ESE's works engine tuner

[2005bully]

I have tuned it a bit now, runs smoother on idle, but as there is no venturi in this carb i figure it will work better on a engine with bigger displacement.
An engine that pulls more air before getting into the pipe so to speak.
I still have this HUGE gap in power when giving it full throttle, it just dies, no fuel is drawn into airstream, until i hit ~11000rpm(when the pipe is pulling hard)

I feel it´s the drawback on this model of carb, it´s a 'slide' model.

Rgds.

SwePatric...

Provided that there are NO air leaks anywhere with in the carb and fuel lines, and the carb is mounted with the pump assembly to the top... The first thing in getting rid of the throttle lag, is to increase the volume of fuel in the chamber located above the fulcrum arm. This makes more fuel quickly available to reach the venturi when the throttle is snapped open. To do this simply raise the fulcrum arm height. Be aware if the fulcrum is raised to far, the back side of the metering diaphragm will make contact with the pump body and prevent the fuel inlet seat from completely closing. To check for this.... After setting the fulcrum arm height, with the pump assembly removed, re-set the pop-off back to the original setting. Then remove the needles put the pump assembly back on and re-check the pop-off through the fuel inlet. It should be with-in less than 1 psi to the same reading as when the pump is removed. Usually the fulcrum height dimension is measured from the gasket surface to the top of the fulcrum arm. With .010" increments being a common adjustment. Lower pop-off settings will also help get rid of this lag, but as you have already seen lower pop-off will have other detrimental effects. If you have the diaphragm start hitting the pump, but still want more volume. An additional gasket can be placed between the metering diaphragm and the pump body. When set at the same pop-off, lighter rate springs also slightly richen up the throttle opening. Hope this helps.... Kermit Buller

[Haufen]

When the engine gets to those high revs, the exhaust note changes; the engine really starts singing. It's a lovely sound.

Are there any further publications planned from the Ryger Team, Frits?

For example power diagrams, emissions vs rpm on a brake dyno, some videos of the engine at full song, explanations on how this engine works etc?

[wobbly]

What sort of pop off pressure is being used in the pumper now ?
I did a 100cc air cooled shifter engine years ago for a restricted kart class, that used a Tillotson 26mm slide carb.
The factory setting for this was 12 psi, but to get enough fuel into the low end transition circuit I had to eventually go to 1/2 this at 6 psi
with the lever height raised 0.5mm higher than stock as well.
The other "trick " is reverse jetting,with something like 2.5 turns on the L jet and 0.25 on the H, but this then needs a higher pop off.
This works well, as the L circuit is air corrected late in the fuel curve and it leans out past peak power, just whats needed.

[Flettner]

HCCI, how does a pulse jet ignite it's charge once up and running? A form of HCCI? There is no timed ignition.

[Frits Overmars]

HCCI, how does a pulse jet ignite it's charge once up and running? A form of HCCI? There is no timed ignition.

Either there is a constant spark that ignites the mixture in the chamber as soon as its concentration and purity are susceptible to ignition,
and/or the fresh mixture is sufficiently heated and compressed by the exhaust gases that swing outward and back in the exhaust duct.

[Flatout]

Does the Ryger design rely mainly on HCCI for its power increase over a conventinal SI engine?

[bjorn.clauw.1]

One more, hcci vs honda atac comparison in a 2 stroke. (Also hcci with and without egr)
https://www.google.be/url?sa=t&sourc...22V6SGSN--WuqQ

Paper states 15:1 compression ratio on pumpgas and internal egr (valve between cilinder & exhaust pipe) regulates the hcci ignition timing. So if we change (read:reduce) the exhaust port area/total port surface this could substitute the internal egr valve
(example in the paper states 25% closure puts the hcci ignition point at tdc)
Because of the piston pumping the ryger can get away with a smaller blowdown area.

Following this bold assumption, the 'transfer' port under the exhaust is just there to increase the under-piston volume (to somewhat increase the 'new' crankcase volume). Maybe a trade off to reduce power loss when not in hcci mode.

Bold assumption no2 (as stated by Flettner before) when hcci kicks in, higher combustion pressure/faster complete burn increases gas flow in the exhaust allowing it to operate as normal at much higher rpm. So nothing to control or regulate at WOT with moving valves or electronics.

Different matter:
Frits, would it be possible to post your leaning tower analogy in this thread? I've enjoyed reading it on another forum but I cannot find it here on kiwibiker.

