ESE's works engine tuner

[Michael Moore]

Also look at the Honda ATVs and scooters, as a lot of them have oil pumps that are chain driven off of a doubled-up cam chain sprocket or a dedicated sprocket on the other side of the crankshaft.

My notes show an XR185/200 oil pump at 1.76:1 reduction (21 drive, 35 driven) is claimed to pump 4.0 L/minute at 8000 RPM, a CB100/125 is 2.4 L/M @ 10000 RPM, the horrid plunger oil pump on a CB175 twin is 3.6 L/M @ 10000. A CM250 twin has the same rotors as an XR185 but 15mm wide instead of 10mm and a 20/40 drive/driven reduction. Honda reuses a lot of the same rotor sets with various gearing changes.

cheers,
Michael

[speedpro]

An FZR250 oil pump might be used as well. Completely self contained with in/out ports and a drive shaft. They bolt to the engines just in front of the drive sprocket. The water pump piggy backs on the oil pump. Could be fitted with a simple adaptor for the oil lines and possibly electrically driven.

[TZ350]

I'll have a dig in the shed and send Rob one, I think i have a CB100 on as well.

I am not sure how I could drive it but I would be very interested in looking at one if you're happy to send it to me.

[adegnes]

Oko Powerjet nozzle too short? Doesn't seem to flow much at all on my bike...
Did you modify/lengthen it on the Beast TZ?


https://www.youtube.com/watch?v=tORlvs9mmJ0

[TZ350]

Oko Powerjet nozzle too short? Doesn't seem to flow much at all on my bike... Did you modify/lengthen it on the Beast TZ?

No, but we did notice on the dyno that some engines (all modified Suzuki GP 125's and OKO carbs) liked having a power jet while others did not. Puzzling because the setups were pretty similar. Also even with the power jets functioning (hose connected) some motors drew fuel through them while others could not suck any fuel up worth a dam. It was pretty random so we just let the motor tell us what it liked.

[adegnes]

No, but we did notice on the dyno that some engines (all modified Suzuki GP 125's and OKO carbs) liked having a power jet while others did not. Puzzling because the setups were pretty similar. Also even with the power jets functioning (hose connected) some motors drew fuel through them while others could not suck any fuel up worth a dam. It was pretty random so we just let the motor tell us what it liked.

Puzzling indeed... Same carb used on the different bikes?
I can clearly see fuel being drawn up the hose but no spray into the venturi.
Maybe the jet is just too small, the hole is tiny.


https://youtu.be/jo_NdwHt9vc

[Frits Overmars]

Oko Powerjet nozzle too short? Doesn't seem to flow much at all on my bike...Powerjets were originally developed for piston port induction, with the nozzle feeding in from the top of the carb bore, the idea being that at part throttle there would be no airflow across the nozzle, so no fuel flow through it. The powerjet would only come into action at full, or allmost full throttle.
Today, powerjets are used in a different way and the top-feed position has no advantages any more, while it still has the disadvantage of a slow reaction due to the long path from float bowl to nozzle exit, plus the fact that the fuel first has to be sucked all the way up to where the hose connects to the nozzle. As long as there is not enough suction to pull the fuel 'over the hill', nothing will happen at all.
If you position the nozzle lower, like on the picture below, response will be a lot better. Make sure that you view the picture in its full format; klick on it 3 times.
328240

[adegnes]

Powerjets were originally developed for piston port induction, with the nozzle feeding in from the top of the carb bore, the idea being that at part throttle there would be no airflow across the nozzle, so no fuel flow through it. The powerjet would only come into action at full, or allmost full throttle.
Today, powerjets are used in a different way and the top-feed position has no advantages any more, while it still has the disadvantage of a slow reaction due to the long path from float bowl to nozzle exit, plus the fact that the fuel first has to be sucked all the way up to where the hose connects to the nozzle. As long as there is not enough suction to pull the fuel 'over the hill', nothing will happen at all.
If you position the nozzle lower, like on the picture below, response will be a lot better. Make sure that you view the picture in its full format; klick on it 3 times.
328240

Thanks Frits!
I'll see if I can fab up something.

On a different subject, my Powerspark ignition is TCI, constant positive battery voltage on the coil, the negative side is switched. It's ment for 11-13v, and I'm not sure how it would react to being fed say 16v.
In the last few runs I was experiencing misfiring at high rpm, and a probable cause(I think) is that battery voltage had fallen to around 11v.

Now, could I keep the 12v battery for powering the ignition unit, but use another one of higher voltage to feed the coil? Common ground for both batteries.

[Tim Ey]

... while it still has the disadvantage of a slow reaction due to the long path from float bowl to nozzle exit, plus the fact that the fuel first has to be sucked all the way up to where the hose connects to the nozzle...
328240

As I have just refurbished the carbs on my Aprilia RS250 (Streetbike with crapy suzuki cylinders, not such fancy stuff as quoted by Frits) I came to notice, that they got a tiny brass reduction mounted in the powerjet hose.

I came to the conclusion, that they might act as a non-return valve hence the power of the suction pulse might be powerfull enough to draw fuel through it, on the contrary they might be too small to let gravity pull it back.

Anyone got experience with those?

[Grumph]

Thanks Frits!
I'll see if I can fab up something.

On a different subject, my Powerspark ignition is TCI, constant positive battery voltage on the coil, the negative side is switched. It's ment for 11-13v, and I'm not sure how it would react to being fed say 16v.
In the last few runs I was experiencing misfiring at high rpm, and a probable cause(I think) is that battery voltage had fallen to around 11v.

Now, could I keep the 12v battery for powering the ignition unit, but use another one of higher voltage to feed the coil? Common ground for both batteries.

In theory, yes you could. But the old "keep it simple" rule should apply. If you're running out of battery voltage, get a better or bigger battery - or use a better charging regime.
I run almost evrything I build as total loss battery powered ignition and job #1 is to use an appropriate size battery for the task.

[TZ350]

I have single cylinder Drag Bikes & personally like/prefer the Air Shifter setup and feel it is much better than any of these transmissions.

I would very much like to know more, is this something I could make easily? are the parts simple, readily available?

[oldjohnno]

Thanks Frits!
I'll see if I can fab up something.

On a different subject, my Powerspark ignition is TCI, constant positive battery voltage on the coil, the negative side is switched. It's ment for 11-13v, and I'm not sure how it would react to being fed say 16v.
In the last few runs I was experiencing misfiring at high rpm, and a probable cause(I think) is that battery voltage had fallen to around 11v.

Now, could I keep the 12v battery for powering the ignition unit, but use another one of higher voltage to feed the coil? Common ground for both batteries.

Increasing the primary voltage is often used to improve the output of inductive ignitions. See http://www.iceignition.com/voltage-boosters

Inductive systems have the advantages of simplicity and ruggedness and a very long duration spark. I've successfully used systems that consisted of a Hall effect trigger, a 14.8v lipo battery and a Ford TFT module and coil. The TFT can even be triggered by points. Very cheap and reliable but the downside is they draw a lot more current than a CDI of comparable output. CDI power consumption is typically only 20% of inductive - not usually an issue in a car but can be a big deal on a bike. Theoretically the faster rise time of the CDI should also be an advantage but I've never experienced plug fouling problems with a good inductive setup.

[adegnes]

In theory, yes you could. But the old "keep it simple" rule should apply. If you're running out of battery voltage, get a better or bigger battery - or use a better charging regime.
I run almost evrything I build as total loss battery powered ignition and job #1 is to use an appropriate size battery for the task.

I am a believer in KISS too, and if running out of juice is the problem I totally agree!
The reason I was down at 11v last session was I had to use a bad battery, I'd killed the one I was using by leaving the water pump on since last weekend...
The dual battery idea was to be able to feed the coil higher voltage than the ignition unit can handle, and thereby creating more spark energy, needed or not.


Increasing the primary voltage is often used to improve the output of inductive ignitions. See http://www.iceignition.com/voltage-boosters

Inductive systems have the advantages of simplicity and ruggedness and a very long duration spark. I've successfully used systems that consisted of a Hall effect trigger, a 14.8v lipo battery and a Ford TFT module and coil. The TFT can even be triggered by points. Very cheap and reliable but the downside is they draw a lot more current than a CDI of comparable output. CDI power consumption is typically only 20% of inductive - not usually an issue in a car but can be a big deal on a bike. Theoretically the faster rise time of the CDI should also be an advantage but I've never experienced plug fouling problems with a good inductive setup.

Thanks for the link, a little pricey for me tho...
Something like a 14.8v lipo as "coil feeder" was what I had in mind!

[Grumph]

Current draw for the inductive systems i've used varies from 1 amp to around 1.8 amp for a big multi using something like a Dyna.

I like the points replacement modules like the Pertronix as a trigger.

[speedpro]

Your little 2-stroke should ideally be running a CDI. Failing that a TCI like you have. If the voltage supply sags out you have a problem.

With a Kettering system which is essentially what you have you need to look at the dwell time required by the coil to build current to maximum prior to the spark, and then a period of time after the spark required by the system before the coil primary current can be switched on again. At say 15,000rpm you have 4mS cycles. A couple of ignition coils I have been looking at lately have a 1.8mS required dwell time + a bit more with spark and after-spark. Say 2.5mS total time per cycle.
If you are dead set on supplying the coils with a separate 12V source you might be able to use something like the LS1, LS2, or LS truck motor coils. They have a built-in igniter so only require the appropriate 12V signal in to switch the major current to the coil primary. I have a couple of LS2 coils and they are a very tidy unit. A lot of the "drifters" use them in their big boost turbo engines. The truck version is supposed to provide a very mean spark but draw a bit of current.

[speedpro]

Coils bought from here: https://www.efihardware.com/products/2039/Coil-LS2-with-inbuilt-Igniter

Very helpful guys

[speedpro]

I had a problem with a CB360 I built in Oz. It wouldn't rev out. It had 12V total loss points ignition. I added a 6v battery in series and the problem went away. I ended up with another problem though - both pistons turned to rubble and fell into the bottom of the engine.

[adegnes]

I had a problem with a CB360 I built in Oz. It wouldn't rev out. It had 12V total loss points ignition. I added a 6v battery in series and the problem went away. I ended up with another problem though - both pistons turned to rubble and fell into the bottom of the engine.

This is kinda what I had in mind, Feed the coil say 16v from separate battery, 12v to the ignition unit from main battery.
Maybe the Spx is not reving out at 17500rpm...:laugh:

[TZ350]

328247

The Bad news .... a broken tooth which showed the classic signs of a fatigue crack ending in a fracture.

The Good news is that there is plenty of oil getting to the gears. No sign of damage that could be attributed to a lack of lubrication.


328246328245

Case spacer and extra wide spacing between crank halves for a bit of extra crankcase volume.

328244

Gearbox oiler tube and KE175 rotary valve cover.

328248

NSR cylinder showing one of the fuel injector ports and rotary valve inner. Not much room left between the RV and gearbox input shaft.

The good thing about having to pull the motor down is that I am now very comfortable with gearbox oil feed of about 1L min from those small pumps is well and truly sufficient.

[DoldGuy]

I would very much like to know more, is this something I could make easily? are the parts simple, readily available?

TZ,

With your Fabrication skills I'm sure you could duplicate most of the components.

http://www.pingelonline.com/air-shifters/803-premium-air-kit-with-1-handlebar-control.asp

[SwePatrick]

Finding a suitable gearbox oil pump has been a bit of a mission. Tried quite a selection of pumps, they all failed at some point or other. There have been vacuum diaphragm pumps, electric centrifugal pumps and plunger pumps. 12V garden feature water pumps, pressure diaphragms and fuel pumps. Mostly 1-3 l/min, 5 l/min seems ideal, inexpensive with low current draw is a must.



Look at toyota car gearbox, in some of those there´s an internal pump to circulate oil and in GT4´s circulate it into an radiator.

http://s227.photobucket.com/user/jesiotrot/media/ben/S1031386.jpg.html

You can pull out the gear as it is married to the shaft, and replace the shaft with 'what ever you like'.

Rgds

[Lef16]

Well,it's a pleasure learning from you guys!
In drag racing we use sleeves intead of nicasil coating,and the piston to cylinder clearence is a little more than road racing or kart engines.
I assume with methanol I'll have to further increase clearence because of the higher comp and advance,and to shorten a little bit the pipe(?)
I think I'll shoot for the safe solution,little less horsepower but for longer with the the long and forgiving power band-power range.

Same situation here in my country's drag bikes with clearence but over here they use racing gasoline and not meth.
I've never build a drag bike but,have you ever try nicasil?Wouldnt it be less compression losses due to high clearence (for example they use clearences as high as 0.10mm in ~72mm bore here) and thus more power???

[2T Institute]

Thanks Frits
Did the riders report any difference in steering characteristics or were possible effects masked by differing weight distribution anyway.
Or was the compactness more to do with engine width?

first question I asked Sandro Cortese was "how much of an improvement was the RSA 125 over the RSW 125"

RSW was still a 'formidable bike when well set up"
RSA had more mid range and over rev.

RSA 125 was faster. With the 250 the RSA appeared to be considerably quicker with better handling. That said a RSW 250 you need to be over the front as far as possible pushing down on the bars as hard as you can before you pin it to the stops.

[husaberg]

first question I asked Sandro Cortese was "how much of an improvement was the RSA 125 over the RSW 125"

RSW was still a 'formidable bike when well set up"
RSA had more mid range and over rev.

RSA 125 was faster. With the 250 the RSA appeared to be considerably quicker with better handling. That said a RSW 250 you need to be over the front as far as possible pushing down on the bars as hard as you can before you pin it to the stops.

I seem to recall there was some talk of the 500 twin having a tungsten front axel, i don't know if its true or a urban leadgon.;)

[Grumph]

I seem to recall there was some talk of the 500 twin having a tunsten front axel, i don't know if its true or a urban leadgon.;)

Ask Kevin Grant - afaik he's got them all. 3 I believe - or at least enough bits to make 3....

[husaberg]

Ask Kevin Grant - afaik he's got them all. 3 I believe - or at least enough bits to make 3....

He still talks to and visits the old man occasionally, his ex works suzuki rider still owes me a clutch lever. I haven't totally given up on getting it back............:laugh:
Thats why i always used to use an XR honda clutch perch and lever always plenty in a paddock or small local bike shop. I guess Kevin thought the same with the Manx.

[Frits Overmars]

I seem to recall there was some talk of the 500 twin having a tungsten front axel, i don't know if its true or a urban leadgon.;)True; anything to stop the bike from wheelieing. What would have been next? Depleted uranium wheel? Water-filled front tire? :whistle:

[husaberg]

True; anything to stop the bike from wheelieing. What would have been next? Depleted uranium wheel? Water-filled front tire? :whistle:

Osmium
1 cubic meter (m3) of osmium
Equals: 22,590.00 kilograms
or about 10 times the mass density of average concrete.
or 3000kg /m3 heavier than tungsten
Not very cheap though. Plus a bit toxic and likely brittle. bound to be other numerous problems, Buts that R&D's issue. I work in the silly ideas department:)
Then again a frame designed for a 500 might have been a goood start, followed with an engine designed as a 500.:msn-wink:
The honda NSR500V was a bit wheelie prone as well but I guess a bit more manageable.

[Frits Overmars]

Osmium. 1 cubic meter (m3) of osmium Equals: 22,590.00 kilograms or about 10 times the mass density of average concrete. Don't talk to me about concrete; I just had lunch.


Not very cheap though. Plus a bit toxic and likely brittle. bound to be other numerous problems, Buts that R&D's issue. I work in the silly ideas department:)Now you're being modest. I bet you're the Head of Department.


The honda NSR500V was a bit wheelie prone as well but I guess a bit more manageable.A lot more manageable. The NSR500V riders I spoke to, all envied the speed of the Aprilia RSW500 but I bet that they would all be completely cured after one ride on it. 250 cc world champion Harada even bluntly refused to ride it after his first few outings. Only fearless Jeremy McWilliams seemed to enjoy wrestling with the beast.

[jamathi]

I seem to recall there was some talk of the 500 twin having a tungsten front axel, i don't know if its true or a urban leadgon.;)

It was one of the things they tried to keep the front wheel down.
Not a success...

[jamathi]

Don't talk to me about concrete; I just had lunch.

Now you're being modest. I bet you're the Head of Department.

A lot more manageable. The NSR500V riders I spoke to, all envied the speed of the Aprilia RSW500 but I bet that they would all be completely cured after one ride on it. 250 cc world champion Harada even bluntly refused to ride it after his first few outings. Only fearless Jeremy McWilliams seemed to enjoy wrestling with the beast.

Harada refused to ride it after the gearbox started to break down.
Not so strange, as it originally came from the 125...
After that a completely new engine was made.
Finally a full 500, but still short stroke
What a waste of time and money.....
Fuel injection was tried, everybody was happy with how it performed on the dyno.
On-track it proved useless however.

[peewee]

frits do you remember the hp and weight of the rsw500 engine? i had a idea of a inline twin of 500cc using the viper cylinders :laugh:

[TZ350]

Fuel injection was tried, everybody was happy with how it performed on the dyno. On-track it proved useless however.

I am not finished yet but it's pretty much my own story so far. I can make good power but getting it ride-able is proving a bit of a challenge.

I would love to know more about the Aprillia EFI setup.

[F5 Dave]

Honing plated bores.


I’ve been reading an article from an ex engine reconditioner bestowing the virtues of diamond honing the plated barrel.
http://www.motoxparts.co.nz/tech/product-technical-information/do-i-need-to-hone-a-motorbike-cylinder-bore-for-new-piston--rings





He claimed that the plated barrel should always be honed or the rings would not seal as well and wear quicker. Certainly on a steel bore I always used to hone or at least cross hatch scuff above the ports if in a rush.



He stated that the common “if you can see the hone marks” idea was flawed as the smaller edges as still worn off.


He warns against using ball hones & of course stone hones, but diamond hone machine costing many 10s of thousands.
Can't imagine anyone local having one.


On my 50 with plated bore the power used to go off as the ring wore. But it always seemed to some back to the same when a new ring was in place. 10 years on the power was down a little. I’d assumed that I’d just worn the plating oval. I bet a hone would have helped there.


I never bothered on my dirtbikes. Maybe scotchbrite and plenty of brake clean.



Wob etc, what is the sage advice?

[Grumph]

NZ Cylinders in Ashburton can certainly do a diamond hone. I've used them with good results.
More reconditioners are buying the gear as nicasil is becoming more common in cars now.
Ring around your area Dave, you may be surprised.

The setup costs per job are higher as apparently it has to be set up much more accurately than the old Sunnens.
I had a multi done and they told me the setup for that was nearly the same as for a single cylinder...

[Frits Overmars]

frits do you remember the hp and weight of the rsw500 engine?Nope. Jan Thiel was decidedly not involved with the RSW500, so we have little solid information.


I would love to know more about the Aprillia EFI setup.All I remember is that it had a big injector in each inlet tract and a small injector in each crankcase.

[FastFred]

Fuel injection was tried, everybody was happy with how it performed on the dyno. On-track it proved useless however.


... pretty much my own story so far. I can make good power but getting it ride-able is proving a bit of a challenge.

Looks like you are in good company TeeZee.

[TZ350]

Might be the only time that I am anything close to being in the same league as the best ..... :laugh:

[Carel H]

Long time reader, admiring the sharing of knowledge here. In the fuel injection misery I want to add a thing or maybe two. Engines are made by mechanical engineers, ingnitions and fuel injection systems are programmed by software people. They leave you nothing but filling in parameters and guessing how they function internally.

A couple of years ago I made a CDI ignition just for fun. One of the things I encountered is acceleration. With just a trigger for ignition the only way to know the rpm is the last rpm, the last spark - the spark before that, but not the current rpm due to the acceleration on the current stroke. A single cylinder two stroke is the winner in this error. I solved this by measuring the rpm on the current up stroke and determine the spark advance after that. 15000 rpm = 250hz. A holiday season for the most modest microprocessors.

