Electronic Valves for IC Engines ?

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rclint

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I have done a little research on this, and very little has been done in the way of electronic valves for modern day engines. I have seen some info where they still use a cam, but in my opinion there is no reason to use a cam when a board the size of a watch could be used instead, and eliminate the cam, and all the components at once.. Those that know about electronic valves I would like to ask is the reason why they don't go in this direction due to the electronic solenoid/valve not being a reliable part the reason ?

I work with electronic valves every day, and they are small, light, and the part driven is also light. I have worked on electronic valves that controlled air ( and very fast off on on this with lots of pressure) and a small object such as a rod, rod attached to a disc etc. They are very easy to program changes to opening/closing times as well, these I worked on are DC, and a board that drives the valves.. board being slang the first older boards were units that were large, and pretty much toast when anything went wrong, if a ceramic liner inside the solenoid wore away causing it to short out. then the next step was a board twice the size of your hand, now a chip on an I/O board pretty much takes care of everything.

I don't understand why this technology does not trickle over to the automotive side.
 
Because of power requirements and the resulting bulk of the actuators to move automotive valves fast enough to function as automotive valves. I think it's safe to say that you would be dealing with kilowatts of power.
 
I seem to recall an auto trade magazine highlighting this possibility, and it was years ago (15 perhaps) I believe it was focusing on the need to move to 28VDC power systems in autos. If you google valeo camless engine

http://www.signonsandiego.com/uniontrib/20051022/news_lz1dd22camles.html

Quote:

Camless engine technology long has been a holy grail of engineers from automakers and suppliers. BMW, for instance, has spent millions trying to perfect a camless system. But no one has developed a camless engine system that delivers the reliability of the camshaft for anywhere near the same price.
 
In October 2005

Quote:
Valeo's CEO, Thierry Morin, says his company has two development contracts for the system.

"As far as we are concerned, we are between 14 and 16 months from market. So you see that we are there," Morin said recently. He expects to have the system in production in North America and Europe as early as 2008.


If they were 14 to 16 months away from market in 2005, how far are they in 2010? 70-72 months?
grin2.gif
 
Has anyone seen that engine design that uses, in essence, a rotary valve system instead of camshafts and traditional valves? The cams are replaced with a hollow metal tube with holes in it that act like valves. The tube ride on top of the cylinder head. Pretty cool design, especially of you added a variable timing actuator. The rpm limits could be incredibly high with a design like that - no valve spring inertia.
 
Originally Posted By: Drew99GT
Has anyone seen that engine design that uses, in essence, a rotary valve system instead of camshafts and traditional valves? The cams are replaced with a hollow metal tube with holes in it that act like valves. The tube ride on top of the cylinder head. Pretty cool design, especially of you added a variable timing actuator. The rpm limits could be incredibly high with a design like that - no valve spring inertia.


Knight Valve Engine

Sleeve Valve disadvantages
 
There are many many ways around this, and actuators ? what do you mean by actuators ? I may be ignorant to some areas of this. I was think a 12V electronic solenoid, and a light weight valve using ceramic in both valve, and insulating of the solenoid. There is no need for huge amounts of power in what I have dealt with springs are used for return, the DC would turn on the magnet which would pull the valve up, and the ones I have worked on work extremely fast, however not to 6 or 7 thousand rpm... I'm not calling you wrong XS650, I'm just trying to work through some of this..

I think there is a opportunity for improvement dealing with the entire fuel delivery.. I'm not sure DI is the way, but I think just think now that if electronic valves could be used, combined with ceramics may make the use of cams, valve train become obsolete.. I also understand the "if they could do this they already would have a long time ago"

One thing I do know the small valves I have worked with the faster you go (higher the rpm) the higher the overlap times, and also there is a "bleed off time" and I was working at speeds 1/3 of engine speed.
 
rclint, find out how much open valve area an IC engine needs, determine the mass of a valve to do that, how fast it has to be actuated to give the valve timing needed to achieve the desired engine power and emissions and then do the math.

Remember that after you open the valve unbelievably fast, you have to bring it to a controlled stop within a total of about 1/2 inch.
 
XS650 I understand what your saying.. what your calling actuated etc time of travel, overlap, and even bleed off time, what we call actuators is say a lever that was used to move or turn on something so I guess same term just used different..

