ESE's works engine tuner

[Grumph]

[QUOTE=TZ350;
Two advantages I can think off straight away.

1) Width of the power spread, if a normal crank has a power spread of 4K then a 2:1 crank would be 8K. An 8K wide power spread from a 2T would be handy.

2) The magic exhaust port duration of 192 for reinforced superimposition of the wave action in the chamber would be easier to achieve with the lower blowdown STA required for a motor doing only half the rpm it was before.[/QUOTE]

The apparent gain in power spread was one of the selling points of Ricky Main's Geneva wheel motor/con trick....IMO the same applies here, not true.
You've still got a piston reciprocating at a finite - and as wob has pointed out, pretty limited velocity. So this crank setup simply means half as many revs at the output shaft for the usual piston speed.

[TZ350]

if a normal crank has a power spread of 4K then a 2:1 crank would be 8K. An 8K wide power spread from a 2T would be handy.An 8K wide power spread is meaningless. Any difference between the maximum and minimum rpm values of a power band is meaningless.

It is the ratio between those maximum and minimum rpm values that counts: http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130525788#post1130525788


I prefer to work not with a powerband but with a power range, which I define as the highest rpm of a power curve, divided by its lowest rpm.


http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130525788#post1130525788 It is all double Dutch to me at the moment, I don't have the slightest clue about what the post is trying to tell us, its a real head scratcher for me. So I will need to make a study of your concept of "power range" and get my head around it because it looks good, thanks for the heads up.

[karter444]

...........

[husaberg]

...........

Thanks for the imput we will all mull it over and consider that thoroughly, Frits are you able to comment on that with out breaching the non disclosure order?

[Yow Ling]

...........

Great post ! keep them coming

[karter444]

Hi I have been reading all the info on this forum with interest for a few months now it really helps amateur engine and pipe builders like myself . I have an engine problem that I need help with , we race 3 kx 250 engines in the nz superkart series and for the past 6 months or so have been trying to diagnos an engine electrical miss at about 7000 rpm plus under acceleration . we did everything electrical you can think of and did most things more than once, finally not thinking that this would fix the problem we swapped the flywheel from another engine and the miss was gone . so then obviously needed another flywheel , ordered one on e-bay fitted to the engine that was now missing a flywheel [ie different engine from the one that had the original miss ] engine miss returns . flywheel has same partnumber , same dimensions and looks perfectly fine . ignition is ignitec , trigger coil and ignition coil wiring has all been separated . Can anyone offer an explaination I don't want to keep buying flywheels until I get one that works
cheers Richard

[Yow Ling]

Hi I have been reading all the info on this forum with interest for a few months now it really helps amateur engine and pipe builders like myself . I have an engine problem that I need help with , we race 3 kx 250 engines in the nz superkart series and for the past 6 months or so have been trying to diagnos an engine electrical miss at about 7000 rpm plus under acceleration . we did everything electrical you can think of and did most things more than once, finally not thinking that this would fix the problem we swapped the flywheel from another engine and the miss was gone . so then obviously needed another flywheel , ordered one on e-bay fitted to the engine that was now missing a flywheel [ie different engine from the one that had the original miss ] engine miss returns . flywheel has same partnumber , same dimensions and looks perfectly fine . ignition is ignitec , trigger coil and ignition coil wiring has all been separated . Can anyone offer an explaination I don't want to keep buying flywheels until I get one that works
cheers Richard

is that all you changed? nothing else, carb?

[karter444]

no changed nothing else 100% sure its flywheel or flywheel related , read somewhere on this forum a post from wobbly about the length of the trigger coil striker plate causing an ignition misfire so he may be able to offer an explanation
should have mentioned that the miss with the flywheel off e-bay wasn't nearly as bad as the original misss and disappeared when the good flywheel was put back on

[husaberg]

no changed nothing else 100% sure its flywheel or flywheel related , read somewhere on this forum a post from wobbly about the length of the trigger coil striker plate causing an ignition misfire so he may be able to offer an explanation
should have mentioned that the miss with the flywheel off e-bay wasn't nearly as bad as the original misss and disappeared when the good flywheel was put back on

Only thing that comes to mind is the air gap on the pulser and loss of magnetism on the flywheel.
Any damage evident from main bearing failure on the inside of the flywheel (ie smearing) or on the pulser protrusion. Is the insides still round?

[speedpro]

The triggering bumps are easy to compare so I expect you have done so. What may be a little less obvious is if you are using the rotor to generate power for the Ignitech and the magnets are "off". If it's rotor related and the triggering is the same I would be looking very carefully at the generated supply current. Not just the DC level but also any AC and if possible look for noise on the supply side. I wonder if the generator magnets are displaced in relation to the triggers if that would have any effect, perhaps one rotor is busy generating electricity exactly when the Ignitech needs it.

[karter444]

we are not using the charging system to charge the battery that runs the ignitec and as I understand it the magnets wont have any effect on the ignition system as they are only there to work in conjunction with the charge coils to charge the battery and supply voltage to the original ignition system . the charge coils have been removed .so now the fjywheel is only there to switch the trigger coil on and off , my feeling is that its not a physical problem as such more of an electrical interference problem .

[seattle smitty]

...........



One of the best posts I've seen; exactly expresses my own bafflement over all these Ryger leaks and hints. Bravo, karter444!! I wish I were as articulate.

[senso]

Can you mount the trigger closer to the fly-wheel?
Use a feeler gauge and gap it around 0.5 or 0.7mm.

Consider using a trigger/pick-up from a foul-stroke, from an R6, they are small compact and made to spend their lifes submerged in hot oil, they are a bit more rugged than almost all the 2 stroke ones that operate in "free" air.

[Grumph]

Can you mount the trigger closer to the fly-wheel?
Use a feeler gauge and gap it around 0.5 or 0.7mm.

Consider using a trigger/pick-up from a foul-stroke, from an R6, they are small compact and made to spend their lifes submerged in hot oil, they are a bit more rugged than almost all the 2 stroke ones that operate in "free" air.

I'd go closer again. I've gone as tight as .3mm. If the pickup is mounted in the cover, measuring can be difficult - plasticine is usually the easiest way to get an accurate figure. The suggestion to use a more rugged pickup is very good.

[wobbly]

What is the diameter of the rotor and what is the trigger lobe length.
In reality the lobe length only needs to be as wide as the magnetic trigger pole.
If the lobe is too long the rising voltage waveform from the upward bump can decay to zero and give a false trigger signal
before the actual dropping edge has left the poles magnetic field.
Re electrical interference, of course you have resistor spark plugs and a resistor cap ( measure both to ensure the resistor element isnt fried ).
And the other trick is to tightly wind the two wires together from the trigger up to the ECU, by holding the ends in a battery drill and slowly winding it over.
This gives good common mode rejection of spurious noise.

[karter444]

Hi Wobbly thanks for the reply the flywheel dia is 88 mm the lobe width is 8.25 and the lobe length is nearly 30 mm
cheers

[ken seeber]

You guys ask me if I can answer your questions. The answer is: yes, I can :devil2:.

(OK, the Ryger is easy to start and idles like a normal 2T. I wonder what this candour is going to cost me; I hope I can settle the matter with some ice cream).

Frits,
The Ryger engine has a lot going for it from what appears on the various forums:
1. 30k potential
2. Lots of power
3. Better fuel consumption and hence less emissions, presumably unburnt HC
4. Low production costs
I can’t help thinking on the 3rd point. You made the comment above re idling. You might need your glasses to read it though.
So, when you said a “idles like a normal 2T”, did you mean a carburetted engine that typically 4 strokes, 6 strokes, 8 strokes etc (a classic” ring-a-ding”) or did you mean a refined clean 2T operation (eg a direct injected engine idles as a true 2T, ie it fires every stroke)?
If it was the former, then it’d be hard to see, from that characteristic, that it could have less fuel consumption and lower emissions.
As to the ice-cream, what would you like, vanilla, chocolate? We have all flavours in the southern hemisphere.:rolleyes:

[kel]

Hi Wobbly thanks for the reply the flywheel dia is 88 mm the lobe width is 8.25 and the lobe length is nearly 30 mm
cheers

I was using a similar setup i.e. KX125 rotor and pick up triggering an ignitech. We ground away the bulk of the lobe length, and closed up the gap between the pickup and lobe to as tight as could be achieved without causing interference. If the gap was opened up just slightly it would start to misfire at around 7k. Dump the original KX pickup (if that's what you are using) and buy one of the ignitech units.

[wobbly]

Yep the lobe is too long - 1/2 its length and all will be fine.
I dont know if the KX trigger is shit, but I have never had any trouble with regular CR125/250 types.
The Ignitech one operates exactly the same as the Kokusan type Honda ones, nothing special at all.
There is an option under special setting called wide lobe, this is probably to suit exactly what you have, but I have never used it.

[Frits Overmars]

when you said a “idles like a normal 2T”, did you mean a carburetted engine that typically 4 strokes, 6 strokes, 8 strokes etc (a classic” ring-a-ding”) or did you mean a refined clean 2T operation (eg a direct injected engine idles as a true 2T, ie it fires every stroke)? If it was the former, then it’d be hard to see, from that characteristic, that it could have less fuel consumption and lower emissions.
As to the ice-cream, what would you like, vanilla, chocolate? We have all flavours in the southern hemisphere.I usually order Malaga (vanilla with raisins soaked in rum) but pure vanilla is OK as well.
Re the idling: good point, Ken. I must admit that up to now I hardly paid attention to the way the Ryger engine idles; we're no idle characters :shifty:.
Pure two-stroking idling in a carburetted engine is nearly impossible to achieve. Igniteability (is that english?) requires a certain minimum quantity and quality of cylinder filling, which in turn will lead to 'too much power'; the idling rpm will be so high that you can't really call it idling any more. For HC-free low-rpm idling you'll need skip-cycle direct injection. But I need not tell you that, coming from Orbital.
We can however have an idling that sounds like two-stroking if the engine is evenly four-stroking or six-stroking. Much depends on the position of the spark plug.
I used to race a big two-stroke single with a choice of plug positions and although it had next to no influence on WOT power, there was a remarkable difference in idling behaviour between a central and an offset plug.

[sonic_v]

For HC-free low-rpm idling you'll need skip-cycle direct injection.

The Evinrude etec outboard engines idle at 500 rpm without using skip injection whilst matching the 4-stroke competition for hc's.

[Frits Overmars]

The Evinrude etec outboard engines idle at 500 rpm without using skip injection whilst matching the 4-stroke competition for hc's.Etec is direct injection, so skipping would be quite simple. Can you be sure that this is not the case?
Injecting a tiny amount of fuel at each revolution does not guarantee combustion at every revolution. For example, if it fails every second cycle, the engine will still sound like it is two-stroking. Failed combustion cycles can occur in an idling four-stroke too, so a HC-comparison must not necessarily lead to the conclusion that the two-stroke does not miss a single beat. And are these HC-data split up in idling, cruising and WOT, or do they just cover over-all usage?

[sonic_v]

Injecting a tiny amount of fuel at each revolution does not guarantee combustion at every revolution.

The etec uses stratified charge combustion at idle and low loads and thus it is certainly feasible to have consistent cycle to cycle combustion.

Some more info http://www.boattest.com/engine-review/Evinrude/22500090_E-TEC-G2-250-H-O-_2014

[Frits Overmars]

Some more info http://www.boattest.com/engine-review/Evinrude/22500090_E-TEC-G2-250-H-O-_2014An interesting read. However I could not find any mentioning of 'idling without using skip injection'. Have you got any more documentation?

[adegnes]

Is the 2 stroke a the stage when there is nothing new to discover with the two stroke. I don't think so .....yet.

Looking through old posts for engmod stuff, found this.

[breezy]

The apparent gain in power spread was one of the selling points of Ricky Main's Geneva wheel motor/con trick....IMO the same applies here, not true.
You've still got a piston reciprocating at a finite - and as wob has pointed out, pretty limited velocity. So this crank setup simply means half as many revs at the output shaft for the usual piston speed.

Has Frits said that the piston rpm is 30,000 or the output shaft can run at 30,000 rpm. if the piston moves through 360 degrees does the output shaft move through 720 degrees? is that the thinking of the crank ratio posts?:sherlock:

[Grumph]

Has Frits said that the piston rpm is 30,000 or the output shaft can run at 30,000 rpm. if the piston moves through 360 degrees does the output shaft move through 720 degrees? is that the thinking of the crank ratio posts?:sherlock:

Semantics....He said he saw 30,000rpm....If the tacho is crank driven, that doesn't necessarily mean the piston is doing the same. If the tacho was picking up impulses from the plug lead, it's a lot more impressive...

[breezy]

Semantics....He said he saw 30,000rpm....If the tacho is crank driven, that doesn't necessarily mean the piston is doing the same. If the tacho was picking up impulses from the plug lead, it's a lot more impressive...

mmmm semantics ..., word trickery....:niceone:

[Tim Ey]

Yep the lobe is too long - 1/2 its length and all will be fine.
I dont know if the KX trigger is shit, but I have never had any trouble with regular CR125/250 types.
The Ignitech one operates exactly the same as the Kokusan type Honda ones, nothing special at all.
There is an option under special setting called wide lobe, this is probably to suit exactly what you have, but I have never used it.

Strange. For the subject of kick-started engines I talked to Ignitech and they told me this:
"Hello,

You have make pulse lobe with lenght about 30 degrees. Surface, height and
width of pulse lobe must be homogenous.
We recommended to use pick-up IP6.

Regards.

Jiri Krejzl
IGNITECH"

My daily driver with ignitech has now exactly 30° of lobe lenght - and I am not able to adjust the idle where I want it to be. 3000RPM is as low as it gets.
On my RZ350 the lobe length seems to be shorter - and this engine has a nice idle.

So talking about the KX engine of karter4444: half of 30mm would be around 20° of lobe lenght. So would that be the general lenght you would recoment for a kickstarted engine?

And is there a base advance I should prefer?
cheers and thanks!
Tim

[wobbly]

The length of the lobe makes no difference to the performance parameters of the Ignitech, except the issues we have seen
when it is too long.
Its the trailing edge position that triggers the spark event, but in some cases the leading edge is used to limit the total advance capability.
Below 300rpm the base timing is the default timing when the ecu first starts to supply a spark, above that the curve takes over.
You want enough base timing to enable ignition to occur early enough, but not so early that you can get "kick back " that can if bad enough
cause the engine to start backwards, or at the least break your leg.
I have found that 10 to 20* of base timing works fine in almost every case with a kickstarter.

[Frits Overmars]

Is the 2 stroke a the stage when there is nothing new to discover with the two stroke...
312695
The man should know...

[Frits Overmars]

Has Frits said that the piston rpm is 30,000?Certainly not :nono:. The piston makes zero revolutions per minute, hopefully. It should only go up and down. A two-stroke piston that rotates, will break its rings.

[husaberg]

Certainly not :nono:. The piston makes zero revolutions per minute, hopefully. It should only go up and down. A two-stroke piston that rotates, will break its rings.
Frits surely they must make at least one per day:shifty:



The man should know...
312697
Nature abhors a vacuum.
Francois Rabelais

The American people abhor a vacuum.
Theodore Roosevelt


Those still out in the empires colonies are still trying to re-invent the wheel though.
312699

[ken seeber]

Etec is direct injection, so skipping would be quite simple. Can you be sure that this is not the case?
Injecting a tiny amount of fuel at each revolution does not guarantee combustion at every revolution. For example, if it fails every second cycle, the engine will still sound like it is two-stroking. Failed combustion cycles can occur in an idling four-stroke too, so a HC-comparison must not necessarily lead to the conclusion that the two-stroke does not miss a single beat. And are these HC-data split up in idling, cruising and WOT, or do they just cover over-all usage?

