasses. . .


   What kind of reasoning is this?


   Lets apply the same reasoning in  the conventional poppet valve engines:
   It leaks (from the cylinder towards the crankcase).
   It leaks back into its own induction track (the leakage to the crankcase is recycled to the induction track).
   So it burns oil and has reduced performance from contaminated inlet gasses. . .


   It would be nice if you could further explain what you mean. 
   And write which kind of PatRoVa engine you mean.


   To make things easier for you:

   In case of model engines, the lubricant into the fuel is the case (as well as the total loss lubrication). 
   Inevitably the PatRoVa model engine (as the rest model engines) will have some oil on the sealing surfaces in the cylinder head.

   In the case of normal size engines (say for motorcycles, cars, airplanes), the cylinder head runs dry. There is no lubricant in the cylinder, only air and fuel. The scrapper rings keep the lubricant from entering into the combustion chamber as in the conventional poppet valve engines. 
   Any leakage towards the cylinder head is recycled during the next combustion. 
   Where the lubricant you talk about comes from? 



   You also write:
   Talking about Rotor Tips is simply an irrelevance as your engine doesn't have them and 99%+ of IC engines don't have them either.

   Try again and you will achieve to see the  great relevance between them. Here is some help for you:

   The model Wankel rotary engine uses a tiny clearance between the  flat sides *of the rotor* and the flat sides *of the casing* to minimize the leakage.

   The PatRoVa rotary valve engine uses a tiny clearance between the  flat sides *of the rotary valve* and the flat sides *of the cylinder head *to minimize the leakage.

   No relevance at all!


   Do you want to get a little deeper?

   In a modified to PatRoVa (according the CAD drawings provided so far) old C50 Honda engine (39mm bore, 41.4mm stroke, 49cc) the width of the combustion chamber equals to the height of the rotor (along the power shaft rotation axis) of the 4.97cc OS Wankel model engine (mentioned in previous posts), and the total length of the slits results the same, too.

   If you want the CAD drawing I will post it.

   Suppose the PatRoVa C50 runs at 2/3 of the revs of the Wankel model engine.

   The one engine is 50cc while the other is only 5cc (i.e. the one tenth).

   The peak pressure in the cylinder is the same.

   So, both appear to have the same absolute leakage (i.e. quantity of gas leaked).

   Think about it once more. 

   Decide which is the maximum permitted leakage for the OS Wankel 5cc engine (more leakage and the engine stops running).
   Do you want a 25% limit?
   Do you want a 50% limit?

   Take the 50% case. 
   So, with 5cc capacity for each chamber of the Wankel, the 2.5cc leak from the sides of the rotor.
   The absolute leakage is the same for the ten times bigger PatRoVa C50 engine, which means that from the 50cc of the charge only the 2.5cc leaks from the PatRoVa rotary valve, which is 5% of the total quantity of mixture in the cylinder.
   Compare the 50% leakage in the Wankel model engine with the 5% in the PatRoVa C50.

   More reasonable is a 10% leakage in the Wankel 5cc engine. In such a case the leakage (which is automatically recycled during the next combustion) from the rotary valve of the PatRoVa C50 becomes 1%. By the way, how much do you think is the conventional leakage from the sides of the piston to the crankcase?

   I admit it is not so easy to get it, but try.
   I am sure somebody in this forum gets it.



   You also write:
   And Finally. 
I have a set of plans for an anti-gravity machine which draws it's power from a greater than unity efficiency engine, you can have a set for £10, it has been proven to work but must be built exactly to the plans ;-)


   Millions of guys proposed the anti-gravity machine before you.
   This is why the serious Patent Offices refuse to receive patent applications for anti-gravity mechanisms and of perpetual motion mechanisms.

   On the other hand, and if you really want to fly, there are more conventional ways than antigravity mechanisms. 
   See for instance the pattakon Portable Flyer project at:

http://www.pattakon.com/pattakonPatTol.htm#PortableFlyerAxial

   As happens with the rest pattakon projects, the OPRE_Tilting engine is patent protected. 











   I suppose you know what Intellectual Property is. If not, I can explain.


   A really smart guy would first try (and try and try and try and try ) to see stereoscopically (all it takes is a pair of eyes and a functional brain) and only after achieving it, he would come joking about antigravity mechanisms etc.  

   Thanks
   [FONT=&quot]Manolis Pattakos
.

[/FONT]


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## Nick Hulme

manolis said:


> The scrapper rings



Yup, 
Those Freudian Slips just keep coming ;-)

Patents mean nothing, without commercial applications there's nothing worth protecting and getting a patent doesn't mean something is of any use either. 
As you've failed to get anything in production in the best part of 10 years of bulling this stuff about I'm guessing that none of what you have is of any commercial interest.

EDIT - 
Just found this howler on the website and couldn't not include it - 
"Considering the flat fronts and the flat lips as parts of spheres (or cylinders) of infinite diameter"

You could consider your toeses are roses but they're not and the logic is flawed, the port is close to the edge of a disc so that infinite stuff is misleading bunk

And 

"At a thermal expansion (or contraction) each rotary valve slides slightly along the splined shaft and continues its friction-free / wear-free cooperation with the respective ports." 

Seriously, you just can't make this stuff up, it's dry and it's close enough to provide a gas seal and it's friction-free and wear-free, got to stop and clean the keyboard, my coffee came down my nose when I read that


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## Mechanicboy

Charles Lamont said:


> If we just ignore him he will probably give up here eventually.



He is expert for writing long story about his invention who is already invented and discarded. Best not to respond to his comments. So, I hope he gives up eventually.


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## t.l.a.r. eng

Nick Hulme said:


> "Considering the flat fronts and the flat lips as parts of spheres (or cylinders) of infinite diameter"
> 
> And
> 
> "At a thermal expansion (or contraction) each rotary valve slides slightly along the splined shaft and continues its friction-free / wear-free cooperation with the respective ports."



Possibly where all the sparks are coming from when it runs. :thumbup:


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## manolis

Hello Nick Hulme.

   You write:
   &#8220;Patents mean nothing, without commercial applications there's nothing worth protecting and getting a patent doesn't mean something is of any use either. 
As you've failed to get anything in production in the best part of 10 years of bulling this stuff about I'm guessing that none of what you have is of any commercial interest.&#8221;


   Patents mean a lot.

   An Examiner (specialized in a narrow field, say in the rotary valves) of the Patent Office wherein a patent application was filed searches for similar inventions / ideas all over the world and decides if the invention in question is new, if it has inventive step and if it is applicable.

   Many of the modern car engines use the Atkinson / Miller cycle (one of the first was the Toyota PRIUS).

   Here you can read the patent of Ralf Miller (filed 23 September 1952) http://www.pattakon.com/tempman/Miller_patent.pdf

   The patents are one of the most useful tools of the modern world.



   You also write:
   &#8220;Just found this howler on the website and couldn't not include it - 
"Considering the flat fronts and the flat lips as parts of spheres (or cylinders) of infinite diameter"
You could consider your toeses are roses but they're not and the logic is flawed, the port is close to the edge of a disc so that infinite stuff is misleading bunk&#8221;


   What is so difficult to be understood?






   In the above drawing the numbers show the diameters of the spheres (some parts of which comprise the PatRoVa rotary valve sealing surfaces). 

   The bigger the diameter, the smaller the total radial force on the rotary valve.

   In the case at right&#8211;bottom, the radius is infinite which makes the working surfaces flat / plain, eliminating the total radial force on the rotary valve.