The mechanicals will say, why bother, the sparkies will say, overcomplex, but I found the numbers then interestingly enough to do it that way.

And off course I quit with motorcycles around that time, so no experience, just the observation here.

[2T Institute]

Only fearless Jeremy McWilliams seemed to enjoy wrestling with the beast.

I asked Jezza about that too "I would wheelie and spin the rear as soon as you touched the throttle mind corner" he said in that Northern Ireland brouge. He thought the 250 was the perfect bike. Jezza spends a few months a year in Australia including riding in 2 of the biggest classic meetings. A lovely bloke with some good stories:laugh:

[TZ350]

All I remember is that it had a big injector in each inlet tract and a small injector in each crankcase.

Thanks for the Aprilia injector position information.


... fuel injection systems are programmed by software people. They leave you nothing but filling in parameters and guessing how they function internally.

With just a trigger for ignition the only way to know the rpm is the last rpm, the last spark - the spark before that, but not the current rpm due to the acceleration on the current stroke.

Yes, I find I am guessing a lot about what the EFI software designer meant with some of their selective options. Interesting about determining the exact crank speed.

[jamathi]

Nope. Jan Thiel was decidedly not involved with the RSW500, so we have little solid information.

All I remember is that it had a big injector in each inlet tract and a small injector in each crankcase.

All the tests were done with a single cylinder engine,
And a 39mm carburetor, with a bigger carburetor the piston would melt in a couple of seconds....
The best power they saw was about 70HP I think.
The same injection was also tried on the 125.
Same HP as with a carburetor.
There was no injector in the crankcase.
I would have loved to have it on the 125!

[Tim Ey]

Yes, I find I am guessing a lot about what the EFI software designer meant with some of their selective options. Interesting about determining the exact crank speed.

Hence you got so much troubles getting to know what the Ecotronics designers wanted to do with some strange variables - why dont you give the ignijet injections a try? Their software seems quite easy and understandable.

[husaberg]

Yes, Jan would do a dual disc now.
Is it fair to say...? Well, yes and no. The RSA was an improvement over the side-disc RSW alright, but not by as much as Jan had hoped for.
But as the RSA was winning GPs, Aprilia-management decided not to spend any time and money on development; there may have been a few more horses in there, waiting to be unleashed.
You're right about the RSA250's rotation direction being reversed, compared to the RSW250. The various shafts in the engine were moved about in order to make it more compact. In the RSW the top crankshaft was driving the clutch; in the RSA it was the bottom crankshaft.
Left to right: RSW250, RSA250, RSA250.


I just figured out something was amiss with my musing......
The Aprilia has contra rotating cranks it wouldn't mater that the direction was reversed, as one would always be rotating the opposite anyway:lol:

[SwePatrick]

I´m having a thought.

Only proper way to get fuelinjection to work fully in a dynamic twostroke raceengine is to add a 3d map with rpm,throttle,airmass inputs.(map sensor won´t work)

As when pipe start doing it´s thing you have to predict fueldemand at fullthrottle without airmass meter, this makes it very off the chart in hitting the throttle again after a 'long' coastdown(pipe has gotten a bit cooler and doesn´t work 100% for a couple of moments until heat is up again)

Problem is the airmass meter unit, you need it close to the carb(to get fast reaction), and carb spits fuel the wrong way sometimes, this will lead to malfunction of airmass sensor.

[Flettner]

https://youtu.be/CnIemdISKrM

All sorted Swepatrick, EFI at work.

[FastFred]

Only proper way to get fuelinjection to work fully in a dynamic twostroke raceengine is to add a 3d map with rpm,throttle,airmass inputs.(map sensor won´t work)

As when pipe start doing it´s thing you have to predict fueldemand at fullthrottle without airmass meter, this makes it very off the chart in hitting the throttle again after a 'long' coastdown(pipe has gotten a bit cooler and doesn´t work 100% for a couple of moments until heat is up again)

Problem is the airmass meter unit, you need it close to the carb(to get fast reaction), and carb spits fuel the wrong way sometimes, this will lead to malfunction of airmass sensor.

Some good thoughts there. At certain rpm Carbs can spit back fuel but TeeZee reports that he has noticed much less spit back through the EFI throttle body, probably because the main injectors are in the transfers and timed to finish squirting by BDC. Interesting thought about the wave collapse in the chamber on over run and loss of bulk air transfer until the pipe heats up again.

[F5 Dave]

So the EFI reverse equivalent of an accelerator pump where it might lean off a bit when EGT drops below ideal for whatever revs. Maybe.

[Ocean1]

So the EFI reverse equivalent of an accelerator pump where it might lean off a bit when EGT drops below ideal for whatever revs. Maybe.

Or you could stick a small restriction in the intake, measure the pressure drop across that and supply fuel to match the corresponding air flow!

I'll just dash off a quick patent before someone else thinks of it...

[jamathi]

I just figured out something was amiss with my musing......
The Aprilia has contra rotating cranks it wouldn't mater that the direction was reversed, as one would always be rotating the opposite anyway:lol:

Crankshaft rotation can have some influence on engine power.
At Aprilia we once tested a kart engine.
Just to see how a reed-valve engine worked.
Originally it had a 30mm carburetor of course.
And non-variable ignition.
Fitting a 41mm Aprilia carburetor didn't make much difference.
And neither did the Aprilia ignition....
Reversing crankshaft rotation gave 1,5HP more!

About the 125 RSA
It was a bit of a delusion, but it gave a little bit more power than the RSW.
A big disadvantage proved to be the, necessarily, inclined carburetor.
It was bad in braking on-track.
And the fuel level in the float chamber lowered at full throttle, making the engine run weak.
To solve this problem finally a fuel pump had to be fitted.
Most dyno work was done solving these problems.
Cylinder development was always done on the RSW engine
In order to use a cylinder on the RSA its 'liner' had to be shortened on the C-side, as it disturbed inlet flow.
After shortening such a cylinder it gave less power on the RSW engines.
And most of our cylinders were destined for RSW engines.

The Aprilia 250 RSA was made to raise the gearbox output shaft.
The frame designers saw that as important.
It had the traditional side inlet.
When the first engine was ready it was tested as a twin, something we normally never did.
It gave the same HP as the RSW, everybody was very happy.
And a bottle of champagne was opened.....

[jonny quest]

The best power for a single cylinder 125? 70hp? I read that as all 500 test were done with a single 125.

Why would it burn down with a larger carb?


All the tests were done with a single cylinder engine,
And a 39mm carburetor, with a bigger carburetor the piston would melt in a couple of seconds....
The best power they saw was about 70HP I think.
The same injection was also tried on the 125.
Same HP as with a carburetor.
There was no injector in the crankcase.
I would have loved to have it on the 125!

[jonny quest]

Why was RSA cylinder development done on the RSW?

Isn't the RSW the design right before the RSA?

[husaberg]

The best power for a single cylinder 125? 70hp? I read that as all 500 test were done with a single 125.

Why would it burn down with a larger carb?

The 70hp was from the 500 which was a twin. and not always 500cc it started off under 400CC and grew.
Its not Frits or Jans favourite engine and as they have said, they had nothing to do with it.
With the testing They likely only used the RSW125 bottom end as a test mule, as it was convenient.
With the 500 fours and 250 twins using a single mule cylinder, allows you to work four times as fast and four times as cheaply.
328286328293


Crankshaft rotation can have some influence on engine power.
At Aprilia we once tested a kart engine.
Just to see how a reed-valve engine worked.
Originally it had a 30mm carburetor of course.
And non-variable ignition.
Fitting a 41mm Aprilia carburetor didn't make much difference.
And neither did the Aprilia ignition....
Reversing crankshaft rotation gave 1,5HP more!

About the 125 RSA
It was a bit of a delusion, but it gave a little bit more power than the RSW.
A big disadvantage proved to be the, necessarily, inclined carburetor.
It was bad in braking on-track.
And the fuel level in the float chamber lowered at full throttle, making the engine run weak.
To solve this problem finally a fuel pump had to be fitted.
Most dyno work was done solving these problems.
Cylinder development was always done on the RSW engine
In order to use a cylinder on the RSA its 'liner' had to be shortened on the C-side, as it disturbed inlet flow.
After shortening such a cylinder it gave less power on the RSW engines.
And most of our cylinders were destined for RSW engines.

The Aprilia 250 RSA was made to raise the gearbox output shaft.
The frame designers saw that as important.
It had the traditional side inlet.
When the first engine was ready it was tested as a twin, something we normally never did.
It gave the same HP as the RSW, everybody was very happy.
And a bottle of champagne was opened.....

Thanks for your reply Jan
I was certainly unaware that a pump was eventually used.
I understand Kenny Roberts ran into trouble with the forward mounted carbs on the triple as well, but in their case under braking.
Pretty sure Wob mentioned the BSL500 had the same issues as the Roberts 3 also
I have seen it written that, If you were going to design a new disc valve single it would be with twin discs one either side.
What size would the disc be, the same as the RSW? or larger?
Also the Derbi reed valve engine you inherited what changes did you make to that?
Frits once posted a dyno graph it was very impressive for a reed valve. likely More than a Honda produced.
328295
Also am i right in sugesting when you say the RSA250 gave the same power as two of the RSW singles, It was only when the APF RSA cylinders were used.
I read on a site that the additional head studs when deleted as a trial actually cost quite a bit of power. Is this because of distortion? distortinn leading to poor sealing
328294

[jonny quest]

Wasn't the RSW a side rotary valve?

Only 70HP front a twin 500? Ouch! Or was the 70hp a 250 single hp number

[husaberg]

Wasn't the RSW a side rotary valve?

Yes. it is a conventional disc valve.
328287


Only 70HP front a twin 500? Ouch! Or was the 70hp a 250 single hp number
But it was a very oversquare very compromised design. That was in essence a overbored 250.
Yes the 70HP rom one cylinder of a 500 twin.

[jamathi]

The 70hp was from the 500 which was a twin. and not always 500cc it started off under 400CC and grew.
Its not Frits or Jans favourite engine and as they have said they had nothing to do with it.
with the testing They likely only used the RSW125 bottom end as a test mule, as it was convenient.
With the 500 fours and 250 twins using a single mule cylinder, allows you to work four times as fast and four times as cheaply.
328286



Thanks for your reply Jan
I was certainly unaware that a pump was eventually used.
I understand Roberts ran into trouble with the forward mounted carbs on the triple as well, but in their case under braking.
Pretty sure Wob mentioned the BSL500 had the same issues as the Roberts 3 also
I have seen it written that, If you were going to design a new disc valve single it would be with twin discs one either side.
What size would the disc be, the same as the RSW? or larger?
Also the Derbi reed valve engine you inherited what changes did you make to that?
Frits once posted a dyno graph it was very impressive for a reed valve.
Also am i right in sugesting when you say the RSA250 gave the same power as two of the RSW singles, It was only when the RSA cylinders were used.

The first RSA engine was made at Derbi, it was meant to be able to beat Aprilia.
The Derbi reed valve engine gave 47,5HP when I arrived there in 2004.
So obviously something new had to be made.
But it was improved to 49.5HP, mainly through better inlet flow and better crankcase cooling.
It's electric water pump proved insufficient, so it was not used on the RSA.

The 250RSA had side inlet, so it used RSW cylinders, all tested and developed on a 125 RSW single.
It simply was a normal 250 with the gearbox output shaft in a higher position, and therefore the crankshaft rotation had to be reversed.

The 125 RSA/Derbi was a completely different engine, with the inlet valve on the rear.
This was done after flow bench tests showed that the RSW inlet flow was very much disturbed by the connecting rod, it seemed logical at the time!
Later we realized that the RSA inlet flow collided with the cylinder wall at the opposite side.
So there was very little gain....
Fins directing the inlet flow versus the transfer tunnels would have helped I now think!

In 2006 a special RSA cylinder was made with the cylinder bolts in a different position.
It had also better cooling of the exhaust duct and small cooling canals through the inside wall of the
transfer ducts, which improved power by 0,5HP!

So I finally came upon the idea of using a disc valve on each side, as already had been done by Exactweld.
But I decided to retire, a Dutch friend made some crankcases, but never finished the work.
So I still wonder how it would have gone....

The 70HP I mentioned for the 500 was, of course, on a single cylinder.
The engine used for those tests was a 500 engine, with only 1 crankshaft fitted.
Testing on 2 cylinders is more complicated and inconvenient.

Derbi was owned by the Piaggio group, which owns several Italian makes.
At the beginning of 2005 Piaggio bought Aprilia.
So they decided to close the Derbi racing workshop and I had to return to Aprilia, which I did in 2006.

The piston melting with a bigger than 39mm carburetor was probably caused by a weak spot just before maximum torque.
Because no powerjet was used at the time....

[husaberg]

The first RSA engine was made at Derbi, it was meant to be able to beat Aprilia.
The Derbi reed valve engine gave 47,5HP when I arrived there in 2004.
So obviously something new had to be made.
But it was improved to 49.5HP, mainly through better inlet flow and better crankcase cooling.
It's electric water pump proved insufficient, so it was not used on the RSA.

The 250RSA had side inlet, so it used RSW cylinders, all tested and developed on a 125 RSW single.
It simply was a normal 250 with the gearbox output shaft in a higher position, and therefore the crankshaft rotation had to be reversed.

The 125 RSA/Derbi was a completely different engine, with the inlet valve on the rear.
This was done after flow bench tests showed that the RSW inlet flow was very much disturbed by the connecting rod, it seemed logical at the time!
Later we realized that the RSA inlet flow collided with the cylinder wall at the opposite side.
So there was very little gain....
Fins directing the inlet flow versus the transfer tunnels would have helped I now think!

In 2006 a special RSA cylinder was made with the cylinder bolts in a different position.
It had also better cooling of the exhaust duct and small cooling canals through the inside wall of the
transfer ducts, which improved power by 0,5HP!

So I finally came upon the idea of using a disc valve on each side, as already had been done by Exactweld.
But I decided to retire, a Dutch friend made some crankcases, but never finished the work.
So I still wonder how it would have gone....

I am familar with the dual disc engine, I was unaware he never finished it though.
Last time i looked at their website, most of the two stroke stuff including their Aprilia like cylinder conversion for Honda RS engines had been removed, A rather sad sign of the times.
328296
The Exactaweld was a great concept but sadly i assume underfunded.
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130703351#post1130703351
When was a kid i used to stare and marvel at pictures of the Chassis they did for the Norton coswoth engine.
328299328300
As an adult i understand that the lack of chaassis is a result of the overly huge engine.

[katinas]

Hi,

Started it yesterday and revs like like crazy chainsaw, I have never heard such a sound from this old engine. For this experiment made 1 cylinder crank, because Honda ns 250 engine is 2 cylinder. Ports timing and size is original . Cold winter outside and now no possibilities try on the road.
Thanks Harry R...

[ken seeber]

Thanks Hooser,

Clearly Jan has a good eye for good 2 stroke ports..:yes:

328305


OK Katinas, good post, BUT you have a lot of questions to answer:

1. To achieve the same port timings, did you use the same (ns250) con rod centres?
2. Did you retain the ns250 pipes?
3. Did you "wet sump" the crankcase?
4. How did you attach the piston rod (approx Ø35) to the cast (?) piston?
5. No con rod upper bearing shown. Was this a one sided thing (the pic) or is this just a mock up?

Certainly I (and I'm sure a shitload of others) look forward to understanding what you have done more. Well done though.

BTW, welcome to ESE.

[SwePatrick]

https://youtu.be/CnIemdISKrM

All sorted Swepatrick, EFI at work.

Yes.. but i still think there can be improvements.
Especially in roadracing.
An mx machine isn´t that sensitive like a hardcore tuned gp machine. ;)

[Peter1962]

Hi,

Started it yesterday and revs like like crazy chainsaw, I have never heard such a sound from this old engine. For this experiment made 1 cylinder crank, because Honda ns 250 engine is 2 cylinder. Ports timing and size is original . Cold winter outside and now no possibilities try on the road.
Thanks Harry R...

So now we have a non-official prototype of the Ryger design, maybe you can do what the Ryger crew did not : dyno it and publish the curve. :msn-wink:

[jonny quest]

One more question for Jan. I'm still trying to figure out why the long rod was better for you. I personally don't think a longer rod is best for ALL applications. It does reduce the time the ports are open.

At which stage did you try it and find more power? Is it making more power from reducing side loading and friction? Or did it just move the piston out of the way at BDC for better flow?

[Flettner]

Yes.. but i still think there can be improvements.
Especially in roadracing.
An mx machine isn´t that sensitive like a hardcore tuned gp machine. ;)

I was down at Link head quarters last week, we talked about using their system on a 125 or 50. They are sure it will work up to that frequency (injector pulsing). Finally their units are packaged in a small case so it may fit conveniently on a motorcycle. They are working on a unit to run direct injection injectors at the moment, interesting. You can run many different inputs into their ECU, yes MAP won't work on a twostroke as normal. But you can 'sample' the intake but only taking a measurement at a certain part of the crank rotation, useful. Link ECU will also allow a combination of MAP and TPS mix.
F9 not a hardcore GP machine? I think it might be a bit sensitive to that satement:bleh: you are right, but never the less the old girl goes pretty nice for what it is, an EFI twostroke test bed.

[peewee]

Only 70HP front a twin 500? Ouch!


your statement cant be serious ? :blink:

[jamathi]

One more question for Jan. I'm still trying to figure out why the long rod was better for you. I personally don't think a longer rod is best for ALL applications. It does reduce the time the ports are open.

At which stage did you try it and find more power? Is it making more power from reducing side loading and friction? Or did it just move the piston out of the way at BDC for better flow?

I first tried it on a 50 cc in 1074: more power.
Going from 80 to 85
Then at Aprilia in 1996: more power.
Without varying the crankcase volume.
We went from 112 to 113 and 115, later 118 was tried, still better.
For the RSA we had to lengthen the connecting rod from 115 to 120 to improve inlet flow: more power.
It is mainly due to piston friction I think.
NSU already found this in 1953, piston friction was the main source of friction in their 250 4-stroke engine.
It may be different for a reed valve engine, I have not much experience with these.
But the piston friction loss will, of course, be the same in a reed valve engine.

Of course at BDC there is no difference as you have to adjust the cylinder height!
Maybe it is interesting that with a longer connecting rod I could use higher transfer ports on my 50.
Getting still more power!

The crankcase volume also changes, of course, unless you change the position of the piston pin in the piston, as we did at Aprilia
This can be better or worse....
You can change your crankcase volume in many ways.
But always keep in mind that flow is more important than volume.....
On rotary valve engines I found the bigger the better, within reason of course....
The Aprilia engines had very narrow crank wheels, (16mm) so a very big crankcase volume. About 660cc in TDC
A big crankcase volume makes very long inlet timings necessary.
And big carburetors.

This is probably the reason why reed-valve engines need a smaller crankcase volume.
The reeds 'decide' for themselves when to open...
They need some depression.
And because maximum inlet flow is probably determined by the reed block, big carburetors won't work on a reed-valve engine.
They just slow down the flow in the carburetor, making for a difficult carburetor adjustment.

So I think that a rotary valve engine will always give about 3-4 HP more (125cc) than a reed valve engine.
Because of its unrestricted inlet flow and less pumping losses.

[katinas]

Thanks Hooser,

Clearly Jan has a good eye for good 2 stroke ports..:yes:

328305




OK Katinas, good post, BUT you have a lot of questions to answer:

1. To achieve the same port timings, did you use the same (ns250) con rod centres?
2. Did you retain the ns250 pipes?
3. Did you "wet sump" the crankcase?
4. How did you attach the piston rod (approx Ø35) to the cast (?) piston?
5. No con rod upper bearing shown. Was this a one sided thing (the pic) or is this just a mock up?

Certainly I (and I'm sure a shitload of others) look forward to understanding what you have done more. Well done though.

