[2stroke] Ryger engine

Don't forget the patent was registered in 2007 and since then a lot could have been changed...
The inlet as seen on the patent drawing  showed valves but a reed valve job on the cylinder  is clearly shown on the CIK homologation pictures. This could mean that the typical patent valves could have been deleted. Anyone else a better idea?

Bob van der Zijden a écrit:

Don't forget the patent was registered in 2007 and since then a lot could have been changed...
The inlet as seen on the patent drawing  showed valves but a reed valve job on the cylinder  is clearly shown on the CIK homologation pictures. This could mean that the typical patent valves could have been deleted. Anyone else a better idea?

Both valves in the same assembly? why not.
Dan

Exactly looks sometimes, there is no membrane bearer's record in the picture of the homologation...

JanBros a écrit:

Sanderhoutman a écrit:

With four rings and 18000 rpm you wont keep it as cool as stated.

only 2 rings (look at the homologation) and it runs a lot cooler tnx to the HCCI ignition (very fast burning so there is less time for metal to heat up).

Does HCCI is high compression ignition? like in Diesel and almost in glow plug engines. On the patent drawings there is no spark plug, but it's possible to use electric ignition and compression ignition, according with the loads and revs of the engine, similar to the Honda patent.
Dan

Something cross my mind !! yes it happens sometime !  If the engine looks like something close enough to the draw and that one port is use as a breather for the crankcase it means the second piston diameter , the lower one, could be considered as a pump, a crankcase pump and so what is the true cylinder capacity ?????? for a concept like this the crankcase and all the lower side of the piston have to be to the atmospheric pressure as a true breather. Am i wrong? knowing that i have specific knowlege about pump or 2T for being honest!!!!

Frits Overmars a écrit:

Dan42 a écrit:

a common license between Ryger and Honda?

Certainly not, Dan. In case you want some literature:
P.M.Najt & D.E.Foster: Compression-Ignited Homogeneous Charge Combustion, SAE Paper 830264
This paper is 32 years old, which solves any HCCI patent questions.
What's more, Homogenous Charge Compression Ignition was first applied in the Lohmanm mopedmotor about 60 years ago

wrong

Model diesel aircraft engines were 1942 and glowhead boat engines 1890.

Niels Abildgaard a écrit:

Frits Overmars a écrit:

Dan42 a écrit:

a common license between Ryger and Honda?

Certainly not, Dan. In case you want some literature:
P.M.Najt & D.E.Foster: Compression-Ignited Homogeneous Charge Combustion, SAE Paper 830264
This paper is 32 years old, which solves any HCCI patent questions.
What's more, Homogenous Charge Compression Ignition was first applied in the Lohmanm mopedmotor about 60 years ago

wrong

Model diesel aircraft engines were 1942 and glowhead boat engines 1890.

It seems "Homogenous Charge Compression Ignition" has only been in use to describe a combustion process since 1979.

Diesel and glowplug engine combustion processes are different to HCCI.

tjbw a écrit:

Niels Abildgaard a écrit:

Frits Overmars a écrit:

Dan42 a écrit:

a common license between Ryger and Honda?

Certainly not, Dan. In case you want some literature:
P.M.Najt & D.E.Foster: Compression-Ignited Homogeneous Charge Combustion, SAE Paper 830264
This paper is 32 years old, which solves any HCCI patent questions.
What's more, Homogenous Charge Compression Ignition was first applied in the Lohmanm mopedmotor about 60 years ago

wrong

Model diesel aircraft engines were 1942 and glowhead boat engines 1890.

It seems "Homogenous Charge Compression Ignition" has only been in use to describe a combustion process since 1979.

Diesel and glowplug engine combustion processes are different to HCCI.

