In the quest for a clean, fuel-efficient engine,why hasn't this technology,EVC,been implemented in today's modern internal combustion engine?

Oh this is near and dear to my heart. I had the misfortune of actually doing this analysis for my employer about 10 years ago. Virtually every manufacturer has built and tested units like this. Also FEV, AVL and a host of others. The problem is that sticky issue of physics.

Here are the assumptions and requirements. You’re smart so I’ll let you do the math.
You want the valves to open and close fast enough to operate in an engine turning 6000 rpm minimum. The mass of the valve is given. Ignore the solenoid actuator as we will make the valve the only moving element. The valve must open 10mm minimum to get the proper swirl and tumble in the cyclinder. Now do the math and calculate the acceleration required to move 10 mm in less than a couple of milli seconds. Now figure the force. F=ma. Now calculate the energy FxD. Now calculate the power based on the number of cylinders per second.
The answer is 2 kW. Now figure the wires required to deliver that power. P= VxI 12volts into 2 kW – ~200 Amps. Let me repeat, 200 Amps! That is a battery cable going to your soleniods . Now you need some way to switch that current on and off quickly with no delay.for 100,000 miles IGBT drivers might work. Experimentally, we can do anything. the problem is the physics.
We need to get that 2 kW at the valves. Our alternator is 75% efficient. Our solenoids are 80% efficient, our drivers and wires are 90%. So that means we need 3700W of electrical power from somewhere and expect to lose 1700W to heat.
Some manufacturers actually ran their testing with external power supplies. But that’s cheating. :-p
You can fiddle a little with the valves make them lighter, reduce the lift reduce the rpm etc. But in the end electrical power and heat are the limiting factors.

There are many alternate designs. Variable valve timing. variable valve lift. Cam phasing Delphi and BMW have clever designs that do both lift and timing.. But the high initial cost is too great for the modest fuel economy gain. Everyone has a trade off. Cost vs % fuel economy. When that gets above 70 it is hard for customers to justify the purchase.
Believe me if they could sell it, they would.

@worriedguy Very nice !

The real question to my mind is why we don’t go back to electric cars. Yes, I say back because around the turn of the last century, EVs outnumbered gas-burners. More energy efficient (Otto-cycle engines have a theoretical maximum efficiency of less than half of what a shitty electric motor has), less maintenance intensive, and quicker off the line for those that like to drag race (or haul heavy loads).

@jerv
I’m glad you like it. That analysis would make a great AP Physics project. So does the battery analysis. Don’t trust the car companies. Do the math yourself. You will get the same answer they got. Darn it!

Sure, the efficiency of an electric motor (`75%) is 2x that of a gasoline engine (35%) but… and you knew the “but” was coming… The energy density of gasoline is 80x that of the best batteries. I’ll leave it to you to spend a few minutes looking around and comparing.
The energy content of 15 gallons of gasoline (100 pounds) would take at least (4000 pounds of batteries – that is with the 2x efficiency advantage.)
How long does it take to ‘recharge’ (refill) the 15 gallons of fuel? At 8 gallons per minute: 2 minutes. How long does it take to charge an electric car with a battery pack one twentieth of the above energy storage? 6 hours. They are working now to get that down to an hour. There are proposals in the works that would have people swap batteries instead of charging.
What is the cost of those batteries and how long do they last? How much did the energy cost to fill those batteries?
There is no easy answer. Until we have the Mr Fusion we will be faced with less than perfect compromises.

@worriedguy I’ve seen lithium-ion batteries that, if hooked to an appropriate power source (by very thick cables) can be charged in three seconds. As my workday is more than three seconds long, I would have no problem with using a smaller cable for a trickle-charge.

As for replacing a pack in under five minutes, that is one of the selling features of the Tesla Model S, as is an optional pack with a 300 mile range more than many cars get on a tank of gas.

Your 8 gallons per minute figure is very optimistic; I have yet to see a gas pump pump that fast. It generally takes me 3–4 minutes to pump 10 gallons into my Corolla, not counting the time it takes to fiddle with the gas cap. More importantly, many people don’t drive that far on a daily basis. The vast majority of people (myself included) drive less than 60 miles a day. That is 2–3 gallons a day for most people, or less than 20% of what you are citing.