BTW, welcome to ESE.
Hi,

At the moment I can not say anything about the engine power characteristic and reliability, only passion as soon as possible to start the engine and to hear is it revs or ..... I never hear before so nice and powerful sound on this engine on full gas (at the moment this all I can tell, I do not have dyno all bikes test on the road). Bike not yet ready only naked chassis, engine, pipe (not full ready), ignition ,carb, wheels. No brakes and other stuffs.
When I started drawings (3 months ago) I begin to understand complexity that Ryger overcome (ex. assembling piston to conrod with that plate). Complete structure depends on how high can lift cylinder. On most motorcycle maybe 30mm is max, because no room in chassis. This is first dimension that you need to consider. And that means its impossible to use (ON MOTORCYCLE) original conrod (too long). Piston structure again depends on how high can lift cylinder. If piston is one peace aluminium, smaller piston can be coated or not. If coated (nicasil or something) seal ring is located in small aluminium cylinder (not coated). If small piston is not coated (cylinder coated or iron) , then seal ring must be on piston (aluminium wear out if seal located on cylinder) and must be lower than piston pin (higher than pin weakens small piston) and seal on the piston means long small cylinder and higher lifted cylinder. So for full aluminium piston, coated small piston is best selection, but Jan Thiel wrote, that Ryger had problems with coated piston.
Other selection is two or three parts piston. I do not have the possibilities to coat piston, so for me left this. It is possible to made three or more different construction. After made first piston, I release that is better options (lighter), but job is done test engine with that.

1. Plate thick 20 mm ( two peace - pate aw 2024, removable small cylinder Al-Si al4)
2. Piston 57 mm. tree parts ( aluminium parts from solid AL 2618, small piston tube CroMo hard chromed 38 mm.)
3. Cylinder 57 mm. Honda ns 400
4. Conrod Kawasaki KX100 (center to center 92 mm. big end 22x29 mm. small end 14x19 mm. .) but now i think KTM SX 85 conrod is beter center to center 96 mm big end 22x28 mm smal end 14x19 and looks stronger.
5. Crankcase with oil, but no sump no anything only conected through bearing with other cylinder crankcase space because this only experiment and if engine works then made two cylinder engine with sump.
6. Pipe is stainless handmade (one honda rs 125 copy other aprilia rsw 125 copy) both tested on normal engine
7. Carburetor Honda nsr 250 mc 28 tb 32 mm. Reed valve std. ns400 four petal.
8. Ignition Honda Rs 250 ND5 1985 (honda made racing ignition for this crankcase in racing version)
9. Combustion chamber 13.5 cc (with plug) squash 0.9 mm

[jamathi]

Very interesting, thank you for publishing this and not being so ridiculously secretive as Ryger.
They seem to have resolved their plating problems I heard some time ago.
They now declare 66HP at 13000 rpm.
But there is no power curve, so I think it is only a simulation....

[WilDun]

Not really involved in the discussion, but I just had to say very good effort, nice to see one about to be tested!:niceone:

I was wondering who would be first to have a serious attempt at an actual "Ryger" clone (well close enough!) - I think there will be a few more "on the verge" of success! - then it'll be all on again and TZ's little thread will once more be swamped! :..........:shit:.........:laugh:

[jonny quest]

I have a 125 dirt bike, and a dyno. Full machine shop too. I haven't studied the Ryger enough to build a prototype to test. But I would be willing if some people helped with what I would need to build this.

My engine is case Reed though. And I wouldn't want to go as far as modifying my cylinder for cylinder Reed. Just remembered that

[TZ350]

So the EFI reverse equivalent of an accelerator pump where it might lean off a bit when EGT drops below ideal for whatever revs. Maybe.

Yes good point, Ecotrons has a set of options where you get to define low, mid and high rpm speed ranges and an acceleration enrichment factor and deceleration enleanmeant factor for each range, default is 1.1 and 0.9 respectively but this can be changed.

The Ecotrons fuel maps are based on engine load which I guess is roughly transfer ratio for a 2T. And my new cylinder and injector layout required a new map but the gearbox broke before I got to finish developing it. I needed a fairly good map before I could properly test the overrun fuel cut option (problem) I discovered earlier.

Interestingly when Honda RS125's were on the dyno the drum would take ages to slow down on over run but my Beast would slow much quicker. After turning off the fuel cut option my Beast started to take much longer to slow down too. I am not sure if a Honda RS125 is meant to idle but if it is it would explain why it would take much longer to slow down on the dyno than my Beast did with its fuel completely cut off on over run.

I am looking forward to getting the Beast going again so I can explore those setup ideas you suggested.

[Flettner]

Hi,

At the moment I can not say anything about the engine power characteristic and reliability, only passion as soon as possible to start the engine and to hear is it revs or ..... I never hear before so nice and powerful sound on this engine on full gas (at the moment this all I can tell, I do not have dyno all bikes test on the road). Bike not yet ready only naked chassis, engine, pipe (not full ready), ignition ,carb, wheels. No brakes and other stuffs.
When I started drawings (3 months ago) I begin to understand complexity that Ryger overcome (ex. assembling piston to conrod with that plate). Complete structure depends on how high can lift cylinder. On most motorcycle maybe 30mm is max, because no room in chassis. This is first dimension that you need to consider. And that means its impossible to use (ON MOTORCYCLE) original conrod (too long). Piston structure again depends on how high can lift cylinder. If piston is one peace aluminium, smaller piston can be coated or not. If coated (nicasil or something) seal ring is located in small aluminium cylinder (not coated). If small piston is not coated (cylinder coated or iron) , then seal ring must be on piston (aluminium wear out if seal located on cylinder) and must be lower than piston pin (higher than pin weakens small piston) and seal on the piston means long small cylinder and higher lifted cylinder. So for full aluminium piston, coated small piston is best selection, but Jan Thiel wrote, that Ryger had problems with coated piston.
Other selection is two or three parts piston. I do not have the possibilities to coat piston, so for me left this. It is possible to made three or more different construction. After made first piston, I release that is better options (lighter), but job is done test engine with that.

1. Plate thick 20 mm ( two peace - pate aw 2024, removable small cylinder Al-Si al4)
2. Piston 57 mm. tree parts ( aluminium parts from solid AL 2618, small piston tube CroMo hard chromed 38 mm.)
3. Cylinder 57 mm. Honda ns 400
4. Conrod Kawasaki KX100 (center to center 92 mm. big end 22x29 mm. small end 14x19 mm. .) but now i think KTM SX 85 conrod is beter center to center 96 mm big end 22x28 mm smal end 14x19 and looks stronger.
5. Crankcase with oil, but no sump no anything only conected through bearing with other cylinder crankcase space because this only experiment and if engine works then made two cylinder engine with sump.
6. Pipe is stainless handmade (one honda rs 125 copy other aprilia rsw 125 copy) both tested on normal engine
7. Carburetor Honda nsr 250 mc 28 tb 32 mm. Reed valve std. ns400 four petal.
8. Ignition Honda Rs 250 ND5 1985 (honda made racing ignition for this crankcase in racing version)
9. Combustion chamber 13.5 cc (with plug) squash 0.9 mm

Good boy, thank you. :first:
We are very interested.

[TZ350]

Fuel injection was tried, everybody was happy with how it performed on the dyno.
On-track it proved useless however.

500


The same injection was also tried on the 125. Same HP as with a carburetor. There was no injector in the crankcase.

I would have loved to have it on the 125!

I would love to know more about your experiences with fuel injecting a 2T. Things that particularly interest me are cylinder capacity, rpm and injector size and position, I would love to hear from anyone who has experience with 2T EFI.

Locally there are two 250cc MX bikes that I know of that have been successfully converted to EFI. They rev to about 9,000 rpm max and are reported to ride very well in the field. The late model YZ uses a single logical injector, made up of two physical injectors fired in parallel, vertically down, one in each B transfer. The Kawasaki Bighorn has the injectors in the crankcase firing horizontally, above and in line with the gap between the flywheels.

My 125 revs to 13,000 rpm max and uses two different size logical injectors. Swapping between them to cover the wider range of the changing time window for the injection cycle. I have found that the position and orientation of the injectors on my bike makes quite a difference and I would love to know more about your experiences, or anyone else's with 2T EFI.

Jamathi came back to me and told me that:-


"I never worked with it, the '500cc people' did. They told me it was fantastic. But the riders refused to ride with it: unrideable they said!"
Well "Fantastic" is encouraging "Unrideable" not so much.

I have heard of a local EFI RZ350, if anyone knows about this bike I would love to know more.

[katinas]

Hi,

Thanks for all replies, during the last four years Jan and Frits release so much brilliant 2 STROKE GP words (later led other open) and if someone collect all they posts from all forums, we should wonderful "2 stroke racing engines book". Thanks very very much.

Maybe, limited information about Harry Ryger engine, forced to act our brain more intensively, it is good in any case.

"Things that left unsaid" about "rygerised" Ns 250
1. Stroke is original 50.6 mm ( no room in 2 cylinder Ns 250 crankcase for 54.5 mm stroke, but for 3 cylinder Ns 400 crankcase its possible, because flywheel is bigger. Ns 400 is 93 mm Ns 250 is 86 mm. But again cylinder must be even higher. ) so with 57 mm. piston, engine is 129 cm3 X 2 259cm3

2. Difference between conrod center to center 17 mm. (Original Ns-250/400r conrod center to center 109 mm. Kx 100- 92mm)

3. Small piston tube length 80mm and radius cut to copy flywheel at BDC. When piston at TDC, small piston 29 mm remained in small clylinder. This is very important dimension (maybe first thing to decide before drawing) for piston stability and durability, longer is better, but again cylinder be lift up, its compromise . From all information that we found about Ryger engine, this dimension is between 10-20 mm. and maybe they the have problems, but maybe I am wrong.
From homologated drawings Ryger small piston dia. 36 mm. ( its minimal for 125 cc solid aluminium piston because no space for adequate strong conrod). For multi parts piston, like mine, minimal tube (with thread) dia. 38 mm. When made this, i release its critical. If tube be without thread, 37mm dia. be minimal.
Ryger piston suction ( 54/36x54.5mm) 69.3cc
Ns piston suction (57/38x50.6mm) 71.7cc

4. Especially important thing about Ryger consruction: all four planes ( crankcase, plate, cylinder) must be PERFECTLY parallel among themselves and PERFECTLY perpendicular to conrod and piston, small and big cylinder must be PERFECTLY in center. Its critical. When I screw one (of four) cylinder bolt, and try rotate crank, its stuck! In usual engine piston adjusts to cylinder. Imagine, when engine hot up and cylinder, like Frits wrote, becomes "banana" what can happen!! So, maybe any gasket under cylinder and plate not recommended. Best O ring or seal like bond 1104 .....
Ryger cylinder centered inside, Ns outside because no metal to centered inside. But exact pin is another solution
Of course this is old Ryger engine dimensions, and maybe they new engine is reliable and powerful.

[d2t]

328296


I have to ask about the dual disc concept. If there are rotary discs on both sides of the crank (and I assume also carbs on either side), where will the output gear go? Seems like there would be some packaging issues.

[Michael Moore]

The Rotax rotary valve MX engines have the primary gear outside the rotary valve on the left side of the engine.

http://www.pulpmx.com/sites/default/files/u165/csteel102_2.jpg

[Muciek]

Also the TM KV series engines

328333

[husaberg]

I have to ask about the dual disc concept. If there are rotary discs on both sides of the crank (and I assume also carbs on either side), where will the output gear go? Seems like there would be some packaging issues.

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130703351#post1130703351
The suzuki gp100 etc engines and kawaski singles have the primary drive outboard of the disc valve as well.
328335328338
not including the Bridgestone and Kawaski disc vlave parallel twins of the 60's
328340
The Kawaski kr250 road bike tandems did as well.
328337
The other solution is to do what Suzuki did with the RG500
328339
The same as Yamaha did with the rd05 or RA31 they also had overlapping discs all in a compact 75 degree angle.
328341 https://enoanderson.com/wp-content/uploads/2016/01/yamaha-ra31-7.jpg

[d2t]

I see. Thanks all for the replies. I have little to go on other than my current batch of modern engines (most of which are reed valved).

:rockon:

[peewee]

hey guys today im very excited the cylinder is leek free. it held 16psi for 5min with zero pressure loss. but I fear the comp ratio still may be a bit high (about 18:1) but im not sure since the fuel is methanol. piston to head clearance im not sure whether its good or not until I try it, maybe there will be contact or maybe not. theres a slight convergance as it goes toward center (.8mm to .9mm). any thoughts or suggestions about these two situations ? i can lower the comp ratio and increase the piston gap if needed or i can try it and see what happens. most importantly the cylinder has no pin holes from all the welding :clap:. now I just pray the studs don't pull up

[TZ350]

hey guys today im very excited the cylinder is leek free. it held 16psi for 5min with zero pressure loss.

Looking good, great work. .... :2thumbsup

My own experiance with Methanol (actually 50/50 methanol acetone) was to leave the compression the same as for petrol because it was thought the extra cooling effect of the alcohol delivered a denser charge so needed comparatively less compression.

[Flettner]

Hi,

At the moment I can not say anything about the engine power characteristic and reliability, only passion as soon as possible to start the engine and to hear is it revs or ..... I never hear before so nice and powerful sound on this engine on full gas (at the moment this all I can tell, I do not have dyno all bikes test on the road). Bike not yet ready only naked chassis, engine, pipe (not full ready), ignition ,carb, wheels. No brakes and other stuffs.
When I started drawings (3 months ago) I begin to understand complexity that Ryger overcome (ex. assembling piston to conrod with that plate). Complete structure depends on how high can lift cylinder. On most motorcycle maybe 30mm is max, because no room in chassis. This is first dimension that you need to consider. And that means its impossible to use (ON MOTORCYCLE) original conrod (too long). Piston structure again depends on how high can lift cylinder. If piston is one peace aluminium, smaller piston can be coated or not. If coated (nicasil or something) seal ring is located in small aluminium cylinder (not coated). If small piston is not coated (cylinder coated or iron) , then seal ring must be on piston (aluminium wear out if seal located on cylinder) and must be lower than piston pin (higher than pin weakens small piston) and seal on the piston means long small cylinder and higher lifted cylinder. So for full aluminium piston, coated small piston is best selection, but Jan Thiel wrote, that Ryger had problems with coated piston.
Other selection is two or three parts piston. I do not have the possibilities to coat piston, so for me left this. It is possible to made three or more different construction. After made first piston, I release that is better options (lighter), but job is done test engine with that.

1. Plate thick 20 mm ( two peace - pate aw 2024, removable small cylinder Al-Si al4)
2. Piston 57 mm. tree parts ( aluminium parts from solid AL 2618, small piston tube CroMo hard chromed 38 mm.)
3. Cylinder 57 mm. Honda ns 400
4. Conrod Kawasaki KX100 (center to center 92 mm. big end 22x29 mm. small end 14x19 mm. .) but now i think KTM SX 85 conrod is beter center to center 96 mm big end 22x28 mm smal end 14x19 and looks stronger.
5. Crankcase with oil, but no sump no anything only conected through bearing with other cylinder crankcase space because this only experiment and if engine works then made two cylinder engine with sump.
6. Pipe is stainless handmade (one honda rs 125 copy other aprilia rsw 125 copy) both tested on normal engine
7. Carburetor Honda nsr 250 mc 28 tb 32 mm. Reed valve std. ns400 four petal.
8. Ignition Honda Rs 250 ND5 1985 (honda made racing ignition for this crankcase in racing version)
9. Combustion chamber 13.5 cc (with plug) squash 0.9 mm

Do you have a video of it running? May we see it?

[peewee]

Looking good, great work. .... :2thumbsup

My own experiance with Methanol (actually 50/50 methanol acetone) was to leave the compression the same as for petrol because it was thought the extra cooling effect of the alcohol delivered a denser charge so needed comparatively less compression.

and im thinking it may beat the hell out of the rod and bearings, not to mention its so damn hard to kick start with that much static pressure. this weekend ill lower it down to a more acceptable ratio.

[F5 Dave]

And the converging squish is a no-no, can lead to deto aand head gasket failure.

[koenich]

4. Especially important thing about Ryger consruction: all four planes ( crankcase, plate, cylinder) must be PERFECTLY parallel among themselves and PERFECTLY perpendicular to conrod and piston, small and big cylinder must be PERFECTLY in center. Its critical.
I thought about that too, the tolerance stack-up for the Ryger set-up is horrible...however, congrats to your effort!

[DoldGuy]

hey guys today im very excited the cylinder is leek free. it held 16psi for 5min with zero pressure loss. but I fear the comp ratio still may be a bit high (about 18:1) but im not sure since the fuel is methanol. piston to head clearance im not sure whether its good or not until I try it, maybe there will be contact or maybe not. theres a slight convergance as it goes toward center (.8mm to .9mm). any thoughts or suggestions about these two situations ? i can lower the comp ratio and increase the piston gap if needed or i can try it and see what happens. most importantly the cylinder has no pin holes from all the welding :clap:. now I just pray the studs don't pull up

Also starting the bike on Gas (fill the carb bowl with premix) will be SO MUCH easier versus the methanol. Wobbly has posted his Methanol Motors like Stupid Compression.

Left Side Kick KTM...440 or 550?

[peewee]

Left Side Kick KTM...440 or 550?

its neither, but rather a mix of parts I put together (550 crankshaft, 500 cylinder, Honda rod and piston). the reason its neither is simple in my eyes. 440 (89x70) is so far over square, I question whether it would make any power at all. 550 used a short rod (140mm) and high piston pin. the result was a very small crankcase volume for such a large engine, not to mention a few other problems associated with a short rod and high piston pin ( aux exh ports couldn't be made much larger because the piston would uncover them at tdc).

by using the longer rod, lower piston pin (with lower side skirting), and 500 cylinder, I was able to lift the cylinder 9mm. crankcase volume increased, aux exh could be made large as I wanted, reduced load on the piston inlet side and surely less friction.

ive ran this lower end on methanol before ( with different cylinder) and it always started just fine on methanol. actually I wonder if it would even start with petrol since the fuel passages are so large. when flushing the engine at the end of the day, 8oz of petrol was all it will consume before it dies. presumably because it just floods the crankcase and cant be burned. to start the engine later, I just drained the bowl of petrol and filled it with methanol from a large syringe. worked a treat everytime

[SwePatrick]

and im thinking it may beat the hell out of the rod and bearings, not to mention its so damn hard to kick start with that much static pressure. this weekend ill lower it down to a more acceptable ratio.

18-1 isn´t high in a twostroke for methanol use.
Maybe when using it with acetone, but not with pure methanol and 4% oil.

I actually never heard of an engine that has broken a rod due to high compression.
Only where mistakes have been made and the piston hits the head and then they have blamed the compression.

[peewee]

Patrick im sure a small 2t would do fine at 18:1 but what about with 90.5mm piston ? unfortunately I have no test dyno to see if it makes the same power at lower comp ratios.

[F5 Dave]

18-1 isn´t high in a twostroke for methanol use.
Maybe when using it with acetone, but not with pure methanol and 4% oil.

I actually never heard of an engine that has broken a rod due to high compression.
Only where mistakes have been made and the piston hits the head and then they have blamed the compression.
Well, to be fair compression is the problem. . . just not compression ratio:shutup:

[husaberg]

18-1 isn´t high in a twostroke for methanol use.
Maybe when using it with acetone, but not with pure methanol and 4% oil.

I actually never heard of an engine that has broken a rod due to high compression.
Only where mistakes have been made and the piston hits the head and then they have blamed the compression.


Patrick im sure a small 2t would do fine at 18:1 but what about with 90.5mm piston ? unfortunately I have no test dyno to see if it makes the same power at lower comp ratios.