Frits,
Checked with a few long lasting Orbital cronies today and they confirmed that they have never deployed a skip cycle operation in any application. They were also 98% sure that the E-Tec is the same, but certainly wasn't used in the earlier Ficht days. Because electronic systems can be well controlled from cycle to cycle, this allows them to lower the idle speed, both for fuel consumption and customer perception.
The ice cream is still here, we just call it rum and raisins, however I am not sure if it is starting to melt though.:confused:

[breezy]

Took the Ryger-kart for a little spin today.
God Almighty!
312179 312180 312181

I've got a fairly good idea of what to expect from a 125 cc kart. But this....
The revcounter could hardly keep up with the crankshaft but in any case it revved much higher than a normal 125 and I reached the end of the straight-away much quicker. What a rocketship!

ok..." the rev counter could hardly keep up with the crankshaft" (not the piston going up and down) ... or semantics?;)

[speedpro]

This is getting boring.

30,000rpm is interesting, but only in so much as it is way out there for regular size engines. Keep the BMEP up and stop it melting and the horsepower doesn't seem unachievable, so is not particularly astounding to me. That rpm though, hmmmm!

[Frits Overmars]

The piston makes zero revolutions per minute, hopefully. It should only go up and down.

Frits surely they must make at least one per dayYou mean, when you turn the whole bike around in order to ride back home, or what? Enlighten me, please.
And while you're at it: how do you attach a PDF here? I have several papers that would have looked good here; I just saw no way of posting them.

[Frits Overmars]

Checked with a few long lasting Orbital cronies today and they confirmed that they have never deployed a skip cycle operation....
The ice cream is still here, we just call it rum and raisins, however I am not sure if it is starting to melt though.I stand corrected; you can have my ice cream, Ken.

[husaberg]

You mean, when you turn the hole bike around in order to ride home, or what? Enlighten me, please. And while you're at it: how do you attach a PDF here?

They have to be a below a certain size 2mb I think. Otherwise it is the same as added any file off your computer.
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=309050&d=1424068367

Sometimes if it has stuff that Is to irrelevant or just too large I will copy the text out of one or down load it as the HTML or I will screenshot it and glue it back together as a JPEG or GIF.
I sometimes add the odd irrelevant pic in there to see if anyone is paying attention.
Pretty sure TZ go his ear tugged for studying one about TZ750 intake diffusers.

Did you read the PDF? I had never heard of the Kiwi one.
As for the piston revolutions, The earth as far as I know still does a full revolution every 24 hours or so.:lol:
Sneaky I know.
http://upload.wikimedia.org/wikipedia/commons/thumb/3/30/Globespin.gif/220px-Globespin.gif

[Frits Overmars]

They have to be a below a certain size 2mb I think. Otherwise it is the same as added any file off your computer.OK, let's try (could not find a paper on TZ750 intake restrictors (I assume that's what you meant by diffusers) so I picked something about a dutch piston alloy:
312706


Did you read the PDF? I had never heard of the Kiwi one. As for the piston revolutions, The earth as far as I know still does a full revolution every 24 hours or so. Sneaky I know.Sneaky indeed, Pete Husa. But to show you there's no hard feelings, let me enlighten you on the Kiwi Pivotal Engineering engine.
Did I hear of it? I discussed it with its builders (they were particularly fond of the liquid-cooled inside of the piston) and took pictures, in 2005. Here they are.
(keep klicking on them for details).

[breezy]

They have to be a below a certain size 2mb I think. Otherwise it is the same as added any file off your computer.
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=309050&d=1424068367

Sometimes if it has stuff that Is to irrelevant or just too large I will copy the text out of one or down load it as the HTML or I will screenshot it and glue it back together as a JPEG or GIF.
I sometimes add the odd irrelevant pic in there to see if anyone is paying attention.
Pretty sure TZ go his ear tugged for studying one about TZ750 intake diffusers.

Did you read the PDF? I had never heard of the Kiwi one.
As for the piston revolutions, The earth as far as I know still does a full revolution every 24 hours or so.:lol:
Sneaky I know.
http://upload.wikimedia.org/wikipedia/commons/thumb/3/30/Globespin.gif/220px-Globespin.gif

"I stand corrected; you can have my ice cream, Ken"

i think maybe the ice creams already spoken for pete...:hug:.

[Larry Wiechman]

It's hard for me to believe the combustion process enjoys square corners.

[Grumph]

It's hard for me to believe the combustion process enjoys square corners.

It's hard for me to believe anyone took that motor seriously...
In about 2002 I went in the wrong door at Mace engineering in ChCh, looking for someone. Lo and behold there was my old race opponent, Paul Mclauchlan playing with some kind of motor. He was kind enough to show me what he was doing - the Pivotal.

Pretty sure nothing has been done on the project for some years now. Post quakes, Mace is still standing and functioning but their core business has gone crazy. They are specialists in repair of large engines - from earthmoving diesels to marine prime movers.

Bill Mace I'm confident was in it for the potential concept sales and licence fees. A short time before Paul approached them, another ChCh identity Ricky Main had gone public in Australia with his Geneva wheel motor - and it was apparent he'd pulled in the cash big time...Sadly for Bill, it doesn't seem to have happened here.

[wobbly]

Square corners isnt really an issue - the rotary that powers your vanilla RX7 has had them forever, and that seal is reliable.
What was ,and still is the issue, as is the case with so many of these ideas, is that although the "different " technology may in fact
be an advantage that could be used in a certain application,completely ignoring what is accepted port STA for that application hamstrings the
project at the outset.
If the designers couldn't design a normal 2T correctly, what chance has the new variant got in reality.

[Martin1981]

http://fs1.directupload.net/images/150610/temp/glqnj6tg.jpg (http://www.directupload.net/file/d/4014/glqnj6tg_jpg.htm)

Frits is a Ryger Guy now :yes:


Frits, did you have the Ryger Technology in your head already some time ago? if so, did you expect it to work in real? if not, why not?

[peewee]

waiting on some welding supplies but when they arrive i plan to fill in the exh bottom like so. what you think ?

[wobbly]

Great idea, and when you have completed the ports in the cylinder and have the effective STA you can then do the calculation
to reduce the duct exit area, and promote flow down the Aux port ducts.
Then a CNC oval to round transition in the spigot.

[peewee]

ya i was gonna have a look at the rsa manifold and see if i couldnt modify my existing manifold in a similar way. weld some wings on the sides or something

im gonna finish all the welding first then put it in engmod but ill probly do something like this. closing up the waterjacket will be easy but i havent thought yet what sort of bubble shape to use. i guess it dont need to be real complicated, as long as water can still circulate through that area

after looking at the manifold i think what i can do would be rather simple. just build up some little wings on the sides then build up the cylinder just alittle to match.

[karter444]

Yep the lobe is too long - 1/2 its length and all will be fine.
I dont know if the KX trigger is shit, but I have never had any trouble with regular CR125/250 types.
The Ignitech one operates exactly the same as the Kokusan type Honda ones, nothing special at all.
There is an option under special setting called wide lobe, this is probably to suit exactly what you have, but I have never used it.
thanks for the explanation I will modify flywheels and let you know after we have raced next
cheers
I also have a small engine inertia dyno for sale was originally used for doing kart engines unfortunately it has no software etc
can be viewed on trade me #901605486 if anyone is interested call 0274949706

[senso]

Dumb question time...
What is that hole above the exhaust port?

[husaberg]

Dumb question time...
What is that hole above the exhaust port?

I was looking at that too, I just assumed it was a detuning bleed. To take some of the pressure and violence out of the blowdown period. Although it seems a little too high?

[F5 Dave]

Make it easy to kick start. My 300 has one. Perhaps valve operated see front manifold pic.

[wax]

I have a question for Frits or wobbly or anyone who thinks they can answer it.
I have a JetSki cylinder with a single exhaust port and so I can't go very wide. Therefore it's not going to drop the combustion pressure the same and so in my mind I would expect it's blowdown time/area to be lower than say a triple exhaust port system. Would it make sense the to have a larger blow down say 36 degrees instead of 32. I'm concerned about not dropping the pressure enough and stalling the transfers. What's the downside to having two much blowdown, would it be that you then don't have enough transfer time/area and the reduce the power of the engine. Thanks a lot

[husaberg]

Make it easy to kick start. My 300 has one. Perhaps valve operated see front manifold pic.

Oh A compression release? I thought they were well out of fashion. Engine braking an option?

[Muciek]

I have a question for Frits or wobbly or anyone who thinks they can answer it.
I have a JetSki cylinder with a single exhaust port and so I can't go very wide. Therefore it's not going to drop the combustion pressure the same and so in my mind I would expect it's blowdown time/area to be lower than say a triple exhaust port system. Would it make sense the to have a larger blow down say 36 degrees instead of 32. I'm concerned about not dropping the pressure enough and stalling the transfers. What's the downside to having two much blowdown, would it be that you then don't have enough transfer time/area and the reduce the power of the engine. Thanks a lot
What is the ports height? On sleds mostly exh was sth like 195 and transfers 110-115.

[wax]

195/120
Exhaust and transfers respectively

[Frits Overmars]

Frits, did you have the Ryger Technology in your head already some time ago? if so, did you expect it to work in real? if not, why not?All credit for the Ryger engine should go to Harry Ryger, and Harry alone. I'd post a picture of the engine's spiritual father, but Harry prefers to stay in the background. Finding his photo on the world wide web may prove to be as difficult as finding the Ryger patents :p.

[peewee]

Make it easy to kick start. My 300 has one. Perhaps valve operated see front manifold pic.
Not valve operated. It does bleed off pressure for easier kicking but in the service manual it also says its for tuning. In the front of the cylinder youll notice a bolt hole in which the bleed hole ca be closed off or left part way open. I may just weld it shut

[F5 Dave]

My GG is just an open hole but small enough that probably doesn't affect power much but at kick over speeds means its no harder than my 200. This is super important to me when tired having stalled half way up some slippery single track.

Saw the bolt hole, what was the brand again? Pumpkin?

[adegnes]

Got engmod, wohoo!!
first of all; a HUGE thank you to Neels for the superb service and great product, and to all of you guys especially wobbly and TZ350 for making me aware of the software and it's capabilities, and sharing all the info!

Everything is working great, no hickups...exept for that I'm experiencing problems when trying to run simulations in turbulent mode (probably user error though...)

heres my combustion data:
312733

heres a simulation running prescribed
312734

and heres what happens(and other variations of wierd output) when I try to run turbulent, no change to the combustion data, just ticked of "turbulent".
312735


What am I doing wrong?

[wobbly]

Occasionally the turbulent model is affected incorrectly by the combustion parameters being out of range ie the duration goes over 100* ( usually squish related ) and
it all goes wrong.
Send a pack to Neels and he will be able to see the issue and advise.

Re the blowdown question - with a single Ex port you are always fighting a lack of blowdown STA, and this is where the only way to balance the power capability's of the transfers
with the Ex is to run the numbers thru an analysis program.
In general it is usually possible to get alot more transfer STA by widening them all to the max, whilst keeping them low to help the blow numbers without jacking up the Ex timing excessively.
Ski engines generally aren't limited badly by close bore centers creating shit transfer ducts, so concentrating on the area can reap good results.

[adegnes]

Occasionally the turbulent model is affected incorrectly by the combustion parameters being out of range ie the duration goes over 100* ( usually squish related ) and
it all goes wrong.
Send a pack to Neels and he will be able to see the issue and advise.



Thanks, I'll do that!

[wax]

Occasionally the turbulent model is affected incorrectly by the combustion parameters being out of range ie the duration goes over 100* ( usually squish related ) and
it all goes wrong.
Send a pack to Neels and he will be able to see the issue and advise.

Re the blowdown question - with a single Ex port you are always fighting a lack of blowdown STA, and this is where the only way to balance the power capability's of the transfers
with the Ex is to run the numbers thru an analysis program.
In general it is usually possible to get alot more transfer STA by widening them all to the max, whilst keeping them low to help the blow numbers without jacking up the Ex timing excessively.
Ski engines generally aren't limited badly by close bore centers creating shit transfer ducts, so concentrating on the area can reap good results.
Thanks wobbly.
Yes we have shit transfer ducts

[jonny quest]

http://blog.motorcycle.com/2014/04/16/design/ronax-500cc-two-stroke-sportbike-coming-june-8/

[marsheng]

I would go bigger in the main jet to get the mixture right in the middle and then go bigger on the air jet to lean out the top, with a recheck of the middle afterwards.

I've got today to play around with this, however, for a wide power band is this mixture not the best ?

Lean at the bottom, this means engine runs hotter, (less fuel cooling) exhaust is therefore hotter so pipe looks shorter and closer to optimal and by the same reasoning, richer at the top means more cooling and temperatures lower and so pipe seems longer ?

I may make more power with changes but a wide band is what I'm after or a 6 speed gearbox.

Cheers Wallace

[wobbly]

Completely opposite logic is needed - unless im reading you wrongly?.
Rich at the bottom to cool the pipe, making it appear longer for drive of slow corners, then lean at the top to get it to spin
up with the higher egt making the pipe shorter.

[marsheng]

Completely opposite logic is needed - unless im reading you wrongly?.
Rich at the bottom to cool the pipe, making it appear longer for drive of slow corners, then lean at the top to get it to spin
up with the higher egt making the pipe shorter.

You are correct, just as well I checked. Brain fade.

[husaberg]

AvGas in NZ is all LL100, this is low lead 100 octain.But the rating is defined differently in avaition.Its approx equiv to 100 "pump" gas, but has a lean rating of 100 and a rich rating of 130.
MNZ Appendix E defines avgas as max 112 MON amd max 108 RON.

Avgas, or any leaded "race" fuel reacts completely differently to unleaded pump gas.
In general terms the unleaded hates compression, but loves timing.Avgas is the opposite in that it makes more power up to the knock limit with more com.
Unleaded makes better power when run rich,avgas makes more the leaner you go.
Tuning in the old days with RS and TZ engines meant using lean mains and small powerjets ( 35 ) as turning off a big jet over the top would mean being too lean in the overev.
Nowdays the unleaded fuel runs rich at peak power, then uses a big powerjet ( 55) to create some heat in the pipe over the top.
Just to be clear.

[peewee]

My GG is just an open hole but small enough that probably doesn't affect power much but at kick over speeds means its no harder than my 200. This is super important to me when tired having stalled half way up some slippery single track.

Saw the bolt hole, what was the brand again? Pumpkin?


dont ask me to explain how it works because i havent a clue. i plan to plug it off

[peewee]

this should do the trick

[F5 Dave]

Ahh, so its an old Pumpkin, maybe before they were pumpkin coloured.

So a bit of extra blowdown in full open position but obviously with some loss esp at lower revs (smoother is a nice way of saying it). You'd obviously be better to block it or better yet push an insert mostly into it, & find more area in the main port or subs. . . .if you weren't dirt riding it. If you were, a thumb operated valve for starting & closed would be best for low down. Or just leave it, it'll have scads more power than most of us need for the dirt.

[peewee]

i figured it would be best to have the exh gas exit all at once rather than have the pressure drop slightly before the main port opens. ktm's logic isnt making sense to me

[F5 Dave]

Too much Weiner Schnitzel at KTM lunch cafeteria.

[TZ350]

Rob will forgive me for saying (i hope) that at times he is a little keen to try to many things.

Youthful over exuberance i guess.http://t1.gstatic.com/images?q=tbn:ANd9GcQ-4VB8FOEjj5ndQ3HF7O2WYdy_8kyn8htPn1BdbYWn2wrh1v4vcg&t=1

Youthful over exuberance ..... too right, or something!!!http://t1.gstatic.com/images?q=tbn:ANd9GcQ-4VB8FOEjj5ndQ3HF7O2WYdy_8kyn8htPn1BdbYWn2wrh1v4vcg&t=1

312774

[husaberg]

Youthful over exuberance ..... too right, or something!!!http://t1.gstatic.com/images?q=tbn:ANd9GcQ-4VB8FOEjj5ndQ3HF7O2WYdy_8kyn8htPn1BdbYWn2wrh1v4vcg&t=1



That bloody quote was over threes years ago.