   You also write:
   &#8220;(Just found this howler on the website and couldn't not include it)
   "At a thermal expansion (or contraction) each rotary valve slides slightly along the splined shaft and continues its friction-free / wear-free cooperation with the respective ports." 
Seriously, you just can't make this stuff up, it's dry and it's close enough to provide a gas seal and it's friction-free and wear-free, got to stop and clean the keyboard, my coffee came down my nose when I read that&#8221;


   On one hand consider the &#8220;zero total force&#8221; characteristic of the PatRoVa rotary valve and, on the other hand, consider the fact that the most frictionless bearings today are neither the roller bearings, nor the plain bearings with hydrodynamic lubrication, but the air bearings.  

   Quote from http://www.newwayairbearings.com/sites/default/files/new_way_application_and_design_guide_%20Rev_E_2006-01-18.pdf (do read it)

   &#8220;What is an air bearing?
   Unlike contact roller bearings, air bearings utilize a thin film of pressurized air to provide a &#8216;zero friction&#8217; load bearing interface between surfaces that would otherwise be in contact with each other (Figure 2). Being non-contact, air bearings avoid the traditional bearing-related problems of friction, wear, and lubricant handling, and offer distinct advantages in precision positioning and high speed applications.&#8221;






   End of quote


   Thanks
   [FONT=&quot]Manolis Pattakos
.
[/FONT]


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## Nick Hulme

Censored 

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## manolis

Hello Nick Hulme

   You wrote:

   &#8220;Saying a flat surface is equivalent to an infinite spherical surface may be geometrically correct but it means nothing significant in your application, you're just using the old charlatan's trick of throwing irrelevant facts into the mix to obfuscate the BS by stating that you've "eliminated" something that isn't there. 

I've made my living room floor comfortable to walk on in bare feet by eliminating all the sharp points in a flooring surface I haven't used and never had - there, easy! 

Patents mean a lot, yes, but I stated thet patents do not mean that an invention is of any use and they do not prove the merit of anything, what percentage of patants granted have ever seen productive use, most of them are useless, verbose rubbish with lots of pretty drawings and little real substance, _ringing any bells here?_ 
The patent office will take the money of any unfortunate who comes along with a novel but worthless idea, sorry pal. 

Air bearings are nothing new but by definition they are a clean technology - the complexity required to make this work with long term reliability in your rotary valve system renders your concept cost-innefective, and to manufacturers, very, very unnatractive, but I guess you've found that for yourself since your "Expo days"? 

Just in case you are unaware and since you haven't mentioned it, to utilise air bearings in an engine environment you will need bump foils and complex surface coatings just to make it feasible for production use, and then you simply have to look at the one area where this is in development _(and ask yourself why)_ - turbos, to see why design engineers aren't using or developing air bearings inside engines simply consider the fact that that _(this is the "why" bit)_ the turbo is a small, light, easily replaced modular unit which is easy to swap out when it inevitably self-destructs and consumers are used to several turbo failures within the life of an engine. 

I'm sure some technologies will come along which render you engine feasible for production but as it stands you've just re-hashed a load of old ideas and changed the shapes enough to get some patents but failed to change the technologies to a degree which results in a practical real world production engine. 

You're a smart lad and you have a set of lovely curiosities but your incessant unproven insistance that they solve mankind's engine related woes coupled with overly verbose BS, huge swathes unnecessary illustrations 
_(I know you bought the software and think it's cute, it wears thin, believe me! You'd have been better spending the money on tooling so your in-house efforts looked more like the CNC work you farm out instead of something from J.C. Carpenters inc. of Nazareth)_ and your failure to sell so much as a toothbrush make you look so much like all previous Snake Oil salesmen and charlatans that it's difficult to resist a game of "Poke the Looney with a Stick" 

I'm sure your ideas will make nice models, toys and perhaps lawnmowers but they are not the answers you keep insisting that they are, they're nice and you are a funny guy, but you need to be quick, have you looked at the market out there? Most of the new lawnmowers coming out are *ELECTRIC* ;-)&#8221;


_It costs nothing to be polite._

_When you rewrite your post politely, I will answer._

   Thank you
   [FONT=&quot]Manolis Pattakos[/FONT]


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## Till

The simply genius aspect of a poppet valve is, that it does not move on the sealing surface when exposed to the maximum pressure of hot combustion gas. It stands still.
 The second genius aspect is, that the hot exhaust gasses do not pass an oil film at any time with high velocity. In fact, the valveguide is protect by a small *pillow* of air next to the stem when the valve opens.
The requirements are met by constructional elements strictly separated, even by time. This is the best you can get in terms of engineering. Each functional surface/element has only one function independent from each other. 
 Plus it's simple and cheap to manufacture, the seal is somewhat selfadjusting in operation AND has proven useful in billions of daily use application.  


 Your valve lacks all of this.
 There is relative movement of the sealing surface when exposed to hot exhaust gas. It is even worse: In the moment your valve opens to exhaust, hot gasses rage through the tiny orifice, heating adjacent material like a blowtorch in a spot that needs plenty of oil for lubrication constantly.
 There IS a gap between your valve and the cylinder head. This ruins all alternative valve designs on the emission side.
 The channels in the valve shaft call for casting as manufacturing process. The sealing surfaces must be hardened and ground, etc... it is rather complex in terms of cost, not small and cheap to manucfature.
 I guess there will be serious distortion and deflection, too, when one side is heated by exhaust gas and the other one is cooled by fresh gas constantly. The sealing surface on the disk calls for absolute precision, see the gap problem some lines above.   


 Now to the constructive part of my post. You can test your valve just the way Felix Wankel did, using a sidevalve engine.


 You might want to have a look at the ballvalve (German: Kugelventil) by Reinholt Ficht. Understand that it's rather advanced in terms of developent progress, understand it's limitations and you will easily understand the problems occuring with your own design.


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## manolis

Hello Till.

   You write:
   &#8220;The simply genius aspect of a poppet valve is, that it does not move on the sealing surface when exposed to the maximum pressure of hot combustion gas. It stands still.&#8221;


   One of the characteristics of the PatRoVa rotary valve is that the total force acting on it, is permanently zero, no matter what is the pressure into the combustion chamber.

   The bearings of the PatRoVa rotary valve run unloaded.












   Spot on the size of the bearings in the drawing, spot also on the slim &#8220;shaft&#8221; (black, 13mm diameter) of the PatRoVa rotary valve of the prototype in the photo.

   Without a force between the cooperating flat surfaces wherein the sealing occurs, the motion of the rotary valve during the high pressure period is not only harmless but advantageous (smooth running at constant angular velocity, vibration free, load free). 

   Do try to understand (to get) this big difference among the known rotary valves and the PatRoVa rotary valve: the same zero total force all around the 720 crank degrees.


   In comparison, the &#8220;non motion&#8221; of the poppet valve at the high pressure period is followed by a period of &#8220;fast motion&#8221; wherein the valve requires strong forces to act on it in order to perform the motion it performs, which in turn results in unsmooth running (in a single or twin at low rpm idling, the flywheel has to be adequately large to store the required energy for the compression of the valve springs), in vibrations, in heavy loads in the valve train, in friction, in wear, in reciprocation of energy between the valve and the rest valve train, etc, etc.

   Not so ideal as you described it.