Excuse the mixing up of terms.
When old model aircrafters talk about diesel it is the type shown as example here:

[Vous devez être inscrit et connecté pour voir ce lien]

The diesel naming had something to do with the fuel.A third ether, a third riscinus oil and a third diesel oil.
But no highpressure diesel injection anywhere.
The were developed/inventedby a swiss mechanic

[Vous devez être inscrit et connecté pour voir ce lien]

When scandinavians or germans are talking glowhead,Gluhkopf ,ignition kuglel  or something like that for fishing boats or agricultural traktors it is an engine like this
[Vous devez être inscrit et connecté pour voir ce lien]
This type has a low pressure injection but not any trace of Diesel injection laws as fuel is injected physically in the hot head around bottom dead centre time.
I have a 265 kb pdf document of SAE2002-01-0115 that has a very good describtion but putting it somewhere here surely gives trouble with copyrigths.

pierre95 a écrit:

Something cross my mind !! yes it happens sometime !  If the engine looks like something close enough to the draw and that one port is use as a breather for the crankcase it means the second piston diameter , the lower one, could be considered as a pump, a crankcase pump and so what is the true cylinder capacity ?????? for a concept like this the crankcase and all the lower side of the piston have to be to the atmospheric pressure as a true breather. Am i wrong? knowing that i have specific knowlege about pump or 2T for being honest!!!!

The true cylinder capacity is done by the main big piston displacement, the pumping device is the pumping chamber ( smaller) added by the small piston inner capacity. This seems similar to a standard design 2t engine in volumes, maybe not in efficiency.
Dan

Dan42 a écrit:

pierre95 a écrit:

Something cross my mind !! yes it happens sometime !  If the engine looks like something close enough to the draw and that one port is use as a breather for the crankcase it means the second piston diameter , the lower one, could be considered as a pump, a crankcase pump and so what is the true cylinder capacity ?????? for a concept like this the crankcase and all the lower side of the piston have to be to the atmospheric pressure as a true breather. Am i wrong? knowing that i have specific knowlege about pump or 2T for being honest!!!!

The true cylinder capacity is done by the main big piston displacement, the pumping device is the pumping chamber ( smaller) added by the small piston inner capacity. This seems similar to a standard design 2t engine in volumes, maybe not in efficiency.
Dan

It's wrong, the inlet volume is only done by the pumping volume, smaller than the engine capacity. The "recess" located in the valves ring has no way with the crankcase ( pages 19; 20 in patent file).Is there a breather? i think no, the pumping effect in the casing is used to lubricate the piston(s) and cylinder(s) by grooves and holes through the rings.
Ex: dia main piston: 54mm; dia sec.piston:40mm( to locate a conrod foot and a pin), engine capacity with 54mm stroke= 125cc; inlet volume in the pumping chamber= 57cc.
Dan

OK Dan you are certainly right
i said that because it seems that on one of the photo posted earlier and on which one we can see on the case a rear port , so if this port pass through the "spacer"  it could make also a small casing inlet which is not design on the patent doc. and so if it is the volume generated by the small piton and is stroke have to be add to the volume generated by the big piston  and so more than 125cc.
that's what i thought  but wish i am wrong!!!!
also i wanted to write in my earlier post "that i have NOT specific knowledge about pumps and 2T engines
Pierre

pierre95 a écrit:

Something cross my mind !! yes it happens sometime !  If the engine looks like something close enough to the draw and that one port is use as a breather for the crankcase it means the second piston diameter , the lower one, could be considered as a pump, a crankcase pump and so what is the true cylinder capacity ?????? for a concept like this the crankcase and all the lower side of the piston have to be to the atmospheric pressure as a true breather. Am i wrong? knowing that i have specific knowlege about pump or 2T for being honest!!!!

The Gerrit's engine crankcase isn't involved in pumping the mixture into the cylinder, whereas on Aprilia RSA and most other two-stroke engines it is.

It uses the annular space outside the lower piston for effective primary compression, and it can pump no more than about 75% of the engine capacity through the transfer ports, assuming the lower piston diameter is half the upper piston diameter, upper piston diameter = stroke, inlet reed closes at TDC, and ignoring dynamic effects.