[Flettner]

Frits, I guess you are right, there is more to this discovery than we might think. If this is what I think it is, then there will also be some VERY interested fourstroke customers, ones that might race in GP class! I can see why you NEED to keep a lid on it.

[Grumph]

Frits, I guess you are right, there is more to this discovery than we might think. If this is what I think it is, then there will also be some VERY interested fourstroke customers, ones that might race in GP class! I can see why you NEED to keep a lid on it.

tease......

[TZ350]

Rob will forgive me for saying (i hope) that at times he is a little keen to try to many things.

Youthful over exuberance i guess.http://t1.gstatic.com/images?q=tbn:ANd9GcQ-4VB8FOEjj5ndQ3HF7O2WYdy_8kyn8htPn1BdbYWn2wrh1v4vcg&t=1
312774 Youthful over exuberance ..... too right, or something!!!http://t1.gstatic.com/images?q=tbn:ANd9GcQ-4VB8FOEjj5ndQ3HF7O2WYdy_8kyn8htPn1BdbYWn2wrh1v4vcg&t=1
That bloody quote was over threes years ago.

I am a slow reader too, just catching up ... :laugh:

[adegnes]

Got an update from Neels, now turbulent works fine.

Newb question:
When using the numbers I got from turbulent, can I play around with ignition timing in prescribed mode, or do I have to run turbulent again everytime I change timing for a rpm point?

[wobbly]

No, once you have saved and imported the turbulent combustion model, you can use that with changed timing numbers, saving it as a new file each time.

[marsheng]

You are correct, just as well I checked. Brain fade.

After a bit of fiddling I made some improvement.

[wobbly]

What about the peak and overev power - the main/corrector system can hves just as much effect there as in the mid.

[190mech]

Poor man's angle porting tool;Thought you all might try making one for small cylinders,
http://i639.photobucket.com/albums/uu112/190mech/ag%201_zpsnuxj7pfy.jpg (http://s639.photobucket.com/user/190mech/media/ag%201_zpsnuxj7pfy.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%204_zpskkyhuvny.jpg (http://s639.photobucket.com/user/190mech/media/ag%204_zpskkyhuvny.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%202_zps1ax8wuvj.jpg (http://s639.photobucket.com/user/190mech/media/ag%202_zps1ax8wuvj.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%203_zpsgd9tzg8i.jpg (http://s639.photobucket.com/user/190mech/media/ag%203_zpsgd9tzg8i.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%205_zpsayiwtblm.jpg (http://s639.photobucket.com/user/190mech/media/ag%205_zpsayiwtblm.jpg.html)

[TZ350]

That is clever.....:niceone: . I like it.

[speedpro]

After a bit of fiddling I made some improvement.

Only a part of the rev range shown. The whole range including overrev will show the total effect of the changes.

[marsheng]

Poor man's angle porting tool;Thought you all might try making one for small cylinders,


Very nice.I'll put that on my todo list.

[marsheng]

Only a part of the rev range shown. The whole range including overrev will show the total effect of the changes.

I need to get my O2 sensor working consistently to do the top end. I was basically just trying to get the bottom end better as the 5 speed MX gearbox is not the best for the track.

My EGT only shows 950 at max power on the track so I still have some work to do. I'm hope the EGT is correct ? Ashburton's dyno shows close to 12.5:1 fuel air so I'm not sure why the temp is so low.

Maybe I need to do a bench calibration of the sensor and GPX Pro box. .

[Grumph]

Poor man's angle porting tool;Thought you all might try making one for small cylinders,

Clever - now put an adjustable stop on the downtube which would bear on one end of the cylinder so as to cut to an exact port height.

[adegnes]

Poor man's angle porting tool;Thought you all might try making one for small cylinders,
http://i639.photobucket.com/albums/uu112/190mech/ag%201_zpsnuxj7pfy.jpg (http://s639.photobucket.com/user/190mech/media/ag%201_zpsnuxj7pfy.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%204_zpskkyhuvny.jpg (http://s639.photobucket.com/user/190mech/media/ag%204_zpskkyhuvny.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%202_zps1ax8wuvj.jpg (http://s639.photobucket.com/user/190mech/media/ag%202_zps1ax8wuvj.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%203_zpsgd9tzg8i.jpg (http://s639.photobucket.com/user/190mech/media/ag%203_zpsgd9tzg8i.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%205_zpsayiwtblm.jpg (http://s639.photobucket.com/user/190mech/media/ag%205_zpsayiwtblm.jpg.html)

Love it!


Clever - now put an adjustable stop on the downtube which would bear on one end of the cylinder so as to cut to an exact port height.

Good idea!

[Flettner]

Poor man's angle porting tool;Thought you all might try making one for small cylinders,
http://i639.photobucket.com/albums/uu112/190mech/ag%201_zpsnuxj7pfy.jpg (http://s639.photobucket.com/user/190mech/media/ag%201_zpsnuxj7pfy.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%204_zpskkyhuvny.jpg (http://s639.photobucket.com/user/190mech/media/ag%204_zpskkyhuvny.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%202_zps1ax8wuvj.jpg (http://s639.photobucket.com/user/190mech/media/ag%202_zps1ax8wuvj.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%203_zpsgd9tzg8i.jpg (http://s639.photobucket.com/user/190mech/media/ag%203_zpsgd9tzg8i.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%205_zpsayiwtblm.jpg (http://s639.photobucket.com/user/190mech/media/ag%205_zpsayiwtblm.jpg.html)

Is that an old Kawasaki cylinder?

[190mech]

Thanks guys!An adjustable stop will be added..Flettner,Thats a 47mm scooter cylinder,I got the idea from your belt drive porting tool you posted here a while back..

[2T Institute]

A fantastic way to make a mess of a good cylinder. fail to see how you get any control with that contraption

[Haufen]

What you can do with any carb, large or small, is to shorten the inlet tract as much as possible. This may allow you to close the disc earlier, giving a more civilized engine behaviour, and still maintain decent crankcase filling at high revs.
Or you could go the opposite route: increase crankcase volume, increase inlet tract length, and leave the inlet disc out altogether: 24/7-inlet. But then you will need some sort of hinged reed to enable starting. And I don't think anybody will manage to get decent carburation in both the reed-phase and the 24/7-phase; It will take fuel injection to get both phases right.

As the 24/7 concept has been successfully tested on a kart engine in the meantime, can you comment on the experience which has been gained, Frits?

Was fuel injection really necessary?
Which factors is it worth paying attention to / is the system sensitive to (crankcase cr, intake length, pipe? etc) if one were to have a go oneselve?

[Frits Overmars]

As the 24/7 concept has been successfully tested on a kart engine in the meantime, can you comment on the experience which has been gained, Frits?I am not at liberty to say any more about it than I already did here, Haufen. You may want to search for 'Modena' and 'Roland Holzner'.
Was fuel injection really necessary?OK, this is a question I can answer because it was obvious for all the world to see that the Modena 24/7 uses the normal homologated 30mm Dellorto carb.
My fears that injection would be necessary were not confirmed. The Modena runs fine with a carb, notwithstanding the fact that they also have a working injection system on the shelf.


Which factors is it worth paying attention to / is the system sensitive to (crankcase cr, intake length, pipe? etc) if one were to have a go oneselve?The 24/7 system depends on the pipe even more than a conventional inlet system does, but the pipe itself does not need to be altered.
Crankcase volume, inlet length and carb diameter all play a role; none of those values are critical, but their combination should yield a suitable Helmholtz frequency.
The most practical way to go about this would be to start with a fairly big crankcase volume and a fairly small carburettor, vary the inlet length and see what happens.

[breezy]

"The 24/7 system depends on the pipe even more than a conventional inlet system does, but the pipe itself does not need to be altered."

Frits, do you think that the amount of power gained by the exhaust system used as it is today,could be better used elsewhere, on a 2 stroke engine, to produce better results? what are your thoughts on piston dwell at bcd, are there any rules which are a must in terms of minimum/maximum?

[jasonu]

Poor man's angle porting tool;Thought you all might try making one for small cylinders,
http://i639.photobucket.com/albums/uu112/190mech/ag%201_zpsnuxj7pfy.jpg (http://s639.photobucket.com/user/190mech/media/ag%201_zpsnuxj7pfy.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%204_zpskkyhuvny.jpg (http://s639.photobucket.com/user/190mech/media/ag%204_zpskkyhuvny.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%202_zps1ax8wuvj.jpg (http://s639.photobucket.com/user/190mech/media/ag%202_zps1ax8wuvj.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%203_zpsgd9tzg8i.jpg (http://s639.photobucket.com/user/190mech/media/ag%203_zpsgd9tzg8i.jpg.html)
http://i639.photobucket.com/albums/uu112/190mech/ag%205_zpsayiwtblm.jpg (http://s639.photobucket.com/user/190mech/media/ag%205_zpsayiwtblm.jpg.html)

Now that is in the 'spirit' of bucket racing!

[TZ350]

312847312848312849

Modena KK1 EFI engine.

[Flettner]

Frits, I guess you are right, there is more to this discovery than we might think. If this is what I think it is, then there will also be some VERY interested fourstroke customers, ones that might race in GP class! I can see why you NEED to keep a lid on it.

So, this IS the game changer? Are we witnessing the end of the fourstroke? Time to change back to the twostroke in GP's as the emission rules no longer apply! Run this in California as much as you want, cleaner than a fourstroke (race engine)! Imagine pistons that never wear out. Good on Ryger.

[Frits Overmars]

Frits, do you think that the amount of power gained by the exhaust system used as it is today, could be better used elsewhere, on a 2 stroke engine, to produce better results? what are your thoughts on piston dwell at bcd, are there any rules which are a must in terms of minimum/maximum?One remark in advance, which regards not only the above question but all questions: unless I say otherwise, all my answers concern conventional engines; they may or may not be valid for the Ryger engine, so don't go jumping to conclusions.

Breezy, a good exhaust system triples the power of a racing two-stroke. How would you use that power elsewhere? By driving a compressor for example? It would help but it's not allowed in most types of motor sport. And in case you mean the amount of energy contained in the exhaust gases: I don't see a way of utilizing that other than in the exhaust pipe.

Re dwelling: a short con rod will cause a higher piston acceleration near TDC and a lower acceleration near BDC, so the piston will dwell longer around BDC.
Assuming the cylinder remains unchanged, a shorter rod will increase angle.areas. For example, The Aprilia RSA has a blowdown angle.area of 14322°mm² and a transfer angle.area of 109969°mm². If we replace its 120 mm con rod with a 100 mm rod (17% shorter), the blowdown angle.area becomes 14609°mm² (2% more) and the transfer angle.area becomes 113119°mm² (2,9% more). The drawback is that the short con rod causes more piston friction and costs crankcase volume.

[husaberg]

One remark in advance, which regards not only the above question but all questions: unless I say otherwise, all my answers concern conventional engines; they may or may not be valid for the Ryger engine, so don't go jumping to conclusions.

Breezy, a good exhaust system triples the power of a racing two-stroke. How would you use that power elsewhere? By driving a compressor for example? It would help but it's not allowed in most types of motor sport. And in case you mean the amount of energy contained in the exhaust gases: I don't see a way of utilizing that other than in the exhaust pipe.

Re dwelling: a short con rod will cause a higher piston acceleration near TDC and a lower acceleration near BDC, so the piston will dwell longer around BDC.
Assuming the cylinder remains unchanged, a shorter rod will increase angle.areas. For example, The Aprilia RSA has a blowdown angle.area of 14322°mm² and a transfer angle.area of 109969°mm². If we replace its 120 mm con rod with a 100 mm rod (17% shorter), the blowdown angle.area becomes 14609°mm² (2% more) and the transfer angle.area becomes 113119°mm² (2,9% more). The drawback is that the short con rod causes more piston friction and costs crankcase volume.
I know this is heathen talk.

Frits say if we deal in gas it changes states m3 and velocity changes from atmosphere the carb to the crankcase to the cylinder.
What we seem to need is the gas actually effectively compressed before it enters the cylinder that way more mass can actually be burned. I can't recall but is the volume mixture drawn in to the cylinder each revolution of the RSA only actually what is contained in the transfers.

Blown down (as far as I am aware) is measured as the time and area prior to the pressure equalizing between the cylinder and transfers to allow the flow into the cylinder is that correct?
So a higher rate of primary compression would (all things being equal allow) allow the same port timing to actually produce more blowdown time area.


I had a wee play looking at hugely variable exhaust port durations and a pipe calculator it looks to me from the quick look that the ex pipe could be made to function over a huge range of engine speeds.

yes I know this is 60's talk, but with advances in ex port variable timing, fuel injection and port shapes, reed valves surely maybe there is actually some room to improve.
I am not simply suggesting a smaller crankcase just a variable size with a higher delivery rate likely remote to minimise heat sink.
I think this can be achieved without the wet crankcase set up we have now so the flow restrictions and oiling cooling issues encountered in the 60's would not be an issue.
Also is there not pressure waves still present in the exhaust when the exhaust port is shut?

Also do the supercharging rules actually really cover the creation of a vacuum rather than positive boost pressure?

Yes I say all of this fully aware that the later RSA made less power when they had crank stuffers fitted.

[senso]

312847312848312849

Modena KK1 EFI engine.

Wow, only 50cc of oil in the gearbox? :eek5:

[Frits Overmars]

Frits say if we deal in gas it changes states m3 and velocity changes from atmosphere the carb to the crankcase to the cylinder. What we seem to need is the gas actually effectively compressed before it enters the cylinder that way more mass can actually be burned. I can't recall but is the volume mixture drawn in to the cylinder each revolution of the RSA only actually what is contained in the transfers.That depends on how you define the transfers. They are not only the ducts in the cylinder but also the sweeping curves in the crankcase. In any case it is not a matter of mixture drawn into the cylinder, but of mixture drawn through the cylinder. Some of it stays there, some of it exits and then comes back, some of it may be lost, especially at revs outside the optimum range. By the way, I like the distinction you make between mixture mass and mixture volume.


Blown down (as far as I am aware) is measured as the time and area prior to the pressure equalizing between the cylinder and transfers to allow the flow into the cylinder is that correct?Correct. Blowdown should be finished by the time the transfers open, but it takes a certain time.area and if this time.area has not been reached by the time the transfers open, the exhaust gas just abuses the transfers as extra exhaust ports.

Maybe we should be more aware of the ambiguity of blowdown. It starts at the angle where the exhaust begins to open, but where does it end? It should end at the opening point of the transfers, but at low revs that is more blowdown time.area than we need, and at high revs the blowdown may carry on past the opening point of the transfers. Usually we take the opening point of the transfers as the end point of the blowdown because we have no simple way of knowing at what crank angle the cylinder and transfer pressures are equal.


So a higher rate of primary compression would (all things being equal allow) allow the same port timing to actually produce more blowdown time area.You're thinking in the right direction but I'd like to rephrase your thoughts. Blowdown time.area is the product of port timings and port areas, divided by revs. If you don't alter the cylinder, the blowdown angle.area and time.area stay the same, irrespective of crankcase pressure. Blowdown should allow the cylinder pressure to drop to the level of the transfer pressure just before the transfers open. So a higher crankcase pressure means that the cylinder pressure does not have to drop quite so far.
In other words, a higher crankcase pressure requires less blowdown time.area.


looking at hugely variable exhaust port durations and a pipe calculator it looks to me from the quick look that the ex pipe could be made to function over a huge range of engine speeds.That's right, but for real power you cannot vary the exhaust timing too much; it has to be about 180° effective or you'll get no true resonance.


Also is there not pressure waves still present in the exhaust when the exhaust port is shut?Yes; that is the main reason that the exhaust timing has to be about 180° effective for true resonance; we want superposition of the old and the new +pulses.


Also do the supercharging rules actually really cover the creation of a vacuum rather than positive boost pressure?They cover both; the variation of the crankcase volume during one crankshaft revolution should not exceed the permissible cylinder capacity, so both suction and primary compression are coupled to piston displacement. In addition, any mechanical device that creates positive boost, is forbidden (an exhaust pipe does that, but it is not considered a mechanical device).