   A high revving engine requires big poppet valves, high valve lift (which means attenuated combustion chamber and low thermal efficiency) and stiff restoring valve springs. 
   If the revs exceed the rev limit (set, in most cases, by the valve train), a collision between the piston crown and the poppet valve is possible.
   If the spring is not adequately stiff, and the acceleration / deceleration / jerk are beyond some limits, the poppet valve rebounds on its seat (or the cam lobe loses the control over the valve) destroying the breathing and causing wear of the parts.

   Besides its high temperature (and the problems it causes) the exhaust poppet valve has another significant problem: it is he pressure into the combustion chamber just before the exhaust valve opening. Take the Ducati Panigale 1299. Its exhaust valve is 38.4mm in diameter, which means 11.5cm2. With 5 bars into the combustion chamber the time the exhaust valve is to open, the required force is increased by 11.5*5=57.5Kp (125lb). 

   Compare with the PatRoVa rotary valve wherein there is neither accelerations, nor jerk, nor resisting pressure.



   You also write:
   &#8220;The second genius aspect is, that the hot exhaust gasses do not pass an oil film at any time with high velocity. In fact, the valveguide is protect by a small *pillow* of air next to the stem when the valve opens.&#8221;

   What do you mean by &#8220;oil film&#8221; in our case.

   The problem of the exhaust valve is not the valve guide. The problem is on the valve head.

   Consider the case the exhaust valve is open for, say, 1mm (the pressure into the combustion chamber is still high, and the temperature is extreme).
   The exhaust gas cannot help passing with supersonic velocity by the narrow gap between the valve head and the valve seat.
   I can&#8217;t imagine worst conditions for a part to live in.
   Red hot gas is bellow the exhaust valve head, red hot gas is passing at extreme speed over the exhaust valve head (in the gap between the valve and the valve seat which is also heated).

   All the cooling in the cylinder head is concentrated around the exhaust valves. Spot on the cooling liquid holes (all but one are at the right side of the cylinder head) :






   I wrote it in previous posts, but it is worth to be mentioned again: the thermal expansion in the cylinder head cannot help deforming the exhaust valve seats from circular (when cold) to oval (at one side of the big diameter exhaust valve seat the head is cold (yellow ellipse), at the other side the head is hot).



   You also write:
   &#8220;Your valve lacks all of this.
There is relative movement of the sealing surface when exposed to hot exhaust gas. It is even worse: In the moment your valve opens to exhaust, hot gasses rage through the tiny orifice, heating adjacent material like a blowtorch in a spot that needs plenty of oil for lubrication constantly.&#8221;

   I explained in the previous paragraph how difficult are the conditions for the &#8220;head&#8221; of the exhaust poppet valve. 

   The conditions during the opening of the exhaust port of the PatRoVa rotary valve are quite similar with the conditions during the opening of the exhaust port of the Bishop-Cross rotary valve (backed by Ilmor and Mercedes).
   No problem ever mentioned.
   In a couple of years they achieved 10% more power than the best Formula1 engines (those with the &#8220;genius&#8221; poppet valves with the more than a century development); then the rules changed to ban the rotary valves from Formula1!

   You phrase &#8220;hot gasses rage through the tiny orifice, heating adjacent material like a blowtorch in a spot that needs plenty of oil for lubrication constantly&#8221; fit perfectly with what happens in the poppet exhaust valves. Rethink about it.

   As for the &#8220;plenty of oil&#8221; you are talking about, please explain what do you mean? Which oil? From where? For what?
   The PatRoVa for normal; size engines (cars, motorcycles, aeroplanes, boats, trucks etc) is to run with dry cylinder head.
   And this way it avoids several problems of the &#8220;genius&#8221; poppet valve cylinder heads such as the oil contamination by the exhaust gas, the oil suctioned through the valve guides, the degradation of the lubricant etc.



   You also write:
   &#8220;There IS a gap between your valve and the cylinder head. This ruins all alternative valve designs on the emission side.&#8221;

   No.
   As explained the PatRoVa rotary valve has an automatic built-in recycling of the leaked gas (it returns in the cylinder and is burned at the next combustion).

   The real question is how much this leakage is.

   If it is less, or comparable, to the conventional leakage from the combustion chamber to the crankcase (gas bypass through the gap between the piston and the cylinder liner), then what are we talking about?

   If it is more, then it is not a matter of emissions (because it automatically recycles the leaked gas), but it is a matter of power loss.

   Read my previous posts wherein the leakage of the PatRoVa is compared with the leakage in the Wankel model engine (the Wankel without side sealing means).



   You also write:
&#8221;The channels in the valve shaft call for casting as manufacturing process. The sealing surfaces must be hardened and ground, etc... it is rather complex in terms of cost, not small and cheap to manucfature.&#8221;

   No. 
   By far no.

   The estimation for the cost of a PatRoVa rotary valve in mass production (including material, hardening, DLC coating, grinding, ect, etc) is: more than ten times lower than the cost of a Ducati Panigale cylinder head, with the PatRoVa being substantially more lightweight and compact and with substantially higher flow capacity and without rev limit and with by far more compact combustion chamber (try to rotate the camshafts of the Panigale at 7,500rpm (15,000rpm of the crankshaft) to see what I mean by no-rev-limit of the PatRoVa cylinder head).

   Why the comparison is with the Panigale?  

   Because it is the only engine that can move reliably such big poppet valves, at such big valve lifts, at such high revs.



   You also write:
&#8221;I guess there will be serious distortion and deflection, too, when one side is heated by exhaust gas and the other one is cooled by fresh gas constantly. The sealing surface on the disk calls for absolute precision, see the gap problem some lines above.&#8221;

   You are wrong.

   At the side of the ports of the PatRoVa rotary valve the tight sealing is useless. What do you need the tight fit when the exhaust valve is open, or at overlap, or when the intake port is open.

   The sealing matters only at the opposite side of the ports, as the following animation shows:






   and here in slow motion:






. 

The red colour of the window shows where high quality of sealing is required. 
   At that area the temperature of the PatRoVa rotary valve is substantially uniform (it is away from the ports). 

   Compare how much better are the conditions for sealing as compared to the Wankel model engine mentioned in the previous posts.

   Compare how much better the two disks are secured to each other (relative to the interconnection of the flat covers of the model Wankel engine).

   Compare what kind of materials can be used in the PatRoVa.

   And let me know.



   You also write:
   &#8220;You might want to have a look at the ballvalve (German: Kugelventil) by Reinholt Ficht. Understand that it's rather advanced in terms of developent progress, understand it's limitations and you will easily understand the problems occuring with your own design.&#8221;

   I saw the patent of Reinholt Ficht in the USPTO ( US4782801 )

   It is like all the other rotary valves of the art (and similar to Cross and to Bishop design, with spherical shape in the middle so that a circular sealing can be used).

   Like all the rotary valves of the prior art it undergoes the full pressure of the combustion chamber and its bearings have a difficult life.
   Without a sealing mean, it is not functional because it cannot have and maintain the required tiny clearances.

   Do you understand its difference from the PatRoVa rotary valve wherein the bearings are completely unloaded all around the 720 crank degrees?

   Quote from http://www.pattakon.com/pattakonPatRoVa.htm :

   &#8220;From a practical viewpoint: 
Leaving free (i.e. without support bearings) the PatRoVa rotary valve on the cylinder head to seat in place and seal, by its oppositely arranged fronts, the two side chamber-ports, and applying a high pressure (like 100bar) in the combustion chamber, the PatRoVa rotary valve has no tendency to move upwards, or downwards, or to the side. 
In comparison, a force of a few tons is required to keep in place a state-of-the-art rotary valve when the same 100bar pressure is in the combustion chamber; the extreme upwards force loads its bearings and causes, among others, the flexing / deformation of the spherical valve, of the shaft of the rotary valve and of the cylinder head wherein the shaft is supported. 

