[2stroke] Ryger engine

fullgazlolo a écrit:

Alors je vais faire simple pour t'aider: si c'est homologué c'est que c'est produit et si c'est produit c'est que c'est développé donc... devrait être en vente libre.
Autant on peut comprendre que tant que ce n'est pas homologué ce soit secret, autant une fois dans le "domaine public" même sous brevet quant à la conception, on a du mal à comprendre pourquoi il n'y a pas de prix, de courbes, de démo, etc, etc...

tout à fait d'accord,d'ailleurs on peut dire que quelques part c'est anti commercial!! il n'à pas été réalisé pour rester dans un coffre fort d'ailleurs la saison de karting commençe bientôt !!

Ha, le commerce, comme "valeeeuuur" première de notre époque... qui fini par altérer nos conceptions.
Bien sur que de ce seul point de vue, ce n'est pas la situation idéale qu'a sans doute souhaité le concepteur qui, comme dit très justement "n'à pas été réalisé pour rester dans un coffre fort d'ailleurs".
Alors ? Entre les rêves des "manadejeurs" et les réalisations, il y a les réalités qui bouleversent les calendriers définis par ceux qui ne font rien ou affabulent que je conchie dans mon post précédent.
Rassurons nous, Ryger engine, c'est des idées et du métal, pas des plannings et c'est pas très courant. Patience.

Cesar aussi utilisait du métal et avait des idées et n'avait pas de planning...
Bon par contre, lui il déconstruisait!

Hi! If the Ryger cylinder set-up where put on an 'in-line' rotary valve engine, like the Aprilia RSA125, wouldn't the scavange cycle be even more efficient?! The rotary valve inlet would of course need to be raised to line up with the cylinder inlet instead. Maybe together with a thinner piston cylinder rod as well, if possible, for more scavenge volume under piston

No Helmers, I think that this would not work like it does now with a reed valve. Due to the absence of the crankcase and its dampening influence the positive and negative pressure waves
are an awful lot stronger than ever before. The reed valve works so much better than with the crankcase system that even with a small carbie of only 30mm the system really seems to go very well. One of the highest qualified 2stroke experts around (unfortunately he does not appear on any forum like our much!!! beloved FOS...) made an assesment/simulation of the RYGER (pronounce RIEGER) and came to the provisional conclusion that this system should work. The only thing we've got to wait for is the first
race in the KZ class against the leading engines like TM. I'm afraid that we ALL (2stroke wankers) have been sleeping more or less! Let's wait and see.

Hi Bob! Thanks for the explanation. Ofcourse Ryger know what they do. I look forward to read more about how it works!!

Is anything known about it's reliability?
30.000 rpm with a connecting rod length of 90mm is asking for trouble!
In my opinion it should be more like 120-130....
And I think the piston will have a very short life anyway!

Hi Mister Thiel,
You could give a phone call to Frits Overmars to get the information first and.
He wrote the conrod is 90 mm and the engine reliable enough to get along with kart competition life.

yesyes a écrit:

You could give a phone call to Frits Overmars to get the information first and.
He wrote the conrod is 90 mm and the engine reliable enough to get along with kart competition life.

it is 90mm, see the homologation papers.

what everybody seems to overlook, is that no one ever has said the Ryger can reliably run at 30.000 rpm, nor that it is meant to run at those rev's. It was only mentionned that it is capable of reving to 30.000 rpm. to me that indicates there is something special about this engine : that even at 30.000 rpm, it is capable of breathing and burn the mixture very fast (for a 125)

Anybody  seriously? mentioning 30k with 54mm bore & stroke behaves a little!!! dddddum.  30k with 54mm stroke would give 54m/s average piston speed as well as corrected piston speed. But with 54 x54mm the correction factor to get corrected piston speed is 1. Wake up mate!
Also up to now nobody seems to understand why the RYGER might do very well. Even our much beloved!!!! 2stroke guru FOS is hiding in silence. The man who is probably THE REAL  expert on 2strokes did
a simple simulation on what's known about the RYGER and came to the conclusion that in simple words the absence of the crankcase as part of the scavenging system is the cause of the totally changed gas dynamics in the above the plate scavenging system Or: the non presence of the dampening effect of the old crankcase changed everything. Conclusion : we 2stroke wankers have ALL been sleeping, how about that? I'm happy that I got my
wake up call from the mentioned expert. It's never too late  to admit one was wrong and learn again!

as you said Bob , it's never too late , but the sooner is the better


be positive guys , it's seem to be hard for some of you , but try , you'll make it


.

