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Pneumatic Digital-Control Engine Valves?

Posted by Peter Brow 
Pneumatic Digital-Control Engine Valves?
July 17, 2016 04:30AM

Ideas of this type have been discussed here, so I figured it might be of interest...
Re: Pneumatic Digital-Control Engine Valves?
July 17, 2016 10:34AM
Hi Peter,

I'd be happier if they showed something beyond animations. I know of at least one auto manufacturer who tried something like this. It worked brilliantly but the power consumption was so high that they joked it would take a second car to carry the power source. The idea of pneumatic springs isn't that wild, Formula 1 does it all the time. I do get a big worried when they talk about sensors on each valve stem ... for a V8 that comes out to 16 or 32 added sensors, more than the total most engines now carry.

Mind you, I'm not shooting the idea down but it's just that most of the presentations for camless valves leave me with more questions than answers. Whether that is because they are "dumbing down" presentations for the general public or because they are still in development is impossible to tell. Shrug....I still have a hunch there is a game changer lurking out there with the potential to make this all moot. A very clean and efficient reformer feeding advanced fuel cells might do the trick. I see fuel cell vehicles all the time at work, they zip around just as nicely as the battery electrics. From what I see in the trades; cost, reliability and longevity are much, much improved. Who knows, though? Maybe someone will develop a wildly efficient thermionic converter next week.


Re: Pneumatic Digital-Control Engine Valves?
July 17, 2016 11:04PM
This is something I have been very interested for along time, digital control valve actuation. Although I use a 12 volt actuator I think this is simpler than a pilot actuation pneumatic system.

With 12 volt actuation the amperage is high and the solenoid winding must be water cooled. Continuous load may exceed 300 amps. However the valve is actuated for a fraction of a second, under these conditions the load overtime is manageable.

It is possible to make a poppet valve camless, work using the technology of my injection valve.

My injection valves have variable lift the same can be achieved with a poppet valve configuration.
Re: Pneumatic Digital-Control Engine Valves?
June 07, 2017 08:54AM
I'm curious how the landing speed is controlled with these pneumatic, hydraulic and electric valve gears. With cams it seems easy to reduce clicking to minimum, as long as there is a self-adjusting lash mechanism.

I want to try to have a microphone to detect clickety, and use heat on one of the valve gear limbs to change its length accordingly.
Re: Pneumatic Digital-Control Engine Valves?
June 07, 2017 10:15AM
Several years ago a man had a model V-8 engine at the model engineering show in PA
With no cam’s just electrically operated valves, controlled by his lap top computer. He could change the RPM to anything he wanted. Amazing stuff.
Re: Pneumatic Digital-Control Engine Valves?
June 07, 2017 07:01PM
I have been doing this for years. I use a variable lift actuation(of the injector valve) to efficiently throttle the engine. No one seems the notice or care. In my current application cutoff is fixed and lift control settings are variable which works great.

I can also use lift duration and also control advance/retard actuation with a digital control, as well as control lift setting. Perhaps Im ahead of my time...
Re: Pneumatic Digital-Control Engine Valves?
June 08, 2017 06:28PM
One thing I would like to point out about digital valves. I have a lot of experience making the switching array.

Theres all kinds of transient voltage spikes that will blow your mosfets. I have some simple pointers if anyone is interested, ask me a question and I will reply here.

For example I use this diode in parallel with my switching mosfet output.


I have 2 on each 40amp mosfet hockey puck.
Re: Pneumatic Digital-Control Engine Valves?
June 09, 2017 09:12AM
Here is an example of an advanced steam engine with a solenoid valve and digital controls. Some of the ideas should work on larger engines.

Lohring Miller
Re: Pneumatic Digital-Control Engine Valves?
June 09, 2017 10:04AM
Here's the same electromagnetic valve but without all the electronics. Just needed a simple distributor system. Note the date.

Re: Pneumatic Digital-Control Engine Valves?
June 09, 2017 03:16PM
The problem with the examples is the "switch" is either a set of breaker points or some sort of commuter.

If It wasn't for the development semiconductors that one can switch without a spark.
Re: Pneumatic Digital-Control Engine Valves?
June 09, 2017 05:40PM
I dunno about any problem. Ralph Hood designed it more than a century earlier. It worked. It even went into production in an automobile. I put a lot of miles on cars with distributors, they also worked fine. From an operator's point of view it's the difference between twisting a knob connected to a circuit card or one connected to the points. Mechanically, there is no actual difference in the two systems.
Re: Pneumatic Digital-Control Engine Valves?
June 09, 2017 11:03PM
The difference is amp's and this is a spec with
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