The *cavity* of the PatRoVa architecture eliminates the radial forces acting on the rotary valve and on its bearings, which is a major (if not the worst) problem of the known rotary valve designs. 

The ceiling of the *PatRoVa cavity* receives the heavy radial forces and releases, this way, the rotary valve from them. 

The PatRoVa cavity is a buckler that protects the rotary valve from the radial forces.&#8221;



   Thanks
   [FONT=&quot]Manolis Pattakos[/FONT]


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## Hopper

The sooner someone builds a model of this rotary valve engine and we find out if it works or not, the better.


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## Cogsy

manolis said:


> The bearings of the PatRoVa rotary valve run unloaded.


 
You keep making this point - zero load on the bearings. They will still require lubrication (obviously) but if they run unloaded at any reasonable rpm they will skid rather than roll, caused by the frictional force of the lubricant. Skidding bearings quickly disintegrate.

Don't think that lubricant creates drag? Think about when you're driving your car and one of the front wheels hits a deep puddle of water - the drag of moving the water out of the way tries to rip the car off the road in that direction. Now consider hitting a much more viscous fluid such as a deep puddle of oil, then the drag force will increase. In critical operations in industry, over lubricated bearings are almost as much of a problem as under lubricated.

So I can only conclude that you're wrong about the bearings seeing zero load (which you keep going on and on about), or your bearing life will be measured in minutes and hours rather than years.


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## Nick Hulme

Censored

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## Nick Hulme

Censored 

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## manolis

Hello Cogsy

   You write:
   &#8220;You keep making this point - zero load on the bearings. They will still require lubrication (obviously) but if they run unloaded at any reasonable rpm they will skid rather than roll, caused by the frictional force of the lubricant. Skidding bearings quickly disintegrate.&#8221;


*Don't forget the size of the roller bearings and the weight of the Patrova rotary valve and of the spline shaft that prevent the skidding you are affraid of *

   I keep making this point because if you understand how important it is, you will get the idea behind the PatRoVa rotary valve.

   The ball roller bearings used in the prototype are sealed at both sides, so they keep their lubricant inside for their life-time and the cylinder had can remain &#8220;dry&#8221; (if desired, ceramic ball bearings can be used, but this is not necessary.

   While these bearings are not loaded by the high pressure acting on the two disks of the rotary valve, they are slightly loaded by the timing belt or chain that drives the rotary valve (it is easy, but not necessary, to remove this load, too).


   And why the zero total force (and so the unloaded roller bearings) are important?

   Take the Bishop rotary valve:






   and think what is happening during the high pressure portion of the cycle (i.e. during the last part of the compression, during the combustion and during a part of the expansion).

   Through the rectangle window the high pressure gas pushes upwards the rotary valve (a rough calculation: with 20cm2 window area and 100 bar peak pressure, at the time wherein the valve is pushed upwards by 2 tons, at the same time it needs its best sealing, i.e. the minimum clearances).

   The Bishop rotary valve (which is a large diameter tube with slim walls and long ports on its periphery) is rotatably mounted on the cylinder head by two big diameter (big diameter: because the fresh charge and the exhaust gas pass though these bearings) needle roller bearings, which are mounted at the sides of the cylinder, i.e. at a long distance from each other.

   Due to the heavy force pushing &#8220;upwards&#8221; the valve, the valve bends / deforms (it is supported at its two ends only) increasing the clearance between its lower side and the window though which it communicates with the combustion chamber.

   It is also the required clearance of the big diameter needle roller bearings: this clearance is added to the rest clearances.

   It is also the distortion of the cylinder head whereon the needle roller bearings abut on, which further increases the clearances.

   Worth to mention: the needle roller bearing at the exhaust side of the Bishop rotary valve runs too hot (all the exhaust gas passes through it).

   Is it possible, without sealing means, to have and maintain the required tiny clearance around the &#8220;window&#8221; during the high pressure portion of the cycle?

   Practice says: No.

   Additional sealing means means friction, wear, complication, cost, reliability issues, need for lubricant (which ends up into the combustion chamber spoiling the combustion and the emissions), etc, etc



   And don&#8217;t think the Aspin rotary valve is better..

   Quote from http://ralphwatson.scienceontheweb.net/rotary.html :

   &#8220;I first became interested in the rotary valve as applied to internal combustion engines around about 1939, after reading an article in a motor cycle magazine describing an Aspin rotary valve four stroke engine. This engine had a capacity of 250 c.c. and it was claimed to produce 29 h.p. at 14,000 r.p.m., using low octane petrol.
   At the time, I was living in Nelson and serving an engineering apprenticeship. On occasion I watched a group of engineers, led by the well-known aviator George Bolt, race one metre hydroplanes on the local model boat pond.
   These model boats were powered by 30 c.c. engines and ran tethered to a central pole in the pond to provide quite exciting action. Being an enthusiastic experimenter, the Aspin engine came to my mind and I decided that I should give them some competition.
   With great, but what turned out to be misguided enthusiasm, I built a model engine based on the Aspin design, which incorporated a cone type valve the same diameter as the cylinder bore, rotating in the cylinder head. The combustion chamber was contained within the rotary valve, which rotated to line up in turn with the spark plug, exhaust port and inlet port.
   Full combustion pressure was applied to the valve, forcing it into the taper of its conical seat with the object of ensuring a good seal, but this arrangement could result in the valve seizing in the head due to lack of clearance and lubrication. In order to counter this, the Aspin design incorporated a roller thrust bearing on the valve stem.
   I used the same arrangement but could not attain an adjustment whereby the bearing took the load and a satisfactory seal was achieved. *When adjusted so that load was on the bearing, the seal leaked and the engine had poor compression and would not run. With load on the cone the valve would seize.* After suffering much frustration with broken drive shafts and stripped gears, the engine was eventually run for short periods with load on the cone, thanks to a copious supply of castor oil. This was supplied under pressure to the valve face, by means of a hand pump. My goal of fitting the engine into a model hydroplane came to naught and George Bolt and company remained unopposed at the model pond.
   However I was able to test the engine running against a brake and it recorded 1/8 h.p. at 8,000 r.p.m., which was a disappointment when related to the figures quoted in the article which had inspired my efforts.
   Many years later the story came out that the Aspin engine was tested by the motorcycle manufacturers Velocette, who found that it produced only half the horsepower claimed, the suggestion being that the original testing had been carried out with a wrongly calibrated tachometer.&#8221;

   End of Quote.



   As Watson writes (and as practice proves) the tiny clearances and the heavy loads on a rotary valve were, so far, two incompatible requirements.

   The PatRoVa rotary valve takes the heavy loads (and cancels them internally without loading its bearings) keeping the tiny clearances tiny.


   If something is confusing, please let me know to further explain.

   Thanks
   [FONT=&quot]Manolis Pattakos

[/FONT]


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## Nick Hulme

Censored  


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## kvom

I keep wondering what the point of this thread might be.  OTOH, Manoli's skills in 3D modeling make interesting viewing.


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## manolis

Hello Kvom.

   You write:
   &#8220;I keep wondering what the point of this thread might be.&#8221;

   I open this thread.