The cylinder capacity is still calculated from the main cylinder area x stroke. The crankcase could be similar to a four-stroke engine.

Citation :

Excuse the mixing up of terms.
When old model aircrafters talk about diesel it is the type shown as example here:

[Vous devez être inscrit et connecté pour voir ce lien]

The diesel naming had something to do with the fuel.A third ether, a third riscinus oil and a third diesel oil.
But no highpressure diesel injection anywhere.
The were developed/inventedby a swiss mechanic

[Vous devez être inscrit et connecté pour voir ce lien]

When scandinavians or germans are talking glowhead,Gluhkopf ,ignition kuglel �or something like that for fishing boats or agricultural traktors it is an engine like this
[Vous devez être inscrit et connecté pour voir ce lien]
This type has a low pressure injection but not any trace of Diesel injection laws as fuel is injected physically in the hot head around bottom dead centre time.
I have a 265 kb pdf document of SAE2002-01-0115 that has a very good describtion but putting it somewhere here surely gives trouble with copyrigths.

That Huntested engine video was quite entertaining, I was trying to guess which direction it would start in, then it changed direction at about 2:44!

I'm sure the inventors of those early engines deserve more recognition.

Ok, i had a look on the photos posted earlier, and i suspect that the 2 and not one added ducts ( one on each side) are the exhausts ducts , located to the rear of the cylider ( rear exhaust design on kart engines). and they confirm that the exhaust ports are very close to the top of the cylinder, according with the patent drawings. Initially I thout that they are water cooling ducts close to the exhaust, ( not so stupid, but probably wrong ).
A very mysterious engine , simple in fact whith fantastic performances.
Dan

Dan, on the FIA paper it's clearly wrote (en français): one exhaust duct!
And 199° angle timing for a 54mm stroke, it's not really "very close" from the TDC.
It's quite important for a standard 2Strokes but "very close, not really.
<- Koninklijke Grolsch of course

Phytus a écrit:

Dan, on the FIA paper it's clearly wrote (en français): one exhaust duct!
And 199° angle timing for a 54mm stroke, it's not really "very close" from the TDC.
It's quite important for a standard 2Strokes but "very close, not really.
<- Koninklijke Grolsch of course

Tu as raison, les angles ne sont pas extraordinaires, il y a certainement eu de nombreuse variantes en 10 ans de développement, mais si l'on se réfère aux crobards du principe de base ( pages 19 et 20 du brevet), l'extension de jupe du piston principal couvre la ( les) lumières d'échappement durant l'admission et vient se garer dans la base de la bride ring valves. La ou les lumières d'échappement sont difficilement de la hauteur habituelle, sinon l'extension de couverture descend très bas derrière le cylindre inférieur du petit piston. Oui: one exhaust duct, comme sur les photos ( une sortie d'échappement), mais il y a des extensions latérales internes dans la fonderie qui laissent supposer plusieurs lumières côte à côte, peut être de faible hauteur ( pour matcher avec une extension de jupe raisonnable). Et effectivement çà peut donner un effet de trompe l'oeil de lumières très "en haut" mais aussi de faible hauteur et très larges. les angles indiqués sont là pour remettre les choses en place, en effet çà parait incroyable de tirer tant de puissance avec un échappement très proche du point mort haut et aussi d'un volume d'aspiration qui ne dépasse pas la moitié de la cylindrée ( si l'on se réfère aux principes du brevet).
Il faut croire que le remplissage et l'efficacité du 2T traditionnel a encore beaucoup à s'améliorer car admettre la moitié de gaz et faire bien mieux que les meilleurs à cylindrés égale.
Dan

Dan42 a écrit:

Phytus a écrit:

Dan, on the FIA paper it's clearly wrote (en français): one exhaust duct!
And 199° angle timing for a 54mm stroke, it's not really "very close" from the TDC.
It's quite important for a standard 2Strokes but "very close, not really.
<- Koninklijke Grolsch of course