There are Toyota Rav4 EVs that went over a decade and >150K miles on their original NiMH battery packs; a cheaper and more robust option for EVs than the Lithium packs, though admittedly they have a lower energy density. But it’s moot since Chevron owns the patents on large-format NiMH batteries and Toyota had to fight them tooth-and-nail to get replacement packs for the Rav 4 EV, so I don’t see NiMH being an option; the legal costs would outstrip the fact that they are a cheaper battery.

Lithium packs are currently less robust and considerably more expensive, but that is changing about weekly. As for the cost of recharging, it’s generally cheap. Plus, I can use my battery more than once; try that with a gallon of gas! I pay less than 11 cents per kWh. While the kW/mile rating of EVs varies considerably between cars and especially driving styles, the White Zombie has been known to go 40 miles on it’s 22.7kWh lithium polymer pack that weighs less than 480 pounds, and I could recharge it for less than the cost of 1 gallon of gas.

Bear in mind that this is a race car (albeit a street-legal one) so it has considerably higher requirements than a normal EV; 2,400 amps @ 355 volts. If you are willing to forgo the ability to do a ¼-mile run in 10.2 seconds with a 0–60 MPH time of ~1.8 seconds, you can get away with a lighter battery or a longer range with the same battery. I mean not everybody needs to beat Corvettes or 485HP Nissan GT-Rs.

Oh, and last I checked, the White Zombie could be replicated for less than $25k, or about the average price of a new car these days.

@worriedguy-Why limit to preconceived parameters? What about rotary encoders? Think of an encoder affixed to a micro drive motor on what would appear to be a locomotive steam piston link and wheel assembly. This technology already exists and could easily be adapted with limited to no friction.

@lucillelucillelucille There are mechanisms now that use rotary valves. They work great when you first put them in the engine. But they are subjected to a constant side load and wear. Remember everything you put in the engine must be rated to last for 200,000 miles. They also affect the charge distribution in the cylinder. We aim for a specific swirl and tumble ratio to get the best distribution and place the mixture so the flame front begins right at the spark plug. That is why valves have the lift they do and why there are 2, 3, or 4 valves per cylinder. There is a new form of combustion – somewhere between Spark Ignition SI and Compression ignition CI (Diesel) called “HCCI”. Check it out. You can spend months looking at all the research. It is the holy grail of operating points and advanced valve trains are the enabling technology. PM me and I might be able to fill you in if you have questions. – but read it first.

@jerv (This is fun. I am glad you are into it.) Yes there are ultra-caps that charge and discharge in an instant. However they do not have the energy density even close to a battery. That is why they are often paired with a battery. One covers the surge the other the long duration. You remember from your electronics experiments, heat is death for electronics. Battery life is severely reduced by subjecting them to rapid charge and discharge. You will cook plates, separate the polymer layers if you force it too many times.
The standard pump fill a couple of years ago was 8 gpm. Some states have reduced that for (questionable) evap emissions reasons. There is talk of reducing it as low as 2 gpm. 5 gpm is typical for most pumps. But that is still orders of magnitude faster than the battery charge process. How long does it take you to charge your cell phone? 2 hours. Why do you think that is? They want the battery to last for 300 charges. That’s it! 300 charges! If a customer only gets 150 too bad. If the battery is charged faster the life is severely reduced. If they could make it charge in 30 minutes they would, but it might only last 50 charges. Customers would be very angry if they had to shell out $40 for a new cell phone battery every 2 months. By the way, doesn’t it get you mad to think that the little battery in your cell phone that holds almost nothing and can’t supply much current, costs half as much as a car battery that will hold 42 amp hours at 12 volts and can supply 600 amps cold?

