One of my favorite automobile engine ideas is the use of camless, electronic valves. It’s an idea whose advantages have been known for 100 years or more, and it’s finally going to be used on a mainstream, commercial car — on this year’s Fiat 500s. Fiat is not going entirely camless, but the plan is to replace the cams on the air intake valves with solenoids. A normal car engine uses cams and lifters to operate the poppet valves used to control the air intake and exhaust. Replacing these cams and lifters saves some weight, and allows the Fiat-500 to operate more efficiently at low power by allowing the engine to use less combustion energy to suck vacuum. The Fiat 500 semi-camless technology is called Multiair: it’s licensed from Valeo (France), and appeared as an option on the 2010 Alfa Romeo.
How this saves mpg is as follows: at low power (idling etc.), the air intake of a normal car engine is restricted creating a fairly high vacuum. The vacuum restriction requires energy to draw and reduces the efficiency of the engine by decreasing the effective compression ratio. It’s needed to insure that the car does not produce too much NOx when idling. In a previous post, I showed that the rate of energy wasted by drawing this vacuum was the vacuum pressure times the engine volume and the rpm rate; I also mentioned some classic ways to reduce this loss (exhaust recycle and adding water).
Valeo’s/Fiat’s semi-camless design does nothing to increase the effective compression ratio at low power, but it reduces the amount of power lost to vacuum by allowing the intake air pressure to be higher, even at low power demand. A computer reduces the amount of air entering the engine by reducing the amount of time that the intake valve is open. The higher air pressure means there is less vacuum penalty, both when the valve is open even when the valve is closed. On the Alfa Romeo, the 1.4 liter Multiair engine option got 8% better gas mileage (39 mpg vs 36 mpg) and 10% more power (168 hp vs 153 hp) than the 1.4 liter cam-driven engine.
David Bowes shows off his latest camless engines at NAMES, April 2013.
Fiat used a similar technology in the 1970s with variable valve timing (VVT), but that involved heavy cams and levers, and proved to be unreliable. In the US, some fine engineers had been working on solenoids, e.g. David Bowes, pictured above with one of his solenoidal engines (he’s a sometime manufacturer for REB Research). Dave has built engines with many cycles that would be impractical without solenoids, and has done particularly nice work reducing the electric use of the solenoid.
Durability may be a problem here too, as there is no other obvious reason that Fiat has not gone completely camless, and has not put a solenoid-controlled valve on the exhaust too. One likely reason Fiat didn’t do this is that solenoidal valves tend to be unreliable at the higher temperatures found in exhaust. If so, perhaps they are unreliable on the intake too. A car operated at 1000-4000 rpm will see on the order of 100,000,000 cycles in 25,000 miles. No solenoid we’ve used has lasted that many cycles, even at low temperatures, but most customers expect their cars to go more than 25,000 miles without needing major engine service.
We use solenoidal pumps in our hydrogen generators too, but increase the operating live by operating the solenoid at only 50 cycles/minute — maximum, rather than 1000- 4000. This should allow our products to work for 10 years at least without needing major service. Performance car customers may be willing to stand for more-frequent service, but the company can’t expect ordinary customers to go back to the days where Fiat stood for “Fix It Again Tony.”
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The mechanical device for changing the date of the closing of the intake valve
http://agahalka.blogspot.ru/2016/10/the-mechanical-device-for-changing-date.html
http://agahalka.blogspot.ru/2016/09/blog-post.html
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Technology Submission – Novel Rotary-Turbo-InFlow Tech – Featured Development
GEARTURBINE PROJECT
Atypical InFlow Thermodynamic
Technology Proposal Submission
Novel Fueled Motor Engine Type
*State of the art Innovative concept Top system Higher efficient percent.
Have similar system of the Aeolipile Heron Steam device from Alexandria 10-70 AD. -New Form-Function Motor-Engine Device. Next Step, Epic Design Change, Broken-Seal Revelation. -Desirable Power-Plant Innovation.
http://www.youtube.com/watch?v=0cPo9Lf44TE
YouTube; * Atypical New • GEARTURBINE / Retrodynamic = DextroRPM VS LevoInFlow + Ying Yang Thrust Way Type – Non Waste Looses
-This innovative concept consists of hull and core where are held all 8 bteps of the work-flow which make the concept functional. The core has several gears and turbines which are responsible for these 8 steps (5 of them are dedicated to the turbo stages). The first step is fuel compression, followed by 2 cold turbo levels. The fourth step is where the fuel starts burning – combustion stage, which creates thrust for the next, 5th step – thrust step, which provides power to the planetary gears and turbines and moves the system. This step is followed by two hot turbo steps and the circle is enclosed by the final 8th step – bigger turbine. All this motion in a retrodynamic circumstance effect, wich is plus higher RPM speed of self reaction motion, because is like when something go to a something is coming. Its a Rotary-Turbo-InFlow Technique principle.
*8-X/Y Thermodynamic CYCLE – Way Steps:
1)1-Compression / bigger
2)2-Turbo 1 cold
3)2-Turbo 2 cold
4)2-Combustion – circular motion flames / opposites
5)2-Thrust – single turbo & planetary gears / ying yang
6)2-Turbo 2 hot
7)2-Turbo 1 hot
8)1-Turbine / bigger
-With Retrodynamic Dextrogiro vs Levogiro Phenomenon Effect. / Rotor-RPM VS InFlow / front to front; “Collision-Interaction Type” – inflow vs blades-gear-move. Technical unique dynamic innovative motion mode. [Retrodynamic Reaction = When the inflow have more velocity the rotor have more RPM Acceleration, with high (XY Position) Momentum] Which the internal flow (and rotor) duplicate its speed, when activated being in a rotor (and inflow) with [inverse] opposite Turns. A very strong Novel concept of torque power thrust.
-Non waste parasitic looses for; friction, cooling, lubrication & combustion. -Shape-Mass + Rotary-Motion = Inertia-Dynamic / Form-Function Wide [Flat] Cylindrical shape + positive dynamic rotary mass = continue Inertia kinetic positive tendency motion. Like a Flywheel.
-Combustion 2Two continue circular [Rockets] flames. [ying yang] opposite to the other. – With 2TWO very long distance INFLOW [inside propulsion] CONDUITS. -4 TURBOS Rotary Total Thrust-Power Regeneration Power System. -Mechanical direct 2two [Small] Planetary Gears at polar position. -Like the Ying Yang Symbol/Concept. -Wide out the Rotor circumference were have much more lever [HIGH Torque] POWER THRUST. -Military benefits; No blade erosion by sand & very low heat target signature profile. -3 points of power thrust; 1-flow way, 2-gear, 3-turbine. *Patent; Dic. 1991 IMPI Mexico #197187 All Rights Reserved. Carlos Barrera.
There are a lot of interesting IC engine designs. I happen to like variable valve timing because I think it does most everything the other designs do in a more elegant, compact package. IMHO, reliability seems like the only reason more companies don’t do this. My hope is that Fiat has overcome this problem, but time will tell.
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