Tu as raison, les angles ne sont pas extraordinaires, il y a certainement eu de nombreuse variantes en 10 ans de développement, mais si l'on se réfère aux crobards du principe de base ( pages 19 et 20 du brevet), l'extension de jupe du piston principal couvre la ( les) lumières d'échappement durant l'admission et vient se garer dans la base de la bride ring valves. La ou les lumières d'échappement sont difficilement  de la hauteur habituelle, sinon l'extension de couverture descend très bas derrière le cylindre inférieur du petit piston. Oui: one exhaust duct, comme sur les photos ( une sortie d'échappement), mais il y a des extensions latérales internes dans la fonderie qui laissent supposer plusieurs lumières côte à côte, peut être de faible hauteur ( pour matcher avec une extension de jupe raisonnable). Et effectivement çà peut donner un effet de trompe l'oeil de lumières très "en haut" mais aussi de faible hauteur et très larges. les angles indiqués sont là pour remettre les choses en place, en effet çà parait incroyable de tirer tant de puissance avec un échappement très proche du point mort haut et aussi d'un volume d'aspiration qui ne dépasse pas la moitié de la cylindrée ( si l'on se réfère aux principes du brevet).
Il faut croire que le remplissage et l'efficacité du 2T traditionnel a encore beaucoup à s'améliorer car admettre la moitié de gaz et faire bien mieux que les meilleurs à cylindrés égale.
Dan

The Gerrit's patent does indeed appear to show that the exhaust port is located very high in the cylinder. However, the patent also states that the drawings are "very schematic .... view", they are not detailed drawings, nor are they scale drawings.

If that patent was applied to a CIK KZ engine, the exhaust open timing can be no more than 199° and the piston skirt would be extended to cover the exhaust port at TDC.

The Ryger KZ engine is based on the VM engine, but the cylinder block casting is different. It includes the inlet port, and has one exhaust port, whereas the VM host engine has inlet on crankcase, and three exhaust ports in the cylinder. It's possible that the blocks are made by same foundry, and they left the outer casing unchanged, except at the inlet port.

Dan

Je parlais de la photo de l'embase cylindre page 47, la dernière , c'est quoi cette ouverture sur l'embase coté échappement?? une communication avec le carter?? dans ce cas et au vue de la patent le second piston devient pompe dans la carter si cela communique avec le cylindre principal 19?? .
Pierre

pierre95 a écrit:

Dan

Je parlais de la photo de l'embase cylindre page 47, la dernière , c'est quoi cette ouverture sur l'embase coté échappement?? une communication avec le carter?? dans ce cas et au vue de la patent le second piston devient pompe dans la carter si cela communique avec le cylindre principal 19?? .
Pierre  

Pierre: sur la dernière image page47 je vois un alignement de carters moteurs recouverts de papier blanc ( bien flous) . Le 1er de la lignée montre en effet comme une ouverture rectangulaire partielle sur le bas moteur , située à droite donc côté admission, sur la "pipe d'admission" d'origine du bloc VM dont le moteur Ryger est issu. il est difficile de déterminer si elle est utilisée ou non lorsque la fameuse bride ring valve est installée. C'est possible???
Dan

Jan Thiel a écrit:

I have absolutely nothing to do with it.
And I would have to see a powercurve before I believe any 125cc engine gives
70HP and revs to 30.000!

Perhaps if you saw the powercurve you still wouldn't believe it, unless you saw the engine on a dyno yourself!

I find it hard to comprehend how the improvement is achieved. It's based on a VM engine, using the same carb, head, exhaust pipe and crankcase.

It seems that the mod kit includes a new (stepped?) piston, shorter conrod, valve plate, modified cylinder with 1 exhaust port (VM had 3), inlet port on cylinder (VM inlet is on crankcase), and something to block the now redundant inlet port on VM crankcase. The oil free mixture is isolated from the crankcase.

Not only is the power higher than, the VM host engine, and other 125cc engines, but the power band is wide too, it can use a smaller radiator and rev to 30,000 rpm.

