It seems everything else is being done by wire, why not have an engine valve system that, instead of mechanical timing, is operated just by solenoids at each intake and exhaust valve by the ECU? That way software can determine the optimum open and close sequence under every condition, and can even account for engine wear. It would also do away with timing chains, belts, cams, and gears. Plus theres the benefit of less drag and fewer moving parts.

Many cars have VVT and other valve system enhancements but they are still mechanically based. I think its just a matter of time, if it hasn't been done already. Anyone else?

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1985 380SE Blue/Blue - 230,000 miles
2012 Subaru Forester 5-speed
2005 Toyota Sienna
2004 Chrysler Sebring convertible
1999 Toyota Tacoma

THere have seen prototype engines that used electronic solenoide valves.......but I guess they have issues to work out yet.........I don't doubt they are in the future however.

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Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
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Section 609 MVAC Certified
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"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

The power required to open and close the valves electrically is economically and practically too high. Did you ever try and squeeze a valve spring? There is a technique that uses hydraulic lifters that have electric control.

Since there wouldn't be a cam, engineers could use a few different valve designs, maybe something that works more like a water faucet rather than a spring-loaded reciprocal valve. They are no longer restricted to the physical constraints of cam lobes.

I agree there would be lots of issues, reliability being the big one. And I've never liked the proliferation of electronic controls in everything. But we are so far down that path, and it would only be one more thing for OBDxx to troubleshoot!

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1985 380SE Blue/Blue - 230,000 miles
2012 Subaru Forester 5-speed
2005 Toyota Sienna
2004 Chrysler Sebring convertible
1999 Toyota Tacoma

Why would you need a valve spring anymore? This is the future, engines that can self valve-tune in a split second. How economical would that be.

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Pxland

2001 Honda Accord

1995 Jeep Cherokee

1973 MB 280SEL 4.5

they once thought that about computers in cars...............that they were too expensive and not reliable enough to work. Now you can't even open the windows without a computer.

__________________
Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
---------------------
Section 609 MVAC Certified
---------------------
"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

It's not the spring itself, its the amount of force needed in that application, there's a reason that spring is a strong one. No matter how you do it that amount of force is still required. Electrical solenoids are good for control but don't have that much power. I figured you would need a huge alternator to run a valve train and that in itself would make electric valves unpractical.

But suppose you did away with the poppet valve and spring. In its place could be a rotating sleeve valve spun by a servo motor. The intake charge travels down the middle of the sleeve and thru a side opening. The servo would have positional stages controlled by the ECU, thus rotating the sleeve valve over the cylinder port. I did some Google searches on this, and found that some types of camless engines are being looked at by a number of people already.

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1985 380SE Blue/Blue - 230,000 miles
2012 Subaru Forester 5-speed
2005 Toyota Sienna
2004 Chrysler Sebring convertible
1999 Toyota Tacoma

I read about one particular design in some hot rod magazine, and the lack of valvetrain weight allowed some serious prolonged RPMS!

I believe the main issue was getting a proper seal while a cylinder is in the "valve closed" position...

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car

I heard GM was working on the idea about 10 years ago. Can you imagine a 4 cycle engine with the drag of a two stroke? It would rev so much quicker!

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'84 300CD

This has been looked into, but I think would be really impractical with a 14V system. In my opinion, one of the factors holding back this technology is the low voltage of the standard car electrical system. Otherwise, it will take a lot of Amps at 14V to power what would have to be some rather powerful solenoids. They could either up the Voltage of the entire system or make a seperate higher volatage system for the valve train. Raising the voltage of the entire system would lead to some serious compatibility problems with the other consumers in the system, so this method may be impractical.

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Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record

Formula 1 cars already do it. It's just a matter of time before they hit real cars, I think.

I've seen car comertials that advertise "variable valve timing" but they didn't give any technical details and I don't remember what car it was.

A lot of cars have variable valve timing. All BMW, Porsche as well as others. My M104 has variable valve timing on the intake cam. The system allows the camshaft to be rotated in realtion the the crank the change valve overlap and time at which the valves open in relation to the crank. Except for the new BMW system, lift and duration are left unchanged, though.

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Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record

all we need is 85gigawatts and a flux capacitor along with a DeLorean, Marty, Doc and plutonium to be happy