Frits, thanks for the link to Flettners work, very interesting lecture. (also big thanks to Flettner for sharing your amazing work).
Also, tried your hcci program and the graphic function works perfectly on my phone with dosbox.
Does anyone have any thoughts on how to get hcci going without a second piston to increase pressure, instead using the hot exhaust gasses to increase the temperature? Thinking of a solution Frits proposed a long time ago on another forum where he opted to put a sliding cone in front of the stinger to (when opened) reduce exhaust gas blowback into the cyilinder (and detonation) of the rsa125 when on part throttle at high rpm.
Also found a link to the wiseman engine, crankshaft looks nice. Not in my power to calculate if this could withstand 15000 or more rpm's + longevity. Fabricating and testing, this I can do.
Is this the crank mechanism you use Flettner?
Certainly looks like it.
Just imagine a bushing around the round rod (guide) and there you have it, tight under piston pump, oil less top end, lightest possible oscillating mass, bigend sees no centrigugal force. And can be balanced I think but will need a balance shaft? Will the gear set stand up to it? I have a fix for that if it happens, if fact I have two more ideas that use different (stronger) gear arangments if needed.
Sorry Terra, thats just me.
But it really isnt true that somehow pressure ( at TDC or BDC ) is even in the same ballpark as the inertia forces of bringing the piston to a stop.
At TDC we have huge combustion pressure - and that cant stop the piston hitting the head past 14500 with 0.75mm clearance.
So the Ryger with its stepped piston compressing the tiny volume above the separator plate has no chance of helping at all.
And re the squish question - the answer lies in the MSV.
If you keep the volume the same, and the squish height the same, then the width that gets the MSV closest to 38M/Sec is the best compromise between
turbulence generation, and the loss of the fuel trapped in the end gas volume that doesnt burn.
But - as the MSV rises,and chamber turbulence goes up increasing flame speed with it, you will need to adjust the ignition timing to optimize for that.
s'allright.
The best thing for all of us will be seeing the Ryger in the wild, explode,win or have clean emissions.
Frits, you don't seem to be struggling with the minimum word length anymore!
I'm wondering if it would be better to put the Ryger cylinder and induction/spacer plate onto a 4t bottom end. Say a 250 dirt bike, with it's pressurised oil system?
Sorta annoyed I just had my classic nx4 cases turn up
Seeing it is Astrya day on Tuesday, I thought it appropriate to respond to crbbt....another aussie.
This has been discussed quite a few times and if we do get to understand how it works and it can be packaged onto a 250/450 MX, then a good idea. You can buy them cheap as chips after the top end has shit itself and it is too expensive to repair.
We extended this idea a bit to create the 3 stroke. Get a Harley, remove the original front cylinder and wack on a Ryger kit. The maths being (2+4)/2 = 3.
If nothing else it would have an unusual exh note.
Sorry Terra, thats just me.
But it really isnt true that somehow pressure ( at TDC or BDC ) is even in the same ballpark as the inertia forces of bringing the piston to a stop.
At TDC we have huge combustion pressure - and that cant stop the piston hitting the head past 14500 with 0.75mm clearance.
So the Ryger with its stepped piston compressing the tiny volume above the separator plate has no chance of helping at all.
And re the squish question - the answer lies in the MSV.
If you keep the volume the same, and the squish height the same, then the width that gets the MSV closest to 38M/Sec is the best compromise between
turbulence generation, and the loss of the fuel trapped in the end gas volume that doesnt burn.
But - as the MSV rises,and chamber turbulence goes up increasing flame speed with it, you will need to adjust the ignition timing to optimize for that.
Fwiw, the piston only arrives at tdc with compression pressure and low combustion pressure. Max pressure is arrived at somewhere around 16 degree ATDC. If combustion pressure was at or very near max at TDC when the piston needs to be brought to a stop then you would have huge deto. Perhaps the much higher compression pressure with HCCI can help in the force needed to stop the piston. I'm not sure how much pressure is created in the top or the bottom of the Ryger. Just a thought anyway.
Here is a cylinder pressure trace of a typical high performance 2T.
At TDC we have 85 Bar = 1250 psi,and it continues to rise as is well known to about 15* atdc.
1250 psi cant do anything to stop rod stretch as i said, and if the Ryger has 1/10 of this at BDC ( wild guess ) it is still useless.
Not with standing rods withstand compression forces much better than the inertial stretch at TDC.
Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.