[breezy]

One remark in advance, which regards not only the above question but all questions: unless I say otherwise, all my answers concern conventional engines; they may or may not be valid for the Ryger engine, so don't go jumping to conclusions.

Breezy, a good exhaust system triples the power of a racing two-stroke. How would you use that power elsewhere? By driving a compressor for example? It would help but it's not allowed in most types of motor sport. And in case you mean the amount of energy contained in the exhaust gases: I don't see a way of utilizing that other than in the exhaust pipe.

Re dwelling: a short con rod will cause a higher piston acceleration near TDC and a lower acceleration near BDC, so the piston will dwell longer around BDC.
Assuming the cylinder remains unchanged, a shorter rod will increase angle.areas. For example, The Aprilia RSA has a blowdown angle.area of 14322°mm² and a transfer angle.area of 109969°mm². If we replace its 120 mm con rod with a 100 mm rod (17% shorter), the blowdown angle.area becomes 14609°mm² (2% more) and the transfer angle.area becomes 113119°mm² (2,9% more). The drawback is that the short con rod causes more piston friction and costs crankcase volume.

Thanks for your reply Frits,:niceone: my thinking with the exhaust is that returning waves pushing fuel back into the cylinder from the fuel held in the very hot exhaust port/ header, would be less volume and less hot than he cooler fuel introduced into the cylinder via the inlet system, and that the exhausts pressure waves , which" triple power ",via the exhaust port wouldnt be any different via the inlet system? (closely resembling tz250 plenum system)
with this in mind if the dwell at bdc could be extended/controlled better filling of the cylinder would be achievable...... i had also thought maybe more control over exhaust ports opening and closing would greatly improve the cylinder filling,.... on a conventional 2 stroke engine.....

[FastFred]

Wow, only 50cc of oil in the gearbox? :eek5:

It looked like it in TeeZees post, but no, the leading digit of the left hand number was obscured.

312870

[breezy]

Wobby, is their any part of the conventional 2 stroke engine cycle which would concern the terms "choked flow" or "positive choked flow"?:sherlock:

[wobbly]

You need to understand the real meaning of the term " choked flow " in relation to the 2T cycle first.
So read the paper I have attached, as this is the best I have seen on the science involved.
In reality most people have a misunderstanding of the effect,in that once the local gas velocity is sonic, no increase in VELOCITY can occur.
But , the mass flow rate CAN increase, under the conditions stated..
I went thru this exercise a while ago in relation to determining if sonic conditions occurred when using a nozzle in the Ex duct, or in the tailpipe.
Short answer is that if a normal sized venturi or duct/pipe restriction are used, the local velocity does not exceed Mach 1.
I found that in the sim ( where determining the local gas velocity at any point is trivial ) as soon as you approached sonic conditions, power went down dramatically.
From this I concluded that the energy required to create sonic flow is very high, and this appears to detract very quickly from the energy being used in the pipe for expansion,compression
and stuffing.
My logic may be faulty, but the end result of sonic conditions for sure are not.

And one small point in relation to blowdown.
Port stagger, front to rear, uses the remnant blowdown pressure ratio at the transfer opening point, to affect the scavenging regime.
Remember, no flow can occur until the pressure ratio at the port face goes negative, thus until the pressure in the duct exceeds the cylinder pressure, flow will stall, or in a worst case
it will be reversed back down the transfer that opens first.
This short moment in crankshaft rotation, is enough to affect the distance traveled by each transfer stream in turn,and is why a KZ2 engine needs the A port opening first - as with no PV
it needs the " natural " effect of that regime to widen the powerband.
An Aprilia on the other hand uses reverse stagger, with the B/C ports opening first, that has the effect of boosting peak and overev power by its change in the scavenging pattern, along with the bigger STA
available from the wide B port being high as well.

[JanBros]

They cover both; the variation of the crankcase volume during one crankshaft revolution should not exceed the permissible cylinder capacity, so both suction and primary compression are coupled to piston displacement. In addition, any mechanical device that creates positive boost, is forbidden (an exhaust pipe does that, but it is not considered a mechanical device).

so in theory it would be "legal" to add let's say a solenoid operated diaphragma to the crankcase that makes the volume larger at high revs and smaller at low revs (or something similar that has the same effects). has anyone ever tried that ?

[wobbly]

No free lunch, any sort of activation device that changes the case vol is no different to a variable Ex port valve setup - not legal.
Same with the 24/7 reed concept, maybe they would allow a spring loaded open/close setup, but any form of servo that was rpm
driven, be it electrical or mechanical, is out.

[husaberg]

No free lunch, any sort of activation device that changes the case vol is no different to a variable Ex port valve setup - not legal.
Same with the 24/7 reed concept, maybe they would allow a spring loaded open/close setup, but any form of servo that was rpm
driven, be it electrical or mechanical, is out.

But Wob why stick to rules like the FIM ones when they just ban the two stroke anyway?
I am not meaning kart controlling bodies.

[TZ350]

312873

A bit of open heart surgery on the Beast.

312876

Cylinder is still looking good.

312877

A bit of rubbish has been bouncing around in the head. I will be able to clean that up, no problems.

312874

Drive side main bearing pretty stuffed, even some of the balls were flaking. The bike was sounding pretty rough for the last couple of hundred dyno pulls.

The bike was blowing a lot of smoke and drinking its gearbox oil. Chambers had this problem before and replacing the oil seal didn't do any good but after he replaced his drive side bearing all the oil burning problems stopped. We put it down to the crank flopping about and making the drive side oil seal act like a pump.

312875

The piston has cracked but I expect to be able to salvage it with a dab of weld.

All in all not bad after several seasons of track time and hours on the dyno.

2T's are just so cheap to run ..... :D

[chrisc]

You're going to reuse that Piston TZ? :scratch: I suppose it is a bucket.
That bearing really chewed itself up huh! Were they the phenolic cage bearings?
Great little engines huh

[wobbly]

I thought we were talking about the Modena and the Ryger and using differing technology to make more power in the only racing class ( CIK - KZ2 )
that has newly homologated engines still being produced every year.
Sure in GP racing all this stuff may be fine , but someone would still need to reverse the FIMs aversion to 2T - and this may in fact be possible if the technology was available
to all ( forget the patent rights ) and it could be shown conclusively to be more eco friendlier than a racing 4T ( not that they are at all ).

[TZ350]

You're going to reuse that Piston TZ? :scratch: I suppose it is a bucket. That bearing really chewed itself up huh! Were they the phenolic cage bearings? Great little engines huh

Yes, I am going to re use the piston, not so much because its a "Bucket" but more because I can and to tease the 4T boys who would have to buy an expensive replacement with no guarantee of reliability.

It was a double row, self aligning phenolic caged bearing that was brought second hand with a bunch of others off Ebay for $1 and gave good service in the Beasts engine for lots of seasons before finally retiring.

Yep, the 70-80's Suzuki GP125 is a great little engine, , cheap as to make race winning power with, same as the other 2T's that run at the front.

[husaberg]

I thought we were talking about the Modena and the Ryger and using differing technology to make more power in the only racing class ( CIK - KZ2 )
that has newly homologated engines still being produced every year.
Sure in GP racing all this stuff may be fine , but someone would still need to reverse the FIMs aversion to 2T - and this may in fact be possible if the technology was available
to all ( forget the patent rights ) and it could be shown conclusively to be more eco friendlier than a racing 4T ( not that they are at all ).

Nah F the FIM.
Why bother with them at all? Remember the good of days before the Bernie Ecclestone's the Dornas and co got involved in motorsport.
Produce a product that people can support and people will get involved.

[peewee]

this evenings adventure. just as things were going great the damn tungsten fell out of the collet. i couldnt believe it. melted it to shit and the party was over. as it was my only 3/32" collet it was time for plan B. install 1/16" collet and continue on :lol:

[F5 Dave]

Yes, I am going to re use the piston, not so much because its a "Bucket" but more because I can and to tease the 4T boys who would have to buy an expensive replacement with no guarantee of reliability.

It was a double row, self aligning phenolic caged bearing that was brought second hand with a bunch of others off Ebay for $1 and gave good service in the Beasts engine for lots of seasons before finally retiring.

Yep, the 70-80's Suzuki GP125 is a great little engine, , cheap as to make race winning power with, same as the other 2T's that run at the front.
Heck yeah. If you lightly centre punch the piston the divets will be the riding surface which will flatten over and you will effectivly decrease the piston clearance so it will be like new. You can't decrease the ring end gap but if you stretch the ring out you will increase the dynamic tension and that helped Charles Atlas kick sand in the face of weaklings on the beach , or so the back of my comic books used to say. Welding rod is expensive, some JB weld should fix that right up if you are just putting it on the inside which is cooled by the gas should be fine you can trust me.

[Frits Overmars]

Wow, only 50cc of oil in the gearbox?
It looked like it in TeeZees post, but no, the leading digit of the left hand number was obscured.50 cc of oil in the primary transmission ('lato frizione') and 250 cc in the gearbox ('lato cambio').
312896

[sonic_v]

Frits

Has the Ryger ever been Dyno tested?

[husaberg]

Frits

Has the Ryger ever been Dyno tested?

I think I can answer for Frits that while he was there he seen no engines running on the Dyno.

I have an question that maybe Frits can answer when Harry Ryger invited you around for a coffee, Did he have biscuits and if so what type were they?

[Frits Overmars]

I have an question that maybe Frits can answer when Harry Ryger invited you around for a coffee, Did he have biscuits and if so what type were they?Yes Sonic, it was dyno tested. Yes Husa, he did have biscuits; they were chocolate-clad.

[Martin1981]

How could ryger say that the engine has 70rwhp if it never was dyno tested?

[Muciek]

How could ryger say that the engine has 70rwhp if it never was dyno tested?



Yes Sonic, it was dyno tested. Yes Husa, he did have biscuits; they were chocolate-clad.


It was.Btw TZ any progress made with RGV cylinder?

[breezy]

You need to understand the real meaning of the term " choked flow " in relation to the 2T cycle first.
So read the paper I have attached, as this is the best I have seen on the science involved.
In reality most people have a misunderstanding of the effect,in that once the local gas velocity is sonic, no increase in VELOCITY can occur.
But , the mass flow rate CAN increase, under the conditions stated..
I went thru this exercise a while ago in relation to determining if sonic conditions occurred when using a nozzle in the Ex duct, or in the tailpipe.
Short answer is that if a normal sized venturi or duct/pipe restriction are used, the local velocity does not exceed Mach 1.
I found that in the sim ( where determining the local gas velocity at any point is trivial ) as soon as you approached sonic conditions, power went down dramatically.
From this I concluded that the energy required to create sonic flow is very high, and this appears to detract very quickly from the energy being used in the pipe for expansion,compression
and stuffing.
My logic may be faulty, but the end result of sonic conditions for sure are not.

And one small point in relation to blowdown.
Port stagger, front to rear, uses the remnant blowdown pressure ratio at the transfer opening point, to affect the scavenging regime.
Remember, no flow can occur until the pressure ratio at the port face goes negative, thus until the pressure in the duct exceeds the cylinder pressure, flow will stall, or in a worst case
it will be reversed back down the transfer that opens first.
This short moment in crankshaft rotation, is enough to affect the distance traveled by each transfer stream in turn,and is why a KZ2 engine needs the A port opening first - as with no PV
it needs the " natural " effect of that regime to widen the powerband.
An Aprilia on the other hand uses reverse stagger, with the B/C ports opening first, that has the effect of boosting peak and overev power by its change in the scavenging pattern, along with the bigger STA
available from the wide B port being high as well.

Thanks for reply, given me something to contemplate.

[FastFred]

Heck yeah. If you lightly centre punch the piston the divets will be the riding surface which will flatten over and you will effectively decrease the piston clearance so it will be like new.

You are on to it, knurling old pistons to take up the slack was the standard procedure back in the day. A knurled piston only needed half the clearance of an ordinary piston.

312899 and 312903


Welding rod is expensive, some JB weld should fix that right up if you are just putting it on the inside which is cooled by the gas should be fine.

Pretty sure TeeZee has already showin you can successfully glue the inside of a piston ..... :scratch:

312902 Page 231


you can trust me.

312901

Sure can .... :laugh:

[wobbly]

Not only were Rolfs fingers tapping the paint cans, they were up teenage girls dresses as well.

[2T Institute]

Yes Sonic, it was dyno tested. Yes Husa, he did have biscuits; they were chocolate-clad.

what no almond speculaas ?

[peewee]

alittle more progress tonight. besides not being the greatest welder, maybe even the worst, what you guys think ? :laugh:

[TZ350]

Looks good, I particularly like that you have deliberately learnt new skills from scratch so you can do this. The true Buckateer way.

Is this cylinder going to have a rasied exhaust port floor dam?

[ken seeber]

You are on to it, knurling old pistons to take up the slack was the standard procedure back in the day. A knurled piston only needed half the clearance of an ordinary piston.

Sure can

At Orbital, we used to centre pop new design pistons on a grid pattern, each centre pop creating a small mound of aluminium around the pop. Then it was run in an engine for a little bit at max power. Taken out, put on a Talyrond roundness measuring machine and the height of the mounds, relative to the surrounding surface was measured. Then, if the mounds were high, then a new profile was developed based on the profile of the heights. This was fed into a Takisawa camless piston turning CNC lathe and a new shape was produced. The goal was to be able to minimise the clearances for performance, durability and NVH reasons. Not completely perfect, but not too bad.


rolf harris was/is a total sleazebag and a knob jockey of the first order and all art awards etc that he seemed to gain in Perth (where he came from) have been removed. Hope he rots and soon.

[TZ350]

Optimising the piston profile that way, now that is very clever....

[wobbly]

When the cylinder has been soaked in 2T oil for years it impossible to get nice a TIG weld without contamination, no matter
how much you clean or acid etch the surface beforehand.
Here is a KTM250 I am doing for kart roadracing.

Re doing the piston shape - we finally got the shape right on the BSL by getting the pistons skirts HPC coated to give zero bore clearance.
Then ran them long enough for the hot piston shape to rub hard enough to wear away the coating.
This was then measured the same way as Ken did it with the results going back to Vertex to reprofile the next batch.
It took 3 goes before the shape of the new ( 59.6mm ) piston was perfect, as proven by the fact we could then warm up a new set with
one heat cycle in the pits - and then go race immediately - no running in at all.

[F5 Dave]

So are super karts now restricted to singles?

[wobbly]

No, there is a class for production 250 singles.

[peewee]

i learned alot just in the last few weeks. 90% of my troubles were gas coverage related. had tungsten sticking out to far, torch tilted to far etc. once i realized that, everything got alot easier. heavy dose of helium sure helped also :laugh:. machine was set at 135amps and mostly i only needed 1/2 to 3/4 peddle. straight argon struggled to get a good puddle at 200amps floor boarded peddle

[sonic_v]

i learned alot just in the last few weeks. 90% of my troubles were gas coverage related. had tungsten sticking out to far, torch tilted to far etc. once i realized that, everything got alot easier. heavy dose of helium sure helped also :laugh:. machine was set at 135amps and mostly i only needed 1/2 to 3/4 peddle. straight argon struggled to get a good puddle at 200amps floor boarded peddle

Are you using DC or AC?

[JanBros]

No free lunch, any sort of activation device that changes the case vol is no different to a variable Ex port valve setup - not legal.
Same with the 24/7 reed concept, maybe they would allow a spring loaded open/close setup, but any form of servo that was rpm
driven, be it electrical or mechanical, is out.

I wasn't talking specificaly for stricly regulated kart engines, more generaly. for example in 125cc bike engines : the displacement of the piston is the limiting factor. having a device that controles the volume of the crankcase in the same way as an exhaust valve - so only working in different rev-ranges, like a controlable solenoid that makes the volume smaller or larger- should have been possible/permitted in GP125's ?

so at lower rev's a smaller crankcase volume that increases the crankcase preasure and lowers actual blowdown-time (as Frits says, there might be more blowdown than needed at low revs). anyone ever treid something like that ?