[Tunisti]

Just wondering whether the (controversial) relatively tight gap (3mm calculated from the drawings) between the adapter plate´s cylindrical part and the "Ryger ports" in the cylinder wall could have a specific meaning. To open the name of HCCI=Homogeunous Charge Compression Ignition, we can see that there must be something in that motor, which makes the charge homogenous enough. Okay, we have this 30mm carburator, but I´d bet that it´s not capable to mix the fuel into the air well enough. Then we have this space beneath the piston, it´s pumping volume is 70cm^3 and it has somewhat small passage. Let's say that it's somewhat 1,5cm^2. Assuming that there would be 70cm^3 of mixture to be pumped through that 1,5cm^2 passage bethween TDC and BDC we could make this coarse assumption, that the mixture would have speed of at least 265m/s@17krpm through that relatively small gap. Sounds like a good change to force the mixture into homogenous state?

Then some other thoughts: as I have written in my two earlier messages, I tend to believe that the port below the exhaust port leads to exhaust duct. Thought a bit more of that, especially the affect of pipe´s pulse effect´s in such situation. Let's assume that the piston has already closed the transfers, and there is fresh mixture entering into the space beneath the piston. Exhaust port is just about to close and pressure wave arrives at the exhaust port, charging the cylinder to, let´s say 2,2bar of pressure. Exhaust port closes and the leftovers of the pulse reflect towards the end of pipe, creating a state of low pressure in the exhaust duct. Now something weird happens: the piston´s exhaust side skirt opens the "Ryger port" beneath the exhaust port, and the low pressure in exhaust duct "sucks" fresh mix into the space benath the piston. As the flow speeds up and the mixture flows into the exhaust duct through that "Ryger port" there happens once again something special - yet absolutely normal. The pulse (that reflected back towards the end of the pipe when the exhaust port closed) comes back and pushes the mixture in the exhaust duct back into the space beneath the piston. Piston´s skirt closes the "Ryger port" and there is somewhat high pressure in that space benath the piston. Exhaust port opens - the even smaller leftovers on the pulse reflect and give some more suction for the beginning of exhaust flow. Same recurs again and again. Pipe is capable of "charging" fresh mixture twice in one circulation - thus making the pipe´s efficiency very high.

Comments?

PS. Had also another theory in my mind. In this scenario the "Ryger port" beneath the exhaust port would feed fresh mixture inside the space beneath the piston (controlled by the piston skirt). The gap is somewhat larger at that point, when the piston is high enough. The mixture would come "Boyesen-style" from the A-transfer ducts, or then there could be that scenario, where the mix preheats in some kind of ducts very close to the exhaust port inner walls. The pulse theory written above, would offer somewhat much preheating for the mixture, and also some internal EGR-characteristics. Just to help the HCCI to stay in good state. The internal EGR-fuction would naturally be stronger when the engine is running below the sweet spot - therefore it´d help help the HCCI to get started more easily.

[MotleyCrue]

Just wondering whether the (controversial) relatively tight gap (3mm calculated from the drawings) between the adapter plate´s cylindrical part and the "Ryger ports" in the cylinder wall could have a specific meaning. To open the name of HCCI=Homogeunous Charge Compression Ignition, we can see that there must be something in that motor, which makes the charge homogenous enough. Okay, we have this 30mm carburator, but I´d bet that it´s not capable to mix the fuel into the air well enough. Then we have this space beneath the piston, it´s pumping volume is 70cm^3 and it has somewhat small passage. Let's say that it's somewhat 1,5cm^2. Assuming that there would be 70cm^3 of mixture to be pumped through that 1,5cm^2 passage bethween TDC and BDC we could make this coarse assumption, that the mixture would have speed of at least 265m/s@17krpm through that relatively small gap. Sounds like a good change to force the mixture into homogenous state?

Then some other thoughts: as I have written in my two earlier messages, I tend to believe that the port below the exhaust port leads to exhaust duct. Thought a bit more of that, especially the affect of pipe´s pulse effect´s in such situation. Let's assume that the piston has already closed the transfers, and there is fresh mixture entering into the space beneath the piston. Exhaust port is just about to close and pressure wave arrives at the exhaust port, charging the cylinder to, let´s say 2,2bar of pressure. Exhaust port closes and the leftovers of the pulse reflect towards the end of pipe, creating a state of low pressure in the exhaust duct. Now something weird happens: the piston´s exhaust side skirt opens the "Ryger port" beneath the exhaust port, and the low pressure in exhaust duct "sucks" fresh mix into the space benath the piston. As the flow speeds up and the mixture flows into the exhaust duct through that "Ryger port" there happens once again something special - yet absolutely normal. The pulse (that reflected back towards the end of the pipe when the exhaust port closed) comes back and pushes the mixture in the exhaust duct back into the space beneath the piston. Piston´s skirt closes the "Ryger port" and there is somewhat high pressure in that space benath the piston. Exhaust port opens - the even smaller leftovers on the pulse reflect and give some more suction for the beginning of exhaust flow. Same recurs again and again. Pipe is capable of "charging" fresh mixture twice in one circulation - thus making the pipe´s efficiency very high.

