Electromagnetic Valve timing - fact or fiction?
Discussion
At the risk of starting a complete net myth, someone who has no reason to lie has just told me that volvo have managed to construct an engine that uses electromagnets to actuate the valve lift and timings.
i.e. NO CAMSHAFT. A chip would adjust each at whatever speed, whatever gear to maximise the power available.
This doesn't laugh at VVT technologies...you're already dead (bad Fist of the North Star reference). Expensive broad power band engines that use 3d contoured horizontally shifting cams like ferraris will also be obsolete.
Its a future of engines thing that's been discussed before, in fact, completely independently me and a electronics mate talked about making one ourselves... sawed a bit of wood into a triangle and banged a nail into it...kinda went downhill form there as I recall...
Edited to say: the only www references l can find are patents that have been registered for this technology.
>>> Edited by funkihamsta on Sunday 22 December 17:06
i.e. NO CAMSHAFT. A chip would adjust each at whatever speed, whatever gear to maximise the power available.
This doesn't laugh at VVT technologies...you're already dead (bad Fist of the North Star reference). Expensive broad power band engines that use 3d contoured horizontally shifting cams like ferraris will also be obsolete.
Its a future of engines thing that's been discussed before, in fact, completely independently me and a electronics mate talked about making one ourselves... sawed a bit of wood into a triangle and banged a nail into it...kinda went downhill form there as I recall...
Edited to say: the only www references l can find are patents that have been registered for this technology.
>>> Edited by funkihamsta on Sunday 22 December 17:06
http://ubermensch.org/cars/technical/cams
Take a peek on here it explains all about how its done, or may be done.
Take a peek on here it explains all about how its done, or may be done.
That's surely easy enough to fix - just do a boxer engine á la Subaru or Porsche, and the valves will be lower
HiRich said: My understanding is that the F1 engine manufacturers, particularly Renault, have been considering this.
Pro's should be greater control, and the ability to go beyong 20,000 rpm.
Major Con has been a whole load of weight high up on the engine
They must be really meaty electromagnets to be able to move the valves that quickly & accurately. Wonder what the power consumption is?
) It is certainly looks like the next big in IC engine technology.
Well the same source said it was half the wieght of a standard engine. (Probably smaller capacity that could make the same power curves due to this technology). This is a great thing for environmentalists and pistonheads alike.
I'm not sure that there is currently a working one in action (F1 is pneumatic BTW but still uses springs to return the valve) Lotus one is likely some massive proof of concept and wouldn't even fit in a truck let alone an elise.
I'm not sure that there is currently a working one in action (F1 is pneumatic BTW but still uses springs to return the valve) Lotus one is likely some massive proof of concept and wouldn't even fit in a truck let alone an elise.
GreenV8S said:
Pneumatic valve springs, I think. I assume they still use a mechanical cam.
That's how I understand it. Classic metal springs reached their limit (valve float and breaking) in the last days of the DFV.
Renault introduced the pneumatc spring when they came to F1 with Williams, which allowed higher rpm (which is where much of the power increase over the past few years has come from). Electromagnetic (whether just as springs or full actuators) should allow you to go further.
Saw a prototype V8 on TV a few years ago with magnetic valve control. The system seemed to have full servo control over the valve position, giving 'infinate' timing/lift/overlap possibilities. The end of the report said "expect to see it from Detroit by the turn of the century" - needless to say, in the usual Tommorows World fashion, I have heard sod all about it since...Until this thread that is.
The problem with electro-mechanical actuation is the the valves are either fully open or fully closed depending on what the solenoid is doing. Closed *bang* open. Open *bang* closed. There is no gentle closing ramp for the valves so you get very large forces on the valves. This kills valves.
You could tune this out with a damper but that would only work for a limited speed range. It's not workable. The Lotus system uses something else to move the valves, as far as I can remember.
You could tune this out with a damper but that would only work for a limited speed range. It's not workable. The Lotus system uses something else to move the valves, as far as I can remember.
Capt. Muppet,
I'm sure you could pulse the charge even in the opposite direction to give the braking needed to cushion the end movements of the valve. The bigger problem is that solenoids can move things with a great force small distances or longer distances but with weaker effect, this speed of operation Vs lift may therefore be the first development hurdle to stop this technology automatically being the death nell to classical head tech.
I'm sure you could pulse the charge even in the opposite direction to give the braking needed to cushion the end movements of the valve. The bigger problem is that solenoids can move things with a great force small distances or longer distances but with weaker effect, this speed of operation Vs lift may therefore be the first development hurdle to stop this technology automatically being the death nell to classical head tech.
many many years ago in the USA they closed the patent office as they thought everything had been invented
Oh to sit and read this thread and realise how things change.Truely awsome concepts that come to the masses,and i dare say in twenty years this will be another one amongst many.Great stuff.
happy chrissy
i don't know where i read it but about six months ago an engineer was talking of using a computer controlled system of oil injected in a chamber to operate valves instead of a spring/cam which enabled smoother operation,frictionless and almost limitless revolutions for the intake/exhaust side of an engine.Interesting possibilities.
Oh to sit and read this thread and realise how things change.Truely awsome concepts that come to the masses,and i dare say in twenty years this will be another one amongst many.Great stuff. happy chrissy
i don't know where i read it but about six months ago an engineer was talking of using a computer controlled system of oil injected in a chamber to operate valves instead of a spring/cam which enabled smoother operation,frictionless and almost limitless revolutions for the intake/exhaust side of an engine.Interesting possibilities.
funkihamsta said: Capt. Muppet,
I'm sure you could pulse the charge even in the opposite direction to give the braking needed to cushion the end movements of the valve. The bigger problem is that solenoids can move things with a great force small distances or longer distances but with weaker effect, this speed of operation Vs lift may therefore be the first development hurdle to stop this technology automatically being the death nell to classical head tech.
Good point.
One of the advantages of the Lotus system was that they could use some of the exhaust gas to start and control auto ignition - giving more efficient combustion (more power and better emissions). Muppet that I am I forgot to dig out the magazine last night...
hertsbiker said: Ummm. Are we sure that high revs is the correct way to go? bearing in mind the diesel is likely to be the fuel of the future, what makes you think that a thrasher engine will be suitable? only curious 'cos it seems like there are 2 technology streams here, and one will win !!!!!
C
Active valvetrain is not all about revs - it's all about efficiency. It'll work on diesels too.
I'm hoping to die before the petrol runs out though.
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