[peewee]

Are you using DC or AC?

there may be special tricks to weld alloys on DC but generally i think its welded on AC, thats what i was using anyways. use a inverter machine if you can, they have much more adjustability and arent much bigger than a home computer tower. for the exh port floor the balance was on 70% and HZ on 120. gas flow around 15cfh. about 5sec postflow. 50/50 AR/HE mix. started out with 3/32 2% ceriated tungsten but it fell out of the collet and burned up the collet so i went to 1/16 setup and it still seemed to work fine. originally i was using a gas cooled torch but it was a pain in the ass so i switched to watercooled torches

[TZ350]

page 1210 ........


Hi I have been reading all the info on this forum with interest for a few months now it really helps amateur engine and pipe builders like myself . I have an engine problem that I need help with , we race 3 kx 250 engines in the nz superkart series and for the past 6 months or so have been trying to diagnos an engine electrical miss at about 7000 rpm plus under acceleration . we did everything electrical you can think of and did most things more than once, finally not thinking that this would fix the problem we swapped the flywheel from another engine and the miss was gone . so then obviously needed another flywheel , ordered one on e-bay fitted to the engine that was now missing a flywheel [ie different engine from the one that had the original miss ] engine miss returns . flywheel has same partnumber , same dimensions and looks perfectly fine . ignition is ignitec , trigger coil and ignition coil wiring has all been separated . Can anyone offer an explaination I don't want to keep buying flywheels until I get one that works
cheers Richard


What is the diameter of the rotor and what is the trigger lobe length.
In reality the lobe length only needs to be as wide as the magnetic trigger pole.
If the lobe is too long the rising voltage waveform from the upward bump can decay to zero and give a false trigger signal
before the actual dropping edge has left the poles magnetic field.
Re electrical interference, of course you have resistor spark plugs and a resistor cap ( measure both to ensure the resistor element isnt fried ).
And the other trick is to tightly wind the two wires together from the trigger up to the ECU, by holding the ends in a battery drill and slowly winding it over.
This gives good common mode rejection of spurious noise.


I was using a similar setup i.e. KX125 rotor and pick up triggering an ignitech. We ground away the bulk of the lobe length, and closed up the gap between the pickup and lobe to as tight as could be achieved without causing interference. If the gap was opened up just slightly it would start to misfire at around 7k. Dump the original KX pickup (if that's what you are using) and buy one of the ignitech units.


Yep the lobe is too long - 1/2 its length and all will be fine.
I dont know if the KX trigger is shit, but I have never had any trouble with regular CR125/250 types.
The Ignitech one operates exactly the same as the Kokusan type Honda ones, nothing special at all.
There is an option under special setting called wide lobe, this is probably to suit exactly what you have, but I have never used it.


Strange. For the subject of kick-started engines I talked to Ignitech and they told me this:
"Hello,

You have make pulse lobe with lenght about 30 degrees. Surface, height and
width of pulse lobe must be homogenous.
We recommended to use pick-up IP6.

Regards.

Jiri Krejzl
IGNITECH"

My daily driver with ignitech has now exactly 30° of lobe lenght - and I am not able to adjust the idle where I want it to be. 3000RPM is as low as it gets.
On my RZ350 the lobe length seems to be shorter - and this engine has a nice idle.

So talking about the KX engine of karter4444: half of 30mm would be around 20° of lobe lenght. So would that be the general lenght you would recoment for a kickstarted engine?

And is there a base advance I should prefer?
cheers and thanks!
Tim


The length of the lobe makes no difference to the performance parameters of the Ignitech, except the issues we have seen
when it is too long.
Its the trailing edge position that triggers the spark event, but in some cases the leading edge is used to limit the total advance capability.
Below 300rpm the base timing is the default timing when the ecu first starts to supply a spark, above that the curve takes over.
You want enough base timing to enable ignition to occur early enough, but not so early that you can get "kick back " that can if bad enough
cause the engine to start backwards, or at the least break your leg.
I have found that 10 to 20* of base timing works fine in almost every case with a kickstarter.


Got engmod, wohoo!!
first of all; a HUGE thank you to Neels for the superb service and great product, and to all of you guys especially wobbly and TZ350 for making me aware of the software and it's capabilities, and sharing all the info!

Everything is working great, no hickups...exept for that I'm experiencing problems when trying to run simulations in turbulent mode (probably user error though...)

heres my combustion data:
312733

heres a simulation running prescribed
312734

and heres what happens(and other variations of wierd output) when I try to run turbulent, no change to the combustion data, just ticked of "turbulent".
312735


What am I doing wrong?


Occasionally the turbulent model is affected incorrectly by the combustion parameters being out of range ie the duration goes over 100* ( usually squish related ) and
it all goes wrong.
Send a pack to Neels and he will be able to see the issue and advise.

Re the blowdown question - with a single Ex port you are always fighting a lack of blowdown STA, and this is where the only way to balance the power capability's of the transfers
with the Ex is to run the numbers thru an analysis program.
In general it is usually possible to get alot more transfer STA by widening them all to the max, whilst keeping them low to help the blow numbers without jacking up the Ex timing excessively.
Ski engines generally aren't limited badly by close bore centers creating shit transfer ducts, so concentrating on the area can reap good results.


I've got today to play around with this, however, for a wide power band is this mixture not the best ?

Lean at the bottom, this means engine runs hotter, (less fuel cooling) exhaust is therefore hotter so pipe looks shorter and closer to optimal and by the same reasoning, richer at the top means more cooling and temperatures lower and so pipe seems longer ?

I may make more power with changes but a wide band is what I'm after or a 6 speed gearbox.

Cheers Wallace


Completely opposite logic is needed - unless im reading you wrongly?.
Rich at the bottom to cool the pipe, making it appear longer for drive of slow corners, then lean at the top to get it to spin
up with the higher egt making the pipe shorter.


You are correct, just as well I checked. Brain fade.


With todays technology the bar can now be raised to around 40 crank Hp without too much drama involved, and thus achieving around 35 RWHp.
Its just a matter of careful parts selection and very careful assembly.

The alloy inserts for the TZ350 was the customers choice - once its all proven, and we get a handle on what the engine likes, then I will do some bronze ones.

AvGas in NZ is all LL100, this is low lead 100 octain.But the rating is defined differently in avaition.Its approx equiv to 100 "pump" gas, but has a lean rating of 100 and a rich rating of 130.
MNZ Appendix E defines avgas as max 112 MON amd max 108 RON.

Avgas, or any leaded "race" fuel reacts completely differently to unleaded pump gas.
In general terms the unleaded hates compression, but loves timing.Avgas is the opposite in that it makes more power up to the knock limit with more com.
Unleaded makes better power when run rich,avgas makes more the leaner you go.
Tuning in the old days with RS and TZ engines meant using lean mains and small powerjets ( 35 ) as turning off a big jet over the top would mean being too lean in the overev.
Nowdays the unleaded fuel runs rich at peak power, then uses a big powerjet ( 55) to create some heat in the pipe over the top.


Got an update from Neels, now turbulent works fine.

Newb question:
When using the numbers I got from turbulent, can I play around with ignition timing in prescribed mode, or do I have to run turbulent again everytime I change timing for a rpm point?


No, once you have saved and imported the turbulent combustion model, you can use that with changed timing numbers, saving it as a new file each time.




313424

After a bit of fiddling I made some improvement.


What about the peak and overev power - the main/corrector system can hves just as much effect there as in the mid.


Only a part of the rev range shown. The whole range including overrev will show the total effect of the changes.


Very nice.I'll put that on my todo list.


I need to get my O2 sensor working consistently to do the top end. I was basically just trying to get the bottom end better as the 5 speed MX gearbox is not the best for the track.

313425

My EGT only shows 950 at max power on the track so I still have some work to do. I'm hope the EGT is correct ? Ashburton's dyno shows close to 12.5:1 fuel air so I'm not sure why the temp is so low.

Maybe I need to do a bench calibration of the sensor and GPX Pro box. .


Wobby, is their any part of the conventional 2 stroke engine cycle which would concern the terms "choked flow" or "positive choked flow"?:sherlock:


You need to understand the real meaning of the term " choked flow " in relation to the 2T cycle first.
So read the paper I have attached, as this is the best I have seen on the science involved.
In reality most people have a misunderstanding of the effect,in that once the local gas velocity is sonic, no increase in VELOCITY can occur.
But , the mass flow rate CAN increase, under the conditions stated..

313426

I went thru this exercise a while ago in relation to determining if sonic conditions occurred when using a nozzle in the Ex duct, or in the tailpipe.
Short answer is that if a normal sized venturi or duct/pipe restriction are used, the local velocity does not exceed Mach 1.
I found that in the sim ( where determining the local gas velocity at any point is trivial ) as soon as you approached sonic conditions, power went down dramatically.
From this I concluded that the energy required to create sonic flow is very high, and this appears to detract very quickly from the energy being used in the pipe for expansion,compression
and stuffing. My logic may be faulty, but the end result of sonic conditions for sure are not.

And one small point in relation to blowdown.
Port stagger, front to rear, uses the remnant blowdown pressure ratio at the transfer opening point, to affect the scavenging regime.
Remember, no flow can occur until the pressure ratio at the port face goes negative, thus until the pressure in the duct exceeds the cylinder pressure, flow will stall, or in a worst case
it will be reversed back down the transfer that opens first.
This short moment in crankshaft rotation, is enough to affect the distance traveled by each transfer stream in turn,and is why a KZ2 engine needs the A port opening first - as with no PV
it needs the " natural " effect of that regime to widen the powerband.
An Aprilia on the other hand uses reverse stagger, with the B/C ports opening first, that has the effect of boosting peak and overev power by its change in the scavenging pattern, along with the bigger STA
available from the wide B port being high as well.


You are on to it, knurling old pistons to take up the slack was the standard procedure back in the day. A knurled piston only needed half the clearance of an ordinary piston.

312899 and 312903
Pretty sure TeeZee has already showin you can successfully glue the inside of a piston ..... :scratch:

312902 Page 231



At Orbital, we used to centre pop new design pistons on a grid pattern, each centre pop creating a small mound of aluminium around the pop. Then it was run in an engine for a little bit at max power. Taken out, put on a Talyrond roundness measuring machine and the height of the mounds, relative to the surrounding surface was measured. Then, if the mounds were high, then a new profile was developed based on the profile of the heights. This was fed into a Takisawa camless piston turning CNC lathe and a new shape was produced. The goal was to be able to minimise the clearances for performance, durability and NVH reasons. Not completely perfect, but not too bad.


Re doing the piston shape - we finally got the shape right on the BSL by getting the pistons skirts HPC coated to give zero bore clearance.
Then ran them long enough for the hot piston shape to rub hard enough to wear away the coating.
This was then measured the same way as Ken did it with the results going back to Vertex to reprofile the next batch.
It took 3 goes before the shape of the new ( 59.6mm ) piston was perfect, as proven by the fact we could then warm up a new set with
one heat cycle in the pits - and then go race immediately - no running in at all.

[peewee]

got the exh hole and some of the roof filled up today. anybody know a easy way to tell if the manifold is regular or stainless steel ? its cr500 manifold im using and its highly magnetic. will probly expose it to water and see if rust forms.

[husaberg]

anybody know a easy way to tell if the manifold is regular or stainless steel ? its cr500 manifold im using and its highly magnetic. will probly expose it to water and see if rust forms.

http://www.google.co.nz/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CBwQFjAA&url=http%3A%2F%2Fdx.doi.org%2F10.6028%2Fjres.011.0 35&ei=KimGVaePN-G7mgWcgLywCw&usg=AFQjCNG3BXeySUq9Mo2YrZ4RvL2UGtSUeA

Spark testing......... is one way, note some high Chromium steels are still magnetic.

[Flettner]

I know how it's done, with a rocker arm ( Ryger ). As Frits said simple, piston and rod are one as we decided before but forget that complicated crank within a crank idea. Round conrod comes down through the "sealed off from oil" guide bush under the piston then terminates at a rocker arm. This arm is anckored at the area where the case reed used to be, there is a solid looking plate covering that hole that looks like it could be more than just a crank case seal, I think something is attached to it. The crankshaft could be connected to this rocker arm further down the fulcrum so the crankshaft stroke is less than 54mm. The problems with bigends are not so much combustion load but load from centripital force so less stroke, less centripital force at higher rpm, no problem with increaseing the combustion load ( leaverage from the arm ). The attachment to the case ( plate ) would need a small secondary linkege to allow for the fact that the lever arm pivots. This attachment linkage could be adjustable to make the piston move higher or lower in the cylinder ie low rpm or high rpm also having a useful effect on the compression and port timing, on the fly. Tell me I'm right!
And I still think they are using combustion pressure to " excite " the crankcase pressure at higher rpm where there is not enough blow down time and higher transfer pressure is needed, probably through a fine wire mesh to take out some of the combustion heat.

And done right you could have a fast / slow piston movement, like an old shaper, fast one way slower the other. Perhaps help with blowdown time?

To be fair, Ken Seeber was the one who noticed the thick alloy cover over the bottom reed housing.

[breezy]

I know how it's done, with a rocker arm ( Ryger ). As Frits said simple, piston and rod are one as we decided before but forget that complicated crank within a crank idea. Round conrod comes down through the "sealed off from oil" guide bush under the piston then terminates at a rocker arm. This arm is anckored at the area where the case reed used to be, there is a solid looking plate covering that hole that looks like it could be more than just a crank case seal, I think something is attached to it. The crankshaft could be connected to this rocker arm further down the fulcrum so the crankshaft stroke is less than 54mm. The problems with bigends are not so much combustion load but load from centripital force so less stroke, less centripital force at higher rpm, no problem with increaseing the combustion load ( leaverage from the arm ). The attachment to the case ( plate ) would need a small secondary linkege to allow for the fact that the lever arm pivots. This attachment linkage could be adjustable to make the piston move higher or lower in the cylinder ie low rpm or high rpm also having a useful effect on the compression and port timing, on the fly. Tell me I'm right!
And I still think they are using combustion pressure to " excite " the crankcase pressure at higher rpm where there is not enough blow down time and higher transfer pressure is needed, probably through a fine wire mesh to take out some of the combustion heat.

can you draw a picture of how you think the rocker turns crank wheels/ shafts..:sherlock: sounds like the set up could look like a 4 stroke valve or desmodronic , with the valve face being the piston...

[breezy]

All credit for the Ryger engine should go to Harry Ryger, and Harry alone. I'd post a picture of the engine's spiritual father, but Harry prefers to stay in the background. Finding his photo on the world wide web may prove to be as difficult as finding the Ryger patents :p.
:grouphug: maybe RYGER is just the tradename?..."spiritual father"... is the original ideas man still with us? maybe ill get its eventually...:confused:

[Yow Ling]

I know how it's done, with a rocker arm ( Ryger ). As Frits said simple, piston and rod are one as we decided before but forget that complicated crank within a crank idea. Round conrod comes down through the "sealed off from oil" guide bush under the piston then terminates at a rocker arm. This arm is anckored at the area where the case reed used to be, there is a solid looking plate covering that hole that looks like it could be more than just a crank case seal, I think something is attached to it. The crankshaft could be connected to this rocker arm further down the fulcrum so the crankshaft stroke is less than 54mm. The problems with bigends are not so much combustion load but load from centripital force so less stroke, less centripital force at higher rpm, no problem with increaseing the combustion load ( leaverage from the arm ). The attachment to the case ( plate ) would need a small secondary linkege to allow for the fact that the lever arm pivots. This attachment linkage could be adjustable to make the piston move higher or lower in the cylinder ie low rpm or high rpm also having a useful effect on the compression and port timing, on the fly. Tell me I'm right!
And I still think they are using combustion pressure to " excite " the crankcase pressure at higher rpm where there is not enough blow down time and higher transfer pressure is needed, probably through a fine wire mesh to take out some of the combustion heat.

