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-   -   Will they ever have a valve engine with no cam shaft? (https://www.bikeforums.net/showthread.php?t=1120419)

windhchaser 08-30-17 09:36 PM

Will they ever have a valve engine with no cam shaft?
 
i figure if they use solinoids to controls valves they could change valve timeing more easy and get more mpg

Shimagnolo 08-30-17 09:43 PM

This has been ongoing for at least four years:

windhchaser 08-30-17 09:48 PM

coolness

dynodonn 08-30-17 10:16 PM

I remember reading about this in the 70's with one engine guru, by the name of Smokey Yunick, having a working small block Chevy outfitted with valve solenoids, and it was claimed that the engine could idle at 200 rpms, and rev to well past 7000 rpm, but mechanical reliability was it's downfall, since 70's technology was not up to the task.

dabac 08-31-17 02:48 AM


Originally Posted by windhchaser (Post 19830446)
i figure if they use solinoids to controls valves they could change valve timeing more easy and get more mpg


Sure.


It's an old idea that's still difficult to turn into reality.


Have you ever felt a valve spring?


They're quite stiff.
And they have to be to close fast enough.
Whatever technology you choose, driving the valves up & down fast enough requires considerable force.


Using "normal" car tech you end up with quite chunky solenoids.
And a bunch of engineering challenges on the drive/control side of the solenoids.
I saw a working prototype years ago.
It used high voltage solenoids.
Worked well enough as a stationary engine, but would have been hard to pack into a vehicle.
The rules & regulations regarding electrical installations alone would have been an obstacle.
But I'd assume the electrics that goes in electrical/hybrid cars would have made that less of a challenge today.
Another option would be to go cryo, superconducting.
That'd give some impressive valve performance.
But add Another bunch of complications.

skidder 08-31-17 07:22 AM

There was someone back in the late 1970s-early 1980s, I think Australian, who developed a two-stroke engine with valves driven directly by linkage from the engine's driveshaft. It improved the efficiency of the two stoke engines, had fewer parts than a standard four-stroke valved engine, and reduced exhaust pollution, but it required more major maintenance (the valves tended to 'gunk-up' more often which reduced their ability to seal properly), so it never really caught on. I tried searching the web for some historical info on it but couldn't find anything.

FBOATSB 08-31-17 08:16 AM

Methinks, if looking toward an engine with fewer or no reciprocating parts, the wankel, or rotary engine is the way to go. Invented in 1929 and constantly being refined for racing and aviation, even motorcycles.

no motor? 08-31-17 02:22 PM


Originally Posted by dynodonn (Post 19830490)
I remember reading about this in the 70's with one engine guru, by the name of Smokey Yunick, having a working small block Chevy outfitted with valve solenoids, and it was claimed that the engine could idle at 200 rpms, and rev to well past 7000 rpm, but mechanical reliability was it's downfall, since 70's technology was not up to the task.

That wasn't the technology that GM used in the V4-6-8 Cadillacs was it? That worked about as well as their diesels.

FBOATSB 08-31-17 02:52 PM

Look Ma, no springs. Desmodromic valve trains were hugely successful in high revving superbike racing. Maybe a double acting push/pull solenoid could get this going in a simple automobile engine. No heavy spring tension could allow this to be pretty light weight, yes?

http://1.bp.blogspot.com/-PeJ0M7F8Sl...0/yoy3g5jd.gif

no motor? 08-31-17 05:58 PM

Desmo valves are a great idea, but I shudder to think of the maintenance costs for a valve adjustment on a car engine with them.

Dr. Desmo makes/made a kit for replacing a port on the valve cover with a piece of clear plastic that would allow you to see the valvetrain in operation when the engine was running. It was pretty cool to watch for a few minutes.

Jseis 08-31-17 10:38 PM

My Kawasaki 175 Bushwhacker had a rotary valve, Husqvarna chainsaw has reed valves, and the .049 model airplane engines had the piston as the slide valve. All hi-rev two strokes. Solenoid operated poppet valves seem like a natural evolution assuming the durability can be worked out. That being said, powering yourself down the road with micro explosions seems quaint.

tyrion 08-31-17 11:58 PM

Soon combustion engines will be exotic, special purpose, special order artefacts of little use to engineers but still interesting to artists and children's science fairs. You can have one 3D printed with solenoids if you want.

dabac 09-01-17 12:26 AM


Originally Posted by FBOATSB (Post 19832043)
Look Ma, no springs

Getting rid of the springs is not a goal in itself. The big payoff is expected from the easily variable timing.
A desmodromic valve train isn't any better at that than a regular camshaft.


