Are the cams days numbered?

[Mo deller]

While reading stuff on the web to try and extend my limited knowledge of how engines work I came across lots of references to camless engines and electromagnetically actuated valves.
I wondered if anyone here has experimented at all.
Most seem to use two magnetic plates and springs like this
http://engineeringmatters.com/EMI%20Electromagnetic%20Fully%20Flexible%20Valve%20Actuator.pdf

I particularly liked this concept but not sure if any of this stuff would be suited to our small scale.
http://www.shelleys.demon.co.uk/faug05ca.htm

Thoughts anyone?

Peter.

 

[mu38&Bg#]

I think it will be a long time before cams are eliminated from engines.

In the model engineering arena we have this:

http://home.cogeco.ca/~davebowesevic/

 

[Artie]

Hi Peter, I agree with Greg. Current technology utilises pneumatic springs, but still cam operated as per Formula One. These can safely operate at 20,000 RPM (current regs stipulate no higher than 18k). In my opinion, fossil fuelled engines will be gone before camshafts evolve out.

Good to see people thinking this way though. Dave has been campaigning his design for several years and if I remember correctly it doesnt cross over to well to 1:1 scale. Ive read that this is primarily due to inertia and solenoids that are powerful enough to operate safely at the upper limits (RPM)are to slow to complete the cycle and 'hungry' (current wise).

I like the concept though.

Cheers Rob

 

[black85vette]

I have thought about this several times. A compressed air engine should not be too difficult. Not too much pressure or heat and speeds are pretty low. I have a Basic Stamp processor that may be fast enough to do this. I have a reed relay output on it so driving a solenoid valve would not be an issue. Could be interesting.

Don't know if this technology will take over. There is a lot to be said for low tech that is reliable, simple, and proven.

 

[vlmarshall]

Eh, a few years ago we made several hundred valve actuating solenoids for a large automotive manufacturer who was testing the idea. The silicon iron cores were lighter than a normal valve train of lifter, pushrod, and rocker. I might still have parts of one at work, I'll have to look around.
I think it'd be a great idea, with the ability to switch 'cam profiles' on the fly, between a high mileage profile at idle, to a high lift, short duration cam at low rpm acceleration, smoothly transitioning into a long duration cam at high RPMs or something mild for cruising. Compression braking, while we're at it?

 

[Mo deller]

Interesting link there dieselpilot, I'll look at that when I have more time.
I may have chosen the wrong title in my post as I wasn't really thinking the cam would vanish but just found the whole idea very interesting and thought perhaps it would inspire some more ideas.

Peter

 

[phlegmatic]

Read in a reputable car magazine in waiting room not long ago about a company here in Sweden that worked on a camless engine, it also had adjustable compression ratio, very high tech, and seemed far developed...but I don thave the article anymore for obvious reasons...It was a SAAB owned company or partner in Ljungbyhed if memeory serves?!

 

[mu38&Bg#]

I think it'd be a great idea, with the ability to switch 'cam profiles' on the fly, between a high mileage profile at idle, to a high lift, short duration cam at low rpm acceleration, smoothly transitioning into a long duration cam at high RPMs or something mild for cruising. Compression braking, while we're at it?

They are doing this with cams now. I've searched patents for variable valve and lift geometry and there is no shortage of concepts.

 

[Lew Hartswick]

Just more electronic JUNK to go wrong. Like engines that can't be shut of by turning
a key. :-(
...lew... (just an OLD curmudgeon)

 

[vlmarshall]

Just more electronic JUNK to go wrong. Like engines that can't be shut of by turning
a key. :-(
...lew... (just an OLD curmudgeon)

I hear ya Lew, and I love my old VW; solid lifters, gear-drive camshaft, brushed generator, centrifugal-advance distributor, points, condensor, and a plain old coil. ;D

 

[Jadecy]

Here is yet another way to skin the cat. This is actually in production some engines.

http://www.coatesengine.com/

 

[vlmarshall]

Here's the stuff we made.
http://www.grandprix.com/ft/ftpw012.html

 

[cfellows]

I've always thought a flamelicker would be a good candidate for a solenoid operated valve. It's very fast acting and requires virtually no energy from the engine. And, it should take too much thinking to get a valve with adjustable open, dwell, and close.

Chuck

 

[vlmarshall]

Well, I still have half of one lying around... I'm such a packrat. ;D