   And the point was to show to the &#8220;Home Model Engine Machinists&#8221; a new different 4-stroke model engine design, with the hope that at least one Machinist to become interested to built a PatRoVa prototype model engine and to evaluate it as a third party.

   This is why the CAD drawings were given: to be used as the basis for modifications.



   Here is the first full size &#8220;low budget / proof of concept&#8221; PatRoVa prototype (75mm bore, 80mm stroke, cylinder and piston rings from an old Yamaha 250XT):






   And here at operation (youtube video):

   [ame]https://www.youtube.com/watch?v=6Q-EGdeS0ws[/ame]  


   Some forum members blamed it for its poor manufacturing quality.

   It is not just poor. 
   Its manufacturing quality is by far worse than poor. 

   Some US20$ were spent for the required materials for the cylinder head and the rotary valve (the rest parts &#8211; i.e. the &#8220;conventional&#8221; parts (even if they are not so much conventional) were available from an older project).


   However, 
   if I were you,
   I would wonder how on earth this prototype, made at such bad quality and at such low cost, does work. 

   And works well.

   See carefully the flame and listen carefully to the sound: there is not even one misfire.

   As for the leakage from the cylinder head of the PatRoVa, what I am sure for, is that it is less than the leakage from the worn cylinder / piston rings.



   You also write:
   &#8220;OTOH, Manoli's skills in 3D modeling make interesting viewing.&#8221;


   To make the thread more interesting, several drawings were made not just in 3D, but in stereoscopic format (or ghost stereoscopic format).

   It is a useful tool when you get it (ask IceFyre13th).

   Several people think they are unable to look &#8220;stereoscopically&#8221;.
   They are wrong. 
   If they have two eyes (both functional) and are capable to see things close to them and away from them, then they have everything it takes to see stereoscopically.


   Give me just 2 minutes of  your time and try to apply exactly the following simple instructions. 






   Put the above pair of photos of the PatRoVa prototype at the middle of the screen.

   There are two flywheels. Do you see them at the bottom of the photo? (the big diameter ring gears).

   Keep your head so that the line connecting your eyes to be parallel to the line connecting the centers of the left and right flywheels (or simply keep your head straight and the screen horizontal).

   Keep the bottom of a pencil by your hand and displace it so that its nose to get at the intersection of the line from your left eye to the right flywheel center and the line from your right eye to the left flywheel center..

   Focus your sight at the top end of the pencil.

   At the background they appear (not very clear, but they appear) three images. 
   Slightly move your sight higher than the pencil nose and focus progressively on the central &#8220;stereoscopic&#8221; image ignoring the side images.


   And let me know.

   Thanks
   [FONT=&quot]Manolis Pattakos

[/FONT]


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## Nick Hulme

Censored


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## Nick Hulme

Censored 


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## IceFyre13th

I would like to thank the "Elite" members here who have now ruined this post for me...............your a bunch of bullying keyboard warriors who have nothing better to do than be rude and inconsiderate of others.

To quote the most obnoxious one *"Silence is Golden, especially when "The Nutter on the Bus" finally gives his mouth a rest"

*How about you take your own quote and effectively do what it says.....or instead of being a "know it all" add something to the conversation constructively.


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## kvom

Given that this is a HOME MODEL site, and that very few of the models we build are particularly efficient, I think that badgering Mr. Pattakos about his design is inappropriate.  If someone wants to build it, they can have at it from the plans.

Let's have no more of this rudeness please.


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## Niels Abildgaard

I will thank mr Manolis for sharing his visions and have at no time felt lured to invest a fortune.
It is to me far more interresting than Olympic games or Brexit.


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## manolis

Hello Niels Abildgaard.

   I hope you will like this post.

   The idea was to design / make a V-2 at 90 degrees (pretty good balancing, low inertia torque, easier cooling, shorter and stronger crankshaft etc). 


   In the initial design (previous posts) the crankshaft extends (as in most, if not all, model engines) at the one only side of the crankpin. While it is simpler and easier to make, it may prove problematic at higher revs. 
   A crankshaft supported at both sides of the crankpin is stronger and preferable, but it requires divided connecting rods.


   In this drawing:






   the crankshaft is supported at both sides of the crankpin.
   The main crankshaft journals are 12mm in diameter while the crankpin is 13mm in diameter. Is it obvious how the single piece connecting rods are assembled?

   In the following drawing:






   at right you can see the crankshaft with the &#8220;secondary&#8221; balance web assembled on it. The big balance web is integrated on the crankshaft. The two balance webs together offer the vibration-free quality of the best V-2 engines (like the Ducati Panigale). 

   The casing is a single piece and comprises the crankcase, the two cylinders and the &#8220;lower half of the cylinder head&#8221; of each cylinder. No studs or bolts are required. 

   Spot on the openings at the sides of the crankcase, and think how much the crankshaft can &#8220;play&#8221; (be displaced) into the crankcase before the installation of the ball roller bearings (which are to be, initially, the conventional &#8220;6201&#8221; 12x32x10, and later spindle ball roller bearings (same dimensions) capable for more than 50,000rpm).

   The freedom of the crankshaft in the crankcase allows the assembly of the single-piece connecting rods and of the pistons. Think of it.


   In the following drawing:






    the ball roller bearings are assembled and keep the crankshaft in place.


   In the following drawing the rest parts (rotary valves, cylinder head covers (blue), sprockets, timing belt etc) are assembled.






   The power is provided by the strong side of the crankshaft (the side wherein the big balance web is (it is the front side in the drawing)).
   The timing sprocket are at the other side of the crankshaft.


   The difficult part is the casing.


   The following drawings show the steps required for the manufacturing of the casing:
















   The first steps are the most significant: boring of the two cylinders, boring of the nests for the roller bearings of the crankshaft. The axes of these three cylindrical cuts must precisely be orthogonal (perpendicular) to each other.

   I think the drawings talk by themselves.

   If there is something confusing, just let me know to further explain.


_  With 13mm stroke and 24.8mm bore the V-2 model engine has a total capacity of 12.5cc. Its bore to stroke ratio is the same with Ducati Panigale 1299 (116mm bore, 60.8mm stroke.

The initial metal plate from were the block was made is 50mm x 90mm x 90mm_


   The architecture looks good not only for model engines, but also for normal size engines (say a V-2 1300cc).

   In case the plain bearings are preferable than the roller bearings (say, as happens with the Ducati Panigale), the ball bearings can be replaced by aluminum rings having the plain bearings at their centers.


   Thanks
   [FONT=&quot]Manolis Pattakos
.
[/FONT]


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## Niels Abildgaard

Hello Manolis

Hirth maneton couplings is a more elegant way to make V2 crankshafts be they 4 or 2 stroke.
If crankshaft is finished machined and then broken like outboard connecting rods, they will be smart and cheap as well.

http://cdn.homemodelenginemachinist.com/attachment.php?attachmentid=61733&stc=1&d=1367340233


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## manolis

Hello Niels.

   Ducati insists on the &#8220;conventional&#8221; single-piece &#8220;heavy&#8221; crankshaft.

   The photos are from the CycleWorld:






   At right is the Panigalle 1299 crankshaft (focus on the balance webs).












   Even in their Superleggera Panigale 1199 (which is their top model at some US70,000$) wherein every removed gram of weight is, literally speaking, &#8220;gold&#8221;, and wherein the rev limit is at 12,500rpm (25.33m/sec mean piston speed), the crankshaft is conventional.