XS650 also I take it your thinking is there is no way at current technology that electronic valves can be used in a modern IC engine.. I assume you may be on to something as it would be cheaper to make an engine with electronic valves...
 
cost

i seem to remember hearing about some formula 1 engines using pneumatic valves, they could work extremely fast but they didnt last more than a few races and were expensive and somewhat unreliable at times.
 
Originally Posted By: Lethal1ty17
cost

i seem to remember hearing about some formula 1 engines using pneumatic valves, they could work extremely fast but they didnt last more than a few races and were expensive and somewhat unreliable at times.


All F1 engines use pneumatic valves, and they are very reliable as compared to their metallic spring counterparts.

Renault made prototype engines with a completely electric actuated valve system. As mentioned above, power requirements were horrendous, and the solenoids needed to move the valve mass were pretty big, and you still have to have some sort of mechanical spring(s) to control valve action. It takes a lot of power to move valves when the RPMs rise. Somewhere there are demo videos of the prototype running on a test dyno stand.

Sleeve/rotating valve systems (Coates was the latest I think) have no long term durability, and have sealing/flow window problems. There are very good reasons we still have cam operated poppet valves on most engines.
 
Last edited:
Originally Posted By: XS650
Originally Posted By: Drew99GT
Has anyone seen that engine design that uses, in essence, a rotary valve system instead of camshafts and traditional valves? The cams are replaced with a hollow metal tube with holes in it that act like valves. The tube ride on top of the cylinder head. Pretty cool design, especially of you added a variable timing actuator. The rpm limits could be incredibly high with a design like that - no valve spring inertia.


Knight Valve Engine

Sleeve Valve disadvantages


There was a company, or an inventor, who recently (within the last decade or so if I recall correctly), that perfected the disadvantages to this design, mainly in the sealing of the sleeve valve. Someone posted a link to an article about it here about 5 years ago. It was pretty amazing.
 
Originally Posted By: Lethal1ty17
cost

i seem to remember hearing about some formula 1 engines using pneumatic valves, they could work extremely fast but they didnt last more than a few races and were expensive and somewhat unreliable at times.


Formula 1 has had pneumatic valve engines for well over a decade.
 
Originally Posted By: Drew99GT
There was a company, or an inventor, who recently (within the last decade or so if I recall correctly), that perfected the disadvantages to this design, mainly in the sealing of the sleeve valve. Someone posted a link to an article about it here about 5 years ago. It was pretty amazing.


When I was doing my thesis, I had a couple of meetings with Arthur Bishop, who was developing a rotary valve arrangement (the sealing of which was another guy's thesis). Really cluey dude, invented variable ratio rack and pinion, and a rack induction hardening machine that measured distortion, and used differential heat treatment to straighten them during heat treat.

http://home.people.net.au/~mrbdesign/PDF/AutoTechBRV.pdf
 
Rotary valves leak - sealing is a problem.

[Sure - anything can work for a short time]


Solenoids are more expensive. It is not the programming that is the stumbling block.
For 95% of the time, valve lift could be reduced quite a lot, with many advantages. [also their timing] Only for full power do the valves need high lifts.
But what happens when a solenoid sticks open or breaks the wrong way? Piston to valve crash!
 
Originally Posted By: Drew99GT
Originally Posted By: Lethal1ty17
cost

i seem to remember hearing about some formula 1 engines using pneumatic valves, they could work extremely fast but they didnt last more than a few races and were expensive and somewhat unreliable at times.


Formula 1 has had pneumatic valve engines for well over a decade.


+1, and there are reasons they use pneumatics instead of electronics. The main one being power density.
 
Originally Posted By: mechtech2
Rotary valves leak - sealing is a problem.

[Sure - anything can work for a short time]


Solenoids are more expensive. It is not the programming that is the stumbling block.
For 95% of the time, valve lift could be reduced quite a lot, with many advantages. [also their timing] Only for full power do the valves need high lifts.
But what happens when a solenoid sticks open or breaks the wrong way? Piston to valve crash!


I have seen malfunctions on electronic valves many times from anything to electronic noise, a short in the solenoid, a bad board, rouge or improper setup, and other weird things.. some very hard to track down... BUT does the engine have to drop the valve into the piston, I guess that's the most efficient combustion chamber design..

I know many people here are talking cost, but if one could eliminate cams, and many other parts of the engine, once the technology became proven, the ground work done, price would be much cheaper. I think ceramics would have to be involved in the solenoid, and maybe the valve itself.. then when you start talking two piece valves I guess that just opens another door for more problems.
 
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