Bell tops out at 15.5-16:1 for a Liquid colled 500 on methanol compared to a 50 or 100 running at 20:1 or 19:1 respecfully.
In the absence of any other futher more up to date information (Frits Wob a or Mr Thiel)or a Sim i would start lower say 13.5:1-14 and work your way up.
You have a tig afterall so making changes later is not to hard.
I have a suspicion the big end bearing and parts hardware rather will actually decide your upper compression limit.
Have you o-ringed the head with something substantial, like SS and maybe order some new head studs and base studs (if the KatieM has them.)
Ps i hope you have starting rollers and a big ol American pick up to drive them.
Maybe a proper manual comp release might be an idea, i know they are available aftermarket for CR500's you could fit one above the exhaust port at 90 degrees to the cylinder.
i recall you having some sort of bleed port their anyway.
For the time you intend running it i don't think long term sealing will be an issue

[SwePatrick]

Patrick im sure a small 2t would do fine at 18:1 but what about with 90.5mm piston ? unfortunately I have no test dyno to see if it makes the same power at lower comp ratios.

The piston can take it, the thing to worry about is small end bearing.
To gain data about this, have a look at those hardcore dragracing banshees in the USA.

rgds.

[peewee]

patrick i dont pay any attention to the usa banshee guys. i think most of them are a bunch of rubes :bleh:. alot of what they do i dont agree with and their 2t ideaology seems to be stuck in 1980. besides that, i find frits, wobbly, jan and everyone else around here to be far more knowledgable :msn-wink:

[wobbly]

The loads imposed by compression forces are a whole order of magnitude less than those of the inertial stress on the piston/rod/bearings etc from
being stopped at TDC/BDC.
I have said this before - you could happily double the power output of an engine and see no evidence of any extra " load " on the working parts as long as the rpm
wasnt increased.
The exception is of course the gear tooth loading, and maybe long term bore/ring wear from the higher gas expansion pressure.

The same small end bearings as are used in a Banshee can be had with silver plated cages if that is a reliability concern, but if they fail it would be because
they are shoving a massive 75mm piston around, when the original design was for a tiny 54mm - 125 sized cylinder.
And I would bet the house on the fact that the failures would be down to the onset of detonation - again,the shock loading of this uncontrolled combustion far exceeds
any forces imposed by a controlled ( relatively slow ) spark ignited gas burn.

As far as compression is concerned in big bore sizes, it has been proven time and again that smaller pistons can be pushed way harder.
19:1 was used with Elf 124 octane in 125/250 GP racing, and is fine with Methanol at over 130 effective octane when running over rich.
In a huge bore i would go 15.5,maybe 16.5 for drag racing where the run time is super short.
But to use these big compression's its super important to have effective squish working and a very cold plug,with water being used properly to cool the threads.
To be sure, the heat released into the pipe is lower, due to a load of unburnt fuel being dumped, but the combustion temp is high that is generating the higher gas pressure
to make more power.

[F5 Dave]

Thoughts on my plated bore hone question a couple pages back??

[wobbly]

Diamond as such isn't really needed, you can hone a coated bore with normal stones easily enough.
The real issue is that " proper " Sunnen honing heads force the stones dead true to the vertical axis of the machine, thus can remove taper or ovality.
This assumes then of course that the bottom deck is true to the bore - not an assumption you should make of course.

The honing pattern is hugely variable depending upon the bore and ring face material.
I recently dyno tested a Vortex ROK engine, the same as the one I did during analysis for NZ Kartsports replacement midget/junior category.
The popular myth was that they never go as well when a new piston is fitted, so to be quick you must have a brand new engine just run in.
Anyway the short of the story is that after testing the actual Ra of a new bore,I tried various surface courseness, and hatch patterns.
The stock new surface Ra from the factory is very fine, but has a huge crosshatch pattern almost 90* and using a $25, 3 stone small engine hone from Supercheap
I could replicate this in 30 seconds with a battery drill running real slow.
Result - same power everywhere within a 1/10th, worst result was from another engine man who had a very course surface with very shallow hatch - 0.8 Hp down ( nearly 10% )
Vortex are no fuckwits it would seem,some engine builders are.

[SwePatrick]

patrick i dont pay any attention to the usa banshee guys. i think most of them are a bunch of rubes :bleh:. alot of what they do i dont agree with and their 2t ideaology seems to be stuck in 1980. besides that, i find frits, wobbly, jan and everyone else around here to be far more knowledgable :msn-wink:


Yes, they might be, but you can´t deny that those bansheeguys actually got a lot of power in their rides?
To be a really good tuner one need to look over the fence also.

[Grumph]

Diamond as such isn't really needed, you can hone a coated bore with normal stones easily enough.
The real issue is that " proper " Sunnen honing heads force the stones dead true to the vertical axis of the machine, thus can remove taper or ovality.
This assumes then of course that the bottom deck is true to the bore - not an assumption you should make of course.

The honing pattern is hugely variable depending upon the bore and ring face material.
I recently dyno tested a Vortex ROK engine, the same as the one I did during analysis for NZ Kartsports replacement midget/junior category.
The popular myth was that they never go as well when a new piston is fitted, so to be quick you must have a brand new engine just run in.
Anyway the short of the story is that after testing the actual Ra of a new bore,I tried various surface courseness, and hatch patterns.
The stock new surface Ra from the factory is very fine, but has a huge crosshatch pattern almost 90* and using a $25, 3 stone small engine hone from Supercheap
I could replicate this in 30 seconds with a battery drill running real slow.
Result - same power everywhere within a 1/10th, worst result was from another engine man who had a very course surface with very shallow hatch - 0.8 Hp down ( nearly 10% )
Vortex are no fuckwits it would seem,some engine builders are.

Never worked on one of them...what's the ring ?

Those small engine hones have saved my bacon a couple of times. Good value.

[Flettner]

Ok, It's me, go round in circles with projects::wacko:
On the weekend I did a trail ride, not unlike other weekends but this one was relatively open and fast. Most upset as I couldn't hold off the 450's. So it is time!
This 360 rotary valve twostroke engine has sat on the shelf for several years now after I came up against a problem with the valve / throttle assembly. I'm assuming if I made the throttle gate a two piece opening from both sides I could have the valve opening at approx BDC on the pipe and after the transfers close at lower off pipe running. To be fair I think Frits already suggested this. The other side (close side) gate will move with revs / throttle as it dose now with my 350 F9. The cylinder already is cast to accept in cylinder injectors. I guess I'm asking is this a fair assumption.

[Grumph]

Ok, It's me, go round in circles with projects::wacko:
On the weekend I did a trail ride, not unlike other weekends but this one was relatively open and fast. Most upset as I couldn't hold off the 450's. So it is time!
This 360 rotary valve twostroke engine has sat on the shelf for several years now after I came up against a problem with the valve / throttle assembly. I'm assuming if I made the throttle gate a two piece opening from both sides I could have the valve opening at approx BDC on the pipe and after the transfers close at lower off pipe running. To be fair I think Frits already suggested this. The other side (close side) gate will move with revs / throttle as it dose now with my 350 F9. The cylinder already is cast to accept in cylinder injectors. I guess I'm asking is this a fair assumption.

I'd always wondered about using a doubled rotary valve the two pieces of which could move relative to each other to vary timing - possibly using a centrifugal mechanism. Your idea (as i understand it) of moving the port opening in the outer cover is probably easier.
But how much difference does varying the valve timing actually make ?
I have also had it suggested to me that it's possible to use both a reed and a rotary valve on the same motor. Rotary timing optimum for peak HP - with the holes filled in by the reed valved "conventional" inlet...Two carbs so KISS goes out the window.
Yes, Husa I do know about the Kawasaki system - KIPS is it ? Additional small reed inlets off the disc cavity.

[husaberg]

I'd always wondered about using a doubled rotary valve the two pieces of which could move relative to each other to vary timing - possibly using a centrifugal mechanism. Your idea (as i understand it) of moving the port opening in the outer cover is probably easier.
But how much difference does varying the valve timing actually make ?
I have also had it suggested to me that it's possible to use both a reed and a rotary valve on the same motor. Rotary timing optimum for peak HP - with the holes filled in by the reed valved "conventional" inlet...Two carbs so KISS goes out the window.
Yes, Husa I do know about the Kawasaki system - KIPS is it ? Additional small reed inlets off the disc cavity.

Not what i was going to say,. lol:laugh:
but years ago i post a dyno graph that shows the effect of just retarding the disc timing itself its very telling. it appears to be a true something for nothing curve extender
Give me a bit of time to find it.
Note the duration of the disc opening in the graph is the same for both examples only the opening and closing timings are different.
328397

[F5 Dave]

Thanks Wob. Does raise the odd question more. . , just trying to formulate an intelligent one,. . .
So were gp teams honing barrels at the track back in the day, assuming they didn't have an endless supply of new barrels?
Are some plating finishes more tolerant?

[Flettner]

Grumph, the rotary valve timing makes a huge difference as I've found on my F9, but I'm only adjusting the shut side. Approx 55 degrees through to approx 78 degrees. I've always understood the open side did not matter so much but once again because i can I'd like to adjust the open as well. On a standard Kawasaki the valve opens after the transfers shut but with 'cut' valves I saw the port open before the transfers shut and I guess on the pipe that's a good thing but how much? I thought I read somewhere here that the transfer event was largely over by BDC , is that so? If so, on the pipe I might as well open the RV as soon as possible.

Real reason. I painted myself into a corner with the throttle gib not having enough room to be able to slide the whole way across the port so if I have another from the other side, mechanical problem solved.

I made a Kawasaki 100, (a 100 years ago) that had both RV and a reed valve in the back of the crank case. Two carbs, standard RV and carb with the reed being (RD250?) through a similar carb. Special throttle cable linkage so RV opened before the reed. Original cast iron cylinder was the blockage though, even being water cooled and ported, transfers were just not big enough, luckily I don't have to put up with that bullshit now.

[TZ350]

Grumph, the rotary valve timing makes a huge difference as I've found on my F9, but I'm only adjusting the shut side. On a standard Kawasaki the valve opens after the transfers shut but with 'cut' valves I saw the port open before the transfers shut and I guess on the pipe that's a good thing but how much? I thought I read somewhere here that the transfer event was largely over by BDC , is that so? If so, on the pipe I might as well open the RV as soon as possible.

From memory.

The most effective suction effect of the pipe needs to be centered around BDC. To get the widest power spread, before at lower rpm and swinging through BDC at max power to after BDC for over rev.

The rotary valve opening point needs to open later and later as the rpm increases so as to give the pipe time to suck up the higher crankcase pressure created at BDC instead of it escaping out the inlet tract.

As the rpm increases the inlet can be closed later and later to take advantage of the increasing energy in the ram effect of the inlet tract.

So if you have enough inlet open duration for the power you want then the hot ticket for greater power spread might be to swing both sides of the inlet timing in unison so the duration stays the same but the inlet opens and closes earlier at lower rpm and as the rpm increases the inlet opens and closes later and later. A true win win at both ends, opening and closing.

[katinas]

Do you have a video of it running? May we see it?

Hi,

I planned to make new header for pipe (shorter, straighter) before second tests , but Flettner forced me rolling the motorcycle on ice with slicks for videos tests ( cold winter -15C, so If I get sick, I hope Flettner will send me New Zealand honey ).
But failed to attach this video, file is to large, although I select very low resolution

[husaberg]

Hi,

I planned to make new header for pipe (shorter, straighter) before second tests , but Flettner forced me rolling the motorcycle on ice with slicks for videos tests ( cold winter -15C, so If I get sick, I hope Flettner will send me New Zealand honey ).
But failed to attach this video, file is to large, although I select very low resolution

Add to youtube or what ever your preference is then post in a link using the video option
Second row fifth from the right it the icon looks looks film roll.
I am picking you were trying to add it as an image or a file attachement, rather than a video.

[TZ350]

TZ your spaced crankcase obviously need some fettling. If you have spare junk cases you can cut big sections out to observe correct operation which is hard with cluster in just one side. The engagement on the broken gear would be the place to start but several others may need reshimming or maybe just observe if there is free float on shafts to start with.

328405

With Glen from Morgan Engineering's help I have followed up on F5 Daves suggestion to use a cutaway gearbox case to help in properly setting up a new gearbox for the Beast.

328404

Well it sure looks the business and should be very useful. The good thing is that I still have a usable set of engine cases as well. They might be useful for a CVT project.

------ :drinkup:

[Frits Overmars]

On a standard Kawasaki the valve opens after the transfers shut but with 'cut' valves I saw the port open before the transfers shut and I guess on the pipe that's a good thing but how much? I thought I read somewhere here that the transfer event was largely over by BDC , is that so? If so, on the pipe I might as well open the RV as soon as possible. At max.torque rpm the transfer event is not even on full song by BDC; the transfer flow is still accelerating.
About 20° after BDC the crankcase pressure has dropped to atmospheric level; then it is time to connect the case to the outside world.
If you open the inlet earlier, you will lose case pressure. If you open it later, the case pressure will drop more than it would need to, slowing down the transfer flow.

There is a reason that the disk opened later on many rotary road bikes: if you let the case pressure drop lower before opening the disk, there will be a stronger suction signal to the carburetter, making carb. setting more responsive. But hey, you've got EFI.

[katinas]

Add to youtube or what ever your preference is then post in a link using the video option
Second row fifth from the right it the icon looks looks film roll.
I am picking you were trying to add it as an image or a file attachement, rather than a video.

Thank you, youtube - Rygerised or https://youtu.be/OnLMiMiXoR8

This, pipe header on video, from Ns 400 3 cylinder, is too long and last time I rode ns 400 two years ago, max power around 10000 rpm. Carburetor and ignition not tested anywhere, so this video only to hear whether it works or not.
Before the test, I was thinking that the engine will fail after 10s, but not. So now, I want only ride and feel what it is (with proper header) , before engine fail.

[katinas]

Thank you, youtube - Rygerised or https://youtu.be/OnLMiMiXoR8

This, pipe header on video, from Ns 400 3 cylinder, is too long and last time I rode ns 400 two years ago, max power around 10000 rpm. Carburetor and ignition not tested anywhere, so this video only to hear whether it works or not.
Before the test, I was thinking that the engine will fail after 10s, but not. So now, I want only ride and feel what it is (with proper header) , before engine fail.

Sorry https://youtu.be/OnLMIMiXoR8

[katinas]

I think there should not be any windows in pistons at all, Peewee. I'd rather bring the inlet port down and shorten the piston. Apart from this, Husas Comet-link is worth reading.
Radiusing all sharp edges is good. Not only for stress concentration avoidance, but also because radiused edges won't scrape as much oil off the bore as sharp edges would.

Hi,

Two years ago tested various "holed" pistons on honda ns-250, and totally agree with Frits, do not make any holes on the pistons with cylinder type like in photo. Holes just not works. Pistons from left to right going better and better. But maybe cooling with holes better. The power maybe similar, but acceleration and controls without holes is best.

[jonny quest]

Katinas, nice vid. I was going to say earlier to you it was your imagination that engine sounded good and different.

It actually does sound very fast revving when it gets on the pipe!

[shnaggs]

@katinas Whoa that thing sounds very rev happy!

[tjbw]

Sorry https://youtu.be/OnLMIMiXoR8

Ryger should put that link on their website, so that potential customers can hear what a Ryger engine sounds like ;)

[peewee]

katinas how does the lower rod and crank bearings get lube if theres no hole under the 20mm plate? maybe im missing something

[Flettner]

yes thank you for your video katinas, now all we need is Trump to write an executive order to ban ice and snow so you can go out and ride it :lol:

Bottom end oiled by splash in it's own bath?

Re the RV gib on the 360, I'm going to have to have a gib on the open side anyway, perhaps I'll just dick with it's opening sequence on a dyno and see what it likes.

[wobbly]

If your engine works "better " with no piston holes, this is because your particular setup isnt making enough power to need the extra inlet flow.
Your engine has huge Boyesen ports, so probably doesnt need any extra intake flow area.
The other effect that will be coming into play is that removing the piston holes will be affecting the cavity resonance of the reed box, and this will be affecting
the reed resonance behavior.
If the engine "accelerates " better,then this is probably down to the reed resonance changing, and this then is also affecting the carb jetting as well.

In EngMod, the intake configuration page calculates the reed box volume, and this changes quite dramatically the petal lift behavior, as does adding or removing Boyesen ports
or piston holes.
I did years ago, dyno tests showing that an old RM125 made more power with no inlet holes at all ie it was piston ported with a reed as well ( it had a boost port that wouldnt work
with just the piston port setup ).
But that old engine made only something like 28 Hp.

As usual in a 2T just changing one thing, affects many others,and these can have far more influence on power than just the one change you made.
Has the piston on the right got big cutaways around the pin like the stock type - if not then this will also be affecting the port linking effects as well.

[wobbly]

I have not looked at the mass flow rates into an RV engine before,but here is the plot of inlet flow and transfer flow of the RSA at 12,000.
Out of interest the timing of the RV is 140 btdc and closing at 90 atdc, with the B port open at 114 btdc.
From the old work i did on the Rotax I know that going back to 135 opening makes little difference, going to 145 makes it impossible to jet.
Pulling back the closing to 85 would kill all the power past 12000,and going past 90 would kill all the mid power, with nothing gained in the overev.
So the closing is super sensitive, the opening not so.
Out of interest I looked at several very fast reed engines ( where inflow is totally dependent upon reed lift ) and the mass flow profiles are all but identical.

[Flettner]

I guess that's why my Kawasaki variable valve housing is so useful then, for the shut side. Wobbly, if you ignore carburetor tuneability, dose the slight more open time help with top end power. As I'm useing EFI I think I can fuel around that issue?

[katinas]

If your engine works "better " with no piston holes, this is because your particular setup isnt making enough power to need the extra inlet flow.
Your engine has huge Boyesen ports, so probably doesnt need any extra intake flow area.
The other effect that will be coming into play is that removing the piston holes will be affecting the cavity resonance of the reed box, and this will be affecting
the reed resonance behavior.
If the engine "accelerates " better,then this is probably down to the reed resonance changing, and this then is also affecting the carb jetting as well.

In EngMod, the intake configuration page calculates the reed box volume, and this changes quite dramatically the petal lift behavior, as does adding or removing Boyesen ports
or piston holes.
I did years ago, dyno tests showing that an old RM125 made more power with no inlet holes at all ie it was piston ported with a reed as well ( it had a boost port that wouldnt work
with just the piston port setup ).
But that old engine made only something like 28 Hp.

As usual in a 2T just changing one thing, affects many others,and these can have far more influence on power than just the one change you made.
Has the piston on the right got big cutaways around the pin like the stock type - if not then this will also be affecting the port linking effects as well.

Thank you, very interesting.

Two last pistons on the right without cutaways.

Yes, maybe this works only with Boyesen ports and without them would be different story. Two years ago, tested many things on Ns 250 ( compression, squash, pipe, reed, ignition, airbox, fuel, carburetor, ....... around 3000km). All tests were with "holed" piston and engine reactions, sometimes better sometimes not. But when I buy new pistons ( without holes ), simply was too lazy to do them again. Effect felt immediately, specific hole around 6700 rpm disappeared and gas felt very linear, but power remained the same. Maybe at lower revs when pipe not do so much, without holes in piston, flow through main transfers ports increase, and when piston is at BDC intake inertial flow impacted to piston and lift up to boos ports and to Boyesen ports. But its only considerations.

Photo I made in 2001 Brno GP Carlos Checa YZR 500 engine. Last, factory bike, two stroke 500 season. Piston and crankcase

[F5 Dave]

Wow, would you u look at that very detailed crank web covering.

[mr bucketracer]

Thank you, very interesting.

Two last pistons on the right without cutaways.

Yes, maybe this works only with Boyesen ports and without them would be different story. Two years ago, tested many things on Ns 250 ( compression, squash, pipe, reed, ignition, airbox, fuel, carburetor, ....... around 3000km). All tests were with "holed" piston and engine reactions, sometimes better sometimes not. But when I buy new pistons ( without holes ), simply was too lazy to do them again. Effect felt immediately, specific hole around 6700 rpm disappeared and gas felt very linear, but power remained the same. Maybe at lower revs when pipe not do so much, without holes in piston, flow through main transfers ports increase, and when piston is at BDC intake inertial flow impacted to piston and lift up to boos ports and to Boyesen ports. But its only considerations.