   Worth to mention:
   The force (either due to the pressure in the combustion chamber, or due to the inertia) on the crankshaft of a V2 maximizes when the piston is close to its Top Dead Center. This force is about equally shared between the left side and the right side of the crankshaft (left and right relative to the crankpin).
   But as regards the torque, only the one side of the crankshaft really works.    



   No doubt, the Hirth maneton couplings is a more elegant way.

   And it allows single piece connecting rods in multicylinder engines.

   However, in terms of strength and of high revving capability, it is not comparable to the conventional single piece crankshafts.

   As for the manufacturing of a Hirth maneton crankshaft, it appears far more difficult than manufacturing the complete PatRoVa engine (the crankshaft included).


   The crankshaft of the last version of the V-2 PatRoVa combines the advantages of both schools: the strength and the simplicity of the conventional single-piece crankshaft with the single piece connecting rods.


   By the way, 
   here is the single-piece crankshaft and the four single-piece connecting rods of the PatOP Opposed Piston prototype Diesel engine:






   And here is the same engine operating on Diesel fuel (compression ignition), standing free on a desk:

   [ame]https://www.youtube.com/watch?v=2ByEgfTTq1I[/ame]

   For more about the PatOP: http://www.pattakon.com/pattakonPatOP.htm )


   Thanks
   [FONT=&quot]Manolis Pattakos
.

[/FONT]


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## manolis

Hello Niels.

   A similar solution, i.e.:

   single-piece crankshaft supported at both sides of the crankpin,
   single piece connecting rod,
   single piece casing (including the crankcase, the cylinder and the cylinder head)

   seems interesting / advantageous for the single cylinder, too (the drawings are stereoscopic):






















Give another look to the above drawing:

It shows the moving parts of this single cylinder PatRoVa 4-stroke engine.

In comparison to a 2-stroke, and excluding the timing belt,  it adds only one moving part (the rotary valve).







   Strong, well balanced and well supported crankshaft,
   single piece crankcase (no need for bolting),
   compact and simpler overall structure,
   etc.






   Thanks
   Manolis Pattakos

 .


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## Toolguy

That is a good looking and interesting design. I am curious - how do you make a 1 piece crankshaft and 1 piece connecting rod and assemble them. Also, how are the valves sealed off from the combustion chamber?


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## manolis

Hello Toolguy

   You write:
   That is a good looking and interesting design. I am curious - how do you make a 1 piece crankshaft and 1 piece connecting rod and assemble them.


   Here is a single piece crankshaft and the single piece connecting rods of the PatOP Opposed Piston prototype engine:






   After the insertion of each connecting rod at its respective crankpin, the plain bearings are inserted and secured. 
   It works in theory.
   It works in practice: 
   Here is the PatOP opposed piston engine. It has a single piece crankshaft, and single piece connecting rods. 
   It is a compression ignition engine.
   The 636cc direct injection Diesel PatOP engine stands free on a desk:

   [ame]https://www.youtube.com/watch?v=2ByEgfTTq1I[/ame]

   For more: http://www.pattakon.com/pattakonPatOP.htm


   In the case of the single cylinder model engine or of the V-2 model engine (drawings and animations in my last two posts), things are way easier than in the PatOP. 
   The big end of the connecting rod has 13mm diameter while the main journals of the crankshaft are 12mm in diameter.






   The crankpin of the crankshaft is properly shaped to allow the assembly of the single piece connecting rod.
   It is easy and simple. 

   More interesting is that the crankcase (wherein the single piece crankshaft is rotatably mounted with the single piece connecting rod(s) driven by the crankpin of the crankshaft) together with the cylinders and the lower side of the cylinder head(s) is a single piece, too.

   Assembly:
   The piston (without the wrist pin) is inserted into its cylinder.
   The crankshaft is inserted into the crankcase (the size of the balance web of the crankshaft allows it).
   The connecting rod is inserted into the crankshaft.
   The assembly of the crankshaft with the connecting rod is moved oppositely to the cylinder until the crankshaft journals to abut on the holes for the roller bearings.
   The piston is pulled towards the lower end of the cylinder and the wrist pin is inserted and secured.
   The assembly of the crankshaft with the connecting rod(s) and the piston(s) is moved at its normal position and the two roller bearings (those supporting the crankshaft on the crankcase) are assembled and locked.



   You also write:
   Also, how are the valves sealed off from the combustion chamber?

   Just think how a ring-less piston seals the combustion chamber in a model engine.

   The PatRoVa rotary valve has a much easier duty than a ring-less piston.



   Please let me know if something is confusing to further explain.

   Thanks
   [FONT=&quot]Manolis Pattakos[/FONT]


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## Toolguy

Very interesting mechanics. Thanks much for taking the time to answer my questions. 

Best Regards -
Warren


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## manolis

Hello all.

   Quote from http://www.cycleworld.com/2014/11/2...alves-motogp-tech-analysis-with-kevin-cameron 

   *Benefits Of Pneumatic Valves*

   MotoGP rookie Jack Miller is feeling the effects of what his Honda engine wants.
   By Kevin Cameron posted Nov 29th, 2014 at 10:00pm

   I noted that MotoGP rookie Jack Miller, describing his recent test at Malaysias Sepang International Circuit, spoke of the smoother, more controlled power delivery of the pneumatic-valve *Honda* RC213V-RS.

   I like to emphasize that pneumatic springs have value other than the raw ability to reach high rpm. What pneumatics do best is make the valves follow short-duration, high-lift cams that metal springs cannot. Engines with metal springs must be given longer duration and reduced lift if they are to reach competitive rpm, and both of these changes compromise performance. Yamaha was behind this 8-ball in 2006.
   Increasing duration (valve open time) to give metal springs longer time in which to accelerate/decelerate valves has two harmful effects:

   1) Keeping the intakes open longer after bottom center (BDC) allows the piston, rising on its compression stroke at low- and mid-rpm, to push out part of the fresh charge it has just pumped in (at higher revs, the inertia of the faster-moving intake flow prevents this). Less charge retained in the cylinder equals less engine torque.

   2) Beginning to open the intakes earlier before top center (TDC) extends the overlap period during which the exhausts are not yet closed yet the intakes have begun to open. This creates a window through which exhaust pipe waves act to create a deep flat spot just before peak torque. (This occurs at mid-rpm when the returning pipe wave is positive and pushes exhaust gas back into the cylinder and possibly even fills the intake pipes and airbox with exhaust. The torque-weakening effect of all this exhaust gas in the cylinder produces the flat spot.)

   The result of the above is both weak torque in the low- and midrange, and a steeper, more abrupt torque rise from the flat spot to the torque peak just above it. The rider finds it tricky to exit corners smoothly when his engine has to accelerate through such a steep torque rise.

   The third effect is reduced intake flow even on top end, caused by the reduction in valve lift required if a metal-spring engine is to reach higher revs.
   In sum, what pneumatic springs really do is allow valve motion to more closely approximate what the engine and its airflow want.

   END OF QUOTE


   It seems the poppet valves have reached their limit in the MotoGP racing engines. 

   For even more power at higher revs, they are required even bigger valves and even longer valve lifts.

   The metal valve springs cannot follow.

   The Desmo of Ducati has reached its limits.

   The pneumatic valve springs are better, however the inertia loads increase with rpm square, they also increase proportionally with the valve lift, they also increase proportionally with the mass of the valve (which increases with the cube of the valve diameter).