Frits has gone quiet, you must be close

[Larry Wiechman]

I envision a Watts linkage in place of a simple rocker; for true straight line motion.

[breezy]

Frits has gone quiet, you must be close

Frits is probably getting stuck into a big barrel of rum and raisen icecream laughing his ***ts off:laugh::laugh:

[wobbly]

Peewee, you are of course going to be tig welding the inside of the steel spigot to grind and match it to the duct exit shape,
by making an oval to round transition - yes.

[TZ350]

Btw TZ any progress made with RGV cylinder?

312969

No not a lot, pulled the old GP EFI motor out of the Beast to recondition it with the view of re fitting it to the new NSR chassis so as to continue the EFI development.

312976

But the whole EFI project is taking to long, so instead of proving everything one step at a time I think I will just take a leap of faith and say the EFI will work and finish the RGV motor complete with the EFI and Plenum system.

312968

Also been helping Chambers a little bit with his RG50 project.

312966 312965 312967

Here is his RG50 cylinder with the 86% exhaust port after we ran it for 20-30 pulls or so on the dyno, looks good, we are aiming for 16-17 rwhp, near 14 is our best so from an RG50.

[sonic_v]

I know how it's done, with a rocker arm ( Ryger ). As Frits said simple, piston and rod are one as we decided before but forget that complicated crank within a crank idea. Round conrod comes down through the "sealed off from oil" guide bush under the piston then terminates at a rocker arm.

This would be even simpler.



http://www.marinediesels.info/Basics/2_stroke_crosshead_labeled.gif

[peewee]

Peewee, you are of course going to be tig welding the inside of the steel spigot to grind and match it to the duct exit shape,
by making an oval to round transition - yes.


weld the red areas was my plan. is the roof and floor of the manifold supposed to flat like the cylinder exit ? i was just going by how the rsa looked. from what i understand, stainless needs a different welding rod than regular steel. ive got some water on the manifold to see if any rust forms. worst case i may have to get a few different rods and see which one works

[Flettner]

weld the red areas was my plan. is the roof and floor of the manifold supposed to flat like the cylinder exit ? i was just going by how the rsa looked. from what i understand, stainless needs a different welding rod than regular steel. ive got some water on the manifold to see if any rust forms. worst case i may have to get a few different rods and see which one works

Use MG 600's

[senso]

A friend of mine makes exhaust pipes and for either steel(zincor) or stainless he always uses stainless welding rods, but not sure if they are 304 or 316 but I think it is 316 stainless ER something something.

That cylinder is looking great, I assume that in the water jacket there is a huge boss to allow some wall thickness for the hole that you plugged, will you grind that boss to reduce wall thickness?
It seems like you have some 10-12mm of wall thickness in the center of the main exhaust port duct.

[husaberg]

I know how it's done, with a rocker arm ( Ryger ). As Frits said simple, piston and rod are one as we decided before but forget that complicated crank within a crank idea. Round conrod comes down through the "sealed off from oil" guide bush under the piston then terminates at a rocker arm. This arm is anckored at the area where the case reed used to be, there is a solid looking plate covering that hole that looks like it could be more than just a crank case seal, I think something is attached to it. The crankshaft could be connected to this rocker arm further down the fulcrum so the crankshaft stroke is less than 54mm. The problems with bigends are not so much combustion load but load from centripital force so less stroke, less centripital force at higher rpm, no problem with increaseing the combustion load ( leaverage from the arm ). The attachment to the case ( plate ) would need a small secondary linkege to allow for the fact that the lever arm pivots. This attachment linkage could be adjustable to make the piston move higher or lower in the cylinder ie low rpm or high rpm also having a useful effect on the compression and port timing, on the fly. Tell me I'm right!
And I still think they are using combustion pressure to " excite " the crankcase pressure at higher rpm where there is not enough blow down time and higher transfer pressure is needed, probably through a fine wire mesh to take out some of the combustion heat.

And done right you could have a fast / slow piston movement, like an old shaper, fast one way slower the other. Perhaps help with blowdown time?

To be fair, Ken Seeber was the one who noticed the thick alloy cover over the bottom reed housing.

Neil My current take (version 3876)is no crankcase at all. But a reed cavity that extends under the reed valve where the original crankcase reed was.
It is driven by either a diaphragm or as illustrated bellow a flapper valve which has variable linkage stroke or speed.
This flapper runs at 2 or 4 times the crankshaft speed to compress and recompress the mixtures (the reed makes sure there is no reverse flow.)
This mixture which has been compressed into the transfers feed direct to the cylinder allows for faster cylinder filling.
The rate of compression of this mixture,as it is controlled by a variable eccentric is thus speed dependant. So it thus very clean.
I have seen no claims that suggest the Ryger mets FIM rules. so I see this as a valid supposition.
This way the bottom end can be conventional with just a plain big end and pressure feed.
312983
This fits in with what the Ryger looks like.

[wobbly]

Yes, you need to shape the manifold floor/roof as per the exit, and this shape as well as the side port ducts need to taper
down smoothly all the way to nothing at the face where the header starts.
I have tested this numerous times and a proper oval to round transition always makes more power than having the steps.
Even if the manifold is stainless I would weld it with soft mild steel rod, as the stainless material is hard as hell ans a complete bitch to grind.

[peewee]

did some digging and found the ER312 rod is used to join stainless to regular steel. so ill just use that, as it will weld to this manifold regardless what meterial it is. hopefully it isnt to difficult to grind. might do a test run on some scrap to see how easy it grinds. ok so the manifold floor and roof should match the exh exit, no steps. then transition to round at the exit of the manifold. got it :niceone:. i hate to even ask but why was the rsa125 not that same way ?


senso thnx mate. yes there is a large boss in the water jacket above the exh hole that i grinded out. i didnt even think of it but now the hole is gone maybe i should grind that boss down. anyways today i added alittle more material on the sides just to be sure. got some alloy tubes of various sizes to cut length wise and weld back over the side water jacket

[speedpro]

I know how it's done, with a rocker arm ( Ryger ). As Frits said simple, piston and rod are one as we decided before but forget that complicated crank within a crank idea. Round conrod comes down through the "sealed off from oil" guide bush under the piston then terminates at a rocker arm. This arm is anckored at the area where the case reed used to be, there is a solid looking plate covering that hole that looks like it could be more than just a crank case seal, I think something is attached to it. The crankshaft could be connected to this rocker arm further down the fulcrum so the crankshaft stroke is less than 54mm. The problems with bigends are not so much combustion load but load from centripital force so less stroke, less centripital force at higher rpm, no problem with increaseing the combustion load ( leaverage from the arm ). The attachment to the case ( plate ) would need a small secondary linkege to allow for the fact that the lever arm pivots. This attachment linkage could be adjustable to make the piston move higher or lower in the cylinder ie low rpm or high rpm also having a useful effect on the compression and port timing, on the fly. Tell me I'm right!.

An interesting idea. Re the attachment to the case being a secondary linkage - The problem I see with that is that you then rely on the piston and the bush the rod passes through to locate the bottom part of the rod so that it only moves vertically. If the rocker arm case pivot was fixed and the small secondary linkage was at the rod end of the rocker arm and connected to the bottom of the rod, any forces exerted on the rocker arm by the crankshaft conrod trying to move it horizontally, due to rod geometry, would be resisted by the solidly fixed pivot. Ideally the rocker arm would be as long as possible which would reduce the effects of it pivoting and therefore the horizontal displacement at the rod end. That does put more moving parts and more reciprocating mass at the end of the rocker arm.

The Watts linkage is another thought, with the crankshaft conrod connected to the lower arm at some point inboard of the vertical link. The vertical link at it's centre essentially moving only vertically and connected to the rod to the piston. It would remove any thrust loads from the bush caused by linkage geometry.

A thought I had was along similar lines to Neil in that there was a rocker arm, free to pivot at one end, and with a link at the other to connect to the rod that goes through the bush and seal to the piston. My idea though was that the connection to the crankshaft was via a pin extending each side of the rocker arm fitted with bearings that ran in mirror image tracks machined into the inner faces of the crank wheels. You could machine any track profile you wanted and create dwell at BDC and have a favourable ramp on the power-stroke side that extracted the most power given the pressure rate profiles. Of course there is probably a very good reason why that has never been done. One of which is obviously the precision required in manufacture and assembly. The 2 "crank" halves would be connected together through the centre as there is no rod that rotates through there.

[Flettner]

An interesting idea. Re the attachment to the case being a secondary linkage - The problem I see with that is that you then rely on the piston and the bush the rod passes through to locate the bottom part of the rod so that it only moves vertically. If the rocker arm case pivot was fixed and the small secondary linkage was at the rod end of the rocker arm and connected to the bottom of the rod, any forces exerted on the rocker arm by the crankshaft conrod trying to move it horizontally, due to rod geometry, would be resisted by the solidly fixed pivot. Ideally the rocker arm would be as long as possible which would reduce the effects of it pivoting and therefore the horizontal displacement at the rod end. That does put more moving parts and more reciprocating mass at the end of the rocker arm.

The Watts linkage is another thought, with the crankshaft conrod connected to the lower arm at some point inboard of the vertical link. The vertical link at it's centre essentially moving only vertically and connected to the rod to the piston. It would remove any thrust loads from the bush caused by linkage geometry.

A thought I had was along similar lines to Neil in that there was a rocker arm, free to pivot at one end, and with a link at the other to connect to the rod that goes through the bush and seal to the piston. My idea though was that the connection to the crankshaft was via a pin extending each side of the rocker arm fitted with bearings that ran in mirror image tracks machined into the inner faces of the crank wheels. You could machine any track profile you wanted and create dwell at BDC and have a favourable ramp on the power-stroke side that extracted the most power given the pressure rate profiles. Of course there is probably a very good reason why that has never been done. One of which is obviously the precision required in manufacture and assembly. The 2 "crank" halves would be connected together through the centre as there is no rod that rotates through there.

At the attachment of the rocker to the case there is a second smaller linkage that allows for this side movement, at right angles up or down to the main rocker. This small linkage would be say 20mm long ish. By adjusting the attachment point ( to the case ) of this small linkage you will adjust where the piston stroke occurs in the cylinder, a bit like a seesaw. This adjustment could be by a small eccentric as not much movement would be required and not much force needed.
Simple and easy to build.

I'll have to try and draw something bugger it!

[speedpro]

I fully understand the adjustment system. That adjustment could also be used in my suggested ideas. The "fixed" pivot for the rocker arm would actually be able to move vertically by say about 2mm. It could be varied with revs or load.

[Ocean1]

A friend of mine makes exhaust pipes and for either steel(zincor) or stainless he always uses stainless welding rods, but not sure if they are 304 or 316 but I think it is 316 stainless ER something something.

304 is normal for car exhaust tubing, (the tube itself). 316 tends to work harden and crack, (the tube and the weld).

I use 309 rods to weld mild/medium steel to stainless, a practice I copied from an experienced pro, seems to work OK all things being equal. All things being no stress risers/sudden sectional changes etc.

[Frits Overmars]

"spiritual father"... is the original ideas man still with us? No need to die first in order to become a spiritual father, Breezy. Harry Ryger is alive and kickin' the two-stroke community.


Frits has gone quiet, you must be closeYour logic leaves something to be desired Yow Ling, just like the wifi on the Sachsenring circuit, where I spent the past couple of days, left something to be desired.
I didn't go quiet by choice, mate.


so the manifold floor and roof should match the exh exit, no steps. then transition to round at the exit of the manifold. got it. i hate to even ask but why was the rsa125 not that same way ?The RSA indeed had steps at top and bottom of the cylinder/manifold junction; something to do with evolution I'd say, like why men have nipples. But I am with Wobbly on this one.
Moreover, the RSA's exhaust port shape as it has become known through the numerous pictures, is not the latest version; the final version had the port floor raised even higher.

[Frits Overmars]

having a device that controles the volume of the crankcase in the same way as an exhaust valve - so only working in different rev-ranges, like a controlable solenoid that makes the volume smaller or larger- should have been possible/permitted in GP125's ? so at lower rev's a smaller crankcase volume that increases the crankcase preasure and lowers actual blowdown-time (as Frits says, there might be more blowdown than needed at low revs).
I know how it's done, with a rocker arm ( Ryger ). As Frits said simple, piston and rod are one as we decided before but forget that complicated crank within a crank idea. Round conrod comes down through the "sealed off from oil" guide bush under the piston then terminates at a rocker arm. This arm is anckored at the area where the case reed used to be, there is a solid looking plate covering that hole that looks like it could be more than just a crank case seal, I think something is attached to it. The crankshaft could be connected to this rocker arm further down the fulcrum so the crankshaft stroke is less than 54mm. The problems with bigends are not so much combustion load but load from centripital force so less stroke, less centripital force at higher rpm, no problem with increaseing the combustion load ( leaverage from the arm ). The attachment to the case ( plate ) would need a small secondary linkege to allow for the fact that the lever arm pivots. This attachment linkage could be adjustable to make the piston move higher or lower in the cylinder ie low rpm or high rpm also having a useful effect on the compression and port timing, on the fly. Tell me I'm right!
And I still think they are using combustion pressure to " excite " the crankcase pressure at higher rpm where there is not enough blow down time and higher transfer pressure is needed, probably through a fine wire mesh to take out some of the combustion heat. And done right you could have a fast / slow piston movement, like an old shaper, fast one way slower the other. Perhaps help with blowdown time? To be fair, Ken Seeber was the one who noticed the thick alloy cover over the bottom reed housing.
Neil My current take (version 3876)is no crankcase at all. But a reed cavity that extends under the reed valve where the original crankcase reed was. It is driven by either a diaphragm or as illustrated bellow a flapper valve which has variable linkage stroke or speed. This flapper runs at 2 or 4 times the crankshaft speed to compress and recompress the mixtures (the reed makes sure there is no reverse flow.) This mixture which has been compressed into the transfers feed direct to the cylinder allows for faster cylinder filling. The rate of compression of this mixture,as it is controlled by a variable eccentric is thus speed dependant. So it thus very clean. I have seen no claims that suggest the Ryger mets FIM rules. so I see this as a valid supposition. This way the bottom end can be conventional with just a plain big end and pressure feed. This fits in with what the Ryger looks like.
An interesting idea. Re the attachment to the case being a secondary linkage - The problem I see with that is that you then rely on the piston and the bush the rod passes through to locate the bottom part of the rod so that it only moves vertically. If the rocker arm case pivot was fixed and the small secondary linkage was at the rod end of the rocker arm and connected to the bottom of the rod, any forces exerted on the rocker arm by the crankshaft conrod trying to move it horizontally, due to rod geometry, would be resisted by the solidly fixed pivot. Ideally the rocker arm would be as long as possible which would reduce the effects of it pivoting and therefore the horizontal displacement at the rod end. That does put more moving parts and more reciprocating mass at the end of the rocker arm.
The Watts linkage is another thought, with the crankshaft conrod connected to the lower arm at some point inboard of the vertical link. The vertical link at it's centre essentially moving only vertically and connected to the rod to the piston. It would remove any thrust loads from the bush caused by linkage geometry.
A thought I had was along similar lines to Neil in that there was a rocker arm, free to pivot at one end, and with a link at the other to connect to the rod that goes through the bush and seal to the piston. My idea though was that the connection to the crankshaft was via a pin extending each side of the rocker arm fitted with bearings that ran in mirror image tracks machined into the inner faces of the crank wheels. You could machine any track profile you wanted and create dwell at BDC and have a favourable ramp on the power-stroke side that extracted the most power given the pressure rate profiles. Of course there is probably a very good reason why that has never been done. One of which is obviously the precision required in manufacture and assembly. The 2 "crank" halves would be connected together through the centre as there is no rod that rotates through there.
At the attachment of the rocker to the case there is a second smaller linkage that allows for this side movement, at right angles up or down to the main rocker. This small linkage would be say 20mm long ish. By adjusting the attachment point ( to the case ) of this small linkage you will adjust where the piston stroke occurs in the cylinder, a bit like a seesaw. This adjustment could be by a small eccentric as not much movement would be required and not much force needed. Simple and easy to build.I can see there are several great minds at work here. No doubt you could design a triple-overhead desmodromic five-stroke with threedimensional variable valve timing, but keeping things simple seems to be more difficult than that.
I hope you will permit me to use the above quotes when I ever get around to putting the Ryger history in book form, so we can all have a good laugh, looking back on it.

