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"New" combustion chambers!

S

StoxResearch

New member
I have been working on a new combustion chamber design for several months, aiming at a patent. Weeks of mathematical calculations, followed by x months of design, construction, and testing, suddenly became dust. I found the same design on the internet. When something has been published, it cannot be patented anymore.

Here are some pictures where the design is compared to a conventional spherical design,

http://stoxresearch.se/pictures_own/combustion_chambers/Stox Front.jpg
http://stoxresearch.se/pictures_own/combustion_chambers/Spherical Front.jpg

http://stoxresearch.se/pictures_own/combustion_chambers/Stox Back.jpg
http://stoxresearch.se/pictures_own/combustion_chambers/Spherical Back.jpg

http://stoxresearch.se/pictures_own/combustion_chambers/Stox vs Spherical.jpg

Some questions:
1. What is it good for? What is the purpose?
2. The design is optimal in a certain mathematical sense, i.e. you cannot do better than that. In which way is it optimal?

Well, find it out yourself, :) All I can say is that it works awesome! That is why I wanted to patent it.

It is worth noting that I was granted funding for this project. Yes, public funding for research on two-strokes!

$hit happens! That's why I love the God-sent two-stroke, :)

If you intend to use this design, remember where you first saw it! :p
 
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So I'm guessing that, from what I could tell from the pics, it is designed to give more swirling of the gasses for more complete burn while getting the spark down in the center of that swirl for a more center out burn instead of a conventional top down burn?

Increasing fuel efficiency and power?

How well does it promote exhaust "scavengeing" (clearing exhaust gases and pulling in fuel/air mix, while not pulling it out into the exhaust)?

How does it affect pipe design?

How prone to Deto is it?

I've often kicked around ideas in my head about 2-stroke head design but am pretty sure I haven't thought of anything yet that hasn't already been tried.
 
looks like you might get better spark concentration in the center of the combustion and have a larger surace area to push off of as well as concentration of the force to the center of the piston......interesting. mix this up with kelseys deal and see what ya get;)
 
I don't think it is patented. Point is, once the idea has reached the public it cannot be patented anymore. Ever. If somebody would still manage to patent it, I will strike down on them and kill the patent. That is a promise. I do not like when people steal existing ideas.

Nobody builds them in greater scale either. I would, but since Sweden is such an expensive country, it is of no use. Anybody could copy the design and produce it cheaper than me. I would sell almost nothing after a while.
 
That style has been around for years, they call it torroidal on the RGV forums, apparently because torroids are used in diesel head design.

Check the link, its a long read, but its got lots of pics :)

Oh, and its not necessarily the best shape, there are quite a few other designs that work, other than the good old hemi.

You have to retard the max timing with the torroidal head because the plug is closer to the center of the chamber. Closer to the piston top too, so be carefull.



http://www.rgv250.co.uk/forums/index.php?showtopic=12867&hl=head design&st=20
 
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Blokhead:
Yep. The Australian bike (if that is what you mean) was what I found on the internet destroying all of my plans, :mad: Maybe it has been around for some time, but not many knew about them. I didn't. But how many have proven that it is mathematically optimal, and in which way? I have, :)

Yes, I know all about the timing already.
 
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Chambers

The basic concept isn't new, though that is more extreme than what I've seen before. Not sure I'd say the idea is good or bad, just different. As mentioned, the net effect is similar to advancing the timing. One downside is that the surface area of the combustion chamber is increased significantly, which wastes a bit more f/a charge (the surface layer is kept too cool to burn). In addition, the close proximity of the spark plug to the piston surface may tend "heat soak" the motor more easily and reduce performance on long pulls, or require the piston design to be changed to handle the extra heat load. Maybe as part of a complete motor package, something like this may have some advantages, but I'm not convinced it will have benefits as a "bolt-on".
 
rocket:
Yup. You are right there. But most of the heat is generated AFTER the mixture is ignited. Therefore, surface area is not that much of an issue as one might think.

And I am sure it would work as a bolt on. Saw it myself. For an 800R that is, which has a lousy design to begin with though (for power). As you can see, I even compared it to a spherical design, and I got an increase in power with it. Not much, but it was better. It was good enough to make me want to patent it, :) It definitely combusts faster.

Try it out yourself and you will most likely be happy. Be sure to adjust the timing as well.
 
Id like to see these calculations and your definition of "optimal", independant testing, papers, CFD results, CA10-90 times, BSFC, ......etc.

Surface area is a very big deal and more SA will increase HT and lower thermal efficiency.

This extended spark plug into the center of the combustion chamber is very sharp and is likely to increase knock.

Not knocking it but big claims need big proof.
 
mustang316:
I am not interested in sharing my mathematical results with anyone. I am not sending it to a conference or something similar so I don't have to. The results are from "calculus of variations" in mathematics. Did I mention that I am a PhD so I know a little bit of math? I don't have to prove anything.

Just try them out and you will see that they work. I am sure people will design combustion chambers like these and try them out very soon.

