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Author Topic: Reed-Less 2 stroke intake valve  (Read 9896 times)

Offline TRX250RACER

Reed-Less 2 stroke intake valve
« on: October 06, 2015, 07:40:39 AM »
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Offline Uns

Reed-Less 2 stroke intake valve
« Reply #1 on: October 06, 2015, 06:34:50 PM »
Looks like a simpler Tesla valve.  Pretty low surface area for flow.  Will probably allow more back-pressure to come through the carb, similar to a broken reed.  Will be interesting to see if it works.
"Valvetrains? Where we\'re going, we don\'t need Valvetrains." - Me

Offline TRX250RACER

Reed-Less 2 stroke intake valve
« Reply #2 on: October 07, 2015, 01:36:51 AM »
I think I read that they were being tested already. So if they work (and hopefully add some power gain) then one less thing to worry about.

Offline rablack21

Reed-Less 2 stroke intake valve
« Reply #3 on: October 07, 2015, 08:38:55 AM »
Yep, this should be interesting. One less part to fail.

Offline Uns

Reed-Less 2 stroke intake valve
« Reply #4 on: October 07, 2015, 12:43:04 PM »
While I want to be jumping out of my seat at the thought of never replacing worn out and expensive reeds again, I really doubt this is going to add power.  It MIGHT make the same, and I think likely it will be a trade-off of power for simplicity, like usual.

I had thought about a Tesla valve for a reed cage a long time ago after running across them, but even Tesla valves, which look like they impede the reverse flow better than this intake will, only offer a ~10 fold reduction in flow per "stack" used.  That resistance does not increase over time, like a "shutting" reed valve will, from "open" to infinity.

The one potentially redeeming feature of this valve is that there is no reed resistance to overcome, though there is momentum in the reverse flow of this system that the new incoming fresh charge has to overcome, so that might be a wash.

And, even the big boys doing modern innovation on two strokes are still using reeds.  Thinking that "The guys behind the smart carb came up with it, and they are amazing!" isn't taking into account the millions in R&D being dumped into clean two stroke tech with direct cylinder injection and 150:1 oil ratios using targeted injection points.  If this was the best way to design an intake valve, they would have thought of it, done it and advertised the hell out of it.

And, all we have is a side-cut view of a 3d model on a computer.  I'll get much more excited when they show the side-cut of an actual valve, some flow simulations, and dyno graphs showing, at minimum, no horsepower loss.

/WetBlanketMode off
"Valvetrains? Where we\'re going, we don\'t need Valvetrains." - Me

Offline Jerry Hall

Reed-Less 2 stroke intake valve
« Reply #5 on: October 07, 2015, 01:14:20 PM »
Quote from: Uns;59562

.................And, even the big boys doing modern innovation on two strokes are still using reeds.  Thinking that "The guys behind the smart carb came up with it, and they are amazing!" isn't taking into account the millions in R&D being dumped into clean two stroke tech with direct cylinder injection and 150:1 oil ratios using targeted injection points.  If this was the best way to design an intake valve, they would have thought of it, done it and advertised the hell out of it..................


/WetBlanketMode off

A patent or patent pending does not guarantee that the patented device works as described in the abstract.  There are millions of patented devices that do not work and are worthless to society.  By the way, Sparky and Red Edmonds, the guys that invented and patented the Smart carb, Lectron, Lakewood injector, Blue Magnum, EI etc died a number of years ago.


I also want to see dyno and field testing results on this device on a number of different engines.

Offline JesseA420

Reed-Less 2 stroke intake valve
« Reply #6 on: October 07, 2015, 01:19:46 PM »
UNS too much rant, u seem like u have an agenda to discredit this idea.
Quote from: Uns;59562
they would have thought of it, done it and advertised the hell out of it.
maybe... maybe not? says who?




nothing wrong with getting excited about innovative thinking.
Quote from: Hawaiiysr;66760
Yup i sucked the head. taste like dirt.

[/FONT]

Offline Uns

Reed-Less 2 stroke intake valve
« Reply #7 on: October 07, 2015, 03:41:00 PM »
Quote from: JesseA420;59565
UNS too much rant, u seem like u have an agenda to discredit this idea.

maybe... maybe not? says who?

nothing wrong with getting excited about innovative thinking.

You got me!  I'm actually an agent from the two stroke reed lobby here to destroy these reed-less heathens and continue to collect my millions in two stroke reed sales!

Really though, I just enjoy science, physics, and have thought of a similar idea before.  After doing 10 minutes of research, learned that valves like this one allow a LOT of backflow, and only "increases resistance" to the backflow, never stopping it, which is not what you want.

The Tesla valve has been known about for literally 100 years.  This design is, in my non-expert opinion, an inferior design to the actual Tesla patent(which utilizes a directional flow barrier in the "loopback" area rather than an open loopback, which is most likely inferior.)  you can see the similarity in the image at: https://en.wikipedia.org/wiki/Tesla_valve

And to expand even further on what Jerry said, not only does the device not have to function as described in the patent, the device doesn't even have to EXIST to get a patent.  All we have right now is a 3d computer model and a patent pending without a number(which reminds me of someone recently, but hell, at least he was shipping actual parts)

All of this being said, I really do hope it works.  If the canary in the birdcage comes out alive, and is priced similar to a reed valve and a set of reeds, I'll be the first in line to buy two.  I'm just glad I'm not the one with my money on the line, is all...
"Valvetrains? Where we\'re going, we don\'t need Valvetrains." - Me

Offline Jerry Hall

Reed-Less 2 stroke intake valve
« Reply #8 on: October 07, 2015, 07:12:19 PM »
Quote from: Uns;59577
Really though, I just enjoy science, physics, and have thought of a similar idea before.  After doing 10 minutes of research, learned that valves like this one allow a LOT of backflow, and only "increases resistance" to the backflow, never stopping it, which is not what you want.


