Fully Variable Valve Actuation

[JBrady]

This inventor from Greece has some outstanding creations. The following link is to his FVVA (Fully Variable Valve Actuation) that allows an infinite range of duration and lift within the confines of the lobe used.

http://www.pattakon.com/fvva/FVVA.htm

Go to the exe on the page and pull up an animation that allows you to try whatever combination you wish.

Once that makes sense you can go and review his Desmodromic Variable Valve Actuation which is his latest evolution of the FVVA and allows the full control WITHOUT the weight and resistance of valve springs. This will allow operation at VERY high RPM and allow an engine to operate with optimal valve timing for any and all RPM/Load conditions. Truly mind boggling when you start getting it into your head!!!

http://www.pattakon.com/fvva/DVA.htm

 

[ed_ma61]

i cant even begin to think how badly that wants to wear itself out, and when it does, on the DVVA there is no failsafe to shut the valve

good idea i guess, but too many bits/linkage/pivots/bearing surfaces, which makes me dislike it a lot!

 

[Zuffen]

If you look at the average cam lobe it has a large surface that gets smacked with the follower every 4 revolutions of the engine.

Bearing surfaces aren't a problem with the correct grade and supply of oil.

Think of the life of an engine bearing.

Once correctly installed they run in they are trouble free for 100's of thousands of Kilometres.

Sure some fail due to operator error, poor assembly or straight out abuse but I have never seen a bearing failure where it couldn't be tracked to poor assmebly, incorrect machining or outright abuse.

I don't count oil surge problems as they are special.

 

[Tacoma_Kyle]

Seems like there would be a lot of resistance based off the angles that the demonstration displays. Maybe more drag.

Neat idea, but it kinda makes me thing of reinventing the wheel. It does the same thing in mechanical motions, just a different angle at it [deep].

Like buying the new lobe, you can get get a new cam.


I am waiting for solenoids. That would be some hot ****.

 

[ed_ma61]

engine bearings run on a different principle (thin film oil wedge lubrication) there is zero metal to metal contact (oil surges exempt)

cam to bucket certainly is a relevant example, but they DO wear (hence hydraulic lifters, screw adjustment rockers and shims. sure, only a bit, as they are large surface area and hardend faces. now take that type of wear to a smaller dia shaft, and multiply the losses by 4. adds up quick. me no like

just adds a heap of complexity to what should, and needs to be, a simple, failproof system

 

[JBrady]

Ed and Kyle...

Did either of you take the time to review his site and work? Or were the observations just initial reactions?

I have been following his work for years now and must say I am surprised at the resistance he gets from the automotive community.

His initial effort was a VVA that used pushrods that seemed tiny and not likely to survive. I was NOT comfortable with the execution. I felt the system looked to fragile but it tested just fine to 7000rpm and has been running around Greece for thousands of kilometers. Here is the link to the first system, take a look at how FRAGILE the actuation rods appear... and yet, it has proven itself completely reliable.
http://www.pattakon.com/vva/main.htm

The power point is complete with videos and power pulls of his operating systems.

His next system was a roller based design he built and has been using on a Honda with complete reliability and revs to 9000rpm (several videos) with improvements in virtually all operating scenarios. Lot's of data and detail posted on all his systems.

I suggest anybody that can get past any initial prejudice to start at the following page and learn what this man has created.
http://www.pattakon.com/indexbeforemay2008.html
If you still are not convinced... that is fine...
However if you can accept that this is a workable system consider the possibilies created!

With the desmodromic system you could literaly test limitless cam designs without regrinds or dissasembly! Simply adjust and test? Optimize valve timing for all conditions. Docile from 400rpm idle all the way to 5 digit RPMs with efficiency accross the board.

You can choose to say "it won't/can't work" or you can choose to say "what if..." Consider the lessons we learned from Nicola Tesla. How many people (including Edison) didn't listen? How many people STILL don't know just how much of modern society he invented (or even WHO Tesla was) Including the internal combustion engine ignition system we use today.

Manolis (Pattakon inventor) may not be Tesla but I am seriously impressed by his work. For anyone that has that wants to know more I HIGHLY recommend reviewing the following powerpoint which explains the desmodromic solution
http://www.pattakon.com/vva/pattakonVVAs.ppt

 

[XR8tt]

Quote..Suffen
If you look at the average cam lobe it has a large surface that gets smacked with the follower every 4 revolutions of the engine.

Rod:: I think you mean:every 4th stroke ?? Every two revolutions..
The camshaft turns at half crank speed for this reason...

 

[Tacoma_Kyle]

You can choose to say "it won't/can't work" or you can choose to say "what if..." Consider the lessons we learned from Nicola Tesla. How many people (including Edison) didn't listen? How many people STILL don't know just how much of modern society he invented (or even WHO Tesla was) Including the internal combustion engine ignition system we use today.

Dude, read what I said. I stated it seemed to have more resistance (more surfaces...) and its like reinventing the wheel.

I didnt question its ability to work.


PS the Tesla-Edison argument is completely different. Edison didn't want A/C because he already denied Tesla and his A/C idea when Tesla worked for him. After Tesla left and formed a partnership with someone else, Edison didnt want it to work because he would have lost the industry; and he did.