Seeing it is Astrya day on Tuesday, I thought it appropriate to respond to crbbt....another aussie.
This has been discussed quite a few times and if we do get to understand how it works and it can be packaged onto a 250/450 MX, then a good idea. You can buy them cheap as chips after the top end has shit itself and it is too expensive to repair.
We extended this idea a bit to create the 3 stroke. Get a Harley, remove the original front cylinder and wack on a Ryger kit. The maths being (2+4)/2 = 3.
If nothing else it would have an unusual exh note.
Hahaha, and scare the bjs out of the owner by quadrupling the power output.
Don't you look at my accountant.
He's the only one I've got.
Here is a cylinder pressure trace of a typical high performance 2T.
At TDC we have 85 Bar = 1250 psi,and it continues to rise as is well known to about 15* atdc.
1250 psi cant do anything to stop rod stretch as i said, and if the Ryger has 1/10 of this at BDC ( wild guess ) it is still useless.
Not with standing rods withstand compression forces much better than the inertial stretch at TDC.
Excellent post Wobbly, I'm glad you persevere in trying to explain this to us. Your logic is undeniable. I must admit my mind made some crazy jumps to try and explain the claims when seeing the pictures. Point is, when you think you've figured it out your mind is quitte happy to leave a few questions unanswered .
Like;
the pressure needed to stop the piston at tdc is more than 250 bar, we would need to beef up the head clamping and structural integrity of the cilinder (a lot)
(Not even trying to think of the pressure needed to stop the piston at bdc with the smaller volume under the piston)
When you slow down the piston at tdc and bdc this cannot be instantaneous. So the procces would have to start quite a few degrees before tdc and bdc.
The piston is connected to the conrod and crankshaft. Wonder what would happen with your rpm's if you slow this assembly down at the end of each stroke?
And say it is possible and we are all proven wrong, when you are at maximum rpm and you would like to stop. Releasing the throttle would surely be a bad idea.
Certainly looks like it.
Just imagine a bushing around the round rod (guide) and there you have it, tight under piston pump, oil less top end, lightest possible oscillating mass, bigend sees no centrigugal force. And can be balanced I think but will need a balance shaft? Will the gear set stand up to it? I have a fix for that if it happens, if fact I have two more ideas that use different (stronger) gear arangments if needed.
Really nice work, would love to see and hear more on your findings.
Link is to a (lengthy) thesis about the subject, including a chapter on balancing and comparing it to a normal slider crank.
Hcci is beyond my grasp at the moment. All the papers I have read use electronics and very fast actuators to control either compression or charge temperature and mixture density. One paper where the compression is fixed and using charge temperature control states a rise from 120°c to 150°c will change the ignition point from 5° after tdc to 15° before tdc. I cannot see how one would combine this with a conventional 2 stroke pipe and carburator. Would like to learn more on this subject.
Looking at the pictures, homologation documents and reading the information available on the net on various message board, I must admit that, up to now, I fail to see why the Ryger should be able to produce 70hp and how. Anybody with any ideas?
Are the homologation documents of the other KZ engines already publicly available, too? I would love to take a look, but my internet search turned out unseccessfully.
Really nice work, would love to see and hear more on your findings.
Link is to a (lengthy) thesis about the subject, including a chapter on balancing and comparing it to a normal slider crank.
Hcci is beyond my grasp at the moment. All the papers I have read use electronics and very fast actuators to control either compression or charge temperature and mixture density. One paper where the compression is fixed and using charge temperature control states a rise from 120°c to 150°c will change the ignition point from 5° after tdc to 15° before tdc. I cannot see how one would combine this with a conventional 2 stroke pipe and carburator. Would like to learn more on this subject.
bjorn, I don't have papers to back up what I do, I just have a go. So, see why I was interested in the compression route, more control over actual ingition time. The trapped exhaust gas method seems too hard to control, a little hit and miss and I imagine less power (lower BMEP). I have refined my test engine a little and will have another try this week if all goes well. I'll post / video the outcome on the foundry thread.
Here is the full Ryger pdf, just issued on the cik site.
Oh - I cant upload a 2.35Mb .pdf, why not?
Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.
Here is the full Ryger pdf, just issued on the cik site.
Oh - I cant upload a 2.35Mb .pdf, why not?
http://tinyupload.com
Most hassle free solution would be to upload the file here and then post the link (no registration required) if you cannot post a link directly to the original location.
2 mb limit is really small.
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