I think what we are all waiting for is some shred of concrete evidence that this engine does what the designer says it is supposed to. I don't think anyone expects it to be reliable at 30K rpm but the fact that it is able to rev there even if briefly before it scatters would be something special. The operating peak HP rpm of 17,500 would surely shorten the rod bearing life but if it lasts a full weekend and produces 70 hp it would make the rebuild at least worth it. Up to now we have a bunch of mystery and a bunch of claims with no substantial proof except for Mr Overmars statements as to its performance. The photos that have been posted and subsequently removed without explanation is silent testimony that there is trouble in paradise. ( I saved them as did most regulars on here so no big deal). Even the public testing resulted in 3 unimpressive laps followed by an unceremonious engine seizure. I hope it is the big breakthrough we all are waiting for with patient anticipation but until I see a kart with one of these engines leading a race or better yet winning a race, I will stay skeptical. Even a dyno sheet would give me some hope but honestly I'm not too impressed yet.

I have a question regarding the section view of the cylinder in the homologation papers.

In the exhaust duct you can see an oval outline on the drawing. At first I thought this was the sub exhaust ducts, but on the cylinder port map, there are no sub ports present..

Is this shape a static vane, or are the sub ducts not in use?

Henrik

Bob van der Zijden a écrit:

Anybody  seriously? mentioning 30k with 54mm bore & stroke behaves a little!!! dddddum.  30k with 54mm stroke would give 54m/s average piston speed as well as corrected piston speed. But with 54 x54mm the correction factor to get corrected piston speed is 1. Wake up mate!
Also up to now nobody seems to understand why the RYGER might do very well. Even our much beloved!!!! 2stroke guru FOS is hiding in silence. The man who is probably THE REAL  expert on 2strokes did
a simple simulation on what's known about the RYGER and came to the conclusion that in simple words the absence of the crankcase as part of the scavenging system is the cause of the totally changed gas dynamics in the above the plate scavenging system Or: the non presence of the dampening effect of the old crankcase changed everything. Conclusion : we 2stroke wankers have ALL been sleeping, how about that? I'm happy that I got my
wake up call from the mentioned expert. It's never too late  to admit one was wrong and learn again!

Thinking of some sort of zero crankcase the damping effect below the piston also helps it to bounce back upwards. And this same effect is present alt tdc under combustion.
It sort of makes sence that these things like to rev since the bowncing of the piston?

Just a thought

The gas dynamics of the positive and negative pressure waves in the limited capacity of the RYGER's inlet and scavenging system are of a totally different order than probably  all of us have been thinking up to now. Only a proper simulation could open our eyes, and in this matter my skills are zero.  So patience is the word. Also my very good friend Jan Thiel who I do know so well since almost 60! years has to wait and see!

Bon, ben voilà quoi!
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Well, I didn't have to wait too long Bob!
No power, no reliability and too much noise......
What more do you want?

Money?
Mais le pire... une fédération mondiale a homologué le truc!
Je trouve que ça éclaire bien l'utilité et la probité de ce genre d'organisation!
On produit, on signe un chèque et... on attend les gogos!
Heureusement qu'il n'est pas presque fiable et que l'importateur a réagi à temps!

The Dracing facebook page said: As there is no proven performance and no proven reliability....
It doesn't mean the engine is not powerfull and not reliable.

Ok, it is more noisy than the FFSA rules.

And don't forget, it is a new project and just entering the production phase. Many small things should be adjusted.

Angelo

Effectivement , curieuse annonce de D racing: niveau de bruit hors norme aux régimes annoncés par le constructeur! et l'homologation alors , elle sert à quoi? si ce moteur peut tourner à Pmax à 17500 tr il ne fait pas le même bruit que ses concurrents à 13000 tr. La puissance et fiabilité (relative d'un moteur racing) çà se vérifie auprès du constructeur et en piste.
Des pressions de constructeurs concurrents? des problèmes de fabrication, de mise au point pour respecter les normes d'homologation? questions.
Dan

Is the FFSA noise limit lower than the homologation limit ???

Angelo

fullgazlolo a écrit:

Bon, ben voilà quoi!
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Any comment from those who are in the know is welcome  
Or at least could them give us the game's name we have been playing fort the last 6 months

Only a few weeks and everything will be explained, so be patient for a little while.

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Whaou , petit encart a tous ceux qui enterre le bébé très peu après sa naissance  :

le jour ou vous inventerez / concevrez  quelque chose ( si cela arrive.... )  ont fera de même , vous verrez que c'est joyeux  de ce faire pourrir de la sorte , à défaut d'être savant et tolérant soyez à minima  silencieux ....


.

Je veux bien tout ce qu'on veut et espère mais à un moment donné... l'Arlésienne sera t'elle une réalité?
Je crains que les photos qui ont "fuité" ne soient que le résultat de la casse.
Ce qui me fait dire que ça pue un peu beaucoup c'est le côté laconique du commentaire de l'importateur.