It's hard to imagine these gains with just porting changes, so what else can be changed, except reducing the compression ratio, and retarding the ignition? The minimum combustion chamber size allowed by CIK for KZ engines is 11cc.

I like the idea of instantaneous combustion at TDC, but how to achieve it?

tjbw, we suppose that you know a Ryger engine in running conditions. Concerning the instantaneous combustion i think you are right, how? maybe in your
informations: one exhaust port instate of 3 on current engines, and low compression ratio. A part mix of exhaust gazes and fresh intake mixture is maybe the key. Concerning 30.000 rpm with this engine, if the process is ok, mechanical parts don't like more than 2, 3 s before failure, except if they had no mass. ( sorry for my bad English).

tjbw, je suppose que tu connais un moteur Ryger en fonctionnement. En ce qui concerne la combustion instantanée, je pense que tu es dans le vrai; comment? peut être avec tes informations: un seule lumière d'échappement au lieu de 3 sur ( le VM de base) les moteurs habituels, et aussi un taux de compression faible. Une partie des gaz d'échappement mélangée à la charge fraîche peut être la clé du succès. En ce qui concerne 30.000 tours /mn possibles avec ce moteur, si le procédé le permet ( en théorie et même pratique), la parties mécaniques n'aimeraient pas plus de 2 à 3 secondes avant casse, sauf si elles ne pèsent rien( ou presque).
Dan

Dan42 a écrit:

tjbw, we suppose that you know a Ryger engine in running conditions. Concerning the instantaneous combustion i think you are right, how? maybe in your
informations: one  exhaust port instate of 3 on current engines, and low compression ratio. A part mix of exhaust gazes and fresh intake mixture is maybe the key. Concerning 30.000 rpm with this engine, if the process is ok, mechanical parts don't like more than 2, 3 s before failure, except if they had no mass. ( sorry for my bad English).

tjbw, je suppose que tu connais un moteur Ryger en fonctionnement. En ce qui concerne la combustion instantanée, je pense que tu es dans le vrai; comment? peut être avec tes informations: un seule lumière d'échappement au lieu de 3 sur ( le VM de base) les moteurs habituels, et aussi un taux de compression faible. Une partie des gaz d'échappement mélangée à la charge fraîche peut être la clé du succès. En ce qui concerne 30.000 tours /mn  possibles avec ce moteur, si le procédé le permet ( en théorie et même pratique), la parties mécaniques n'aimeraient pas plus de 2 à 3 secondes avant casse, sauf si elles ne pèsent rien( ou presque).
Dan

Thanks for English text

I also think think elevated temperature at the time exhaust port closes is a factor.

Regarding the 30,000 rpm, perhaps it would be safer, and less costly, to detune the engine to limit rpm.

the engine can rev to 30.000, probably because of the HCCI which shorten's the time the combustion takes up quite a lot, but I don't thinck when in use it'll go that high.
since it makes it top HP at 17.500, I guess max rpm will be 20.000, which in itself is also pretty crazy.

Does a video whith a Ryger engine in running conditions exist?
Dan

30000 rpm with 54 stroke is a sick joke to talk about it.
At 30000 with 54 stroke the average piston velocity as well as the corrected are 54m/s. If one knows the accelleration as well as the decelleration values at this rpm the forces on the piston can be calculated. When studying I was able to do so , not anymore now as I'm concentrating on practical matters in our field. But who is going to present us some figures? Regarding the RYGER engine more and more people have even more than reasonable doubts about this project. Up to now at NO occasion the RYGER has shown better lap times on ANY circuit than a top KZ engined kart, in many cases TM's 125. But time will tell and the RYGER deserves the benefit of th doubt, seeing is believing
however.
Just one remark about the TM 125 KZ engine : top engines seem to produce 46-47 HP at the crank with a 30mm carb and fixed ignition, pretty impressive I think!
Ciao for now to everyone.

Bob