Originally Posted by FBOATSB (Post 19832043)
Desmodromic valve trains were hugely successful .....

Were they really?


Originally Posted by FBOATSB (Post 19832043)
... in high revving superbike racing.

High revving being the operative word.
Insufficient understanding of harmonics and self-oscillation made the valves "float" instead of moving cleanly from open to shut. A minor tweak of valve mass and/or spring rate sorted it out w/o the complicated mechanics.


Originally Posted by FBOATSB (Post 19832043)
Maybe a double acting push/pull solenoid could get this going in ... automobile engine.

Unlikely.
The spring isn't the problem. Valves needs to be forcibly moved in both directions. Springs exist as a short cut to get away from the double lifter/closer arrangement of the desmodromic system.
The trouble is the valve itself.
It still has mass enough to be difficult to shuttle back & forth by electro-magnetic force at the speed required by a combustion engine.

Valves operated directly by solenoids is doable as such. But it is proving difficult to get it compact enough.
High-voltage and cryo can fix it, but brings it own problems.

A lighter valve material would make it easier. Some weird ceramic with magnetic properties perhaps.

The Koenigsegg video briefly mentioned "pneumatics", so I think they're using solenoids as control valves for compressed air that becomes the force that moves the engine valves.

Originally Posted by FBOATSB (Post 19832043)
a simple automobile engine.

Don't understand what you mean by that.
In one sense race engines have it easier. Less emission requirements, not much interest in doing well on partial loads etc.

Zinger 09-01-17 02:24 AM

http://www.transportarchive.org.uk/aimages/G2689.jpg

There was the 18 cylinder air cooled Bristol Centaurus sleeve valve aircraft engine . It used a set of helical gear shafts to turn and reciprocate the steel cylinder sleeves which had the valves cut into their sides.That enabled more valve area than poppet valves were capable of, including those in hemispherical combustion chambers.

It was derived from the earlier simpler Willys-Knight sleeve valve design.



.......................................................................Sounds like this

Sangetsu 09-01-17 07:08 AM


Originally Posted by FBOATSB (Post 19832043)
Look Ma, no springs. Desmodromic valve trains were hugely successful in high revving superbike racing. Maybe a double acting push/pull solenoid could get this going in a simple automobile engine. No heavy spring tension could allow this to be pretty light weight, yes?

http://1.bp.blogspot.com/-PeJ0M7F8Sl...0/yoy3g5jd.gif

Like my old Ducati. I had to carry a set of wrenches and a feeler gauge under my seat, as the valves needed adjusting every two or three weeks.

Mechanical valve systems are used because they are simple, reliable, and require little in the way of maintenance. They are also inexpensive. An electromagnetic valve train would require several things, a fair amount of copper and magnets, as well as a larger alternator/generator to provide the power to open and close the valves. An alternator under a normal load absorbs a fair amount of power from your engine, turning on your headlights causes enough drag that the engine was to kick in a little more fuel and air to maintain the same idle speed. The amount of energy needed to operate at least 2 valves per cylinder would be significant. Though combustion would indeed be more efficient, the amount of electrical energy needed to run it might cause more mechanical resistance than a conventional valve train system.

Though modern engines aren't fundamentally different than engines of half a century ago, they are remarkably efficient at powering vehicles. If you live in an area without hydroelectric, wind, or nuclear power, a gasoline powered car uses less fuel than an electric car, when you consider how much gas, coal, or oil which must be burned to create the electricity to charge your car (only 25% of what a power plant makes is delivered to your home, 75% is lost in transmission). Hydrogen fuel cell cars are also not very efficient, as more than 95% of hydrogen used today is created by burning fossil fuels. And, lastly, the amount of C02 created to build modern electric car batteries is incredible. Studies show that it would take a gasoline-powered car 8 years to generate as much C02 as is emitted in the production of an electric car battery system. And for those of you who own electric cars, you know that batteries must be replaced more often than once every 8 years.

Personally, I will stick to a good, old-fashioned internal combustion car. If I ever buy a car, I have been car free for 9 years now.

dynodonn 09-01-17 08:07 AM


Originally Posted by no motor? (Post 19831975)
That wasn't the technology that GM used in the V4-6-8 Cadillacs was it? That worked about as well as their diesels.


I'm sure that this was an independent design by Smokey Yunick, and the one of his most promising engine designs of his that I thought would take off, but didn't, was his hot air/vapor design. The 2.5 liter engine made 250 hp, got 50 mpg, accelerated the test car to 6 second 0 to 60 mph times, and exceeded all of the emission standards of the day.