Photo I made in 2001 Brno GP Carlos Checa YZR 500 engine. Last, factory bike, two stroke 500 season. Piston and crankcasebuy the looks of that picture ,they new more about 2 strokes than anyone here , thanks for the picture

[katinas]

katinas how does the lower rod and crank bearings get lube if theres no hole under the 20mm plate? maybe im missing something

Hi,

Before assembly pour oil in crankcase ( in both working and free crank spaces ) . This engine is 2 cylinder, but only for tests made special 1 cylinder crank with long axis trough second cylinder crank space for ignition. So it is 3 main bearings and center bearing without seal. Working cylinder generate pressure and air with oil flowing through this center bearing to free space of 2 cylinder. But this is only for tests and of course for proper work need to do much like 4 stroke with small reed for depression with hoses for air and oil.

[katinas]

buy the looks of that picture ,they new more about 2 strokes than anyone here , thanks for the picture

when I'm getting ready to do the same with with Norick Abe engine, mechanic cover the engine with a shirt

So far, I feel very bad when I remember what happened to him, such a great guy

[mr bucketracer]

when I'm getting ready to do the same with with Norick Abe engine, mechanic cover the engine with a shirt

So far, I feel very bad when I remember what happened to him, such a great guyits a shock whats happen to alot of racers outside the sport )-:

[husaberg]

its a shock whats happen to alot of racers outside the sport )-:

Yip tragically Hailwood was just popping down the takeaways, to pick up fish and chips.
Juan Garriga, 90's GP 500 rider road bike crash.
Juan López Mella 90's GP 500 rider car crash
Ronnie Smith ex TT winner and PB tester scooter crash

[TZ350]

328422

F5 Dave is right, having a dummy cutaway case is great for checking the position of the gears. It looks like I need to move the selector drum 1.5mm left to the drive side to get the sliding gears in the right place.

[breezy]

Sorry https://youtu.be/OnLMIMiXoR8

nice work.... finally we hear the engine sound... :eek: would you say the rpm level gained is purely down to the lower piston friction ? and nothing to do with sealing the crankcase from the cylinder?

[wobbly]

So just to educate all the people in here that obviously know very little about a 2T - please do tell what is in that shot of the Yamaha V4 500
that wasn't common knowledge to every engineer in pit lane at the time,let alone 17 years later.

[philou]

Yamaha love case stuffing

[Grumph]

[QUOTE=TZ350;1131029490

F5 Dave is right, having a dummy cutaway case is great for checking the position of the gears. It looks like I need to move the selector drum 1.5mm left to the drive side to get the sliding gears in the right place.[/QUOTE]

Not uncommon. On the Aermacchis, I set up the endfloat on the selector drum first, then mock up the box, one shaft at a time. Peering at it through the cylinder hole - obviously without the crank in...
But they're Italian - and you expect to have to do that shit.

[jonny quest]

So just to educate all the people in here that obviously know very little about a 2T - please do tell what is in that shot of the Yamaha V4 500
that wasn't common knowledge to every engineer in pit lane at the time,let alone 17 years later.

The tubes feeding the front transfers from crankcase? Or were they directing a mixture to underside of piston?

[WilDun]

Yip tragically Hailwood was just popping down the takeaways, to pick up fish and chips.
Juan Garriga, 90's GP 500 rider road bike crash.
Juan López Mella 90's GP 500 rider car crash
Ronnie Smith ex TT winner and PB tester scooter crash

Ron Grant from America (formerly from Britain) who came over here often to race at Wanganui, drowned I believe while water skiing.

Geoff Perry from Auckland (son of famous Kiwi rider the late Len Perry) a very promising rider, died in a plane crash near Tahiti on his way to America to ride a 750 triple for Suzuki.

Brian Scobie - well known rider from Hamilton and his wife died in a car crash in America.

[wobbly]

Well we have found one person that knows less than Yamaha did back then.
They arent " tubes " they are the heads of Ti capscrews that run down into the case each side of the main bearing saddles.
A common idea used in many engines.

[jonny quest]

I was sooooo close! Lol

[Grumph]

Well we have found one person that knows less than Yamaha did back then.
They arent " tubes " they are the heads of Ti capscrews that run down into the case each side of the main bearing saddles.
A common idea used in many engines.

Not sure if yamaha did it in their 2T's first but they certainly use it in their 4T's - makes their inline fours harder to work on than they need be.

[husaberg]

Not sure if yamaha did it in their 2T's first but they certainly use it in their 4T's - makes their inline fours harder to work on than they need be.

Not sure what came first but the RD200/125 and earlier tiddler twins have the saddles.
They actually have the center lab seal arround the bearings as well.
Plus the upper part also forms the sides of the transfers.
328430328431328432328433

[TZ350]

Page 1660 ........

Ryger.....


https://www.google.be/url?sa=t&source=web&rct=j&url=https://researchbank.rmit.edu.au/eserv/rmit:161450/Jiang.pdf&ved=0ahUKEwjR1Of2ypDSAhVBsxQKHY0jAXgQFggaMAA&usg=AFQjCNF6u_x75BOckv5tiBjXhHajpVuNAA&sig2=SejXqSoVJoAk0M2iu5-Mdg


Race one Tepuke , Fatboy pulls the plug. https://youtu.be/NFRyZpzsyY8


race 2 , regans chain comes off but alex has the ride of his life and takes his first north island win. https://youtu.be/dBDWdq9k6Nc

Links to Katinas Ryger like engine build. You will have to follow the links back to see all of the the pictures.

This post of Katinas has some dimensional information.


Hi,When I started drawings (3 months ago) I begin to understand complexity that Ryger overcome (ex. assembling piston to conrod with that plate). Complete structure depends on how high can lift cylinder.

328449



Lots of detail on this post too.


Hi, Maybe, limited information about Harry Ryger engine, forced to act our brain more intensively, it is good in any case.

"Things that left unsaid" about "rygerised" Ns 250
1. Stroke is original 50.6 mm ( no room in 2 cylinder Ns 250 crankcase for 54.5 mm stroke, ...........


Hi, Started it yesterday and revs like like crazy chainsaw, I have never heard such a sound from this old engine.


Do you have a video of it running? May we see it?


Hi, I planned to make new header for pipe (shorter, straighter) before second tests , but Flettner forced me rolling the motorcycle on ice with slicks for videos tests ( cold winter -15C, so If I get sick, I hope Flettner will send me New Zealand honey ). But failed to attach this video, file is to large, although I select very low resolution


<iframe src="https://www.youtube.com/embed/OnLMIMiXoR8?ecver=2" width="640" height="360" frameborder="0" style="position:absolute;width:100%;height:100%;left:0" allowfullscreen=""></iframe>


Rygerised https://youtu.be/OnLMIMiXoR8

This, pipe header on video, from Ns 400 3 cylinder, is too long and last time I rode ns 400 two years ago, max power around 10000 rpm. Carburetor and ignition not tested anywhere, so this video only to hear whether it works or not.
Before the test, I was thinking that the engine will fail after 10s, but not. So now, I want only ride and feel what it is (with proper header) , before engine fail.


Ryger should put that link on their website, so that potential customers can hear what a Ryger engine sounds like ;)


katinas how does the lower rod and crank bearings get lube if theres no hole under the 20mm plate? maybe i'm missing something


Hi, Before assembly pour oil in crankcase ( in both working and free crank spaces ) . This engine is 2 cylinder, but only for tests made special 1 cylinder crank with long axis trough second cylinder crank space for ignition. So it is 3 main bearings and center bearing without seal. Working cylinder generate pressure and air with oil flowing through this center bearing to free space of 2 cylinder. But this is only for tests and of course for proper work need to do much like 4 stroke with small reed for depression with hoses for air and oil.



katinas,do you know what the engines bottom end comp ratio is?
Hi, Volume under the piston at TDC and palate, with reed block in place, around - 310 cc. Suction volume -71,6 cc., Volume under the piston at BDC and plate- 238.4cc Bottom compression around - 1.3 Crankcase not measured


I don't know if anyone follows the Macad Ryger FB page but this popped-up a few days ago:
328448

It's a 50cc engine with a Ryger spacer so I guess they've found a way to go even smaller. Of course, there's no info on it's construction but I see fins on the spacer for additional air cooling maybe? I had thought the Ryger was destined to be smoke and mirrors until seeing your work, katinas. Keep it up! :2thumbsup



Ryger Question:

The displacement in the chamber below the piston is roughly half the cylinder displacement - thus the pumped volume is about 70cc in a 125cc engine. So relying on pumping only at theoretical best we can only get a delivery ratio of 50% (Aprillia RSA125 ~ 140%) so where does the rest of the charge come from?

You would need some super pipe to create this sort of suction to make up the difference and that is just to match the RSA125, but the Ryger is supposed to be relatively insensitive to pipe design so not this?

The inertia of the gas flowing through the ports can help a small amount but nowhere near this difference.
So there is NO reason why it should give more than about 30HP I can think of.....

Frits has ridden a Ryger powered Go Kart and Katinas has made a great looking come working Ryger like engine, page 1662 has some discussion about Rygers claims for their engine. It will be great to hear Katinas impressions of his Ryger when he gets to ride it.


As Katinas wrote earlier, nor his engine, nor the Ryger has auxiliary exhaust ports because those would require a wider piston skirt, that would in turn hamper the flow into the transfers. Since I read it here, I can react without endangering my NDA (thank you Katinas). And what follows now, is purely my own guesswork since I never received any relevant information from Ryger.
From the Ryger homologation papers we can see that the exhaust timing is lower than the Aprilia RSA timing, so the Ryger's blowdown angle.area is tiny compared to the RSA's. And when taking the initially quoted maximum torque rpm of 17500 into account, the Ryger's blowdown time.area was almost non-existent. It nevertheless did not stop it from producing over 70 hp.

And before anybody says that they've never seen any proof of this amount of power in the form of a real dyno graph, let me say that neither have I, but I was lucky enough to get a seat-of-the-pants impression of the original Ryger prototype before problems with the production engines brought the operation to a halt, and my pants are not that easily fooled, having ridden motorcycles with several hundred hp.
By the way, what made me decide to step out of the project, was the lack of frankness. I would have loved to take part in the development of that engine, but it turned out that I was only recruited to generate publicity. I'm sure I could have prevented some of those technical problems if only there had been an exchange of thoughts, but all I ever got were promises. It's a pity....

OK, back to my theory. Seeing that the in-cylinder pressure of the RSA is about 12 bar at exhaust opening, and given that the Ryger is claimed to produce about 20 hp more than the RSA, and given that the Ryger's blowdown time.area is so much smaller, there must be a huge amount of spent gases that enter the Ryger's transfer ducts, raising the pressure in the sub-piston volume and the density of the mixture (well observed, Philou). The higher pressure may lead to a much faster transfer flow, with more mixture inertia. This inertia then ought to pull more fresh mixture through the reed inlet valve.
I only wonder how effective this inertia can function, as the Ryger's transfer ducts are very short and anything but flow-encouraging.


One thing about Ryger engine, which might have been expected, and it has proved after first static test, it is very low mechanical noise. Very lovely..........

That was also my second impression after the staggering acceleration: the beautiful sound. When you would expect a regular 125 cc engine to reach the end of its power band, the Ryger started to sing; that's the best I can describe it. This lovely sound, in combination with the large amount of hot exhaust gas that enters the transfer ducts and is subsequently recycled into the cylinder, made me think in the direction of Homogeneous Charge Compression Ignition with its very fast, short combustion phase; maybe ten times as fast as regular spark-ignited combustion. HCCI would also account for low fuel consumption, comparatively clean exhaust gases, and the need for only a small cooler, although I could not verify these claims.



Chairs, the latest ones i see are are digital now though, so they will have a curve i hope.
They are still a neat little set up, and cheap as chips.
328749328750
Price:$299.00 + $4.49 shipping
https://www.amazon.com/DIGITAL-IGNITION-CONVERSION-2009-2013-SXS12050039/dp/B00CFL5QLU

http://www.ktm-parts.com/mm5/graphics/00000001/SXS12050039.pdf

For an idea just how big they are for those unfamilar with the little KTM's
328751

[wobbly]

So - still waiting Mr Bucketracer ( wanker ) ( troll ) to tell us what Yamaha new ( knew ) that we ( the 2T dumbarses - who can spell ) still don't.

[41juergen]

Like the TZ engines have... :msn-wink:

328440

[katinas]

nice work.... finally we hear the engine sound... :eek: would you say the rpm level gained is purely down to the lower piston friction ? and nothing to do with sealing the crankcase from the cylinder?

Hi,

I know nothing about level, just chainsaw sound. Only testing on road will reveal the truth. Once, I asked my friend (biophysicist) how much idea proved in practice, his answer was about 15 per cent and at the end told that our brain is a rough tool.

Seal is at higher part of small cylinder, 4.5 mm lower than edge. Had to be 2 parts, Torlon® 4301 PAI (http://www.boedeker.com/torlon-4301.htm) and
grey PTFE, but should be an other solution. Still waiting Torlon so made one peace PTFE ( 37.8x42.6x2.4 mm). Its soft, so install it without cut, just like rubber O ring, torlon hard, to be cut. It is very critical part of Ryger conception, and I think that fuel always percolate into the crankcase oil (Bob van der Zijden, direct, high pressure EFI, maybe eliminate this to minimum ) . But for short racing time its good.
The more think about Ryger engine, the more it seems that reliability depends on "smaller" piston size. Jan note, somewhere in forum, "is very high load on very small surface" like always is accurate. Bigger "small" piston made engine more reliable ( from 41 mm and bigger, but that means bigger main piston, higher stroke ,higher engine capacity.)
With small "small" piston (from Ryger homologated drawings 36mm. 1 year old info. ) they needed very special aluminium coating, maybe nicasil not withstands load. So, maybe new Ryger engine had very special materials and tolerance like watch, and it requires a lot lot of time.

Found this, it is old but... http://www.ceramicindustry.com/articles/82778-a-new-coating-process-for-aluminum

[katinas]

Like the TZ engines have... :msn-wink:

328440

Hi

In 2001 the most surprised me, that pistons on factory 500 is without cut, maybe for better cooling from stream or something

[steamroller]

So - still waiting Mr Bucketracer ( wanker ) ( troll ) to tell us what Yamaha new ( knew ) that we ( the 2T dumbarses - who can spell ) still don't.

How is mr Charlotte top supper bike rider go on the 400 that you just built for him. Rsuults not great what is going on?

[katinas]

So - still waiting Mr Bucketracer ( wanker ) ( troll ) to tell us what Yamaha new ( knew ) that we ( the 2T dumbarses - who can spell ) still don't.

Hi

I am sorry that this picture spread anger, yes his post was offensive ( sometimes we made mistakes), but I just remember that photo, because of our discussion about holed pistons . I just wonder that factory piston on intake side are without cut.

Thanks for your very insight and interesting posts.

[mr bucketracer]

Hi

I am sorry that this picture spread anger, yes his post was offensive ( sometimes we made mistakes), but I just remember that photo, because of our discussion about holed pistons . I just wonder that factory piston on intake side are without cut.

Thanks for your very insight and interesting posts.I worded wrong .went to change but ya quoted to qick .was going to change to we all could learn something from this .hay they won world titles

[steamroller]

I worded wrong .went to change but ya quoted to qick .was going to change to we all could learn something from this .hay they won world titles

And still given away t shorts:shit:

[Carel H]

I see Yamaha stole my 1983 tilted split crankcase!

[katinas]

I worded wrong .went to change but ya quoted to qick .was going to change to we all could learn something from this .hay they won world titles

Hi
Do not worry, we are all sensitive people, photos just specialy for you, for free.

[katinas]

Maybe, the best "Ryger ready" cylinder for motorcycle on market, is from aprilia rs 125, but it is 54mm, so if bored to 58mm It would be easier made "small" piston 38 or 39mm.

But I do not know what is more suitable for Ryger engine: exhaust with satellites or without, because main piston sides lower edges performs timing function (maybe for Ryger it is new four timing along with intake, transfer and exhaust ) on transfer windows for filling. With ex. satellites piston ex. side skirt must be wider. and masked some parts of trans. windows when piston moving up. With one ex. window and narrower piston skirt, all transfers fully opened and is mo powerful suction. But maybe when engine is on pipe it is no mater, pipe made all suctions.

[Frits Overmars]

I am sorry that this picture spread angerDon't worry about it Katinas. That picture you posted was completely harmless and you are not responsible for other people's reactions.
I must add that both Jan and myself are fascinated by your posts. Keep up the good work!

[d2t]

Bigger "small" piston made engine more reliable ( from 41 mm and bigger, but that means bigger main piston, higher stroke ,higher engine capacity.)
With small "small" piston (from Ryger homologated drawings 36mm. 1 year old info. ) they needed very special aluminium coating, maybe nicasil not withstands load. So, maybe new Ryger engine had very special materials and tolerance like watch, and it requires a lot lot of time.
[/url]

I don't know if anyone follows the Macad Ryger FB page but this popped-up a few days ago:
328448

It's a 50cc engine with a Ryger spacer so I guess they've found a way to go even smaller. Of course, there's no info on it's construction but I see fins on the spacer for additional air cooling maybe?

I had thought the Ryger was destined to be smoke and mirrors until seeing your work, katinas. Keep it up! :2thumbsup

[TZ350]

I must add that both Jan and myself are fascinated by your posts. Keep up the good work!

Yes me too, for anyone else interested in the Ryger concept (I guess most of us are) there is a collection of links to Katanis "Ryger style engine" at the top of page 1660.

[katinas]

I don't know if anyone follows the Macad Ryger FB page but this popped-up a few days ago:
328448

It's a 50cc engine with a Ryger spacer so I guess they've found a way to go even smaller. Of course, there's no info on it's construction but I see fins on the spacer for additional air cooling maybe?

I had thought the Ryger was destined to be smoke and mirrors until seeing your work, katinas. Keep it up! :2thumbsup


Spacer is high and maybe more trust on small piston at TDC.

[shnaggs]

Hi,

I have no words, all in this photo is simply amazing. Its like late Christmas present. Thank you very much.
Spacer is high and maybe more trust on small piston at TDC.

I would think that a thicker spacer is really the best walk around to the force issue on the "small" piston, as you stated earlier katinas. Of coarse you are limited to the height of the head/cylinder. Looking at the new KTM125 sx at my shop, there seems to be quite a lot of space between the head and the frame. Would have to modify the head though to incorporate an angled spark plug. Maybe I could source a rs250 cylinder/head, if memory serves me correctly, the one cylinder head has a canted plug to make room for....something???

[wobbly]

Not the right place to air the laundry but here is the list of unnecessary bullshit that has ruined Dennis's debut with the new 400.

Brand new VeeForce reed fell to bits the first time it started,dumping a pile of shit thru the inlet ports - result,lump of chrome off the bore.
Brand new Nova close ratio gear set, jumps out of 3rd under power - yes its shimmed properly.
Brand new Hinson extra plate race clutch slips under power - yes its rated at 100 Hp.

All of this is completely my fault of course, as what the fuck do I know compared to the 500 guys in the Yamaha race dept.

[breezy]

Hi,

I know nothing about level, just chainsaw sound. Only testing on road will reveal the truth. Once, I asked my friend (biophysicist) how much idea proved in practice, his answer was about 15 per cent and at the end told that our brain is a rough tool.

Seal is at higher part of small cylinder, 4.5 mm lower than edge. Had to be 2 parts, Torlon® 4301 PAI (http://www.boedeker.com/torlon-4301.htm) and
grey PTFE, but should be an other solution. Still waiting Torlon so made one peace PTFE ( 37.8x42.6x2.4 mm). Its soft, so install it without cut, just like rubber O ring, torlon hard, to be cut. It is very critical part of Ryger conception, and I think that fuel always percolate into the crankcase oil (Bob van der Zijden, direct, high pressure EFI, maybe eliminate this to minimum ) . But for short racing time its good.
The more think about Ryger engine, the more it seems that reliability depends on "smaller" piston size. Jan note, somewhere in forum, "is very high load on very small surface" like always is accurate. Bigger "small" piston made engine more reliable ( from 41 mm and bigger, but that means bigger main piston, higher stroke ,higher engine capacity.)
With small "small" piston (from Ryger homologated drawings 36mm. 1 year old info. ) they needed very special aluminium coating, maybe nicasil not withstands load. So, maybe new Ryger engine had very special materials and tolerance like watch, and it requires a lot lot of time.