Also, saying a car goes 40 miles on batteries is not really comparing apples to apples. There are gasoline cars that get 1200 mpg. I think the record now is 3000 mpg. (Might be higher.)
You have to go with the energy stored x the efficiency of the prime mover and then consider the container (gas tank or battery), how much it costs, and how long it lasts.
You mentioned the White Zombie with a battery pack that holds 22.7 kWh and weighs 480 pounds. That is the same energy content as 0.65 gallons of gasoline, which weighs 3.8 pounds. Let’s say the electric motors are 2x the gas engine. So that means the 480 pound lithium polymer pack is 480 pounds vs 7.6 pounds of gasoline. 63:1 (very similar to what I quoted above.) Think what a difference you can make by designing the car lighter because the fuel is lighter, the frame is lighter, the brakes can be make lighter…and so on.
At 11 cent per kWh that is $2.49 for a the tiny fill-up. Nice. Let’s compare with gasoline. Call gasoline $3.00 per gallon. The energy equivalent of 22.7 kWh is 0.65 gallons. Multiply by 2 for the efficiency difference x$3 = $5.20 for the tiny fill-up. The people in CA remember when they paid 30 cents per kWh not 11. That comes to $6.81 for the fillup on batteries. Now look at the cost of the battery. Thousands. I can’t even guess. Cost of a tank to hold 1.6 gallons of gas. Cheap. The new plastic tanks last forever. The batteries do not. What does it take to make a tank? What does it take to make a lithium polymer battery? Yikes! What do you get all the lithium?
Eventually things will be electric. That is the future. But it will use a battery technology that is 10x better than LiPo, electric power will be 0.04 per kWh and gasoline will be $10 per gallon. Then we’ll all be humming to work.
Whew! I have to get to bed.

Oh I forgot Batteries storage severely limited when cold. It can be ¼ to ⅓ of the storage at room temp. Gasoline has virtually no effect. You can check.

I never saw a Lithium-ion capacitors. I was referring to these batteries

Try designing a car with that much torque and that quick acceleration and you might be hard pressed. I mean, how many gas-burning cars do you know that can match the White Zombie? I don’t know if you noticed, but the Dodge Viper’s V-10 alone weighs nearly as much as an entire ‘71 Datsun 510, and the Nissan GT-R is far from light, and neither has much over half the foot-pounds of the WZ’s “Siamese 9”.

Now, remember what I said about the WZ being a race car first that just happens to be street-legal? Also remember that it is a home-brew. Now, imagine what would happen if it were actually done by some company with deep pockets, a fair-sized R&D budget, and the economy of scale.

Eventually all things will be electric? That is the past! I can’t help but laugh my ass off at that fact. Ecclesiastes 1:9 is right.

And while temperature has no real effect of the energy density of gasoline, it has a rather large effect on the efficiency of the engine, especially an older engine like mine and especially one that is just starting out. I mean, I have a carburetor and a cooling system that keeps my drivetrain too cool to engage overdrive at 45F even with a sheet of cardboard blocking off a portion of the radiator, so you can imagine how bad I have it in the wintertime. Even with modern fuel injection, is it possible to have an intake charge cold enough to make the fuel mist re-condense into something that burns less efficiently.

Oh yeah, many home-brew EVs are “lead sleds” for financial reasons. They are heavy and have limited range, but are quite cheap. I’ve even seen an F-250 lead sled. And, for a while, the White Zombie was a lead sled; back then, it’s performance was more inline with a sports car of 2–20 times the cost rather than blowing them away.

@jerv – Thisis fun but I have to run to work now so this will be quick.
Deep pockets still won’t enable them to violate the laws of physics.
I said cold the energy density of fuel is virtually unchanged. It does take a little more for the first 30 seconds to get a modern engine running correctly . My car is designed to sit at -40 for 2 days and still start in less than 5 sec. It will have almost the same range 95%? 98% as it does hot. The LiPo, LiThCl, can’t do that. Not even close.
And the waste heat from the gas engine heats the passenger compartment. Figure out how long the battery would last if it has to run cabin heaters Or A/C units.
Performance? Granted electrics do have great 0–60 times since an electric motor has peak torque at 0.
It still the energy density issue and the cost of the battery materials. Gasoline holds a lot of energy in a small light package.

I’m still think something like Mr Fusion would be best. Back to the Future 1:9 ;-)

@worriedguy -;)

AFAICT, Hondas VTEC engine and Toyotas Variable Valve Timing with intelligence accomplish these benefits of the all electronic valve timing controls without the inherent “downsides”....Maybe another idea just simply before it’s time….

”Now the downside. Eliminating all of the valvetrain reduces the cost and complexity engine and reduces the internal drag, but not as much as you might think. Opening and closing the valves takes a certain amount of power, whether that power comes through a timing belt or a wire, it has to come from somewhere. In this case, the power would have to come from a huge alternator. This is not really a problem, but it is an extra cost that isn’t initially obvious. More serious is the question of how to close the valves quickly but still have it land on the valve seat gently. With a cam, you just shape the lobe so it drops shut quickly and then slows down just before the seat. With a solenoid operating the valves, it takes sophisticated electronic controls”

“Finally, there is the matter of rpm limitations. Ideally, with strong enough solenoids, the engine would be able to spin even faster then a conventional engine, but the current solenoids have a hard time working that fast. On the flip side, though, because the valve opening speed is not engine related, mid rpm performance could be greatly improved by having the valves slam to full open much faster than a conventional valvetrain, improving volumetric efficiency and making more power.”