Pontiac Fiero Hot Air Engine Setup - Hot Rod Network

Juan Foote 09-01-17 08:11 AM


Originally Posted by FBOATSB (Post 19831009)
Methinks, if looking toward an engine with fewer or no reciprocating parts, the wankel, or rotary engine is the way to go. Invented in 1929 and constantly being refined for racing and aviation, even motorcycles.

It is my understanding that the rotary engine as we know it is much less efficient than it should be. The 'wives tale' goes that some high up oil guru bought the original design features that made it super efficient and left Wankel with the light, high power version we see used much today. Bad on gas and emissions.

I have zero actual evidence to back my fairy tale up, so it could well be just that. It was always interesting to discuss among fellow RX owners about the mileage and stink.

mconlonx 09-01-17 08:54 AM


Originally Posted by Sangetsu (Post 19833240)
Like my old Ducati. I had to carry a set of wrenches and a feeler gauge under my seat, as the valves needed adjusting every two or three weeks.

Wow... how old a Ducati? Modern ones use shims to adjust and the adjustment interval is 7500, with many finding that clearance hasn't changed enough to warrant adjustment in even 20k mi.

There are engines which have been designed with pneumatic valves, but it's still basically a spring setup with cams. Renault developed a system of cam-less control of hydraulic valves, but they never developed a working engine that utilized it.

fietsbob 09-01-17 09:19 AM

Piston-port 2 strokes .. carburetor is attached to the crankcase..

bigbenaugust 09-01-17 11:44 AM

Didn't Honda or someone make an engine with magnetic valves?

dabac 09-01-17 12:15 PM


Originally Posted by Juan Foote (Post 19833405)
It is my understanding that the rotary engine as we know it is much less efficient than it should be. The 'wives tale' goes that some high up oil guru bought the original design features that made it super efficient and left Wankel with the light, high power version we see used much today. Bad on gas and emissions.

Nah, that's just conspiracy theories.

The wankel have two basic design challenges:
1) the shape of the combustion chamber, surface area vs volume. Wankels have a very shallow and elongated combustion chamber. It's harder to get a good burn through that squished shape as compared to a regular cylinder. There tends to be unburnt residue clinging to the periphery of the chamber.
2) the seals, overall length and fit. Piston engines have piston rings. Quite easy to make, and they have a fairly easy job. Wankels have seals instead. The overall length of seal is greater in a wankel, and due to how they fit and how parts move, wankel seals wear out a lot faster than piston rings. That's the main cause for the dreaded, early engine rebuild.

There were hopes that improvements in material technology would allow a rebirth of the wankel.
Ceramic surfaces in the combustion chamber would run warmer, giving a cleaner burn.
Slicker, more wear-resistant materials to make the seals last longer.

But so far, This has failed to happen.

Dan Burkhart 09-01-17 03:06 PM

A decade or more ago, there was lots of buzz in trucking trade publications about the development of camless diesels for highway use. The perceived benefits would be infinite incremental control of the timing, interval and duration of valves and injectors. Makes perfect sense because when these functions are slave to a cam lobe, it's all about compromises when setting up the engine.What's efficient in one operating environment is less so in another.
All the engine manufacturers were pursuing this technology in conjunction with Jacobs manufacturing. Yup, the same company that makes chucks also had decades of experience controlling engine valves hydraulically for engine braking. ever hear of the Jake Brake.
Anyway, with modern electronic controls, it seemed like a no brainer that valves and injectors could be actuated hydraulically without the need of a camshaft.
So what happened to this bright idea?
No idea. It suddenly fell off the radar and so far has not made it to market.

Michigander 09-04-17 11:21 AM

I am hugely skeptical that US and Europe budget car companies could do it affordably and reliably. Honda and Toyota, maybe, but their reserved, careful designs are why I doubt they'd bother.

Like other exotic systems, it's all fun and games until you see a repair bill. And that's giving them the benefit of the doubt they'd have a highly effective fail safe for interference engines.


Originally Posted by tyrion (Post 19832906)
Soon combustion engines will be exotic, special purpose, special order artefacts of little use ...

I sure hope so. If battery and charging technology can continue maturing, and we can get there without burning coal to a similar effect of gasoline, that'd be wonderful.

Dan Burkhart 09-04-17 12:09 PM

Looks like they have not abandoned the idea yet.This article is from 3 years ago.
AutoSpeed - Camless Engines
There are some heavy hitters working on developing the technology, and Jacobs is still in the game.
I think we will see it become reality.

Wulf 09-04-17 06:41 PM

Rotary valve enginehttps://www.google.com/url?sa=i&rct=...04658281097770


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