Comments?

PS. Had also another theory in my mind. In this scenario the "Ryger port" beneath the exhaust port would feed fresh mixture inside the space beneath the piston (controlled by the piston skirt). The gap is somewhat larger at that point, when the piston is high enough. The mixture would come "Boyesen-style" from the A-transfer ducts, or then there could be that scenario, where the mix preheats in some kind of ducts very close to the exhaust port inner walls. The pulse theory written above, would offer somewhat much preheating for the mixture, and also some internal EGR-characteristics. Just to help the HCCI to stay in good state. The internal EGR-fuction would naturally be stronger when the engine is running below the sweet spot - therefore it´d help help the HCCI to get started more easily.

What I have read and seen getting HCCI to happen in an engine is simple enough, but getting it to happen the right way under various conditions is the big challenge and companies with lots of money have thrown lots of money and electronics at it for 30 years. HCCI is next thing to explosive so it cant just happen randomly or the engine will suffer badly. The Ryger engine has no electronic feedback control or mechanisms to regulate HCCI under varying conditions, so maybe it makes 70 HP HCCI, but reliably under racing conditions up for grabs.

[bjorn.clauw.1]

Just wondering whether the (controversial) relatively tight gap (3mm calculated from the drawings) between the adapter plate´s cylindrical part and the "Ryger ports" in the cylinder wall could have a specific meaning. To open the name of HCCI=Homogeunous Charge Compression Ignition, we can see that there must be something in that motor, which makes the charge homogenous enough. Okay, we have this 30mm carburator, but I´d bet that it´s not capable to mix the fuel into the air well enough. Then we have this space beneath the piston, it´s pumping volume is 70cm^3 and it has somewhat small passage. Let's say that it's somewhat 1,5cm^2. Assuming that there would be 70cm^3 of mixture to be pumped through that 1,5cm^2 passage bethween TDC and BDC we could make this coarse assumption, that the mixture would have speed of at least 265m/s@17krpm through that relatively small gap. Sounds like a good change to force the mixture into homogenous state?

Then some other thoughts: as I have written in my two earlier messages, I tend to believe that the port below the exhaust port leads to exhaust duct. Thought a bit more of that, especially the affect of pipe´s pulse effect´s in such situation. Let's assume that the piston has already closed the transfers, and there is fresh mixture entering into the space beneath the piston. Exhaust port is just about to close and pressure wave arrives at the exhaust port, charging the cylinder to, let´s say 2,2bar of pressure. Exhaust port closes and the leftovers of the pulse reflect towards the end of pipe, creating a state of low pressure in the exhaust duct. Now something weird happens: the piston´s exhaust side skirt opens the "Ryger port" beneath the exhaust port, and the low pressure in exhaust duct "sucks" fresh mix into the space benath the piston. As the flow speeds up and the mixture flows into the exhaust duct through that "Ryger port" there happens once again something special - yet absolutely normal. The pulse (that reflected back towards the end of the pipe when the exhaust port closed) comes back and pushes the mixture in the exhaust duct back into the space beneath the piston. Piston´s skirt closes the "Ryger port" and there is somewhat high pressure in that space benath the piston. Exhaust port opens - the even smaller leftovers on the pulse reflect and give some more suction for the beginning of exhaust flow. Same recurs again and again. Pipe is capable of "charging" fresh mixture twice in one circulation - thus making the pipe´s efficiency very high.

Comments?

In theory this could be possible alltough I think this would really help when you have a large crankcase volume (under piston volume).
When piston passes tdc and goes down, the exhaust pushes mixture through the 'ryger' port (which as you stated was sucked out just before) but pressure will rise quickly because piston is compressing a small volume, worst case scenario is piston pushing part of the charge through the 'ryger' port into the exhaust before it closes.

I am pretty sure the sides of the transfer under the exhaust ('ryger' port) connect with the left and right transfer ducts, so the piston skirt isn't really closing off the port.

[SwePatrick]

SwePatric...