   Here is a PatRoVa Rotary valve with tapered disks (the exhaust exits from the centers):
















   and a stereoscopic animation (instructions on how to see it at http://www.pattakon.com/pattakonStereoscopy.htm )







   Thoughts?

   Objections?

   Thanks
   Manolis Pattakos


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## Niels Abildgaard

I like it very much and think it will look even nicer as uniflow Two stroke with a single chain or belt for exhaust-valve drive


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## manolis

Hello Niels

   You write:
   &#8220;I like it very much and think it will look even nicer as uniflow Two stroke with a single chain or belt for exhaust-valve drive&#8221;


   A 2-stroke version of the PatRoVa is in the &#8220;rotary valve&#8221; web page of the www.pattakon.com


   On the other hand, with 4-strokes capable to rev at extreme revs, the 2-stroke seems not the ideal choice 


   Back to the moto-GP engines and their need for &#8220;square valve lift profiles&#8221;:


   In this plot ( from http://www.pattakon.com/pattakonPatRoVa.htm ) :






   it is shown the way the PatRoVa rotary valve can give as square profile as desirable.


   According the above plot, the (peak) valve area is the area of the &#8220;blue&#8221; window times two (because there are two such windows that cancel out the total force applied by the high gas pressure (during compression, combustion, expansion) on the rotary valve, and on the bearings of the rotary valve).

   Keeping constant the area of the blue window (and its radial dimension), 
   and increasing the diameter of the rotary valve (the rotation axis of the rotary valve (at the cross, at top) moves away from the window), 
   the f1 angle decreases (and the f4 angle increases by the same amount to keep the inlet duration: 2*(f1+f4) constant).

   As the diameter of the rotary valve increases, the duration the window remains completely open during the induction (which is: 2*(f4-f1) ) increases, while the duration of the two ramps (2*(2*f1)), which is when the blue window is &#8220;partially open&#8221 decreases.  

   For instance, if the diameter of the rotary valve doubles (keeping the area of the blue window and its radial &#8220;height&#8221; unchanged), the f1 halves, which means the duration of the two ramps halves and the angle 2*(f4-f1) during which the blue window remains completely open increases by the same amount (simply talking: what is lost at the ramps is added to the &#8220;full open&#8221; duration).

   Increasing more and more the diameter of the rotary valve, the &#8220;valve lift profile&#8221; gets more and more square. 
   Theoretically, it can be as square as desirable.


   Increasing the external diameter of the PatRoVa rotary valve, and keeping unchanged the radial &#8220;height&#8221; of the window, the hub (or shaft) of the PatRoVa rotary valve gets even stiffer, while the exhaust port on the rotary valve moves away from the &#8220;high pressure sealing area&#8221; of the rotary valve (the area on the two opposed disks where the window gets red), which further helps in keeping the &#8220;sealing clearances&#8221; (between the rotary valve and the windows of the combustion chamber) too small:






   Worth to note here: 
   The sealing of the PatRoVa is not based on the contact of some surfaces or sealing means (as happens, for instance, in the Cross-Bishop rotary valve, wherein the sealing is based on a set of immovable seals abutting onto the working cylindrical surface of the rotary valve).


   According all the previous, the increase of the external diameter of the PatRoVa rotary valve (in order the valve lift profile to be more and more &#8220;square&#8221 does not limit the rev limit of the engine. Because its bearings are rid of loads, and because its &#8220;sealing&#8221; is not based on the contact of surfaces (which means, it is a frictionless sealing).

   The only limitation is the required space for the bigger diameter PatRoVa rotary valves.


   By the way, in the moto-GP revs (r.p.m.), a substantially bigger clearance is allowed because the time for leakage is substantially reduced as compare to that of non-racing engines.

   Achieving at, say, 200 rpm of the manual cranking, such a compression (the valve is dry):






   the clearance required at, say, 100 (a hundred) times higher revs (20,000r.p.m), where a motoGP PatRoVa is to work, is by far bigger and way easier to be achieved and maintained.   



   QUOTE from http://www.pattakon.com/tempman/Bishop_Rotary_Valve_AutoTechBRV.pdf

   Testing of these engines (the Bishop Rotary Valve F1engine) was prematurely terminated when the FIA announced changes to Article 5.1.5 of the engine regulations late in 2004 with the specific purpose of banning this rotary valve technology.

   End of QUOTE.


   Does anybody know whether the rotary valves are already banned in the motoGP engines? 


   Thanks
   Manolis Pattakos


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## 2002hummer

Question? What sort of compression ratio do you get. With the large volume in the rotary valve assembly there must be a way to bring the compression up around 9.5 to 1, a good compression for a gas engine.


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## manolis

Hello 2002hummer.

   You write:
   &#8220;Question? What sort of compression ratio do you get. With the large volume in the rotary valve assembly there must be a way to bring the compression up around 9.5 to 1, a good compression for a gas engine.&#8221;


   The following drawing is based on the first PatRoVa prototype (nothing to do with optimization):






   The volume in the cavity is 25cm3.

   The total port area (12cm2) is, more or less, as having on the cylinder head two intake an two exhaust poppet valves of 32mm diameter each (the Honda 1,600cc VTEC engine (B16A2, one of the best sport car engines, ever) has 33mm intake valves diameter, 28mm exhaust valves diameter and 5.5mm valve stem diameter.

   Note: the 33mm diameter intake valve seats on a &#8220;hole&#8221; having a diameter of 28.5mm).

   Note also: each cylinder of the Honda VTEC is 400cc.

   With the same cylinder (81mm bore, 400cc capacity) and 1mm clearance between the (flat) piston crown and the cylinder head, the resulting compression ratio for the PatRoVa is: 14.3:1.

   According the Bishop Rotary Valve team, in their F1 test engines (more at http://www.pattakon.com/tempman/Bishop_Rotary_Valve_AutoTechBRV.pdf ) &#8220;no evidence of knock has ever been observed&#8221;, even at compression ratios as high as 17:1 (their optimum compression ratio was 15.3:1 for F1 use).

   I.e. the 14.3:1 is not too much.

   The compact and fatty combustion chamber of the PatRoVa (compare it to the skinny and attenuated combustion chamber of a Ducati Panigale 1299 Superleggera) can offer a combustion that completes almost entirely inside the cavity (the flame has a short distance to travel till the ends of the cavity), leading to a, say, 13:1 to 14:1 mean expansion ratio which can increase substantially the brake thermal efficiency, decreasing at the same time the exhaust gas temperature (as Mazda calls it: a low temperature combustion).



   In short stroke racing engines (say, bore to stroke ratios 2.0:1 to 3.0:1 ), the design with the tapered disks allows a &#8220;shorter&#8221; engine (the lower &#8220;side&#8221; of the two oppositely arranged fronts &#8211; i.e. the two flat sealing surfaces of the spool &#8211; &#8220;get&#8221; into the piston crown, if desirable) and a higher compression ratio:








   If desirable, the compression ratio can further increase either by shaping properly the ceiling and the side walls of the cavity (which, besides occupying a good part of the cavity, can also improve the air-flow capacity) add/or by using en extension on the piston crown that gets into the cavity, say like:







   Thanks
   [FONT=&quot]Manolis Pattakos[/FONT]


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## Nick Hulme

manolis said:


> With substantially faster combustion and with substantially more compact combustion chamber, things improve a lot (fuel efficiency, clean exhaust, less cooling, etc).
> .



You are assuming combustion takes place while all the mixture is in the chamber, how much advance and what speed of flame front propagation will be required for that to happen at the revs normal for the engine you are using as a basis for this comparison?


