New OPTIMAL Combustion Chambers!

NEW OPTIMAL COMBUSTION CHAMBERS!

Some of you might remember my failed attempt to obtain a patent for a "new" type of combustion chamber. The reason is that those chambers already exist. They are called "Toroidal chambers". The name is taken from mathematics because of the shape. You can read about it here,

http://www.snowest.com/forum/showthread.php?t=122454

If you read the text in the link you will also find that I claimed that the Toroidal chambers are optimal in a certain sense. THAT STATEMENT WAS INCORRECT! More correctly, they are not optimal in the sense I wanted them to be. Intuitively, I felt that something was wrong. Therefore, I checked my math over and over again, and found a serious assumption/simplification error at one point.

After doing the math again I ended up with a different design, which also makes sense intuitively. This time, I am 100% sure that THE NEW DESIGN IS OPTIMAL.

I thought about patenting it, but I decided not to due to several reasons;

1. Patenting combustion chambers is almost impossible here in Sweden. That I was told the last time.

2. Even if I could patent them it would be incredibly tedious. Here in Sweden you basically have to prove your claims by testing a prototype, with testing data certified by a reliable source. That means money, time, more money, and even more time.

So therefore I instead decided to publish my findings so nobody can patent it anymore, ever! Not anywhere in the world. I will instead rely on the fact that I am one of the very few who can design these combustion chambers. You cannot design them by trial and error like you can with the Toroidal design (simple radius, all you need is knowledge of CAD and some time). If you try doing so, you will fail miserably. In order to get you anywhere, brutal and cumbersome math is needed! If someone still wants to give it a try, be my guest,

So what is optimal about these combustion chambers? Since I am not patenting them and heavy math is needed to design them, I can reveal the secret. They are optimal in the sense that if you fix a plateau (for the spark plug) at a certain height in the combustion chamber (quick combustion), this design minimizes the surface area of the dome/head (lower heat losses). To conclude, if you intend to improve on this design and get a lower surface area still, you cannot do it. Therefore, this design is OPTIMAL!

Well, since there is no name for these heads yet, and I am likely the inventor, lets call them "Stox Chambers", shall we?

Now, here comes what everybody has been waiting for. A few examples.

EXAMPLE ONE:
Here is the outline of half a dome of a combustion chamber. The dome is created by rotating the figure around the axis of rotation (center), which is the y-axis to the left. Green Line - Spherical (conventional) design, Red Line - Toriodal design, Black Line - Stox design (optimal).

The spark plug would be entering through the plateau to the left. Note that the spark plug can be placed much further down than with the Spherical design.

http://stoxresearch.se/pictures_own/stox_chambers/StoxOptimal150.jpeg

Here is the outline of the complete combustion chamber, including piston dome, for the Stox design. Note the uniqueness of the design.

http://stoxresearch.se/pictures_own/stox_chambers/StoxOptimal150chamber.jpeg

EXAMPLE TWO:
Half a dome for a lower compression ratio. All colors mean the same as before.

Note that in this case the optimal design is not useful in practice. Here the black line even protrudes into the spark plug area, which of course is no good. Math is not bothered with "minor" issues like that,

http://stoxresearch.se/pictures_own/stox_chambers/StoxOptimal135bad.jpeg

So how to resolve the problem encountered above? One idea is to impose a restriction on the design. Here the problem is resolved by forcing the design to stay outside of a conic including the spark plug area. The design is still optimal (with the imposed restriction), and surface area will be increased very slightly. Voila, problem solved!

http://stoxresearch.se/pictures_own/stox_chambers/StoxOptimal135.jpeg

And finally, here is the complete combustion chamber design including the restriction. Again, it looks almost too cool!

http://stoxresearch.se/pictures_own/stox_chambers/StoxOptimal135chamber.jpeg

That completed the presentation of the optimal Stox Chambers. I don't know if somebody is interested in this or not, but if you are you probably understand this is still in its first stages. I will probably be selling this as replacement domes for existing heads (at first). Since I am not interested in buying a zillion different heads just for designing, I would be happy to work together with somebody to speed up the process. Please contact me per email to get things going.

As a side-note I am wondering if somebody is interested in hiring me? I am trying to find a job in Canada or the US, but that is very hard at the moment. Basically, I am sick and tired of the "half-communist" system and mentality here in Sweden, it just sickens me. If somebody is interested, please do not hesitate to contact me, preferably per email.

I hope you realize these torroid shapes are ALREADY in use by Rotax and Apillia.

The shapes you show are not new in the U.S.

There are many of us,,( Wobbly included) that use a torroid in one form or another.

I wish you the best in your quest to come to the states or Ole, Canada .

Gus

gus bohne:
If you read the text more carefully, you will notice that my combustion chambers do not have the usual toroidal shape. My design is completely different! Toroidal shaped heads consist of one single radius for the "ears", mine are, well look for yourself,

Thanks! I would love moving over to your place. I am done with Sweden. Hard working, highly educated, and risk-taking people are punished over here. I am fed up!

How does this compare to a soft head for detonation suppression and power output??

Good stuff!

