New OPTIMAL Combustion Chambers!

[StoxResearch]

sledr2:
Hire me and I promise to come over and make a ton of them,

I can get the cost down significantly if I order them in greater numbers, say a minimum of 50 units. I have that confirmed from several places. But even then I cannot compete with the manufacturing costs you mention. To make it even worse, because of the massive taxes a bigger margin is also needed, i.e. a higher selling price. I will not be selling them with a minimal margin, no way. Such an approach only supports the sick Swedish system and I am working my a$$ off for nothing.

If I would even give it a shot, I would risk sitting on hundreds or even thousands of domes I cannot sell. Not an option.

 

[sledr2]

sledr2:
Hire me and I promise to come over and make a ton of them,

Sorry, don't need the headache of having an employee.

I was just giving you some real world prices on domes. I'm not going to jump into the head business. (allthough its a really easy part to make) There's plenty of people doing it allready, RKT is just up the road from here and CPC's are made just down the street.

 

[Rms Rydning]

This domes you have designet looks very good. But they look very simular to the best 125 gokart engines I have been looking into lately.

 

[LRD]

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

I have seen those heads and my guess it was a desperation move on Polaris part to lower the compression on the original heads without having to make all new heads for warranty to keep them from blowing up.

Good Luck

 

[StoxResearch]

I haven't been to this forum for a looooong time, but I still get a notification when this thread gets updated. That isn't too often

Rydning:
If I would have to make a guess the heads you have seen is the "Toroidal" design. If you read from the beginning of this thread you will understand the difference. Having said that, sooner or later more people will learn how to design my combustion chambers (if they want to). There is a lot of complicated math involved, but I am not the only one who can do it, for sure.

By the way. I have designed these combustion chambers for a 1425 Two-stroke Turbo (three cylinders) we are building over here Fun! I have also designed an mathematically (in a certain sense) optimal header for the engine where all "legs" are equal in length. The header design is not as nice as I would have hoped for, but I am still working on improvements. I have done three different designs so far, where each design took me a couple of months I am NOT giving up. I never give up! The math behind my combustion chambers is EASY compared to that for the stupid stupid header,

 

[4Z]

I have seen those heads and my guess it was a desperation move on Polaris part to lower the compression on the original heads without having to make all new heads for warranty to keep them from blowing up.

Good Luck

That right there (by LRD) I would agree with 100%. They don't have any of these type of Swedes working there. Just Bidnessmen.

 

[Daltech]

Looks nice. And good there`s somebody thinking on there own.
Just one question, the edge of the sparkplug hole is pretty thin. Not afraid it would act up as a hot spot when its that thin?

If you are as good engener as it seems to, there should be a well paid job for you in Norway I would assume

 

[StoxResearch]

Daltech:
Hi! I have been afraid of many things, that is just one of them Instead of just assuming and rejecting stuff beforehand I decided to try it out. Being close-minded often hinders progress. I constantly try to avoid that! I guess that's why I'm a scientist You might have missed it, but I have a PhD degree in Control Engineering.

It should be noted that I could easily make the area around the spark plug wider. In fact I already did but very slightly. I can also easily increase the distance between the spark plug and the piston if needed. My design methodology has a lot of freedom built in. You just specify 1) a "plateau" for the spark plug (position, width), 2) a squish band (position, angle, width), and 3) a volume. The rest follows automatically.

Here is the thing though. So far I see no reason why I should change any of that. We are constantly pushing the envelope for compression ratios, and have had absolutely NO failures so far. I just finished designing a combustion chamber for my own 1080 two-cylinder engine with 12.5 CR (pump gas). I think that's pretty high for such a big engine. I have no doubt it'll work. If it works I will go even higher.

Yes. I have seen that Norway's unemployment rate is close to zip. Get me a nice job and I'll come over to your place

 

[winter brew]

What do you see for dyno numbers on the big twin?
12.5 doesn't seem high to me, pretty typical for pump gas at low elev. on a big twin.

 

[gus bohne]

Paul, the fuel is NOT 91 octane over there..

Its mostly 85 ish...ouch....!!

Though my friends in norway say avgas is availible..

 

[Daltech]

Paul, the fuel is NOT 91 octane over there..

Its mostly 85 ish...ouch....!!

Though my friends in norway say avgas is availible..

Nearly. We have two kinds of octane ratings, 95 and 98 octane, measured in RON.

95 RON is equal to 85–86 MON, or 90-91 AKI
98 RON is equal to 89-90 MON, or 93–94 AKI

(AKI is RON+MON/2) And is the common way to state octane number of fuel in Canada, USA and Brazil.
AKI can also be called RdON or PON.

So that makes our fuel comparable to yours

 

[Daltech]

The AC M1000 has a CR of 12.4:1 stock. Works fine.

If your looking for jobs over here, check out www.finn.no
Alot of oportunities here

Daltech:
Hi! I have been afraid of many things, that is just one of them Instead of just assuming and rejecting stuff beforehand I decided to try it out. Being close-minded often hinders progress. I constantly try to avoid that! I guess that's why I'm a scientist You might have missed it, but I have a PhD degree in Control Engineering.

