Cam-less engine:

[Rex Schimmer]

This is a great vid of how Koengisegg is developing valve actuators that do not use a cam shaft and also some of the additional power ideas that can be developed with this type of valve actuation.

http://www.enginelabs.com/news/video-see-how-the-koenigsegg-camless-engine-works/?utm_source=rss&utm_medium=rss&utm_campaign=video-see-how-the-koenigsegg-camless-engine-works

Pretty interesting.

Rex

[bbarn]

I love this idea, always have. I wish I had the engineering time and budget to develop this years ago. Think about an infinitely variable custom ground cam in real-time. Not only can you customize it on the fly, you could customize it per cylinder to maximize efficiency.

Program it to give great fuel mileage on the way to the track, then switch it to a hot setup and crank up the boost.

You can have infinite overlap if you have clearance and use a post run setup to put cold air through the motor at the end of a run to dissipate heat. Think about it as a true pump. You could pump twice as much cold air without spark by cycling the valves on every stroke if you wanted. Obviously you have to work out shock-cooling issues and optimize the cooling rate to not hurt things but it is all possible....so many ideas, so little money!

I saw them working on this in big diesels back in the '90s. For them it was mostly about weight though. With the cam weighing in at over 180 pounds it reduced drag on the motor plus the weight savings.

[noboD]

How does a pneumatic valve work?

[kiwi belly tank]

With air pressure & an ECU.
  Sid.

[WhizzbangK.C.]

Model size engines with solenoid valve actuation have been built for years.

http://www.evicengines.com/

[ETM]

Solenoid controlled valves have been done in the past.  Those engines under perform when compared to cammed engines because they could not run the valve durations that cams can.  

The piston closely chases a closing exhaust valve upward. The opening intake valve closely chases the piston downward.  This is controlled by the ramp angles ground into the cams. The rate at which the valves opens and closes matches the pistons changing acceleration and deceleration rates as RPM change.  Since solenoids typically snap open and closed at a constant rate cam-less engines have had to stay away from durations that will create close piston to valve clearances.  Durations that are possible with a cam.  How has Koengisegg solved the problem?  Non-interference engines tend to be limited to low compression.  Is this intended to be used in high overlap long duration engines or is it limited to lower performance but fuel efficient engines?

[Milwaukee Midget]

My concern is that the video depicts the connections to the actuators as what appears to be a printed circuit board.  Not knowing what the substrate is made of in this application, or the manner in which the circuit board is printed, I'm leery.

Most of the failures I see coming through our AV shop are not electronic or electrical, but mechanical connection failures due to a combination of heat cycling and vibration.  

Without knowing what our friends at Koenigsegg are using or intending to use for substrate or how they intend to bond the conductor to the substrate, I think the idea of a printed circuit board directly above the combustion chamber is a recipe for inconsistent durability.

[noboD]

With air pressure & an ECU.
  Sid.

  Thank you. So what produces enough air to do this in say a Formula 1 engine? My simple thinking would be that air is too slow to close a valve fast enough for the rpm produced. How much air pressure is needed?

[floydjer]

Ferrari F1 engines use them...Only takes 4 laptops to start one. And it idles at 7,000 rpm

[bbarn]

Not saying any of the below is a good idea, but it does raise some interesting concepts.


Low compression isn't a bad idea of you are running it blown. This is why I wish I had money and time to play with this kind of stuff. I think there is an answer there given today's technology. If I would have hit the power ball for 1.5B last night I bet I could have made this work!

I think actuators may be the wrong way to go. Fast acting steppers may be a better approach so that you can control height, distance and timing of the valves more accurately.

I know this has been done before and this isn't something new, like I said, I saw it under R&D back in the 90s. Technology has come a long way since then. With ECU controlled timing, controlled boost and a programmable cam you really would have a high level of control over an engine and "on-the-fly" tuning with real differences in power settings.

Even today, with basic electronic tuning you can easily adjust horsepower +/-15% (conservatively) with the flip of a switch. I predict when this gets the right tech and innovation applied to it we will be talking multiplication factors of HP change not percentages.

You could take a v8 and open the wastegates so that it makes no boost. Program the ECU and "virtual cam" to run minimum power settings with maximum efficiency while driving on the highway. Stomp the pedal to the kick-down switch, slam the wastegates closed, reprogram the cam, adjust the fuel flow and viola! out comes 1800HP without anything but a computer command. Release the pedal and go back to economy cruise. Maybe before that go into a cool-down phase then into eco-cruise.

Ok, way out there in the theoretical - What would stop you from switching into a 2-stroke cycle if you were running direct injection? Decoupling the mechanical connection of the cam from the crank means you could run it as a 'one-put', a 2-stroke or a 4-stroke or any other method you want really. "Theoretically" you could run even numbered cylinders in 2-stroke and odd numbers in 4-stroke. Not saying it would be a good idea but you could have that level of control.

 

[bbarn]

Ferrari F1 engines use them...Only takes 4 laptops to start one. And it idles at 7,000 rpm

Only 4? Pfft...flea-bay has laptops galore!

[WhizzbangK.C.]

Not saying any of the below is a good idea, but it does raise some interesting concepts.


Low compression isn't a bad idea of you are running it blown. This is why I wish I had money and time to play with this kind of stuff. I think there is an answer there given today's technology. If I would have hit the power ball for 1.5B last night I bet I could have made this work!

I think actuators may be the wrong way to go. Fast acting steppers may be a better approach so that you can control height, distance and timing of the valves more accurately.

I know this has been done before and this isn't something new, like I said, I saw it under R&D back in the 90s. Technology has come a long way since then. With ECU controlled timing, controlled boost and a programmable cam you really would have a high level of control over an engine and "on-the-fly" tuning with real differences in power settings.

Even today, with basic electronic tuning you can easily adjust horsepower +/-15% (conservatively) with the flip of a switch. I predict when this gets the right tech and innovation applied to it we will be talking multiplication factors of HP change not percentages.

You could take a v8 and open the wastegates so that it makes no boost. Program the ECU and "virtual cam" to run minimum power settings with maximum efficiency while driving on the highway. Stomp the pedal to the kick-down switch, slam the wastegates closed, reprogram the cam, adjust the fuel flow and viola! out comes 1800HP without anything but a computer command. Release the pedal and go back to economy cruise. Maybe before that go into a cool-down phase then into eco-cruise.

Ok, way out there in the theoretical - What would stop you from switching into a 2-stroke cycle if you were running direct injection? Decoupling the mechanical connection of the cam from the crank means you could run it as a 'one-put', a 2-stroke or a 4-stroke or any other method you want really. "Theoretically" you could run even numbered cylinders in 2-stroke and odd numbers in 4-stroke. Not saying it would be a good idea but you could have that level of control.

 

You could take it even further. Build the engine with a mechanical compression ratio as high as you want, 30:1 or higher. Use the valve timing to control actual compression ratio. Direct injection means you don't have to worry about pre-ignition, since fuel isn't in the cylinder till you're ready for ignition. Fire cylinders only when needed, hit-and-miss style, to produce the power required at any given moment. Leave the valves closed on non firing cylinders to use spring back effect. Exhaust gas re-circulation can be used to dilute incoming air O2 so that less fuel is required to prevent lean conditions when a cylinder does fire. One engine could produce 1,000 HP or 1 HP, depending on the immediate need. 

[bbarn]

....love this kind of discussion! Theoretical with practical application. The dynamics of the possibilities has always intrigued me with going camless.