A few questions:

1) What size engine was this tested on?
2) How was it proven to be optimal? What testing and test method was used?
3) What , exactly, did you gain to quantify that thise design was more optimum over the other designs (Hemi, Toroid).
4)You mentioned:

They are optimal in the sense that if you fix a plateau (for the spark plug) at a certain height in the combustion chamber (quick combustion), this design minimizes the surface area of the dome/head (lower heat losses).

Click to expand...

Why do feel this is an important parameter?

I have designed heads with a "plateau" (as you call it) for the plug also..There are many methods for doing this. What is different about yours?

Thanks, and I look forward to your reponses

Kelsey

triple7:
I am sorry, but I do not understand the term "soft head". Never heard or read that before. But I am sure it will work. I have designed several Toroidal (single radius) heads over here. People are amazed with how well they work, and so am I.

The reports from the people who have tried the Toroidal design can be condensed to; Significantly faster throttle response, engine feels "stronger" in a subtle way, and seems to run better at part throttle. One guy running an 800R had to change his pins in the primary from 16.7grams to 22grams. We did jet it down a little bit too, but everything else is stock except for the head. Another one started with an already good spherical design, and switched to toroidal. He played around with the ignition as well, he always does. There is no denying these heads work. A third one is running SnoX. They all work, plain an simple. Those running the heads seem to be surprised with how well they work. I am too. We have not encountered a single drawback so far, at least not what we could notice.

We have tried everything from 12.5:1 to 15:1 compression ratio. No issues.

Regarding the power output. Well, I do not know if I should write such things, I don't want to enter the "Inflated hp race". I never will. But on the 800R (stock) for instance, we gained a couple of hp on the dyno from the head alone, and that is not inflated. The power is improved everywhere. More important is how well it seems to work in practice. To be honest, some of the hp increase should come from the more aggressive timing with the Toroidal heads (faster combustion).

My new design (Stox) should be even better! That is a bold claim, I know, but I can't see anything that does not support that.

RKT:
1. I did not test this new design yet, since it is absolutely fresh. But I did design several Toroidal heads (single radius) people are using over here.

2. In common language, "optimal" can mean basically anything. Typically, when something is well calibrated people say it is optimal. In mathematics, you put up a criteria that should be minimized (or maximized) and when you have done that, the solution is optimal. My new heads are optimal in the sense that the surface area is minimized (spark plug location fixed). Since heat losses are proportional to surface area, they should decrease too. That is the idea.

3. Well,

It does not beat a hemi (spherical) when it comes to surface area. A hemi has the lowest surface area you can get. Mathematicians have proven that a long time ago. The drawback is that combustion takes much longer.

It beates the toroidal in the sense that if you have the same "plateau" as the toroidal, the new design (Stox) has a lower surface area. It is optimal. You can also come down a little bit further with the spark plug if you like.

It beates the bathtub design (traditional, flat top-round corners) with ease. If you place the spark plug at the same height as for the bath-tub, surface area is lower. You can also place the spark plug further down.

How does it all boil down to hp at the end? Well, I did not even make one yet, so I don't know. I did not even have too many of the toroids on the dyno yet, only the 800R. It picked up a couple of hp, and runs like a champ. I am running a Crank Shop RV1000 and I was amazed with how well it ran.

By the way, do you have a better name than "plateau", I am from Sweden you know,

4. Mine is different since it has the lowest surface area possible.

Stox... Thanks for the reply..

Do you plan on testing this new design on an engine in the near future? I am very interested to see how it does..

How do you feel this new design effects scavenging (loop) flow in the chamber and residual purging (any pockets)?

Kelsey

RKT:
Yes. I will be testing them,

I really do think they will work . Basically, they are "tweaked" Toroidals, a head design that is already known to be good.

Wouldnt this cause greater piston crown temps, perhaps losing reliability? How tight of a compression ratio can one run with this head before plug to dome clearance is a issue? Is the squish band altered in anyway?
Just some thoughts that came up.

Is the squish band kind of large on this? I thought there was a point where the larger the squish band the worse off you were. I'll admit that I know very little about it I just like the topic. Great post

BCP:
Yes, that could be a concern. I was wondering as well. In practice we haven't had a single issue whatever we tried (so far). It might be that the faster combustion makes the time for heat-soaking the piston so much shorter that it doesn't matter. Whatever the reason, it worked so far, One guy has been running his (ported) 670/740 at close to 13:1 compression ratio at (close to) sea-level for about (I am guessing a little here) 1100kms without problems.

When designing, I am able to place the spark plug virtually at any (useful) height, so clearence never becomes an issue, I designed the squish band in the same manner as always.

olymon:
Yes. These designs (the toroidal versions) were designed for a SnoX machine, so squish velocity is pretty high. I thought that would be a good idea. The guy using them seems happy, so it cannot be all bad, Anyway, I can design whatever squish band is wanted.

That's very interesting.

So if I understand your theory correctly here Stox ; the smallest surface area (or the shortest "Toroidal" line or shape you can draw (then revolve) with the help of a math function) from corner of "spark plug boss" to corner of "squish section" will enable the chamber to loose the absolute minimum amount of heat during ignition of the fuel mixture/explosion, thus creating a more powerful explosion.