@worriedguy Engines must have advanced quite a bit in the last few years then; I never had that sort of quick warm-up when I lived in New England, even with OBDII cars, and I could generally count on my MPG dropping considerably (10–20%, depending on the vehicle) in the wintertime. True, batteries suffer worse, but you’re talking to someone who often had to buy an oversized battery to get their cars to even think about cranking over during the winter. (I think you know what that is like!) Maybe it only takes 30 seconds for the catalytic converter to reach operating temperature, but the engine itself… there are days where I didn’t even achieve that in 30 miles.

Electrics put out a fair amount of heat; enough that many battery packs require their own cooling system. I don’t see that as an issue. Then again, I’ve had a lot of gassers that didn’t put out much heat either, so it would be more accurate to say that it’s a wash.

As for A/C, that is an economy robber even with gassers, but there isn’t any real problem having the compressor turned by an accessory motor, possibly the same one used for the power steering (assuming you don’t go with the modern electrical system that some new cars use).

I feel that Lithium is, in some ways, a step backwards. You mention battery life and how after 300 cycles, the battery is dead. I could be wrong, but I think that the Rav4 EVs underwent more than 300 cycles in 150K miles, so that isn’t an issue for NiMH. As for Lithium, that is changing too, and the actual number of charge cycles is higher than you suggest, though they still can’t match NiMH.

I have yet to see any breakdown of maintenance costs though. Oil changes alone run me over $100/yr and I do them myself to save money. That doesn’t count spark plugs, timing belts, exhaust work, and all sorts of other things that add up over the course of.. well, about the lifespan you assume for a battery. In that regard, the costs of ownership are more comparable than you think; it’s just that you often pay a little more up front.

FYI, the Nissan Leaf still has >50% of it’s range at 14F with the heat on in stop-and-go city traffic (62 miles), and at 49MPH at 110F (68 miles). Even that reduced range is further than most Americans drive in a day. Considering that we can do that in a $25K car now, imagine what we could do with more research?

EVs don’t make sense for everyone, of course, but when you consider than the majority of Americans live in cities in more temperate climates than the Northeast, they do make sense for a lot of people. And by “a lot”, I mean at least one-third of drivers in the US, and a larger portion of those in Asia and Europe.

@Cruiser I remember seeing a few different ideas for solenoid-actuated valves, and what you describe are among the reasons we still use camshafts. Well, except in Wankel engines, but those have their own issues :P

@Cruiser-Much easier to accomplish than an electric car. How about instead of government motors being forced to build presently unattainable idea, they focus on EVC instead.

@lucillelucillelucille If something we did over a century ago is “unattainable” then we should just give up and shoot ourselves right now.

EVC was proven to be problematic long ago; even more problematic than electric vehicles ever were. Put another way, at least EVs work in the real world. A far more workable system seems to be Fiat’s Multiair system demonstrated here

Then again, diesel also works (as Europe knows all too well) but us Americans won’t even consider them. We have this notion that diesels are smelly, slow things, and refuse to believe that cars like the Audi R15 TDI are even possible, let alone actually exist.

@lucillelucillelucille According the my research, EVC as it stands and taking into consideration the considerable amount of effort and R&D already invested into EVC, I don’t hold much hope of EVC being anything other than a great idea that is not practical or cost effective for mass production purposes. It looks like great technology for people who can afford it. That being said, I would have expected the high end car companies to embrace and or further develop EVC if it truly had the promise you apparently think it has and I don’t see that happening either!

@Cruiser The way I see it, if the F1 racing world rejected solenoid-actuated valves then there must be reasons. They have tried all sorts of crazy things, like turbocharging, various forms of fuel injection, etcetera ad nauseum. Some of those worked and found their way into production vehicles, and some didn’t.
Various forms of VVT (Variable Valve Timing) have found their way into cars all up and down the price spectrum, If EVC really showed promise then they would find a way to make it better and cheaper. Honda did it with VTEC and then i-VTEC.