 

[gloverman]

Truely amazing for a mechanical system. interesting the carb butterfly gets wired open. I think this would account for the leaner mixtures due to the reduced intake manifold vaccuum. Just think what would be possible with some stepper motors and fine tuned injection. I like the idea of reducing valve lift and overlap at lower revs. I agree solenolds would be awesome but time will tell if they can be fast enough and reliable. Would it need a failsafe if it didn't fail?
I would like to see the system with my own eyes. Other questions would be would it make more power if more fuel was supplied? I try and keep my mind open to different ideas. One customer mounted his wastegate on the intake pipe not the exhaust manifold and it worked(see tread elsewhere) I see some potential with this valve train system.

Good reading - Cheers

 

[3barboost]

this is similiar to the BMW valvetronic system

 

[turboandrew]

Infiniti has infinitely variable valve lift, too, on their 3.7 liter V6. Throttle valve no longer needed

 

[JBrady]

Dude, read what I said. I stated it seemed to have more resistance (more surfaces...) and its like reinventing the wheel.

I didnt question its ability to work.


PS the Tesla-Edison argument is completely different. Edison didn't want A/C because he already denied Tesla and his A/C idea when Tesla worked for him. After Tesla left and formed a partnership with someone else, Edison didnt want it to work because he would have lost the industry; and he did.

That is why I asked if you had spent any time reviewing the work at Pattakon. Manolis Pattakos is the inventor and he has placed a great deal of wealth online for review. BTW, modern tire technology is undeniably better than a stone cart wheel so... re-inventing the wheel continues

The Tesla and Westinghouse vs. Edison chapter was dramatic. Westinghouse spent so much money on the battle that Tesla absolved him of his AC motor royalty contracts. Westinghouse recovered but Tesla (the inventor of so many of today's applications) died essentially pennyless when he should have been seriously wealthy. The best way of doing something is certainly not guaranteed to reach the market or prosper.

That said my second post was posted not as a jab at you but more towards motivating the general community with hopes of spurring serious conversation. No insult was intended.

To the posts that bring up BMW's "valvetronic" :

Manolis makes a direct comparision between the BMW's systems and his own. BMW uses a complex arrangment that is too heavy for high RPM operation. If you watch the Pattakon Honda revving to 9000rpm and consider that using desmodromic operation MUCH higher RPM is possible... the possibilities especially for performance addicts like Lextremer's should bet excited! For pictures of BMW's valvetronic see the powerpoint link in my 2nd post above.

 

[JBrady]

I don't know, I thought more people here would/could grasp just how potentially amazing this design is!

Being able to tailor the valve timing and lift to meet the engines requirements from low to high RPM and load is mind boggling.

Realize that you could have an engine that maximizes its torque from idle to redline. Idles smooth as a factory Lexus actually SMOOTHER and would rev to over 10,000 rpm while making fantastic high RPM power!!!

This uses components that are easily and inexpensively manufactured that use designs that are proven and extremely durable. Simple activation that can be mechanically or electronically controlled.

I URGE anyone that is feeling ANY of this to check out the following animation that lets you change either or both of the pivot points and draws the corresponding valve event. I suggest simply starting with the "random change" and watch the events created.

In the words of Morpheus "Free your mind"

http://www.pattakon.com/tempman/DVVA1.exe

 

[Muzza_NZ]

I checked out the links in your original post and found it very very interesting. Reading the powerpoint presentation in conjunction with the two executables does give you a pretty good understanding of the concept, and that the inventor gives so much information free shows just how much he believes in the concept.

For me (without actually playing with the mechanics first hand) the stand out things on the pattakon design are: The ability to control airflow entirely with an infinite combination of intake valve lift/duration thus allowing the engine to breathe much more efficiently, and the increase in rev range that removal of the valve springs (mass and spring time constant) permits. The fact that people may not grasp is the extra components aren't really reciprocating (i.e. it's not like another cam rotating as a function of crank speed), and only change position when a change in lift/duration is required. The 'extra' complexity of the pattakon design seems hardly more than modern roller-rocker hydraulic lifter assemblies.

Well that's my two cents worth anyway, albeit in a longwinded, poorly worded piece of prose.

Nick M

 

[JBrady]

I checked out the links in your original post and found it very very interesting. Reading the powerpoint presentation in conjunction with the two executables does give you a pretty good understanding of the concept, and that the inventor gives so much information free shows just how much he believes in the concept.

For me (without actually playing with the mechanics first hand) the stand out things on the pattakon design are: The ability to control airflow entirely with an infinite combination of intake valve lift/duration thus allowing the engine to breathe much more efficiently, and the increase in rev range that removal of the valve springs (mass and spring time constant) permits. The fact that people may not grasp is the extra components aren't really reciprocating (i.e. it's not like another cam rotating as a function of crank speed), and only change position when a change in lift/duration is required. The 'extra' complexity of the pattakon design seems hardly more than modern roller-rocker hydraulic lifter assemblies.

Well that's my two cents worth anyway, albeit in a longwinded, poorly worded piece of prose.

Nick M

Nick, I applaud your thoughtfullness. This is what I hope people will do... just consider the possibilities. This engineering needs to get exposure and the first step is LOOK. THINK. DREAM.

I contacted Manolis some time back about doing his roller/conventional valve spring design for the GM LSx engines. Now, with the desmodromic completely controllable design I can see a 1UZ conversion that would rev to the moon and still be Lexus smooth WITH optimized low speed torque. Think of the RMS engine in a street car with OEM idle and drivability.

Now, take the RMS effort and extend the operating RPMs to 12,000 with valve timing to match!!! 330 lbs of torque at 12000rpm = 753hp

To anyone that thinks this would somehow lack durability... WHY? For the majority of operation the valves would barely open. This would probably outlast the rest of the engine.