[husaberg]

I can see there are several great minds at work here. No doubt you could design a triple-overhead desmodromic five-stroke with treedimensional variable vale timing, but keeping things simple seems to be more difficult than that.
I hope you will permit me to use the above quotes if I ever get around to putting the Ryger history in book form, so we can all have a good laugh, looking back on it.

I thought mine was simple, it even had a drawing of sorts.........

[Frits Overmars]

Are you trying to tell me that you don't want to be in the book, Husa? :whistle:

[husaberg]

Are you trying to tell me that you don't want to be in the book, Husa? :whistle:

Well I wouldn't go that far just yet. (Small h remember)
I would rather be remembered for that one time I was actually right about something though.

Ps should Pewee look at the FPE engine in regards to the EX outlet.
Where is Mr Paykart it would be nice to hear his thoughts on the Ryger?

[Frits Overmars]

Ps should Pewee look at the FPE engine in regards to the EX outlet.That would be quite instructive, even though the FPE is based on the 'regular' RSA engine.


Where is Mr Paykart it would be nice to hear his thoughts on the Ryger?Maybe Francis hasn't even noticed the commotion about the Ryger yet; I didn't write a single letter about it on his 'home' forum www.pit-lane.biz (http://www.pit-ane.biz).
In fact I didn't start the Ryger tumult on any forum; I had intended not to spread any rumours until I could back them up with facts, but I was forced to react on posts that others started spreading.

[ken seeber]

In fact I didn't start the Ryger tumult on any forum;
Dunno if we can believe you one this one Frits. A tumult is:

1. * The din and commotion of a great crowd.
*2. *
*a. * A disorderly commotion or disturbance.
*b. * A tempestuous uprising; a riot.
*3. * Agitation of the mind or emotions

Anyways, I think the messages from Frits are clear. The thing is simple mechanically and we're a great crowd. :clap:.

To prevent any further tumult Frits, do you have any idea of when the patent will be finalized? Husa is ranting at the bit and Neil has got his design and pattern making team ready on standby at full penalty rates, costing him a fortune.

[Frits Overmars]

Dunno if we can believe you one this one Frits.
A tumult is: 1 The din and commotion of a great crowd. 2a A disorderly commotion or disturbance. 2b A tempestuous uprising; a riot. 3 Agitation of the mind or emotionsOption # 3 would qualify, wouldn't it Ken? Anyways, english is not my native language so I will be grateful for all pointers you can give me.


Anyways, I think the messages from Frits are clear. The thing is simple mechanically and we're a great crowd. You seem to have grasped it. Now let's see how long this understanding of simplicity will last before new complicated ideas start rearing their heads again.
Not that I mind; they can be quite inspiring.


To prevent any further tumult Frits, do you have any idea of when the patent will be finalized? Husa is ranting at the bit and Neil has got his design and pattern making team ready on standby at full penalty rates, costing him a fortune.Asked and answered. But I'd like to stress once more that I don't understand the first thing about legal matters; I'll have to wait and see like the rest of us.

[adegnes]

If the Ryger engine has a conventional port layout (it may not, but let's say it does) it would run out of time area long before 17000rpm, and certainly 30k, with a traditional crank.
If you want to keep it simple you can't do anything about the area part, that would take a lot of complicated stuff like moving walls with linkages and whatnot.
But what about the time part? Could the crank assembly be asymmetric in a way that during one revolution the piston moves slower where it matters - during blowdown and around bdc? A scotch yoke could do this right? Or any other "cam like" crank assembly.
With enough time there's no need for any additional pressure.

Just like the FOS cylinder takes care of the problem with more area in all the right placed, maybe the Ryger does it with more time in all the right periods during one revolution.

How it all survives I have no clue.

[breezy]

Thanks for reply, given me something to contemplate.

Wobbly, what impact, would being able to vary the compression ratio of the 2 stroke engine have, if were possible , whilst it was running and have a pretty much variable unrestricted induction air/fuel flow capability?:sherlock:

[Flettner]

I can see there are several great minds at work here. No doubt you could design a triple-overhead desmodromic five-stroke with threedimensional variable valve timing, but keeping things simple seems to be more difficult than that.
I hope you will permit me to use the above quotes when I ever get around to putting the Ryger history in book form, so we can all have a good laugh, looking back on it.

O well at least we tried, the team will have to stand down for now, tell Ryger he's welcome to my rocker idea, maybe he could build a decient twostroke using it anyway:lol:

[Haufen]

I don't know if this has been asked before - does the ryger engine use the stock pipe?

[wobbly]

If you have variable compression ( I assume the basic idea is - high com in the mid range, low com on the pipe ) then some form of the system used by Yamaha
in 500GP of a moving insert controlled by gas pressure would ( and did to a certain extent ) work fine.
Thus when the trapping and scavenging efficiency is low, overcompressing this compromised mixture would pump up the midband power.
Then when the dynamic com is high, as are the scavenging and trapping efficiency - along with a high delivery ratio, you can back the com off and use the extra energy in the pipe.
The above scenario would work even better, using the 24/7 idea as well, as this dramatically increases the delivery ratio, thus increasing the dynamic com,enabling even more use of the
available fuel energy in the pipe by lowering the static compression ratio.

[breezy]

If you have variable compression ( I assume the basic idea is - high com in the mid range, low com on the pipe ) then some form of the system used by Yamaha
in 500GP of a moving insert controlled by gas pressure would ( and did to a certain extent ) work fine.
Thus when the trapping and scavenging efficiency is low, overcompressing this compromised mixture would pump up the midband power.
Then when the dynamic com is high, as are the scavenging and trapping efficiency - along with a high delivery ratio, you can back the com off and use the extra energy in the pipe.
The above scenario would work even better, using the 24/7 idea as well, as this dramatically increases the delivery ratio, thus increasing the dynamic com,enabling even more use of the
available fuel energy in the pipe by lowering the static compression ratio.

thanks again:niceone:

[husaberg]

I spelt it wrong too i guess "Polini" powerhead

http://www.kpmotosolutions.com/img041.jpg
plus 10 more carrots
313009313010

[Flettner]

I can see there are several great minds at work here. No doubt you could design a triple-overhead desmodromic five-stroke with threedimensional variable valve timing, but keeping things simple seems to be more difficult than that.
I hope you will permit me to use the above quotes when I ever get around to putting the Ryger history in book form, so we can all have a good laugh, looking back on it.

Frits, are spotachtig us:laugh:

[Flettner]

I fully understand the adjustment system. That adjustment could also be used in my suggested ideas. The "fixed" pivot for the rocker arm would actually be able to move vertically by say about 2mm. It could be varied with revs or load.

Sorry Mike, I guess I didn't read your post properly.

[2T Institute]

I know how it's done, with a rocker arm ( Ryger ). As Frits said simple, piston and rod are one as we decided before but forget that complicated crank within a crank idea. Round conrod comes down through the "sealed off from oil" guide bush under the piston then terminates at a rocker arm. This arm is anckored at the area where the case reed used to be, there is a solid looking plate covering that hole that looks like it could be more than just a crank case seal, I think something is attached to it. The crankshaft could be connected to this rocker arm further down the fulcrum so the crankshaft stroke is less than 54mm. The problems with bigends are not so much combustion load but load from centripital force so less stroke, less centripital force at higher rpm, no problem with increaseing the combustion load ( leaverage from the arm ). The attachment to the case ( plate ) would need a small secondary linkege to allow for the fact that the lever arm pivots. This attachment linkage could be adjustable to make the piston move higher or lower in the cylinder ie low rpm or high rpm also having a useful effect on the compression and port timing, on the fly. Tell me I'm right!
And I still think they are using combustion pressure to " excite " the crankcase pressure at higher rpm where there is not enough blow down time and higher transfer pressure is needed, probably through a fine wire mesh to take out some of the combustion heat.

And done right you could have a fast / slow piston movement, like an old shaper, fast one way slower the other. Perhaps help with blowdown time?

To be fair, Ken Seeber was the one who noticed the thick alloy cover over the bottom reed housing.

The "artist impression" that rapidly disappeared off FB is pretty much this but connected to a conventional crankshaft . I have a artists impression of a artists impression at home ;)

[Flettner]

Ok, you want simple ( ish ) try connecting the end of your chamber ( reverse cone ) to the crank case via some sort of membrane ( diapham ) Sucking when it should, pumping when it should. There is your supercharging ( and crank case volume change every cycle )

[husaberg]

Ok, you want simple ( ish ) try connecting the end of your chamber ( reverse cone ) to the crank case via some sort of membrane ( diapham ) Sucking when it should, pumping when it should. There is your supercharging ( and crank case volume change every cycle )

Pretty sure I suggested that one it was husas guess version 687.....

[Flettner]

Pretty sure I suggested that one it was husas guess version 687.....

There is no I in TEAM. Now it's called team work. :shifty:

[peewee]

[FONT=arial]That would be quite instructive, even though the FPE is based on the 'regular' RSA engine.

theres been a few pics of the rsa cylinder exit and manifold. how do i know if its a regular cylinder or not ?

[husaberg]

There is no I in TEAM. Now it's called team work. :shifty:

Aye I only have a few personalities..........
I bet you a virtual beer it has a piston.

[Frits Overmars]

theres been a few pics of the rsa cylinder exit and manifold. how do i know if its a regular cylinder or not ?Finally a question that I can answer without worrying about non-disclosures. And it's a simple question as well; thank you peewee.
Easy answer: if it's on a photo it's regular; there are no published pictures of the experimental stuff I was talking about.

[Frits Overmars]

I bet you a virtual beer it has a piston.You've got a lot of virtual nerve Husa. Remember this? http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page1187?p=1130869024#post1130869024

[husaberg]

You've got a lot of nerve Husa. Remember this? http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page1187?p=1130869024#post1130869024

Yeah but can you confirm that it is a Piston.............:lol:

[Haufen]

I don't know if this has been asked before - does the ryger engine use the stock pipe?

Okay, I think we might have a hit here (or I just missed something).

[adegnes]

I've modeled my engine with the iame m50 cylinder and my hackjob pipe as accurate as I can in engmod.
My crank is 39.1mm stroke, vs the iame 39.4mm, I've fixed this by taking 0.5mm off the top of the cylinder, 0.2mm extra for more transfer duration.
I've also further raised the main exhaust 0.9mm and the aux 1.4mm

Ignition timing is set to keep tumax below 960, but not optimized at all.
The pipe is something for a scooter with a homemade header and tailpipe+restrictor.

Here's the numbers and result:

313040

313038

313041

313039


Is this realistic?

i know there's lots more that can be done, but I wanted to start out with something I could easily do in real life with minimum chance of screwing up...

[JanBros]

was wondering about the ryger, and I don't thinck it's possible the piston/round conrod is a fixed unit with it only moving up and down through a seal in the spacer under the cylinder.
the spacer isn't thick enough. I seriously doubt it's thick enough to compensate for the skirts (?) sticking out at the underside of the barrel, so no space to fit in the seal + guide. As the piston would only move up and down it's skirts could be made shorter as they wouldn't be as nescesary to guide the piston, but than the exhaust port might be uncovered in TDC.

[Flettner]

was wondering about the ryger, and I don't thinck it's possible the piston/round conrod is a fixed unit with it only moving up and down through a seal in the spacer under the cylinder.
the spacer isn't thick enough. I seriously doubt it's thick enough to compensate for the skirts (?) sticking out at the underside of the barrel, so no space to fit in the seal + guide. As the piston would only move up and down it's skirts could be made shorter as they wouldn't be as nescesary to guide the piston, but than the exhaust port might be uncovered in BDC.

Just because the spacer looks 20mm thick on the outside doesn't mean the guide isn't taller inside, the spacer could have been machined from something much thicker or the guide ( being longer ) isn't pressed or screwed into this plate. The spacer could well fit right up to the underside of the piston at BDC.

[JanBros]

forgot to mention : if the Ryger uses 98% parts of a conventional 2-stroke engine, a different piston/crank/conrod/... + rockers/links... wouldn't fit inside the 98%

[Frits Overmars]

forgot to mention : if the Ryger uses 98% parts of a conventional 2-stroke engine, a different piston/crank/conrod/... + rockers/links... wouldn't fit inside the 98%Like I said, I did not do a parts count, but I posted the parts list, so be my guest if you feel so inclined, Jan.
I wrote 98% to give an impression of the simplicity of the modification, but maybe it's only 90%; who cares.

[wobbly]

Yep, there appears to be nothing outrageous in the IAME sim at all.
The bmep is reasonable, there is good superposition at peak power along with good depression around bdc, and importantly the
tuned length is on the money as the peak stuffing pressure is well before the piston closes the port.
To reduce the crank power a bit drop the combustion efficiency.
With a cleverer pipe and a proper restrictor at the header and stinger entry it would make better power everywhere - but a good start.

[adegnes]

Yep, there appears to be nothing outrageous in the IAME sim at all.
The bmep is reasonable, there is good superposition at peak power along with good depression around bdc, and importantly the
tuned length is on the money as the peak stuffing pressure is well before the piston closes the port.
To reduce the crank power a bit drop the combustion efficiency.
With a cleverer pipe and a proper restrictor at the header and stinger entry it would make better power everywhere - but a good start.

Great! Thanks!
I'll start working on that cleverer pipe!

[Flettner]

Don't tell me it's as simple as a hose clip clamped around the con rod holding a rubber boot that is also anchored to the alloy plate in the crank case? There we have it:bleh:

[m4r]

regarding to that Ryger Engine, what about asymetric transfer timing, or at least one extra port above the normal tranfers, with round about the same height as the exhaust port. This extra port you would be able to only open on the compression stroke? It should catch the returning wave from the pipe below resonance rpm instead of reflecting it on the cylinder walls after normal transfers would be closed and wasting it out through the exhaust again. Also this would charge your intake volume, and you would have more pressure next time transfers open. Maybe because of that you could even lower the standard transfers and get more Blowdown TA for higher rpm.

[husaberg]

Don't tell me it's as simple as a hose clip clamped around the con rod holding a rubber boot that is also anchored to the alloy plate in the crank case? There we have it:bleh:

A zip tie would be simpler.
313042

[Flettner]

A zip tie would be simpler.

That's ten years development right there.
Hose clips are more manly, zippie ties are for pussy's.

[husaberg]

That's ten years development right there.
Hose clips are more manly, zippie ties are for pussy's.

That pussy comment pieced me.
Harry Ryger actually mentioned bellows.

[PVO]

Wobbly, I appreciate the following info you have supplied regarding exhaust duct sizing.

"Next issue that is my favorite hobby horse for today is Ex duct exit area.
You will find a heap of free power, when using a T port or a Tripple port configuration, by limiting the duct exit area to around 75% of the Total Ex Port Effective.
Then make the header start at the area = to the Total Effective.
Join these with an oval to round adapter in the spigot or flange, where the width = the header dia all the way thru, to enhance the flow from the blowdown area,and
the height at the flange face forms an oval to give the correct 75% area.

Simple answer re the odd shape and reduced area of the Ex duct exit is that with a 3 port cylinder, the area of the main port is plenty big enough to support the gas flow
created by the power being made.
The big Aux additional area allows better Blowdown STA, but this area is only needed above TRO.
Thus having a huge duct simply drops the velocity, reducing the wave amplitude into the header.
The Aprilia shape promotes the flow from the Aux ports by keeping the extra horizontal area all the way into the pipe - thus helping blowdown flow and overev power..
Reducing the duct vol by having area reducing steps, keeps the velocity high and again promotes the flow regime in the side ports.
There may be a case to say that the steps reduce backflow from the pipe at low rpm when it is too short,but for sure there is no outflow disruption,and in any case tests showed that power went up as the duct became smaller.
I have exhaustively ( pun ) tested the vol/shape effects on a T port ( as has Mr H ) and an oval to round transition with no steps works better."