It should be noted that I could easily make the area around the spark plug wider. In fact I already did but very slightly. I can also easily increase the distance between the spark plug and the piston if needed. My design methodology has a lot of freedom built in. You just specify 1) a "plateau" for the spark plug (position, width), 2) a squish band (position, angle, width), and 3) a volume. The rest follows automatically.

Here is the thing though. So far I see no reason why I should change any of that. We are constantly pushing the envelope for compression ratios, and have had absolutely NO failures so far. I just finished designing a combustion chamber for my own 1080 two-cylinder engine with 12.5 CR (pump gas). I think that's pretty high for such a big engine. I have no doubt it'll work. If it works I will go even higher.

Yes. I have seen that Norway's unemployment rate is close to zip. Get me a nice job and I'll come over to your place

 

[TARI]

you said,

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!



OK, so you mention that this design makes faster combustion because the spark plug is closer to the piston or should we say more air fuel ratio. But does it make more hp because of the design or because it is similiar to the toroidal design, over the stock rotax design? I know something you mentioned you weren't sure of. (2 hp?)
You should try to make note of the flame or combustion what is happening with it, in your head design at high speed,(in milliseconds) optimun would be to have a super high speed camera there is a couple around.

Ted,
Terra Alps Racing inc.

 

[StoxResearch]

winter brew:
Hi! Of course you can run higher CRs than that. However, my personal preference is to lean the **** out of engines so I get a reasonable fuel consumption/range. I don't like paying Swedish rates for fuel (about twice what you're paying) nor getting towed out of the woods . What is a reasonable consumption/range? Well, that's a personal matter of taste. As an example, my Crank Shop RV 990 seemed to use less or as much fuel as my brother's Rotax 670 (stock but jetted) each time we checked during a winter. So in my book, 12.5 CR is plenty. I am crawling upwards

Power? I have no idea. This is a Crank Shop RV 990 I am rebuilding to 1080ccm. The RV 990 is no slouch I can assure you that. The funny thing is that I haven't had it on the dyno because I spun the clutch on the crank the first season I had the engine. I don't want to kill my dyno! The crank shaft looks like a mess but it works. As long as Crank Shop isn't starting giving away crank shaft parts for free I won't fix that

By the way, I love the RV 990. Best engine ever!

Daltech:
The Cat 1000 engine also has some fancy electronics preventing pistons from reaching the liquid state Personally, I hope that Cat will put some more effort into that engine. A knock sensor would be nice.

Thank you for your link. I will look into that! I am pretty much fed up with Sweden. However, Norway has a very similar system so I am not sure But at least you are paying some oil-driven salaries over there.

TARI:
Well, faster combustion (at least at the beginning, not sure for how long) is the idea. I have no extensive dyno results to back it up with, nor do I have any interest to work with this any further in this country. Working your *** off only to getting opposed by the system itself is no fun in the long run, I can assure you that. I have thrown in the towel! Oooops, do I sound bitter and filled up with hate

People who have used my design want it again and again so it can't be too bad.

 

[Thunder101]

is it not true that the toroidal design is best used with a flat top piston ? your design would fall under the same ?

 

[Wayniac]

I admire your enthusiam and efforts to try and come up with a better dome profile. Keep up the good work. I gotta say though, that dome profile looks really similar to what we have been running on our 800CC Kawasaki watercraft engines in race applications. That being said, it works really well!

Wayne

 

[gus bohne]

is it not true that the toroidal design is best used with a flat top piston ? your design would fall under the same ?

Not exactly, flat tops like a torroid to a point but it also likes a hemi thats narrow on sqiush and shallow on depth.

gus

 

[9 Iron]

dont wants to rain on anybodys perade here but this is not a new design. I sent my head off when i did the big bore, they came back, milled obeviously, and looked identical to this optimal design.

skidoos head design is very similar just needs a little reworking and easily looks like this

 

[TARI]

If you tried to machine out a stock head design to look like a torridle design there would be no material left in it, it would be into the water jacket. Doing a stock head mod is not the best way to go if you want the best out of a bigbore. more of a budget route.

 

[StoxResearch]

Man. You can really tell winter is closing in Do you have snow over there yet?

Thunder101:
If torroidal designs work best with flat top pistons or not, I really can't comment on that since I haven't compared a gazillion different head and piston designs. However, personally, I do believe that it also has to do with what the designs look like. You can make them more or less extreme. Also, I am pretty much like a mathematician. I tend to view most everything mathematically. Therefore, in my view many of todays pistons are close to being flat. For example, my new 95mm pistons are only 5mm higher in the center than at the edge. How can that make such a big difference? I don't know, maybe it does, but the engine characteristics has to follow a pretty non-linear function then.

Wayniac/9 Iron:
Well, if you view every design where the spark plug protrudes even a tiny bit (or more) into the combustion chamber as the same, then you are correct. Using the same logic, you can also claim that every design with a spark plug is the same

gus bohne:
Well said! There is not just one truth. Therefore, I am very careful about general statements (everybody does mistakes though). Well, except for one thing: Four-strokes are junk