Provided that there are NO air leaks anywhere with in the carb and fuel lines, and the carb is mounted with the pump assembly to the top... The first thing in getting rid of the throttle lag, is to increase the volume of fuel in the chamber located above the fulcrum arm. This makes more fuel quickly available to reach the venturi when the throttle is snapped open. To do this simply raise the fulcrum arm height. Be aware if the fulcrum is raised to far, the back side of the metering diaphragm will make contact with the pump body and prevent the fuel inlet seat from completely closing. To check for this.... After setting the fulcrum arm height, with the pump assembly removed, re-set the pop-off back to the original setting. Then remove the needles put the pump assembly back on and re-check the pop-off through the fuel inlet. It should be with-in less than 1 psi to the same reading as when the pump is removed. Usually the fulcrum height dimension is measured from the gasket surface to the top of the fulcrum arm. With .010" increments being a common adjustment. Lower pop-off settings will also help get rid of this lag, but as you have already seen lower pop-off will have other detrimental effects. If you have the diaphragm start hitting the pump, but still want more volume. An additional gasket can be placed between the metering diaphragm and the pump body. When set at the same pop-off, lighter rate springs also slightly richen up the throttle opening. Hope this helps.... Kermit Buller

I have response, it´s like 'snap' response, very quick.
But when trying to make a pull in dyno it leanes out after about a half second on full throttle.
Above 11000rpm all is fine, response and does not lean out.

I have tried different fulcrum heights, no difference with this problem, just made difference to less throttleopenings, with that said, i can make a dyno pull all the way from 4000rpm to 13500rpm on half throttle, no problem.
But that won´t make any power
The popoff pressure i have tried different pressures, the same there.
It alteres the way carb is working on small throttleopenings, no difference in full throttle, the same symptom.

I have tested three different springs and i was recommended between 0.55 to 0.75bar
Mine was running best at 0.55bar
The other pressures i got was 1bar and 0.7 with those i had to turn out the lowspeed needel about 4revolutions before it was running good on idle.
With 0.55 i just have about 1.3-1.5turns.

Trying to give a IRL explanation:
It seems like the carb is loosing all 'signal' and airspeed and just shuts off when hitting full throttle to early in revband, just like hitting fullthrottle with big 'normal' carb on low gears at low rpm´s.
I can freerev it, no problem at all.
Sound like a beast, but when giving the engine load it just leans off in about a half second.
My pulls with this little engine is about 12s long with my inertiabench.
And when the engine is hitting the pipe the airspeed increases and the carb is working fine again, above 11000rpm
It made 26hp but with a very very bad torqueband as i couldn´t give it full throttle until 11000rpm.


I combined the answer to Kermit and Wobbly but only quoted kermit.

[SwePatrick]

Tunisti, I´m sorry.
I don´t buy your theory, if the exhaust is connected to the transfers, how do you get it to compress the gasses in the 'crankhouse' so it can reach the cylinder?
It has to be a controlled valve in that case, and there´s none on the drawings.

Rgds.

[Lightbulb]

What I find with the published Ryger stuff is the simplicity. I am sure there will be lots of things that are not quite so obvious
that can have a large impact on performance that is not always easily observed. An example of something that can improve performance
but not be noticeable is the width of the bottom of an exhaust port relative to the direction and position of the side transfer ports. I have seen
on a 2.5cc engine where a change in the exhaust port width of 0.1mm made a significant gain, approx 400 to 500 rpm tested on 10 engines.
I have also seen an 800 rpm loss when it was widened too far by yours truly on the development engine.
Neil

[Yow Ling]

Tunisti, I´m sorry.
I don´t buy your theory, if the exhaust is connected to the transfers, how do you get it to compress the gasses in the 'crankhouse' so it can reach the cylinder?
It has to be a controlled valve in that case, and there´s none on the drawings.

Rgds.

There were some photos of the cylinder, but they are all removed , even the ones that husaberg captioned are gone. One had a port that was above the exhaust which I thought could have been egr. I saved a copy so I have a look later

[Grumph]

Tunisti, I´m sorry.
I don´t buy your theory, if the exhaust is connected to the transfers, how do you get it to compress the gasses in the 'crankhouse' so it can reach the cylinder?
It has to be a controlled valve in that case, and there´s none on the drawings.

Rgds.

If - and it's a big if - the port below the exhaust is connected to the exhaust duct then the missing picture of the piston is the key.
It showed that the piston skirt on the exhaust side was close to "normal" length - but only on that side.
Aside from being long enough to stop the exhaust opening into the under piston area at TDC, the lower edge of the skirt would time the open period of that port under the exhaust.
Given the piston guidance by the "trunk" tubular lower end, the only reason I can see for the skirt to be any longer than needed to close off the main ex port is to time this extra port.