Found this, it is old but... http://www.ceramicindustry.com/articles/82778-a-new-coating-process-for-aluminum

katinas,do you know what the engines bottom end comp ratio is? now you have no crankcase to fill? any idea what your crankcase cc is?

[katinas]

Don't worry about it Katinas. That picture you posted was completely harmless and you are not responsible for other people's reactions.
I must add that both Jan and myself are fascinated by your posts. Keep up the good work!

Thank you very much for 2 stroke life support.

More photos from Brno GP 2001.

[peewee]

Yes me too, for anyone else interested in the Ryger concept (I guess most of us are) there is a collection of links to Katanis "Ryger like engine" at the top of page 1660.

i didnt follow the ryger story but i thought i remember something about sparkless combustion even though i believe there was a plug in the photo i seen. is this how you remember it?

[TZ350]

i didnt follow the ryger story but i thought i remember something about sparkless combustion even though i believe there was a plug in the photo i seen. is this how you remember it?

I think the Ryger is normal spark ignition, sparkless combustion was something else. Flettner made an engine along those lines to test the idea behind the sparkless combustion HCCI homogeneous charge compression ignition idea.

As I understand it. HCCI requires a well timed sudden increase in compression to start the homogeneous charge burning at all points in the combustion chamber. Flettner got his concept engine to run.

And the Ryger concept improves the delivery ratio, particularly at high rpm. Whereas the conventional two stroke has the pipe vigorously sucking the fresh charge into the cylinder at the same time as the crankcase gently squeezes fresh air/fuel charge into the transfer ducts the Ryger improves the transfer ratio by vigorously expelling the complete contents from the space under the piston into the cylinder. With the added benefits of the lower end lubrication being sealed off from the air/fuel transfer combustion process just like a four stroke does. I think a Ryger with direct injection could be a very clean 2T machine.

Anyway that is how I roughly understand it. There will be people with a better understanding than me and I would love to hear more about it from them.

[Grumph]

Not the right place to air the laundry but here is the list of unnecessary bullshit that has ruined Dennis's debut with the new 400.

Brand new VeeForce reed fell to bits the first time it started,dumping a pile of shit thru the inlet ports - result,lump of chrome off the bore.
Brand new Nova close ratio gear set, jumps out of 3rd under power - yes its shimmed properly.
Brand new Hinson extra plate race clutch slips under power - yes its rated at 100 Hp.

All of this is completely my fault of course, as what the fuck do I know compared to the 500 guys in the Yamaha race dept.

Were you happy with the pistons in the end ?

[wobbly]

The same 66mm Wossners have now done over 500 race Km in the TZ400 reving to 12,000 all day.
They started at 0.06 and are now 0.08, see no reason to take them out yet.
So pistons are fine,though I did drill a couple of holes in the skirts each side of the Ex port as the Aux port bridges in the new engine were getting shiny before
the rest of the bore.

[katinas]

katinas,do you know what the engines bottom end comp ratio is? now you have no crankcase to fill? any idea what your crankcase cc is?

Hi,

Volume under the piston at TDC and palate, with reed block in place, around - 310 cc.

Suction volume -71,6 cc.,

Volume under the piston at BDC and plate- 238.4cc

Bottom compression around - 1.3

Crankcase not measure

[oldjohnno]

... Whereas the conventional two stroke has the pipe vigorously sucking the fresh charge into the cylinder at the same time as the crankcase gently squeezes fresh air/fuel charge into the transfer ducts the Ryger improves the transfer ratio by vigorously expelling the complete contents from the space under the piston into the cylinder...

Has anyone done the sums on the pumping losses incurred between TDC and transfer opening as the fresh charge is compressed below the piston? I imagine that it could be significant, especially with the high CRs possible with a Ryger-style isolated crankcase. And none of that energy is recouped - the air is just squished up and then released, just like a Jake brake. I'd have thought that getting the pipe to provide as much of the pressure gradient across the ports as is possible would allow lower primary CRs to be used along with lower pumping losses?

[breezy]

Hi,

Volume under the piston at TDC and palate, with reed block in place, around - 310 cc.

Suction volume -71,6 cc.,

Volume under the piston at BDC and plate- 238.4cc

Bottom compression around - 1.3

Crankcase not measure

ok.. thanks for that info.. i thought you would be able to give me that information because i can see you have gone into this engine set up in a good technical way...lets hope for good weather for you to test under load... thanks:sherlock:

[wobbly]

A 125 cylinder with 310cc of " case " volume at tdc would have a primary com of 310/310-125 = 1.67.
That ratio would indicate huge pumping losses.
But the engine with 310 at tdc and 238 at BDC is only 1.3 - perfectly normal for a race 125.
So what am I missing in the Ryger " concept " of using big primary com to force transfer the charge into the cylinder, instead of an efficient pipe
pulling it thru around BDC.

[TZ350]

So what am I missing in the Ryger " concept " of using big primary com to force transfer the charge into the cylinder, instead of an efficient pipe pulling it thru around BDC.

The max possible pressure differential across the port that can be created by a pipe alone is 1 bar, and pipe plus primary com of 1.3 would be 1 * 1.3 = 1.3bar max differential across the port.

The Ryger using big primary com ratios could easily have a much bigger differential across the port than that. The Ryger also utilises a pipe, maybe more for improving trapping efficiency than transfer ratio.

But there must be more to it than that to justify the big Ryger hp claims...... :scratch:

[husaberg]

A 125 cylinder with 310cc of " case " volume at tdc would have a primary com of 310/310-125 = 1.67.
That ratio would indicate huge pumping losses.
But the engine with 310 at tdc and 238 at BDC is only 1.3 - perfectly normal for a race 125.
So what am I missing in the Ryger " concept " of using big primary com to force transfer the charge into the cylinder, instead of an efficient pipe
pulling it thru around BDC.

I think it comes down to the higher speed at which the smaller "crankcase" volume attains its peak efficiency.
With the conventional style engines reducing the primary comp to anywhere near the same level had required the crankcase airflow and transfer flow to become so hugely stifled it became irrelevant, I believe it was because it created huge boundary friction in the areas around the crank wheels. plus other flow airflow restrictions.Thus I muse separating the crankcase might be the difference.
Also it would seem the ryger benefits from modern transfer control and durations. As devloped over the last 40 years.


There is an engine speed at which maximum air delivery to the cylinder occurs, and that this engine speed is inversely proportional to crankcase volume, but that the maximum value changes only slightly with changes in crankcase volume. To put it another way, the crankcase-pump's volumetric efficiency is nearly constant, but the engine speed at which it attains maximum efficiency rises as crankcase clearance volume is reduced. pumping losses (horsepower absorbed in doing this work) rise as to the third power of compression ratio. Researcher Fujio Nagao, of Kyoto University

or it might just be overhyped horse poo.

[breezy]

A 125 cylinder with 310cc of " case " volume at tdc would have a primary com of 310/310-125 = 1.67.
That ratio would indicate huge pumping losses.
But the engine with 310 at tdc and 238 at BDC is only 1.3 - perfectly normal for a race 125.
So what am I missing in the Ryger " concept " of using big primary com to force transfer the charge into the cylinder, instead of an efficient pipe
pulling it thru around BDC.

are you able to factor in a cooler intake charge and reduced crankcase turbulance, as the fuel air is no longer being churned around and heated up prior to entering the transfer ports. if the high primary comp forces a fast movement of charge into the cylinder, wouldnt that pressure drop cause the reeds to open allowing a secondary wave of intake flow?:sherlock: like a pumping action.

[Grumph]

are you able to factor in a cooler intake charge and reduced crankcase turbulance, as the fuel air is no longer being churned around and heated up prior to entering the transfer ports. if the high primary comp forces a fast movement of charge into the cylinder, wouldnt that pressure drop cause the reeds to open allowing a secondary wave of intake flow?:sherlock: like a pumping action.

How much masking effect does the dirty great post down the center have ?
Still got to get the mixture in and distribute it to the transfers....

[peewee]

are you able to factor in a cooler intake charge and reduced crankcase turbulance, as the fuel air is no longer being churned around and heated up prior to entering the transfer ports. if the high primary comp forces a fast movement of charge into the cylinder, wouldnt that pressure drop cause the reeds to open allowing a secondary wave of intake flow?:sherlock: like a pumping action.

couple questions from a dummy trying to figure it out. true it wouldn't be churned up but wouldn't it be compressed more, between the piston and plate ? this would add heat also, in the same way high comp ratios in the cylinder , between piston and head , or am I thinking wrong ? how much combustion heat would travel into the big plate ? and if the primary ratio is through the roof , 1.67 or what ever, wouldn't that meen a much lower average pressure delivered to the cylinder ?

[Vannik]

Ryger Question:

The displacement in the chamber below the piston is roughly half the cylinder displacement - thus the pumped volume is about 70cc in a 125cc engine. So relying on pumping only at theoretical best we can only get a delivery ratio of 50% (Aprillia RSA125 ~ 140%) so where does the rest of the charge come from?

You would need some super pipe to create this sort of suction to make up the difference and that is just to match the RSA125, but the Ryger is supposed to be relatively insensitive to pipe design so not this?

The inertia of the gas flowing through the ports can help a small amount but nowhere near this difference.

[husaberg]

Ryger Question:

The displacement in the chamber below the piston is roughly half the cylinder displacement - thus the pumped volume is about 70cc in a 125cc engine. So relying on pumping only at theoretical best we can only get a delivery ratio of 50% (Aprillia RSA125 ~ 140%) so where does the rest of the charge come from?

You would need some super pipe to create this sort of suction to make up the difference and that is just to match the RSA125, but the Ryger is supposed to be relatively insensitive to pipe design so not this?

The inertia of the gas flowing through the ports can help a small amount but nowhere near this difference.

My initial guess is directly through the very short piston skirt on the inlet, ie it does not shut until well after the transfers opens.
but i have never tried to map it out, but i am picking you may have though:innocent:

[Flettner]

Ryger Question:

The displacement in the chamber below the piston is roughly half the cylinder displacement - thus the pumped volume is about 70cc in a 125cc engine. So relying on pumping only at theoretical best we can only get a delivery ratio of 50% (Aprillia RSA125 ~ 140%) so where does the rest of the charge come from?

You would need some super pipe to create this sort of suction to make up the difference and that is just to match the RSA125, but the Ryger is supposed to be relatively insensitive to pipe design so not this?

The inertia of the gas flowing through the ports can help a small amount but nowhere near this difference.

Fairy dust.

[jamathi]

Ryger Question:

The displacement in the chamber below the piston is roughly half the cylinder displacement - thus the pumped volume is about 70cc in a 125cc engine. So relying on pumping only at theoretical best we can only get a delivery ratio of 50% (Aprillia RSA125 ~ 140%) so where does the rest of the charge come from?

You would need some super pipe to create this sort of suction to make up the difference and that is just to match the RSA125, but the Ryger is supposed to be relatively insensitive to pipe design so not this?

The inertia of the gas flowing through the ports can help a small amount but nowhere near this difference.

So there is NO reason why it should give more than about 30HP I can think of.....
It MIGHT be overhyped horse poo....

[Vannik]

So there is NO reason why it should give more than about 30HP I can think of.....

I updated my software to simulate stepped pistons, both ways, the traditional bigger bottom step and the Ryger smaller step, and I have tried many ways without ever exceeding 30hp on the Ryger. Maybe I am missing something....

[katinas]

ok.. thanks for that info.. i thought you would be able to give me that information because i can see you have gone into this engine set up in a good technical way...lets hope for good weather for you to test under load... thanks:sherlock:

now, I think its not weather, just time needed to assemble the bike....

Jack Findlay n1 in photo

[TZ350]

Maybe I am missing something....

Maybe we all are, or Maybe not.

I am looking forward to hearing Katinas impressions when he gets to ride his bike.

[cotswold]

Farmer Ken had his new engine on track today, a few nice home made goodies in this baby, NSR250 pot on TF bottom end, stroked crank, power valve, quick shifter, it's fully loaded

Getting a bit pissed off with my correct way up photo's getting rotated by this forum

[mr bucketracer]

Farmer Ken had his new engine on track today, a few nice home made goodies in this baby, NSR250 pot on TF bottom end, stroked crank, power valve, quick shifter, it's fully loaded

Getting a bit pissed off with my correct way up photo's getting rotated by this forumthanks for the pictures , was told when driving home he had made this engine up , was guted i had not seen it .

[cotswold]

thanks for the pictures , was told when driving home he had made this engine up , was guted i had not seen it .

I mentioned to Reagan that his green meany may be a weapon water cooled and stroked to 110cc

[TZ350]

328502

Great to see the first race ready 110cc H2O special out on the track, big up's to FarmerKen ..... :2thumbsup

[TZ350]

I mentioned to Reagan that his green meany may be a weapon water cooled and stroked to 110cc

Maybe 110's are the future for F4 2T Buckets.

The important parts are from bikes that were commonly sold in NZ, and gets away from the questionable and rather grey practice (in Bucket terms) of buying special after market cylinders from Europe in an attempt to make a competitive 2T engine.

Like the rules, I think Buckets should be all about making best use of original non competition motorcycle engine parts not clever use of a credit card.

[jamathi]

I updated my software to simulate stepped pistons, both ways, the traditional bigger bottom step and the Ryger smaller step, and I have tried many ways without ever exceeding 30hp on the Ryger. Maybe I am missing something....

Maybe at Ryger they have the same problem......
They can test for free at many dyno's in the Netherlands.
But they never do.....

[philou]

The compressed gases are more density than the suction gases.

Occupancy rate would be better

The volume of the "crankcase"may not be sufficient to supply the cylinder

Ryger works like the engines of the 1970s

[katinas]

Not serious, lightly, just imagining: what it would be if no working volume under piston at all ( like Ryger main and "small" pistons would be same size), just intake (with or without reed) directly connected to transfers and exhaust. All work left to pipe. Start is impossible, but if engine is 2 cylinder, and one would normally operating, then head pipes of both cylinders connect together ( at right angles ) and then to one pipe (or two). Maybe suction waves start fill that cylinder and ........ But maybe I write nonsense.

Interesting, what influence on Ryger performance made squash between piston and small cylinder upper surface. On intake side, I left the piston skirt , because want, that last stream from squash directed to main transfers, not to reed block. Because want to make plate thin as possible, small cylinder upper surfaces hiding in piston at BDC ( 2 mm. if measure from lower edge of piston side skirt, but side gap is 1.5 mm. (piston inside dia. at top 52mm. small cylinder outside dia 49mm.) ) But on original Ryger engine ( from homologation ) small cylinder not hiding , so its ok.
Maybe, it is possible to explode the piston at BDC if gap between small cylinder outside wall and piston skirt is too small and hide too deep.

[katinas]

The compressed gases are more density than the suction gases.

Occupancy rate would be better

The volume of the "crankcase"may not be sufficient to supply the cylinder

Ryger works like the engines of the 1970s

Hi,

One thing about Ryger engine, which might have been expected, and it has proved after first static test, it is very low mechanical noise.

Very lovely, but maybe until..........

[Frits Overmars]

Ryger Question: The displacement in the chamber below the piston is roughly half the cylinder displacement - thus the pumped volume is about 70cc in a 125cc engine. So relying on pumping only at theoretical best we can only get a delivery ratio of 50% (Aprillia RSA125 ~ 140%) so where does the rest of the charge come from?
You would need some super pipe to create this sort of suction to make up the difference and that is just to match the RSA125, but the Ryger is supposed to be relatively insensitive to pipe design so not this? The inertia of the gas flowing through the ports can help a small amount but nowhere near this difference.

I updated my software to simulate stepped pistons, both ways, the traditional bigger bottom step and the Ryger smaller step, and I have tried many ways without ever exceeding 30hp on the Ryger. Maybe I am missing something....As Katinas wrote earlier, nor his engine, nor the Ryger has auxiliary exhaust ports because those would require a wider piston skirt, that would in turn hamper the flow into the transfers. Since I read it here, I can react without endangering my NDA (thank you Katinas). And what follows now, is purely my own guesswork since I never received any relevant information from Ryger.
From the Ryger homologation papers we can see that the exhaust timing is lower than the Aprilia RSA timing, so the Ryger's blowdown angle.area is tiny compared to the RSA's. And when taking the initially quoted maximum torque rpm of 17500 into account, the Ryger's blowdown time.area was almost non-existent. It nevertheless did not stop it from producing over 70 hp.
And before anybody says that they've never seen any proof of this amount of power in the form of a real dyno graph, let me say that neither have I, but I was lucky enough to get a seat-of-the-pants impression of the original Ryger prototype before problems with the production engines brought the operation to a halt, and my pants are not that easily fooled, having ridden motorcycles with several hundred hp.
By the way, what made me decide to step out of the project, was the lack of frankness. I would have loved to take part in the development of that engine, but it turned out that I was only recruited to generate publicity. I'm sure I could have prevented some of those technical problems if only there had been an exchange of thoughts, but all I ever got were promises. It's a pity....

OK, back to my theory. Seeing that the in-cylinder pressure of the RSA is about 12 bar at exhaust opening, and given that the Ryger is claimed to produce about 20 hp more than the RSA, and given that the Ryger's blowdown time.area is so much smaller, there must be a huge amount of spent gases that enter the Ryger's transfer ducts, raising the pressure in the sub-piston volume and the density of the mixture (well observed, Philou). The higher pressure may lead to a much faster transfer flow, with more mixture inertia. This inertia then ought to pull more fresh mixture through the reed inlet valve.
I only wonder how effective this inertia can function, as the Ryger's transfer ducts are very short and anything but flow-encouraging.


One thing about Ryger engine is very low mechanical noise. Very lovely....That was also my second impression after the staggering acceleration: the beautiful sound. When you would expect a regular 125 cc engine to reach the end of its power band, the Ryger started to sing; that's the best I can describe it. This lovely sound, in combination with the large amount of hot exhaust gas that enters the transfer ducts and is subsequently recycled into the cylinder, made me think in the direction of Homogeneous Charge Compression Ignition with its very fast, short combustion phase; maybe ten times as fast as regular spark-ignited combustion. HCCI would also account for low fuel consumption, comparatively clean exhaust gases, and the need for only a small cooler, although I could not verify these claims.

Could you persuade your software to take a look at these thoughts, Neels?

[peewee]

frits your theory is interesting. in a normal 2t we don't want any exh pushing back into the transfers. but in katanis/ryger style engine you think plenty of exh is pushing back through the transfers and pressuring the 'crankcase' and perhaps this is how such a small pump volume is able to work ?

[Haufen]

I updated my software to simulate stepped pistons, both ways, the traditional bigger bottom step and the Ryger smaller step, and I have tried many ways without ever exceeding 30hp on the Ryger. Maybe I am missing something....

I can confirm your results. Even when going beyond what would normally be realistic figures in primary compression ratio, burn duration etc., all I got was a very peaky 37ish hp in the end. More or less what I would expect a 125cc engine with reduced breathing capacity to be able to achieve.



That was also my second impression after the staggering acceleration: the beautiful sound. When you would expect a regular 125 cc engine to reach the end of its power band, the Ryger started to sing; that's the best I can describe it. This lovely sound, in combination with the large amount of hot exhaust gas that enters the transfer ducts and is subsequently recycled into the cylinder, made me think in the direction of Homogeneous Charge Compression Ignition with its very fast, short combustion phase; maybe ten times as fast as regular spark-ignited combustion. HCCI would also account for low fuel consumption, comparatively clean exhaust gases, and the need for only a small cooler, although I could not verify these claims.

