Saab isn't dead. Okay, well it mostly is. But this particular one isn't.

[thesameguy]

I first read about this type of technology like 20 years ago - I think BMW was working on it at the time but never got anywhere. Sounds like Koenigsegg has...

http://jalopnik.com/what-its-like-to...ine-1529865968



Camless engines, ho!

[Random]

BMW eliminated (or has the ability to eliminate) the TB with the amount of control they were getting with the most recent generation of VANOS/whatever they use to control lift. Sounds like two ends of the same problem: greater efficiency and control.

edit: "Valvetronic" is what they call it. Variable lift.

[thesameguy]

Yeah, but this is one step beyond that - it eliminates the mechanical link between the engine and the valves altogether, allowing everything from a cycle change to individual and multiple cylinder deactivation. If this could be put into production, with direct injection and forced induction you could have motors that were simultaneously ultra-efficient and ultra-powerful. It would be unsane!

[Random]

Yup.

[Crazed_Insanity]

Sounds great, but why don't they race with this in F-1? Due to regulation that engines must have cams?

[thesameguy]

Could be engine speed. There is almost certainly a ceiling to this type of technology, and it's probably much lower than the revs race motors run.

Also, could just be an application issue - race motors tend to run in a narrow RPM band because racers aren't just cruising around the track very often. Street driven motors have to do everything from idle to redline and part throttle to full throttle and back and forth all the time. Being able to produce an optimal intersection of power and economy for any given engine speed is great for street motors, probably less so for race motors.

[Random]

Regulations require a cam.

edit: went back and looked at this in partial response to LHutton's comment below regarding pneumatic actuation (that he since deleted). There is not actually an explicit requirement to use a camshaft in the technical regulations. It is stated that the valves are to be circular, reciprocating, poppet type, and that no variable valve timing or lift is allowed. The material and construction specifications for camshafts are given, as well, but there isn't a line item that says "thou shalt use a camshaft to actuate the valves." Interesting.

Technical regs are here if anyone wants some night-time reading.

Engine nerds will be interested to know that the engine manufacturers use the hollow camshafts as the oil supply lines to the valvetrain and head. Neat.

[thesameguy]

ROFL. F1 is the NASCAR of racing.

[Random]

They are using pneumatic valve springs, but valve actuation is still by cam.

[Godson]

Which is dumb.


I want the limits of engineering to be pushed, on all levels.