That is also my first impression.  It looks like it function parallels how a labyrinth seal functions.

My curse is I am an engineer.  Older engineers are often labeled as closed minded and critical of new ideas.  Engineers are trained to pursue ideas that are supported by physics and the other disciplines of science as they pertain to the task or device that we are trying to design, or improve.  We are trained to find flaws in everything we do and we see flaws in everything around us that science can be applied too.   Because of this we are labeled as being critical.  This training causes us not to pursue ideas not supported my science or projects that seem closely related to other failed projects or ideas that we have personally experienced or seen others experience.  Many of my customers, guys on the forums and some younger enthusiastic engineers often see me as closed minded to ideas that they consider to be new or revolutionary.  As I grow older and accumulate experience in my field, I have seen and been in involved in more failed projects and designs than I would care to admit.  I try diligently to avoid making the same mistake twice and also try diligently to warn others of not making the same painful and expensive mistakes I have personally made.  Some called it closed mindedness and critical, I just call it experience.

A two stroke engine needs some type of valve at low RPM that allows the crankcase to pump efficiently at various throttle positions and various RPMs.

With the proper intake tract dimensions a two stroke will run at high RPM with the reed petals held wide open.  

The 24/7 type of reed valves have been undergoing development in the back rooms of engine companies for a number of years.  The 24/7 reed has petals and functions like a conventional reed valve at the lower RPMs.  At a predetermined RPM when the inertia in the intake tract is sufficiently high the reed petals move out of the way and we have an unobstructive intake port that is open 24/7.

Over the years I have experienced a lot of broken reed petals on two stroke engines.  These engines with a missing petal or hole in a reed petal will usually start and idle because the area under the closed carb slide has a smaller area than the hole in the reed petal.  The engine will die when the throttle is opened because the crankcase stops pumping air into the engine when the flow area through the carb is larger than the hole in the petal.  As the piston goes up, the crankcase sucks air in through the reed cage windows that have good reed petals and through the window of the missing petal.  When the piston goes down, the pressure in the crankcase will cause the good petals to seal shut but some of the crankcase mixture will be forced through the hole in the broken petal before the transfer ports open.  The amount of crankcase mixture that flows through the window with the broken petal depends up on the RPM, throttle position and size of the hole.

I think a reed assembly needs to seal relatively well (stop reverse flow) when the flow through the intake is low due to low RPM and or small throttle openings and have enough window area to flow enough air to support the HP capability of the engine at high RPM.  

I see this new design as possibly having too much reverse flow at small throttle openings and not enough flow area at the discharge end to support the engine's air flow requirements at high RPM.   If the discharge end area is increased, the velocity may drop enough to keep the design from stopping the reverse flow to an acceptable level.  As the air flow increases I think the efficiency of stopping the reverse flow increases with increasing throttle position and RPM.  It seems to have flow characteristics that are opposite to what most two stroke needs.  I would like to see the flow ratio of:

  (forward flow) / (reverse flow)  

 with the same pressure ratios applied to the upstream and downstream ends of the valve.  

It will be interesting to wait and see flow and power test results to see if this is going to be something revolutionary or the same old pig we have seen many times before with a different color of lipstick.

Offline udontknowme

Reed-Less 2 stroke intake valve
« Reply #9 on: October 07, 2015, 07:55:05 PM »
i was thinking the same thing. at first glance it seems like it might allow to much backflow at low engine speeds and not enough at high engine speeds but thats just assumption at first glance. apt is known for throwing products in the public eye well before its thoroughly tested or even available for purchase. a strategic sales tactic im quit sure of it. no different than what they did with smart carb
to much power is almost enough

Offline udontknowme

Reed-Less 2 stroke intake valve
« Reply #10 on: October 07, 2015, 10:09:12 PM »
haha
to much power is almost enough

Offline TRX250RACER

Reed-Less 2 stroke intake valve
« Reply #11 on: October 07, 2015, 10:30:04 PM »
I have absolutely no idea what all you experts are talking about,  I just thought it would make a cool conversation piece. That all.

Offline christph

Reed-Less 2 stroke intake valve
« Reply #12 on: October 07, 2015, 11:54:47 PM »
It looks like the hooked features that provide the back pressure would make its forward flow too restrictive.  I don't see today's reed technology, e.g., Mototassinari, as being a limiting factor in two stroke performance.
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Offline rk88r

Reed-Less 2 stroke intake valve
« Reply #13 on: October 08, 2015, 07:54:49 AM »
Maybe it can be tuned for a narrow rpm range and used on generator/pump engines.
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Offline Jerry Hall

Reed-Less 2 stroke intake valve
« Reply #14 on: October 08, 2015, 10:46:14 AM »
Quote from: rk88r;59610
Maybe it can be tuned for a narrow rpm range and used on generator/pump engines.
 

Purpose built engines in this category do not need reeds or anytype of intake valve.  They have specially designed intakes that use wave tuning and inertia of the column of intake mixture moving inside a very long intake port to trap the charge in the crankcase.

 

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