Did you see the rpm on a rev counter, Frits? Or could it have been short gearing, that a narrow road and a shot of nitrous oxide? Did you have a second kart with a standard engine to switch to for comparison?

HCCI is very dificult to control, there is no way this can be achieved with a 30mm carb, and it is typically uses for lower load applications. What happened when you closed the throttle after a full load run? Was the engine responding with a delay? HCCI normally works with excess air, so even if you'd manage to get the required amount of air in, you'd still be better off, hp-wise, running on the rich side, e.g. AFR 12.

[Frits Overmars]

Did you see the rpm on a rev counter, Frits? Or could it have been short gearing, that a narrow road and a shot of nitrous oxide?
Did you have a second kart with a standard engine to switch to for comparison?Asked and answered ages ago Haufen. I watched the revcounter until the power rush set in. Then I had to concentrate on staying alive. We were not on a race track, just on a stretch of quite narrow road with protruding manhole covers in the center.
There definitely was no on-board provision for nitrous oxide. And before you ask: I would recognize the smell of nitromethane miles away, and there wasn't any.
There was no standard kart present, but I know how a regular 125 cc kart behaves and I've got the lap times to prove it. Like I said, I'm not that easily fooled.


HCCI is very dificult to control, there is no way this can be achieved with a 30mm carb, and it is typically uses for lower load applications. What happened when you closed the throttle after a full load run? Was the engine responding with a delay? HCCI normally works with excess air, so even if you'd manage to get the required amount of air in, you'd still be better off, hp-wise, running on the rich side, e.g. AFR 12.You might want to read what Flettner wrote about it.

[breezy]

Might be worth a go at sealing off the crankcase with a rubber boot, reducing the under piston area and see what you got, still running on premix.....:sherlock:

[jasonu]

Farmer Ken had his new engine on track today, a few nice home made goodies in this baby, NSR250 pot on TF bottom end, stroked crank, power valve, quick shifter, it's fully loaded

Getting a bit pissed off with my correct way up photo's getting rotated by this forum

Are there any carb size restrictions for 110cc watercooled buckets?

[FastFred]

Are there any carb size restrictions for 110cc watercooled buckets?

Yes, any 2T over 104cc is restricted to a 24mm carb.

[Flettner]

Yes, the fun we had:laugh: with the Ryger guessing game, here we go again. It certainly has 'sparked' up this thread again.
Smallish exhaust port hole, large nozzleing effect, The whole system is running at a higher pressure including the exhaust. Pulsing and ramming effect must have more energy over a standard system. Just like a water ram running a very high head of pressure (high pumping pressure), when the reverse wave happens there is still a negative pressure applied to the ram valve as to let it drop into the water flow (or lack of it at that point) to start the process all over again. Even on the highest pressure Ram Pumps.
In the Ryger I imagine no matter how high the internal 'pulse' pressure is, there will always come a time when there is a negative pressure at the transfers somewhere throughout its open cycle, to draw in more charge, past the crank case.
As the pressure in the exhaust increases, does the wave run faster? It certainly will have more energy, both positive and negative.

[ken seeber]

This Ryger discussion is interesting, if nothing else to get the brains working in trying to understand the design subtleties that might give it its claimed advantages.

For many, many years I have been interested in a direct air inlet system, totally by passing the crankcase, ie a “wet sump” bottom end. Essentially it could mean 5 passages drawing from atmosphere and entering the cylinder in the current “conventional” positions. This would mean 5 passages, 2 entering the cylinder in the A positions, 2 into the B positions and another into the C position. Something like what it shown in the pic, this being in the B position.

The whole thing is dependent on the exhaust system having the ability to draw sufficient air into the cylinder. This would obviously mean both the delivery ratio & trapping efficiency be maintained at a high level. I figure if the 24/7 concept works, this must work bypassing the many aero losses in passing through the crankcase.

I do recognise that the power band of the engine would be limited, as it doesn’t get any benefit from crankcase pumping, particularly at the lower speeds. Obviously starting would be something to be addressed, but there might be answers there. How it is fuelled is another matter as well, but in its simplest form, it could have a carburettor attached to each passage (= 5 carbs).

Obviously, I must answer the question of “why bother?” Although I’d be keen on seeing the 70hp from a 125 cc cylinder for the world of Wobblys, I am more interested in a lower cost & cleaner 2 stroke concept.

328503

[jonny quest]

The pumping loss would be minimal on a Ryger. The full are of piston on bottom is not used for Primary Compression

[ken seeber]

Hi,

One thing about Ryger engine, which might have been expected, and it has proved after first static test, it is very low mechanical noise.



In terms of low mechanical noise, this is pretty subjective in that it also depends when this observation is made. For example, a typical KZ piston might have a “drop” over its length (difference between the max dia at skirt to the top land) of 0.3. Add to that a typical cold fit clearance of 0.07. So, 0.07 at the base of the skirt and 0.37 at the top. Pretty sloppy in anyone’s language. And nothing really to stop the piston rocking from side to side, almost rolling about the skirt. It’s gotta be noisy and they are.
However in the Ryger situation, we have the main piston connected rigidly to the smaller/guiding piston. Apart from what I would expect a small clearance for the smaller piston, the main piston is fundamentally prevented from rocking. Perhaps taking up the cold clearance at most.
When an engine is at power operating temp, the ideal situation probably is that the bore is round and straight and the piston has expanded much more at the crown and is almost cylindrical, ie a constant clearance at all positions. Whether the engine is as mechanically noisy under these conditions is unknown to me as there are many other noise sources that would dominate, ie exh and inlet.
End of the bullshit, however I can’t help but agree that the Ryger might rattle less when cold, at least and that can only be a good thing.

[SwePatrick]

Without any proof or other evidence of that Ryger engine actually working as stated i get the feeling it´s only smoke and screens to get new investers spend money, to secure some guys income without actual work.
Very common actually, getting investors to spend money on highrisc projects.
Often, very often this is conned by old guys figured out how to rip money off those rich people.

And it stinks Gizmondo....(google: https://www.google.se/webhp?sourceid=chrome-instant&rlz=1C1RUCY_svSE723SE723&ion=1&espv=2&ie=UTF-8#q=gizmondo+stefan+eriksson)

[SwePatrick]

328522

A little trip back in time regarding using concrete constructing dynorollers.
DO not!!!!!!!!! use concrete on the outside of the steeldrum :brick::eek5::Oops::wacko:
A friend of mine bought this little dyno, i warned him.
He spun the rollers almost 2000rpm,, BLAM!!! :eek5::eek5:

Fortunatly no one got hurt.
And the 'megafortunatly' was that a guy stood directly behind the rollers when it went off.

Rgds
Patrick

[philou]

Dyno it is a product sold commercially as dyno ?

[katinas]

As Katinas wrote earlier, nor his engine, nor the Ryger has auxiliary exhaust ports because those would require a wider piston skirt, that would in turn hamper the flow into the transfers. Since I read it here, I can react without endangering my NDA (thank you Katinas). And what follows now, is purely my own guesswork since I never received any relevant information from Ryger.
From the Ryger homologation papers we can see that the exhaust timing is lower than the Aprilia RSA timing, so the Ryger's blowdown angle.area is tiny compared to the RSA's. And when taking the initially quoted maximum torque rpm of 17500 into account, the Ryger's blowdown time.area was almost non-existent. It nevertheless did not stop it from producing over 70 hp.
And before anybody says that they've never seen any proof of this amount of power in the form of a real dyno graph, let me say that neither have I, but I was lucky enough to get a seat-of-the-pants impression of the original Ryger prototype before problems with the production engines brought the operation to a halt, and my pants are not that easily fooled, having ridden motorcycles with several hundred hp.
By the way, what made me decide to step out of the project, was the lack of frankness. I would have loved to take part in the development of that engine, but it turned out that I was only recruited to generate publicity. I'm sure I could have prevented some of those technical problems if only there had been an exchange of thoughts, but all I ever got were promises. It's a pity....

OK, back to my theory. Seeing that the in-cylinder pressure of the RSA is about 12 bar at exhaust opening, and given that the Ryger is claimed to produce about 20 hp more than the RSA, and given that the Ryger's blowdown time.area is so much smaller, there must be a huge amount of spent gases that enter the Ryger's transfer ducts, raising the pressure in the sub-piston volume and the density of the mixture (well observed, Philou). The higher pressure may lead to a much faster transfer flow, with more mixture inertia. This inertia then ought to pull more fresh mixture through the reed inlet valve.
I only wonder how effective this inertia can function, as the Ryger's transfer ducts are very short and anything but flow-encouraging.

That was also my second impression after the staggering acceleration: the beautiful sound. When you would expect a regular 125 cc engine to reach the end of its power band, the Ryger started to sing; that's the best I can describe it. This lovely sound, in combination with the large amount of hot exhaust gas that enters the transfer ducts and is subsequently recycled into the cylinder, made me think in the direction of Homogeneous Charge Compression Ignition with its very fast, short combustion phase; maybe ten times as fast as regular spark-ignited combustion. HCCI would also account for low fuel consumption, comparatively clean exhaust gases, and the need for only a small cooler, although I could not verify these claims.

Could you persuade your software to take a look at these thoughts, Neels?

Thank you very much for this post. Now, I understand more clearly this "ryger story", and if I read some old posts again, I get the full completely different picture. I can't imagine that conspiracy is possible in such small team working together on so interesting project . Jan and you, four years ago began to reveal so much interesting information about RSA/RSW, that I think this is not just new information about 2 stroke, its new communication level.

Thank you for sharing your excellent knowledge.

[mr bucketracer]

Dyno it is a product sold commercially as dyno ?looks like a break testing device for very slow rpm

[Haufen]

Like I said, I'm not that easily fooled.



HCCI is very dificult to control, there is no way this can be achieved with a 30mm carb, and it is typically used for lower load applications. What happened when you closed the throttle after a full load run? Was the engine responding with a delay? HCCI normally works with excess air, so even if you'd manage to get the required amount of air in, you'd still be better off, hp-wise, running on the rich side, e.g. AFR 12.

You might want to read what Flettner wrote about it.

Can you provide us with other information - besides your seat of the pants dyno - which would lead to the conclusion that there is actually something more inside this whole ryger story besides a lot of hot air and fairy tales?

And could you provide a link to what Flettner wrote? I don't think I have read what you are referring to. I have read what european and asian oem and some universities have published about the subject of HCCI though. And this is what led to my sentence in the quote above.

HCCI on Wikipedia is a quicker read and not so bad either (https://en.wikipedia.org/wiki/Homogeneous_charge_compression_ignition).

in 2013 for example, a study found that:

5. Conclusion
CAI/HCCI engines still have not met the level of development and cost that would make a market introduction possible at the moment. The technical challenges facing both gasoline
and diesel HCCI combustion are their limited operational range and less optimized combustion phasing, owing to the lack of direct control over the start of ignition and the rate
of heat release. ... source (https://www.hindawi.com/journals/jc/2013/783789/)

And last but not least, F1 would not be running prechamber ignition if they had yet found a way to use full load HCCI.

[marsheng]

Hi Frits

We are modifying a 1970 Kawasaki disk valve 350 twin. I wanted to know if your generic 2s exhaust design is a good starting point or is it for more modern bike?

Alternatively is there a better starting point for a design ?

Thanks Wallace

[Frits Overmars]

Can you provide us with other information - besides your seat of the pants dyno - which would lead to the conclusion that there is actually something more inside this whole ryger story besides a lot of hot air and fairy tales?No. Like I wrote, the lack of communication was the main reason that I quit the project. And I do not feel any obligation to defend Ryger's claims.


And could you provide a link to what Flettner wrote?About here: https://www.kiwibiker.co.nz/forums/showthread.php/162399-The-Bucket-Foundry?p=1130931750#post1130931750


F1 would not be running prechamber ignition if they had yet found a way to use full load HCCI.I'd love to hear your explanation why Flettner's engine is running full-throttle without a spark and revving like mad.



We are modifying a 1970 Kawasaki disk valve 350 twin. I wanted to know if your generic 2s exhaust design is a good starting point or is it for more modern bike? Alternatively is there a better starting point for a design ?There are better ways Wallace, EngMod2T for example, but it would require about 50 times as much input values as the simple FOS concept that I wrote to help aspirant-twostroke tuners on their way.
My concept will provide a good starting point, provided that you enter a realistic max.power rpm-value, based on the small angle.areas of that 1970 Kawa.

[marsheng]

I'd love to hear your explanation why Flettner's engine is running full-throttle without a spark and revving like mad.


I had that on my Maico. Throttle closed, ignition off and it sat at around 5-6K. The plug was red hot. Only way to stop the motor was stall it with the clutch. The motor did this while it was being warming up on the Dyno. Throttle closed, ignition off and it sat at around 5-6K.

[jamathi]

Without any proof or other evidence of that Ryger engine actually working as stated i get the feeling it´s only smoke and screens to get new investers spend money, to secure some guys income without actual work.
Very common actually, getting investors to spend money on highrisc projects.
Often, very often this is conned by old guys figured out how to rip money off those rich people.

And it stinks Gizmondo....(google: https://www.google.se/webhp?sourceid=chrome-instant&rlz=1C1RUCY_svSE723SE723&ion=1&espv=2&ie=UTF-8#q=gizmondo+stefan+eriksson)

Exactly my idea too, 2 years of big talking without any proof!
Complete bullshit...
This project seems to be failing in a bad way.
No engines are being sold....although they are for sale now since a couple of month's
No one is believing these people anymore.
Now they will have to proof themselves on a real racing track!
And then there is still the reliability problem....
Spare pistons will not be cheap, after hundreds of them have been made without success.
And piston life will always be quite short, due to the very high lateral forces acting upon it.
Caused by the very short connecting rod.
Now a 50cc version is being made, with some very capable people working on it.
This may be the final proof I think.

[katinas]

I had that on my Maico. Throttle closed, ignition off and it sat at around 5-6K. The plug was red hot. Only way to stop the motor was stall it with the clutch. The motor did this while it was being warming up on the Dyno. Throttle closed, ignition off and it sat at around 5-6K.

It happened in 1991, I was testing motorcycle ( in photo ) with tuned outboard engine "Vihr-30" 488cc two cylinder with discs valve intake, like this ( https://www.youtube.com/watch?v=PQ2wOx2jgTE ). I can't remember whether it happen, on full open throttle or not, I just heard the blast from under seat pipes and then bike began accelerate. Close the throttle, ignition off, but it accelerate. I do not remember how managed to stop, with clutch or rear brake, but when I return to garage with trebling hands, my friend, who saw everything from side laughing told that saw flame from pipes and then bike disappeared.
It never happen again with my any other motorcycles. Maybe after explosion in the pipes, high pressure provoke something in this engine .

[wobbly]

Some may think I am like Luc, talking up shit to justify myself, but we must apologize to Hinson for thinking the clutch was slipping on the RS400.
In fact when it finally had two reed valves working, the 4 off M6 caps holding the cush drive together, sadly, gave up.
Now I have 4 off 8mm Titanium pieces doing the job, so hopefully its reliable again.

[katinas]

Hi Frits,

Maybe you know something about this "half moon" plates in this titanium YZR 500 headpipes. I can only guess.

Thanks

[Ocean1]

Some may think I am like Luc, talking up shit to justify myself, but we must apologize to Hinson for thinking the clutch was slipping on the RS400.
In fact when it finally had two reed valves working, the 4 off M6 caps holding the cush drive together, sadly, gave up.
Now I have 4 off 8mm Titanium pieces doing the job, so hopefully its reliable again.

What are the screws holding down Wob? Like how rigid is the retainer? Those rubbers are going to extrude laterally under load, making for potentially a lot of force just to one side of the screws...

[dutchpower]

50 cc is tested but has not the expected HP

[husaberg]

Hi Frits,

Maybe you know something about this "half moon" plates in this titanium YZR 500 headpipes. I can only guess.

Thanks

Det buttons we have talked about them before.
here. later
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130263736#post1130263736
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130792235#post1130792235
328563328564

[katinas]

Det buttons we have talked about them before.
here. later
i can't find it.

Thank you, I missed

[husaberg]

Thank you, I missed

No Worries, it comes up about every year or so.
I am glad to help, I really enjoy your work.
I have added some links above

[lucf]

Some may think I am like Luc, talking up shit to justify myself, .........................


Thanks !!
:clap:

[katinas]

As Katinas wrote earlier, nor his engine, nor the Ryger has auxiliary exhaust ports because those would require a wider piston skirt, that would in turn hamper the flow into the transfers. Since I read it here, I can react without endangering my NDA (thank you Katinas). And what follows now, is purely my own guesswork since I never received any relevant information from Ryger.
From the Ryger homologation papers we can see that the exhaust timing is lower than the Aprilia RSA timing, so the Ryger's blowdown angle.area is tiny compared to the RSA's. And when taking the initially quoted maximum torque rpm of 17500 into account, the Ryger's blowdown time.area was almost non-existent. It nevertheless did not stop it from producing over 70 hp.
And before anybody says that they've never seen any proof of this amount of power in the form of a real dyno graph, let me say that neither have I, but I was lucky enough to get a seat-of-the-pants impression of the original Ryger prototype before problems with the production engines brought the operation to a halt, and my pants are not that easily fooled, having ridden motorcycles with several hundred hp.
By the way, what made me decide to step out of the project, was the lack of frankness. I would have loved to take part in the development of that engine, but it turned out that I was only recruited to generate publicity. I'm sure I could have prevented some of those technical problems if only there had been an exchange of thoughts, but all I ever got were promises. It's a pity....

OK, back to my theory. Seeing that the in-cylinder pressure of the RSA is about 12 bar at exhaust opening, and given that the Ryger is claimed to produce about 20 hp more than the RSA, and given that the Ryger's blowdown time.area is so much smaller, there must be a huge amount of spent gases that enter the Ryger's transfer ducts, raising the pressure in the sub-piston volume and the density of the mixture (well observed, Philou). The higher pressure may lead to a much faster transfer flow, with more mixture inertia. This inertia then ought to pull more fresh mixture through the reed inlet valve.
I only wonder how effective this inertia can function, as the Ryger's transfer ducts are very short and anything but flow-encouraging.

That was also my second impression after the staggering acceleration: the beautiful sound. When you would expect a regular 125 cc engine to reach the end of its power band, the Ryger started to sing; that's the best I can describe it. This lovely sound, in combination with the large amount of hot exhaust gas that enters the transfer ducts and is subsequently recycled into the cylinder, made me think in the direction of Homogeneous Charge Compression Ignition with its very fast, short combustion phase; maybe ten times as fast as regular spark-ignited combustion. HCCI would also account for low fuel consumption, comparatively clean exhaust gases, and the need for only a small cooler, although I could not verify these claims.

Could you persuade your software to take a look at these thoughts, Neels?

Very likely, that spent gases began firstly enter sub-piston volume through fifth transfer window. .

[Frits Overmars]

Very likely, that spent gases began firstly enter sub-piston volume through fifth transfer window.That would be a perfect example of history repeating itself. Suzuki used this idea in 1962; they made the third transfer port of their 50 cc works racer as high as the exhaust port, with the intention of pressurizing the crankcase. But in 1963 this third transfer port was no longer any higher than the others...

[shnaggs]

Fritz, If your theory is correct about the Ryger, wouldn't the hot spent gasses ignite the inlet mixture that is in the sub-piston area? Also if this theory is true, wouldn't that method play havoc on a reed valve?

I think I have mentioned this before, but what if we do the same thing, but use the returning pressure wave from the exhaust but shoot it down into the sub-piston area when the pipe tuning is working against itself. You could have a valve in the exhaust that would route the pressure to the sub-port, and then have another reed valve to keep the pressure in the sub-piston.

[Frits Overmars]

Fritz, If your theory is correct about the Ryger, wouldn't the hot spent gasses ignite the inlet mixture that is in the sub-piston area? Also if this theory is true, wouldn't that method play havoc on a reed valve?My theory may be incorrect Shnaggz; I'm just guessing and trying to stimulate the brains around here.