Is that right or i'm in the field ?

That wasn't an easy sentence by the way...

TLKDPROD:
I understand your sentence, And yes, that is the idea.

Actually it is not entirely that easy. It also depends on the flow pattern. For example, I know there are some other designs in use/being tested as well, using "stagnant" areas, for isolation basically. Saw it somewhere on the web for a TZ250(?) I believe. But that is another topic and harder to derive designs for. I am taking the "easier" route and minimize surface area. You cannot go wrong with that either. As I said, the regular Toroidal design already seems to work well. And believe me, the math behind my design is not too light either,

BUT, what is really nice is that I can shape my design for "stagnant" areas also if I wish, by modifying the optimal design with "kinks". But it is hard to tell (at least for me) how to place them at the right locations so that they actually improve the design. One drawback with this is that it increases the surface area, how much depends on the number of kinks and where they are placed. If somebody wants that, it can be done.

Stox OPTIMAL Chambers - Finished Design

Back again! Here is just one example of what a finished STOX OPTIMAL insert might look like. Unfortunately, we were stupid enough to polish the inserts before the photo-shoot, so it is hard to see much. You live and learn,

Notice that the Stox design is similar to a Spherical/Hemi design close to the squish band, but still the spark plug protrudes deep into the combustion chamber. If somebody doesn't remember what this is good for can (if they like) start reading from the beginning of the thread.

One smart guy also pointed something out to me that I didn't think of myself. Thank you! This design is all about minimizing combustion chamber surface area, but as a nice side-effect, it also concentrates more air-fuel mixture closer to the spark plug compared with the more traditional Toroidal design. What does that mean? Faster combustion!

http://stoxresearch.se/pictures_own/stox_chambers/StoxOptimal_1.jpg

http://stoxresearch.se/pictures_own/stox_chambers/StoxOptimal_2.jpg

http://stoxresearch.se/pictures_own/stox_chambers/StoxOptimal_3.jpg

http://stoxresearch.se/pictures_own/stox_chambers/StoxOptimal_4.jpg

http://stoxresearch.se/pictures_own/stox_chambers/StoxOptimal_Head.jpg

Now I am only waiting for the report how this works in the field. I already know what he is going to say, more or less, Maybe I will post a video here later.

faster combustion should allow you to run more compression, if you did a a dozen of dyno runs with increasing comp ratios until you find the limit ,it would be interesting to know - learn the amount of increased compession this design allows, ofcoarse it would be knowledge for only that engine but facts are facts. Nice work and all the best

Thunder101:
Thank you! Yes. What you mention is just one of the advantages following from this, And no, I do not intend to do any extensive dyno testing. Somebody else can do that if they like.

I checked the cost for manufacturing these domes here in Sweden and here is what I found out. If I order them in small quantities I would have to sell them crazy expensive, something like +$200 for each dome! If I want to avoid crazy prices I have to order a gazillion of them at a time. Later on I would probably see companies in North America copy them, produce them for less, and then sell them back to Sweden. I am not going that route, too frustrating! To sum it all up, I am fed up! We are far from being the richest country, but production is expensive like hell anyways. Our industry is dying. The crazy thing is too many think it is purely a natural development and not to the slightest extent imposed by zip flexibility, the highest taxes in the world, the killing off of almost all benefits that should come from education and hard work, and a public sector that is absolutely massive. The half-communist mentality over here is killing us. Can somebody in Canada or the US hire me please so I can leave this f'kin country! I am not taking it anymore. Now, enough for now,

Oh yeah. To the manufacturers. I believe this design is a step forward when it comes to lowering emissions and lowering fuel consumption (related to each other) for non-DI two-stroke engines. What we did notice is that the engines we tested earlier with conventional Toroidal design seem to run better in the problematic part-throttle region. We could also see a noticeable drop in fuel consumption. No scientific testing at all so it isn't for sure, but it seems to be clear enough. My design should be even better than the Toroidal's. Use it to kill all four-strokes!

PS. A little anti-four-stroke propaganda at times is very important,

Great thread! Very interesting!
Have to call you some day, need to dyno my TM8 when its done.
If your dyno can handle the power?

this is very similar to the recently released warantee upgrade for the 800cfi polaris

Barrett:
Hey! Don't tell me Polaris started using the Toroidal design? If so, that's nice, The two-strokes are attacking! If we are lucky we will soon be living in a four-stroke-free world,

I don't think Polaris is using my optimal design, but the traditional Toroidal one. Much easier to design. But if they figured it out it's even better (at least that is what I believe).

StoxResearch said:

Thunder101:

I checked the cost for manufacturing these domes here in Sweden and here is what I found out. If I order them in small quantities I would have to sell them crazy expensive, something like +$200 for each dome!

Click to expand...

Seems kinda expensive there in Sweden.

Each dome has about $4 in material and probably 6 min cycle time, so $10 bucks labor and would have to throw some profit in there so add $25. You should be able to easily get them done for $40 a dome in the US.