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## manolis

Hello.


Regarding the spark advance and the combustion duration in the PatRoVa rotary valve:


QUOTE from http://home.people.net.au/~mrbdesign/PDF/AutoTechBRV.pdf about the Bishop rotary valve engine:

&#8220;This oblique flow through the window is responsible for one of the rotary valves most useful attributes - its strong in-cylinder tumble flow. The tumble ratio on engines with near square bore/stroke ratios is typically twice that reported for similar 4 valve engines. Unlike the poppet valve this high tumble flow is generated without any loss of volumetric efficiency (VE) and is responsible for very fast burn rates observed. Production based engines built in the early 1990&#8217;s had ignition timing of 15°, or less than half that of the best four valve engines.&#8221;

End of QUOTE


In the PatRoVa the combustion chamber (i.e. the cavity at the &#8220;top&#8221; of the cylinder head) is substantially more compact and more fatty and more concentrated around the spark plug than the combustion chamber of the Bishop rotary valve.

The high tumble flow in the PatRoVa remains strong even at the end of the compression (piston at the TDC) because of the shape of the cavity.

These characteristics make the required spark advance substantially shorter than in a Cross-Bishop rotary valve engine (and a few times shorter than in the best 4-valve engines), and the combustion ends shortly after the TDC.


For comparison with a high-tech poppet valve engine:

Think of the combustion chamber of the Ducati Panigale 1299 (116mm bore, 60.8mm stroke, 12.6:1 compression ratio (i.e. mean &#8220;height&#8221; of the combustion chamber when the piston is at the TDC: 4.5mm)) which is like a coin with abnormal top and bottom surfaces (valves, valve pockets etc).

The flame in the Panigale 1299 propagates in two only dimensions, while in the PatRoVa the flame propagates in all three dimensions.

The flame in the Panigale has to travel twice the distance it travels in the PatRoVa.

The stronger tumble, swirl and turbulence in the PatRoVa force a substantially faster flame propagation.






With the combustion completed substantially earlier in the PatRoVa Panigale, the actual expansion ratio is substantially bigger, the fuel efficiency is better, the exhaust gas temperature is lower and the power output is higher.

Thanks
Manolis Pattakos


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## Nick Hulme

manolis said:


> The flame in the Panigale 1299 propagates in two only dimensions



Think that through and get back to me once you understand what you've said there and it's implications for Physics as we know it.


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## manolis

Hello.






Thanks
Manolis Pattakos


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## Nick Hulme

A one dimensional figure is a line with only length, not a tube, a two dimensional figure is a plane with no thickness, not a cylinder, a two dimensional combustion chamber, among other things, would give you an infinite compression ratio,  
Thanks, 
Nick


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## manolis

Hello all.


   The following drawings show a 2-stroke Flat-Head PatRoVa:































   The last animation is stereoscopic (more on how to see stereoscopically at http://www.pattakon.com/pattakonStereoscopy.htm ) 

   The piston is shown in the BDC (bore 116mm, stroke 60.8mm, i.e. as in the 4-stroke Desmo Ducati Panigale 1299)

   The blue rotary valve spins at half crankshaft speed.

   There are two exhaust ports on the ceiling of the combustion chamber, and two &#8220;cuts&#8221; on the rotary valve.

   The passageway around the hole for the spark plug (at the centre of the cylinder head) provides &#8220;pressure&#8221; at the top of the rotary valve, so that the rotary valve can spin without friction (the flow of the exhaust gas happens only through the bottom side of the  rotary valve).


   If the exhaust ports at the top of the combustion chamber seem not big enough, then a different version can be used wherein the rotary valve rotates at crankshaft speed and serves two neighboring cylinders (twin even firing 2-stroke), with the rotation axis (or the shaft) of the unique big-diameter rotary valve being between the two cylinders; in such a case, the area of the exhaust port on the ceiling of the combustion chamber can be as big as the piston area.

   Thanks
   [FONT=&quot]Manolis Pattakos[/FONT]


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## dkwflight

HI
I wonder about sealing and the changes from heat.
I suppose with careful choice of materials the dimension changes due to temperature rise would be minimal.
Still what about sealing?
If the valve leaks by the engine might have trouble idling.
Starting may need high speeds to initiate combustion.
Good luck with the development of this engine
Dennis


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## manolis

Hello Dennis and thanks.

 The sealing is based on keeping the clearances too small, preferably without sealing means (which require lubrication, consume energy, etc).

   The question turns to whether the PatRoVa design can keep the clearances as small as required.


   The form of the PatRoVa rotary valve (a short and extremely stiff hub / shaft having two disks secured at its ends),






the loading of the PatRoVa rotary valve from the high pressure gas (which eliminates the total force acting on the valve and on its bearings),

   its unconventional architecture according which: 
only the one dimension relates with the sealing clearances (the other two dimensions are insignificant for the sealing efficiency), 
   the combustion chamber has uniform temperature (because every point of it relates equaly with the intake and the exhaust), 
   the width of the combustion chamber is small (keeping small the thermal expansion), 
the limited angle (some 90 degrees) around the rotary valve wherein a tiny clearance between the disks of the rotary valve and the ports of the combustion chamber is required,

   etc,

   allow (and, more important, can maintain during the operation) the required tiny clearances.

   Thanks
   Manolis Pattakos


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## manolis

Hello all.

   According an Issue Notice of the US Patent and Trademark Office:






   a patent is granted for the PatRoVa Rotary Valve.

   The patent number is US9,677,434.

   Thanks
   Manolis Pattakos


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## Nick Hulme

dkwflight said:


> Still what about sealing?



It will work fine dry if the tolerances are tight enough, the down side is that a system with such tight tolerances will not be tolerant of any contaminants and, like Ducati engines, will eat itself in an interesting way at an unpredictable point ;-) 


The patent is a great (but expensive to enforce) protection against the hordes wanting to use your design without paying  

 - Nick


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## manolis

Hello all.

Today the US-PTO published the USA patent granted for the PatRoVa rotary valve.

Here is the link:

http://patft.uspto.gov/netacgi/nph-...50&s1=9677434.PN.&OS=PN/9677434&RS=PN/9677434

Thanks
Manolis Pattakos


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## manolis

Hello all.


Today the US Patent Office (USPTO) mailed the Issue Notice for a patent granted for the PatATi engine:







More at http://www.pattakon.com/pattakonPatAT.htm and http://www.pattakon.com/pattakonPatATeco.htm

Officially the patent is to be published July 4, 2017.

Thanks
Manolis Pattakos


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## humblemechanic

just an idea:  2 stroke operation with reed valve crankcase induction and exhaust in the cylinder head.
the rotary valve ports could be angled to be 'pushed' around by the impinging exhaust gas pressure; in
effect a 'compound' engine configuration. the rotary valve could possibly have multiple ports, resembling
a turbine, putting power into the crankshaft, geared to it with the suitable ratio.
2 stroke cycle operation would resolve lubrication problems (if any) but 4 stroking could also be possible.
I 'feel' your rotary valve architecture offers favourable timing possibilities for timing variations for c. e.
operation. I haven't got the time to fully investigate this idea by 'gedanken' experiment for possible snags
and being computer 'semiliterate' I can't post pictures or drawings but I have not overlooked the main point
of your design; the absence of pressure on the valve. so far the full combustion pressure on the valve negated
all the other r. v. configurations I have noticed.


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