Koenigsegg camshaftless engine
Discussion
DrTre said:
Slightly hyperbole re: "existing only in F1" in that it hasn't ever been raced and I sincerely doubt it's only F1 that has an interest in this technology.
Slightly more than hyperbole. F1 engines use a camshaft, but they don't use springs to open the valves because they don't work properly at such high revs. The only place this technology has existed previously is Longbridge, but I doubt anyone will mention that...Article about a number of manufacturers having camless prototypes back in 2000:
http://money.cnn.com/magazines/fortune/fortune_arc...
http://money.cnn.com/magazines/fortune/fortune_arc...
davepoth said:
Slightly more than hyperbole. F1 engines use a camshaft, but they don't use springs to open the valves because they don't work properly at such high revs.
They do use springs, just not metal coiled ones because as you say, they "bounce" at such high revs. they use pneumatic springs.Electrically operated valves are very much possible and, whilst very lossy, there is a lot of scope for energy recovery and mechanical cams are pretty horrible for energy loss too.
This guy was doing model engines way back in 2000, at rotational speeds well above those in F1 etc. http://rbowes1.11net.com/dbowes/index.htm
This guy was doing model engines way back in 2000, at rotational speeds well above those in F1 etc. http://rbowes1.11net.com/dbowes/index.htm
Fiat system still uses a camshaft - CLICKY and BMW Valvetronic is another (earlier) version of variable valve lift control, ie not just variable timing.
Lotus Engineering have been playing with this for several years now, and when it happens it will transform the ICE.
2 valves per cylinder
4 valves per cylinder
cylinder deactivation
valve timing adjustability
valve lift adjustability
valve overlap adjustability
The possibilties are just endless.
2 valves per cylinder
4 valves per cylinder
cylinder deactivation
valve timing adjustability
valve lift adjustability
valve overlap adjustability
The possibilties are just endless.
bobmcgod said:
Haven't fiat being selling engines with this tech for ages in their multi-air range?
Fiat Multi-air engines still have camshafts, they just have a variable follower between the cam and the valve which dictates how much of the cam duration is transferred. This means that it can transfer as much or as little of the cam duration as it wants (even more than one opening per cam revolution). It can also have spikier cams as standard, as it doesn't have to use all of the cam all of the time.The way it achieves this is using a hydraulic chamber with a solenoid valve. The solenoid valve can be opened and closed quickly (electrically) as required, and can therefore act as a solid follower, or as only partially solid (or not solid at all) as required.
http://www.lotuscars.com/engineering/en/active-val...
Lotus have a similar system for research engines.
Lotus have a similar system for research engines.
Megaflow said:
Lotus Engineering have been playing with this for several years now, and when it happens it will transform the ICE.
2 valves per cylinder
4 valves per cylinder
cylinder deactivation
valve timing adjustability
valve lift adjustability
valve overlap adjustability
The possibilties are just endless.
If it happens.2 valves per cylinder
4 valves per cylinder
cylinder deactivation
valve timing adjustability
valve lift adjustability
valve overlap adjustability
The possibilties are just endless.
At the moment, the power required to drive the valves is simply nowhere near worth consuming. We're talking of more than a kilowatt per valve, and the greatest advantage of the system is in improving part-load efficiency. Problem is, at low loads, you're not producing big power numbers, so the drain from powering the valves will be catastrophic and has, so far, made any camless engine I've heard of less efficient.
The idea's kinda nice, but sadly the mass of the valve and the ridiculous speed it needs to move at (accelerations well over a thousand m/s^2) make it extremely difficult to actuate electronically. Look how hard modern diesel injectors are, and then see how tiny their moving parts are in comparison!
If it gave good gains at full load, it would be worth having. But high-performance valvetrains are set up to give the best performance at full load already, so the variation the camless system offers only helps at low load, which it murders by consuming so much power. See what I mean?
If you could find a good way to power the valves without draining power from the engine, though.. Now you might be getting somewhere.
Its never gonna make it to joe average's car, the cost is far too much, even if it is adopted by many companies and a working system developed there just isnt enough oil left for there to be 15/20 years of technology filtering down, we already are in the golden age of average cars imo, after this there isnt much except insanely expensive bio fuel for enthusiasts, engine development is pretty much done (has been nearly done since 80's).
davepoth said:
Slightly more than hyperbole. F1 engines use a camshaft, but they don't use springs to open the valves because they don't work properly at such high revs. The only place this technology has existed previously is Longbridge, but I doubt anyone will mention that...
Springs don't open the valves, they close them.And as for high revs, Honda motorcycle race engines were revving to 22,000rpm in the 1960s and they had conventional springs. A road-going Yamaha R6 will rev to 16,000rpm again with ordinary metal springs, so slightly less than hyperbole, perhaps.
Electrical actuation is for entirely different reasons.
Decky_Q said:
engine development is pretty much done (has been nearly done since 80's).
I think that's a little harsh. For example, VAG's 1.9 diesel developed about 75PS in the late 80s, but was developing 160PS 20 years later. New technology (variable vane turbochargers, high pressure fuel systems) allowed VAG to generate double the power and torque from the same basic engine. I think double the power output in 20 years qualifies as development. As other have pointed out, Fiat's Air technology allows F1 like pneumatic valve features while retaining the mechanical advantages and low power requirement of a camshaft. It's all still internal combustion, but the engines are very different to the engines you would find under the bonnet of an 80s Fiat.
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