For auto enthusiasts: Major breakthrough with the internal combustion engine

[EE_]

That's what I get for writing it first thing in the morning.  Springs force it closed... not so much gravity.

Yep, and the higher the tension in the valve springs the quicker the valves will close. That's why racing engines can redline at much higher RPMs than normal engines. I think a honda s2000 has a 8000 rpm redline. NASCAR engines can achieve 10,000 RPM despite their huge size. The penalty for high tension valve springs is that they require more force (and friction) from the camshaft to open. That energy (thousands of times a minute) is lost and never reaches the road.

 

More simply, the valves must be closed by the time the spark plug fires and ignites the fuel/air mix. Otherwise bad things happen to the engine.

 

F1 engines can achieve 20,000 RPM but they replace the mechanical valve spring with a pneumatic (compressed nitrogen) spring. Not feasible for daily drivers.

 

The advancement here is that the actuators (electromagnets) are probably very strong. The strength of an electromagnet (which would determine how fast a valve could be closed) depends on how much electrical current can be pushed through it. 

 

Voltage = Current X Resistence    (ohms law)

To increase the current you either reduce the resistance of the coil wire (ie junk yard magnets use thick copper wire coils) or you increase the voltage very high. You can't lower the Resistence in a small actuator so they probably go the high Voltage route. High speed mosfets (used as electrical switches here) are a lot better than they were a decade ago. Maybe they are also using some of the newer niobium electromagnets.

 

If the video is true that these actuators can go to 20,000 RPM that would allow for very small yet powerful engines. Valve timing is another way to gain efficiency. Honda first had variable valve timing with their Vtech in the early 90's but it is still mechanical and not as easily optimized as purely electrical timing.

 

You can already buy a 67 MPG (80MPG in imperial units) Ford Focus turbo diesel in Europe. Not here though. I think they would be big sellers but the best we can get is probably the VW TDI (passat, golf, jetta). With sedate driving you can get some great mileage with them. http://blogs.cars.com/kickingtires/2012/05/84-mpg-couple-break-mileage-record-with-passat-tdi.html

[nate]

Yeah, it is pathetic that diesel has not caught on here yet.  Huge fuel savings and they are no longer polluters as they were decades ago.  The engines last forever too.

[EE_]

Yeah, It's not uncommon to see diesel farm tractors from the 40's and 50's still chugging along after tens of thousands of hours. There is actually some demand in other countries for those mid 80's mazda trucks with a small diesel engine. Diesel has about 30% more energy per gallon than gas which accounts for most of the mpg gain but they are also clean now. I'm all for using hybrid/electric technology but the prospect of buying a whole new battery bank every few years isn't appealing.

[nate]

Not to mention that the battery is heavy and the nickel mining process is just as bad if not worse for the environment than the CO2 coming out of the tail pipe of a diesel.

[Spencer]

The rear end looks fine, though it looks to be catching a lot of flak from peeps chiming in in the comments sections of review sites.

I think they knocked this one out of the park.

 

All that performance and engineering is a friggin steal at $52k starting.