By the way. I think you are too deep into "four-stroke land". Four strokes are more sensitive when it comes to (for example) quick combustion and high peak pressures. They have high peak pressures and high peak temperatures to begin with. Yes, four-strokes are useless, :p
 
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What kind of Comp Ratio are you using this design at?

Are you producing them for sale?

If not in order to test/try your optimal design wouldn't you have to share at least some of the math/dimensional data with people in order to try them?

That and please share how it "works awesome"

Power?
Efficiancy?
Torque?
All of the above?

Different people look for different things out of a motor so spending a pile of time and research not to mention money to build them would be useless to someone looking for something that they cannot provide. for instance if they are great at providing fuel efficiancy but only average or less power or oposite of that scenario the time and money would be wasted for the person doing the development trying to achieve the latter.

Just throwing the idea out there and saying it works awesome isn't going to get a bunch of people to jump on board with you.

PS I am interested even if for nothing more than learning and discussions sake.
 
XC700116:
Ok, here goes. I understand people are sceptical, I would be myself, :) But this works, believe me. I'll think about what I'll do for a day or two. Most likely I will give you a design to try out for yourself. That is the only way to make people believe in this. Since it is common nowadays to let's say "exaggerate" results, people would still be sceptical if I would provide you with dyno results, data, or whatever. The best thing would be to try it out for yourself.

I will get back to you.
 
Honestly I wouldn't be trying it out any time soon as I'm running a turbo now and until I learn all the ins and outs of that I'm not going to mess with anything.

I was more or less trying to just learn a little more about a potential new product offering for our sport. Much like the fact that I have no delusions of riding or building a Turbo Yamaha anytime soon but I still read a lot about them.

As far as everything else. Unless you come to the table with all the data that 99% of people won't understand you get exactly the type of response that you got above and even then you still might get that response. Unfortunately (or perhaps fortunately for the consumer) "It works Believe me" doesn't cut it if your trying to sell something especially over the internet. I also realize that your not necessarilly trying to sell them but you get the idea.

I was more than anything else just trying to learn something about it and get a more productive conversation going about it other than "it works awesome" and "it's got too much surface area".
 
Oh and by the way I do appreciate everything that everyone has done to further our sport and educate those of us not fortunate enough to have the knowlege that some of you do. Which is also the same reason that I try to help out anyone I can when they have questions and the main reason I spend so much time on this forum.
 
XC700116:
That is a good idea. Not to mess around with anything when it works, :) I am running a Crank Shop RV990 right now. Great engine. I know there is power left on the table regarding jetting, compression and other stuff, but I do not care. As long as I think it runs like a beast I won't be touching anything. Why should I when I am happy? :)

And you are right: Me and other's should do better than talking above the head of most people. I apologize. It easily becomes like that when you learned the basics yourself way back. The whole idea of the head design is to speed up combustion. That is what it is all about. This serves several purposes (hopefully): You won't be heating up the end gases as long (enabling higher compression) because you ignite the mixture later, and you won't be "building up as much pressure" before top dead center (increases useful work on the piston).

You are right about another thing too: I really do not care if I sell any of these heads or not. Firstly, I won't be producing any myself, Sweden is too expensive. What I maybe could sell is the designs themselves, but frankly I do not care about that either. I would never lie to sell anything, which in the world of business is more of a weakness than an advantage. Unfortunately.
 
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mustang316:
I am not interested in sharing my mathematical results with anyone. I am not sending it to a conference or something similar so I don't have to. The results are from "calculus of variations" in mathematics. Did I mention that I am a PhD so I know a little bit of math? I don't have to prove anything.

Just try them out and you will see that they work. I am sure people will design combustion chambers like these and try them out very soon.

By the way. I think you are too deep into "four-stroke land". Four strokes are more sensitive when it comes to (for example) quick combustion and high peak pressures. They have high peak pressures and high peak temperatures to begin with. Yes, four-strokes are useless, :p

PhD in what?
BFD, I will hopefully be starting my PhD this sem too.

As a scientist you should be well aware of how to back up your claims. I dont take anybodies word for anything, I need to see results.

FYI I know just as much about 2jokers too. See my sig pict.

GL with your head design.
 
mustang316:
PhD in Control Engineering. LOTS of math. Yes, I know I should back up my claims, if I would care about it, :) This is not a technical paper or a conference, this is Snowest, :p I am like you, need to see results as well before I believe anything.

Cool. Good Luck with your PhD! It really is fun.
 
Its my understanding the torroidal shape came from the GP race bikes when Moto-GP went to regulated/mandated fuel octane. They found they could make more power with less octane with a torroid shape v. the old design and unlimited fuel blends.

And yes they do work very well...

torroid.jpg
 
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Backcountry:
Man. So you did try them also? Why did I spend all the time and money developing something already existing, :( Anyway, I can't be that stupid since I have been developing them independently all by myself, :p

Nice that someone is backing up my claims, :)
 
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