I think I have mentioned this before, but what if we do the same thing, but use the returning pressure wave from the exhaust but shoot it down into the sub-piston area when the pipe tuning is working against itself. You could have a valve in the exhaust that would route the pressure to the sub-port, and then have another reed valve to keep the pressure in the sub-piston.Yes, you did mention this before. That falsely-timed returning wave from the exhaust would arrive back at the cylinder somewhere between BDC and transfer closure, or even before BDC at low revs. It might work. But it would require a valve that switches in the tiny, almost non-existent period of time between the end of the suction wave and the beginning of the returning pressure wave, with the frequency of the crankshaft rotation, at some rpm values but not at others. Not so simple...

[jonny quest]

Wobbly, Recluse Torque Drive clutch. You won't even remember Hinson name after you try one.

[bjorn.clauw.1]

https://www.google.be/url?sa=t&source=web&rct=j&url=https://researchbank.rmit.edu.au/eserv/rmit:161450/Jiang.pdf&ved=0ahUKEwjR1Of2ypDSAhVBsxQKHY0jAXgQFggaMAA&usg=AFQjCNF6u_x75BOckv5tiBjXhHajpVuNAA&sig2=SejXqSoVJoAk0M2iu5-Mdg

[jamathi]

That would be a perfect example of history repeating itself. Suzuki used this idea in 1962; they made the third transfer port of their 50 cc works racer as high as the exhaust port, with the intention of pressurizing the crankcase. But in 1963 this third transfer port was no longer any higher than the others...

I think, and always thought, that this was just a mistake made by the draughtsman.
Or a 'joke' from Suzuki, as this is just impossible....maybe to mislead the opposition.....

All 'normal' 2-stroke engines are rev-limited by the blowdown.
When the blowdown becomes insufficient, at high rpm, exhaust gases enter the crankcase.
They usually cause backfiring in the carburettor, sometimes destroying even the inlet valve or reeds.
At Aprilia we could see this very clearly: the transfer passages and crankcase inside became black.

The Ryger, of course, has far insufficient blowdown.
Without it's extremely high crankcase compression it would probably not rev past 10.000rpm.
I really wonder if mixing burned gases with the fresh charge can in any way be positive....
It really can cause auto-ignition of course!
We'll see, the 50cc development will not remain a secret for a long time I suppose!
The spacer under the cylinder looks higher then normal.
Maybe because of a longer connecting rod, which would be good for reliability.....
The people working on it are among the best and most experienced in Holland.
So if they don't make a success of it there really is no hope....

[ken seeber]

Hi Frits

I wanted to know if your generic 2s exhaust design is a good starting point or is it for more modern bike?

Alternatively is there a better starting point for a design ?

Thanks Wallace

I used Frits’s empirical FOS method to design the 3 pipes for the world famous slider engine. Seeing I don’t have EngMod, the FOS method is quick & easy and the slider is just so different, I figured that it’d be shitload better than me throwing darts against the wall.

Just finished adding the convergent cones and tailpipes. Note that it hasn't run with these, but so far they haven’t not worked !!
We based the styling of the tailpipes, fortunately or unfortunately, after some well-known twittering dude.

328571328572

[katinas]

I think, and always thought, that this was just a mistake made by the draughtsman.
Or a 'joke' from Suzuki, as this is just impossible....maybe to mislead the opposition.....

All 'normal' 2-stroke engines are rev-limited by the blowdown.
When the blowdown becomes insufficient, at high rpm, exhaust gases enter the crankcase.
They usually cause backfiring in the carburettor, sometimes destroying even the inlet valve or reeds.
At Aprilia we could see this very clearly: the transfer passages and crankcase inside became black.

The Ryger, of course, has far insufficient blowdown.
Without it's extremely high crankcase compression it would probably not rev past 10.000rpm.
I really wonder if mixing burned gases with the fresh charge can in any way be positive....
It really can cause auto-ignition of course!
We'll see, the 50cc development will not remain a secret for a long time I suppose!
The spacer under the cylinder looks higher then normal.
Maybe because of a longer connecting rod, which would be good for reliability.....
The people working on it are among the best and most experienced in Holland.
So if they don't make a success of it there really is no hope....

Maybe, on the 50 cc, is a very small difference between the bigger and smaller piston parts, because adequate strength con rod small end, requires relatively more spaces. This is just a guess
With bigger engine ( from 150cc and more) task is simpler, the relative difference between combustion and pumping volume is getting smaller with bigger bore, because of con rod small end dimensions.

[husaberg]

So I finally came upon the idea of using a disc valve on each side, as already had been done by Exactweld.
But I decided to retire, a Dutch friend made some crankcases, but never finished the work.
So I still wonder how it would have gone........


Do you think you would you have had the carbs operating progressively like the Exactweld did Jan?
Also what carb and intake port sizes would you have started with? 2x 30MM?
Pretty sure Flettner could be persuaded to make one to see how it would have gone.
If you give him some basic dimensions. I have some DEA cylinders that could be modified to more closely replicate your originals.

[speedpro]

I used Frits’s empirical FOS method to design the 3 pipes for the world famous slider engine. Seeing I don’t have EngMod, the FOS method is quick & easy and the slider is just so different, I figured that it’d be shitload better than me throwing darts against the wall.

Just finished adding the convergent cones and tailpipes. Note that it hasn't run with these, but so far they haven’t not worked !!
We based the styling of the tailpipes, fortunately or unfortunately, after some well-known twittering dude.

328571328572

I looked at that and immediately thought about a 3 cylinder version in a motorbike. It'd be a good test of the pipe builder.

[Niels Abildgaard]

The Youtube : https://www.youtube.com/watch?v=PQ2wOx2jgTE from Katinas look decidedly strange.
Two 180 deegre apart exhaust pulses in a common bulb ?

[SwePatrick]

328640328639328638

How about this one?
anyone got info?
it´s an supercharged twostroke from what i can see.
No crankcase like an old diesel twostroke?

[SwePatrick]

The Youtube : https://www.youtube.com/watch?v=PQ2wOx2jgTE from Katinas look decidedly strange.
Two 180 deegre apart exhaust pulses in a common bulb ?

Very common in snowmobiles.
Search artic cat, skidoo, polaris, lynx, yamaha for example.

Pipe is just doing what it should do, one piston is at top when other is at bottom.
Just twice as much pulses in pipe, simple described.

[wobbly]

I searched everywhere and it seems Rekluse does not make a clutch for the Banshee/YPVS.
But knowing Yamaha seems to use common shafts /splines etc for model after model, I would think maybe a YZF250 or 450 MX might be able to fitted
with some work ?

[koba]

Hey all,

I love all of the really interesting talk on this thread however I've not had much input in a long time.
I've got a selfish request though, there is something that's bugging me.

The question is, is there a good guideline for revs that rings can do?

Obviously the mass of a given thickness varies based on the bore...

I'm trying to find the sensible limit that I should work to for a standard MB100.
I know I'd be much better off de-stroking and going to a kart piston, or even better, keeping it square and getting something to fit. (not happening) but if I want to make a basic build with the standard slug and the big fat 1.5mm rings what's a sensible rev number? (I hope I have that right...)
The bore is 50.5mm.

I'd really be keen to know the thoughts on the numbers here.
I think I've been pushing it how it is, things seem to go wrong just after 12,000rpm, I'm wondering if this is the reason.

[koba]

On the sheared bolts on the clutch...

Mechanically ignorant here, but could this be put together with some kind of rivet to avoid the stress raisers in the threads?
Thinking out loud here...
Still, sounds like it is too close to the edge right? More bolts required?

[Niels Abildgaard]

Very common in snowmobiles.
Search artic cat, skidoo, polaris, lynx, yamaha for example.

Pipe is just doing what it should do, one piston is at top when other is at bottom.
Just twice as much pulses in pipe, simple described.


Thank You and sounds OK.
Has it been used on a normal twin-twostroke bike.?

[husaberg]

Hey all,

I love all of the really interesting talk on this thread however I've not had much input in a long time.
I've got a selfish request though, there is something that's bugging me.

The question is, is there a good guideline for revs that rings can do?

Obviously the mass of a given thickness varies based on the bore...

I'm trying to find the sensible limit that I should work to for a standard MB100.
I know I'd be much better off de-stroking and going to a kart piston, or even better, keeping it square and getting something to fit. (not happening) but if I want to make a basic build with the standard slug and the big fat 1.5mm rings what's a sensible rev number? (I hope I have that right...)
The bore is 50.5mm.

I'd really be keen to know the thoughts on the numbers here.
I think I've been pushing it how it is, things seem to go wrong just after 12,000rpm, I'm wondering if this is the reason.
What you are asking about is called ring flutter
The MB100 has rather thick keystone rings. well at least the top one is from memory?

There are CR85 overbore pistons that can be used but they are a little spendy as only Wiesco provide them.
I think it was Bert that used NOS 1980's RM100 pistons on one of his projects. talk to him resizes
I am pretty sure it has room near the top for a dykes ring to be added. Ask Ken about sizes available
The dykes kart ring will handle the revs but will likely wear you bore faster
Anyway Sorry its not metric and it likely only applies for plain rings
Gordon Jennings

For rings having a 0.125-inch thickness, 40,000 ft/sec2
0.094 “ “ 53,000 ft/sec2
0.063 “ “ 80,000 ft/sec2
0.047 “ “ 106,000 ft/sec2
0.039 “ “ 138,000 ft/sec2

http://www.amrca.com/tech/tuners.pdf
PG9
Yours from memory would likely corrospond to .63 or about 1.5mm


12000 rpm and a 49.5mm stroke and 100 c-c rod equals
i only came up with 31K? i must have buggered up?

Anyway TKRJ a while back did a run of RG400 pistons
https://www.tkrj.co.jp/goods/m-AS8060X-21A04-21A14.php
no idea re the rng widths though but they were 14mm gudgeon

[jonny quest]

Wobbly we use the Rekluse on the MX bikes. Sorry I just assumed they had one for a banshee. I'd email them. Hindsight here, they typically use stock baskets with completely new insides. I probably don't have to get into the design if you've Googled them and looked at pics.

[jamathi]

Do you think you would you have had the carbs operating progressively like the Exactweld did Jan?
Also what carb and intake port sizes would you have started with? 2x 30MM?
Pretty sure Flettner could be persuaded to make one to see how it would have gone.
If you give him some basic dimensions. I have some DEA cylinders that could be modified to more closely replicate your originals.

The idea was to start with 34mm.
Progressive opening was certainly thought of, and would surely have been tried.
The engine was to have been made for a Chinese factory.
But unfortunately they decided not to continue their racing program, after a very bad experience with a very 'famous' designer who made a totally useless engine, based on a kart engine fitted 'upside down' in a motorcycle......
It had no power and kept seizing, a real disaster.....

Exactweld has gone to 36 with good results I heard.
But, interestingly, its designer wanted to make a rear-disc engine, that was never finished.

A friend in Holland has made a 50cc twin-disc.
For the moment it is inferior to the single-disc.
Maybe because of the unequal inlet duct length, caused by the primary drive.
2 22mm carburetors are used.

DEA cylinders seem to have narrower A-ports, to make the engine rev more.
That was necessary, he told me, because in karting electronic variable ignition is not allowed.
So the exhaust temperature became too low at high rpm.

[husaberg]

The idea was to start with 34mm.
Progressive opening was certainly thought of, and would surely have been tried.
The engine was to have been made for a Chinese factory.
But unfortunately they decided not to continue their racing program, after a very bad experience with a very 'famous' designer who made a totally useless engine, based on a kart engine fitted 'upside down' in a motorcycle......

Exactweld has gone to 36 with good results I heard.
But, interestingly, its designer wanted to make a rear-disc engine, that was never finished.

A friend in Holland has made a 50cc twin-disc.
For the moment it is inferior to the single-disc.
Maybe because of the unequal inlet duct length, caused by the primary drive.
2 22mm carburetors are used.

DEA cylinders seem to have narrower A-ports, to make the engine rev more.
That was necessary, he told me, because in karting electronic variable ignition is not allowed.
34mm Wow thats a huge carb area eq to about a 48mm carb
36 that like a single 51mm carb.
The Dea ones i have the molds for have been improved in the design of the septums, you could actually shave with them. i feel they would work rather well though if i could get the transfers to go supersonic.
I have always wanted to try a disc valve with a offset disc by about 20mm so it could be uterly huge. Thus fully open for a longer time period for a given timing duration.
Never finished.... is actually my middle name:weep:

[speedpro]

Hey all,

I love all of the really interesting talk on this thread however I've not had much input in a long time.
I've got a selfish request though, there is something that's bugging me.

The question is, is there a good guideline for revs that rings can do?

Obviously the mass of a given thickness varies based on the bore...

I'm trying to find the sensible limit that I should work to for a standard MB100.
I know I'd be much better off de-stroking and going to a kart piston, or even better, keeping it square and getting something to fit. (not happening) but if I want to make a basic build with the standard slug and the big fat 1.5mm rings what's a sensible rev number? (I hope I have that right...)
The bore is 50.5mm.

I'd really be keen to know the thoughts on the numbers here.
I think I've been pushing it how it is, things seem to go wrong just after 12,000rpm, I'm wondering if this is the reason.

My 19.9hp MB100 sidecar saw 13,000rpm all the time and lasted at least a few years before a serious dose of over-revving at Taupo saw the crank expire at the next meeting. My 22.5hp MB100 revved to 12,000rpm and lasted 6 years before I exploded it by downshifting at max revs in 2nd.

Technically I don't think they are supposed to rev that high but in fact they seem to be fine.

Standard RG400 rings are 1mm IIRC as I used RG400 pistons in my TS100.

With the kart pistons in my good MB motor it was doing 14,000rpm regularly. The little end cage was in 3 pieces when we pulled it apart and the big end cage had 3 cracks

[dark art]

A friend in Holland has made a 50cc twin-disc.
For the moment it is inferior to the single-disc.
Maybe because of the unequal inlet duct length, caused by the primary drive.
2 22mm carburetors are used..

Maybe the second disc creates a lot of friction for a small engine?

[lodgernz]

Hey all,

I love all of the really interesting talk on this thread however I've not had much input in a long time.
I've got a selfish request though, there is something that's bugging me.

The question is, is there a good guideline for revs that rings can do?

Obviously the mass of a given thickness varies based on the bore...

I'm trying to find the sensible limit that I should work to for a standard MB100.
I know I'd be much better off de-stroking and going to a kart piston, or even better, keeping it square and getting something to fit. (not happening) but if I want to make a basic build with the standard slug and the big fat 1.5mm rings what's a sensible rev number? (I hope I have that right...)
The bore is 50.5mm. really be keen to know the thoughts on the numbers here.

I think I've been pushing it how it is, things seem to go wrong just after 12,000rpm, I'm wondering if this is the reason.


Malcolm, as Jan said a page back, and I think I've heard it said before, most 2-strokes will reach the limits of blowdown well before any ring flutter sets in. However, 1.5mm is a bit of a fatty, so it could be your problem.
What we're talking about is ring flutter (as Husa said), which is reached when the maximum piston acceleration (not piston speed) exceeds accepted threshholds. You need the stroke and rod length to calculate it. Bore does not factor in the calculation.
Here's the formula I use:

Max Piston Acceleration = (RPM^2)*Stroke*(1+(Stroke/(2*RodLength)))/182400 m/s/s

Limits given by Blair (or was it Irving?) correspond to about 26000m/s/s for 1.5 mm rings, but I think that's pretty conservative. I've seen other opinions that suggest 32500m/s/s is more realistic for 1.5mm rings.
You can do the calcs and see if it's the problem. For my engines, 10,800 would be the limit with 1.5mm rings, which is why I use 0.8mm ones on the 50. The 90 runs 1.2mm rings and happily revs to 12,000, which sounds about right.

Please, anyone, correct me if I have any of this wrong.

[F5 Dave]

As I'vesaid several times before, the MB pistons are swhite for several reasons . I think you need more beers imibibed, perhaps my garage is not the ideal sermon tea

What the heck is predictive text doing?

The KT piston is shorter and has a 1mm ring. This helps create big power. The sucky thing is the mondo over square engine it creates.

The YZ100 piston is much better than mb but not really available in 2017 and needs a Yamaha 16mm small end rod somehow adapted.

[F5 Dave]

And its been several months since one of my musical interludes, which Ihighly rrecommend

https://m.youtube.com/watch?v=7YDPNl7PeUU

Holding on to everything
That's not what it seems.

The apostrophe confuses me, but so be it.

[tjbw]

....

I have always wanted to try a disc valve with a offset disc by about 20mm so it could be uterly huge. Thus fully open for a longer time period for a given timing duration.

...




My head hurts ;)

[bjorn.clauw.1]

But unfortunately they decided not to continue their racing program, after a very bad experience with a very 'famous' designer who made a totally useless engine, based on a kart engine fitted 'upside down' in a motorcycle......
It had no power and kept seizing, a real disaster.....



http://www.karting1.co.uk/death-of-the-carburettor-kartings-fuel-injected-future/

Hi Jan, was following the athena story about direct injection with great interest. Until I remembered from where I knew the name of their famous designer. Still, it put a smile on my face reading it, so I guess it was not a complete waste of time.

[polinizei]

Neels describes in "Using Post2T to investigate Detonation" TUBmax should be lower 950° for AV Gas.
Is there any temperatur recommendation for unleaded 95/100 Fuel?


[ATTACH=CONFIG]328646

[bjorn.clauw.1]

I searched everywhere and it seems Rekluse does not make a clutch for the Banshee/YPVS.
But knowing Yamaha seems to use common shafts /splines etc for model after model, I would think maybe a YZF250 or 450 MX might be able to fitted
with some work ?

this looks like a nice clutch basket:
http://www.fastfromthepast.com/95-h120

dry clutch would be nice too. :rolleyes:

[husaberg]

My head hurts ;)

Time area is increased with a larger valve timed to the same duration.
It would have to be driven by a cross shaft doubling as a balance shaft to avoid an overly long intake track.

[TZ350]

Hey all, I'm trying to find the sensible limit that I should work to for a standard MB100. I know I'd be much better off de-stroking and going to a kart piston.

You are in luck. No need to de stroke.

The 110 thing was brought in specifically so MB100's and other 100cc engines could use the KT100 pistons without going to the trouble of de stroking their cranks.

But if you do go to the bother of de stroking the crank to 48mm then you could use an old salvaged (re plated) 54mm water cooled NSR cylinder or de stroke to 45.5 and use a salvaged RGV 56mm cylinder.

I have to admit that I objected to the 110 thing but now that its here it opens the doors to traditional Bucket engineering by making good use of a lot of worn out old cheap stuff that is floating around.

The 110 thing really opens the door to improved reliability for 2T Buckets that are built in the traditional way.

[Peter1962]

34mm Wow thats a huge carb area eq to about a 48mm carb
36 that like a single 51mm carb.
The Dea ones i have the molds for have been improved in the design of the septums, you could actually shave with them. i feel they would work rather well though if i could get the transfers to go supersonic.
I have always wanted to try a disc valve with a offset disc by about 20mm so it could be uterly huge. Thus fully open for a longer time period for a given timing duration.
Never finished.... is actually my middle name:weep:


Husa, I must admit that I do not understand what you mean by this. (sorry...)
Could you please explain what you are aiming for ?

[wobbly]

The Hinson spring clutch for the Banshee is way heavy and way expensive.
I have changed the csk cap screws on the cush drive plate from 6mm to 8mm and used 12.9 grade plus i have ordered some
Lurethane rod that is used in race car suspension bushing to make the cush drive buttons,its way denser and much stronger than the soft " rubber " originals.
Hinson say the 8 plate billet clutch is good for 100 Hp,but i think constant speed shifting creates big shock loads that simply smash the stock cush drive.
I hope what i have done for now will work.
Rekluse do clutches for later model big Yamaha MX bikes, so i am researching if Yamaha has done as they always do, use very similar shafts and splines from model to model.