Is it beneficial also to raise the exhaust port floor up to reduce duct volume? If this were done the total effective exhaust area would be reduced and subsequently the duct exit area and starting diameter for the manifold (if your rule of thumb sizing recommendations were followed). Blowdown and transfer STA are what primarily influence power so raising the exhaust port floor up may not hurt power until the port radii start to have an effect on the blowdown STA? I'm assuming the raised port floor would also help to prevent short circuiting of the A transfers? If I did this would I find that the duct volume can be made too small? I'd be very appreciative of any further insights you are willing to share on the sizing and design of the exhaust ducts.

[wobbly]

Jan raised the Aprilia port floor at the duct entry 2mm ( on a 54.5 stroke ) above BDC I believe, and the bottom corner rads were
made progressively bigger and bigger to reduce the duct volume.
This is dyno proven ( his and mine ) to make better power, so go there straight away, but as you say dont reduce the blowdown width
of the main port above TRO.
Testing the reduced duct area at the port, and reducing/varying the area at the duct exit is easily optimized in EngMod, except of course as its not a 3D FEA flow code
like Fluent etc it cant verify the effect on power of reducing short circuiting.

[PVO]

Jan raised the Aprilia port floor at the duct entry 2mm ( on a 54.5 stroke ) above BDC I believe, and the bottom corner rads were
made progressively bigger and bigger to reduce the duct volume.
This is dyno proven ( his and mine ) to make better power, so go there straight away, but as you say dont reduce the blowdown width
of the main port above TRO.
Testing the reduced duct area at the port, and reducing/varying the area at the duct exit is easily optimized in EngMod, except of course as its not a 3D FEA flow code
like Fluent etc it cant verify the effect on power of reducing short circuiting.

Thanks for the info Wobbly, that will get me going in the right direction.

Do you have any recommendations on the port exit angle? I'm aware the RSA was 30 degrees from horizontal. If I recall this angle was partly chosen for packaging reasons. Obviously as duct angle decreases port effective area increases, but there is a trade-off with gas flow. Do you know if 30 degrees was also the best flow angle or has another angle between 0 and 30 been proven to work best?

[wobbly]

Jan tested everything and 25* was best.

[peewee]

does anyone know how high the exh floor can be raised before power drops ? seems like jan mentioned he was working on figuring this out but never got time to finish. would the window need to be any lower than the blowdown phase, thats the question i guess

[husaberg]

does anyone know how high the exh floor can be raised before power drops ? seems like jan mentioned he was working on figuring this out but never got time to finish. would the window need to be any lower than the blowdown phase, thats the question i guess

If you look at some of Frits posts when Rob was doing the dam in the ex port.

Quote Originally Posted by Jan Thiel

So that you might be able to raise the exhaust's 'floor'.This helps improve blowdown flow, as seen on a flowbench.In 2007 we started to raise the underside of the exhaust port.The first results were very promising!But at the end of 2007 I retired, so I could not finish what I started.The idea was to raise the exhaust underside as much as possible until power dropped.
And then, with a smaller exhaust port underside it might have been possible to widen the A-ports more
without losing the fresh charge into the exhaust.


284480

The piston skirt was exposing the bottom of the exhaust port at TDC so as an experiment I am screwing and gluing a piece of alloy into the exhaust port floor. With any luck this will let the piston seal the crankcase and I have made the wall a little higher than the piston at BDC.

I remember (hopefully correctly) Frits talking about Jan experimenting with this and that it made more power by reducing short circuiting.

But they had not found the upper limits of how high the wall could be. If I can make the wall high enough it might not be to far fetched to add another transfer port there, after all once exhaust blow down is complete there is little point to the lower 1/3 or so of the exhaust port.


284547284546


The stuffer plate is held down by screws through the exhaust port floor, the glue is only there to seal it.


Here's an example, something on raised exhaust port floors from Jan Thiel on that same page too.
It seems that one have to click the link (arrow thingy to the right of "Frits Overmars") to see the picture..

Now, piston rings might not like that export witdth.


To make the raised floor work as part of an overall plan that was seen all the way thru by Jan at Aprilia, the area reduction at the port should be extended all the
way to the flange.
Making this oval, and reducing the duct volume all the way to the exit then works with the 75% area guideline for T or tripple port duct exit geometry.



When I first tried the Triple Exhaust I got 29.5 rwhp (I had previously done better with a single port at 31 rwhp)

Tried to improve the Triple Exhaust and it fell to 18.6

Raised the exhaust port floor and went from 18.6 to 24.8

Thrown the cylinder in the bin and started again.

[Frits Overmars]

does anyone know how high the exh floor can be raised before power drops ? seems like jan mentioned he was working on figuring this out but never got time to finish. would the window need to be any lower than the blowdown phase, thats the question i guessHere are some pictures to help you on your way Peewee.
313049 313050 313051 313052 313053

[wobbly]

The only kicker in the idea of lifting the Ex floor is as I stated before - Jan only actually dyno tested the small 2mm
step, and then the corner rads were changed by CNC machining the duct to get better power again ( as per Frits left hand drawing )..
I also have only gone 2.5mm on a 54.5 stroke and actually proven it on the dyno ( so as to not make the added material so obviously against the regs ) - so going there immediately is a no brainer.
Going higher without the dyno work is just a guess.

[Martin1981]

jan once told that (one of the) last cylinders he has made had their ex floor as high as the transfer roof. but then he realised that he would retire and see no test results anymore...so he had machined the floor down to standard....

[husaberg]

jan once told that (one of the) last cylinders he has made had their ex floor as high as the transfer roof. but then he realised that he would retire and see no test results anymore...so he had machined the floor down to standard....


Quote Originally Posted by Jan Thiel

So that you might be able to raise the exhaust's 'floor'.This helps improve blowdown flow, as seen on a flowbench.In 2007 we started to raise the underside of the exhaust port.The first results were very promising!But at the end of 2007 I retired, so I could not finish what I started.The idea was to raise the exhaust underside as much as possible until power dropped.
And then, with a smaller exhaust port underside it might have been possible to widen the A-ports more
without losing the fresh charge into the exhaust.




Helmholtz frequency, my dear Watson. The smaller crank will give the pipe more crankcase volume to breathe from. This larger volume will also lower the resonance frequency of the inlet system, hence the drop at high rpm. It can be compensated with a shorter inlet tract, a bigger carb diameter and a later inlet closure. To put it real simple: if you have more volume, you need more time to fill it. But more time, i.e. later closure, has adverse effects at low revs. So my preference is a shorter tract (unless you go the 24/7-way and employ a reed for the low revs, and swing it out of the way at high revs).




To put it real simple: if you have more volume, you need more time to fill it.


Most of the volume is concentrated in the transfer ducts. Then there is the volume inside the piston of course, and the 1 mm shear-avoiding clearance at all surfaces of the crank.
But that is not nearly enough volume. If you take another look at the Aprilia crank below left, you will notice that the space between the crank webs is the same as the space needed for the big end bearing. In other words: the crank webs have flat insides, good for another 60 cc or so, if I remember correctly.

Summary: you need a large crankcase volume. Ideally all of this volume should be situated in the transfer ducts. In real life you will also need to lodge part of this volume between crankshaft and piston, i.e: use a long con rod. Avoid nooks and crannies. Crankshafts should be small and smooth. Big end bearings must never be shrouded by recesses in the crank webs or by stuffers.


Frits on the Ryger?

[TZ350]

313065313064

This exhaust port floor dam gave a very positive result on the dyno but the cylinder was written off before I could finish the experiment. An exhaust port floor dam is something I am defiantly going to include in my next motor.

[twotempi]

I am defiantly going to include in my next motor.

The word " Definitely" may be a better choice to use in this phrase ??

[peewee]

frits your a great help but i dont understand your 8.1% corner radius. i only know radiuses in mm.

tz350 what is a damn ? is it just a term for filling in the exh floor like me and wobbly are doing ?

[F5 Dave]

I am defiantly going to include in my next motor.

The word " Definitely" may be a better choice to use in this phrase ??

You may wish to be careful on a single ex port engine. As Frits says if the blowdown is not sufficient the pressure will abuse the transfers as make shift exhaust ports. This will still happen but if you seriously raised the port floor to the transfer level it would be worse. But that's an extreme case of course.

[Grumph]

I am defiantly going to include in my next motor.

The word " Definitely" may be a better choice to use in this phrase ??

Well, i've met both you and Rob. Defiantly works for either of you...Didn't you tell me you had enough Benelli barrels to keep you happy playing for years ?
tried doing a triple exhaust in one yet ?

[TZ350]

well, i've met both you and rob. Defiantly works for either of you...

................. true, well I hope so anyway. :laugh:

[TZ350]

313074313073


tz350 what is a dam? is it just a term for filling in the exh floor like me and wobbly are doing ?

I am not sure what the proper name is or even if there is one but I called it a dam because it seems to work by reducing short circuiting from the transfers and damming the flow of incoming fresh air/fuel charge preventing it looping over and easily flowing out of the exhaust port. Just like a dam on a river.

[Frits Overmars]

i dont understand your 8.1% corner radius. i only know radiuses in mm.It's 8.1% of the cylinder bore, like all the other percentages in that drawing.
313075

[husaberg]

Jan raised the Aprilia port floor at the duct entry 2mm ( on a 54.5 stroke ) above BDC I believe, and the bottom corner rads were
made progressively bigger and bigger to reduce the duct volume.
This is dyno proven ( his and mine ) to make better power, so go there straight away, but as you say dont reduce the blowdown width
of the main port above TRO.
Testing the reduced duct area at the port, and reducing/varying the area at the duct exit is easily optimized in EngMod, except of course as its not a 3D FEA flow code
like Fluent etc it cant verify the effect on power of reducing short circuiting.


Jan tested everything and 25* was best.


RSA ex port
The exhaust port isn't canted downward 30°. The flange mounting face is canted downward 30° but the roof of the exhaust duct exits the cylinder at 25°.
The reason is that this angle gives the best flow. Frits I think?

The cylinder I have also has its exhaust port above bdc by about 2mm.
But I would suggest the bottom of the exhaust port has a distinct curvature near the outlet.

[Frits Overmars]

RSA ex port: The exhaust port isn't canted downward 30°. The flange mounting face is canted downward 30° but the roof of the exhaust duct exits the cylinder at 25°.
The reason is that this angle gives the best flow.
Frits I think?Guilty, your Honour.

[husaberg]

Guilty, your Honour.

ok any ideas what this cylinder is it was in my Aprilia pics but it doesn't look in place.

[Frits Overmars]

ok any ideas what this cylinder is it was in my Aprilia pics but it doesn't look in place.
Provisions for coolant hose pillars left and right; could be a kart cylinder (they all copied Aprilia).

[mudbugracer]

I would like to give the good old Suzuki TF125 engine a wake up, can anyone give info about port measurements? also need to use factory carb so any idea on jet sizes after the port work? Or any other idea to wake her up?

[ken seeber]

Report from northern hemisphere.

313088313089

[FastFred]

I would like to give the good old Suzuki TF125 engine a wake up, can anyone give info about port measurements? also need to use factory carb so any idea on jet sizes after the port work? Or any other idea to wake her up?

This whole thread is about giving 2T engines a wake up.

313090

And your best friend will be a degree wheel like this one made by gluing a paper printout onto piece of sheet metal another easy way is to buy a large protractor from a stationary shop.

[mr bucketracer]

I would like to give the good old Suzuki TF125 engine a wake up, can anyone give info about port measurements? also need to use factory carb so any idea on jet sizes after the port work? Or any other idea to wake her up?sorry they only put things to sleep in here lol:violin:

[Flettner]

Report from northern hemisphere.

313088313089


Ha Ha ha. What, didn't they like you telling them we know what was inside?
A little wind up never hurt.

[twotempi]

Well, i've met both you and Rob. Defiantly works for either of you...Didn't you tell me you had enough Benelli barrels to keep you happy playing for years ?
tried doing a triple exhaust in one yet ?


Yes - i have enough to get me into trouble for quite some time.

The trouble is that when ever I think i know what I want to do some sod goes and posts more information on this thread and i have to change what i thought I was going to do !!!

[F5 Dave]

Report from northern hemisphere.

313088313089



Thanks Ken that made me laugh.

Hey where did the other text go? Must have changed it in between reading it & my post.

[peewee]

anybody welded on a iron sleeved cylinder ? got some of those reproduction yamaha cylinders i was going to add some aux exh ports but im thinking the casting will pull away from the sleeve. maybe its best to cut out the sleeve with a lathe or something and install a new one afterwards ?

[husaberg]

anybody welded on a iron sleeved cylinder ? got some of those reproduction yamaha cylinders i was going to add some aux exh ports but im thinking the casting will pull away from the sleeve. maybe its best to cut out the sleeve with a lathe or something and install a new one afterwards ?

Yamaha (along with most other production bikes) sleeves are corrugated and bonded with a coating then cast in place (to achieve a good surface area and avoid slipping).
A pressed in sleeve will not achieve the same thermal properties.
Neither are as good as plating on a complete alloy cylinder. ie no iron sleeve.

[peewee]

these are reproductions. not near the qaulity of yamaha oem but theyre a fraction of the price. $300 for 2 new sets of cylinders ( 2 lefts and 2 rights). ill be plating the sleeve once all the work is done. thinking the casting will pull away from the sleeve because a while back when i tried that brazing rod i noticed some pull back in a few areas. maybe they will react different with welding as there isnt a constant 700F temp as with the brazing rod

[Grumph]

these are reproductions. not near the qaulity of yamaha oem but theyre a fraction of the price. $300 for 2 new sets of cylinders ( 2 lefts and 2 rights). ill be plating the sleeve once all the work is done. thinking the casting will pull away from the sleeve because a while back when i tried that brazing rod i noticed some pull back in a few areas. maybe they will react different with welding as there isnt a constant 700F temp as with the brazing rod

The older aircooled yam iron liners were plain parallel shrink fit. Certainly up to the RD350. If the repro barrels are that cheap, i'd put money on them being the same as it's the cheapest way. Pre heat - plenty of preheat, with the liner clamped in so it doesn't move. Good luck...

[Grumph]

Yes - i have enough to get me into trouble for quite some time.

The trouble is that when ever I think i know what I want to do some sod goes and posts more information on this thread and i have to change what i thought I was going to do !!!

So now you're hamstrung, waiting to see how much of the Ryger you can use ?.....

My excuse is much simpler, i have 2 kawa rotary valve motors here plus 2 RG400 barrels - and i can't be arsed walking through snow to the workshop. plus too much customer stuff here as well.

[husaberg]

The older aircooled yam iron liners were plain parallel shrink fit. Certainly up to the RD350. If the repro barrels are that cheap, i'd put money on them being the same as it's the cheapest way. Pre heat - plenty of preheat, with the liner clamped in so it doesn't move. Good luck...

Well I am confused because I think that is where I first seen them, Pretty sure the Hondas are the same?

313100313101313102313103

[F5 Dave]

anybody welded on a iron sleeved cylinder ? got some of those reproduction yamaha cylinders i was going to add some aux exh ports but im thinking the casting will pull away from the sleeve. maybe its best to cut out the sleeve with a lathe or something and install a new one afterwards ?
Yes by a, sort of mate who thought he could weld. OK maybe I'm still bitter from 20yrs ago about a virgin barrel being fecked. First iteration where we didn't get near the liner was ok. But the water jacket leaked into the exhaust. After that it went downhill & was separating liner to ally. Just slightly, but if you can see it- its a mile.

[twotempi]

frits your a great help but i dont understand your 8.1% corner radius. i only know radiuses in mm.

tz350 what is a damn ? is it just a term for filling in the exh floor like me and wobbly are doing ?

A reminder that the European convention for decimals is that a decimal place is a comma , not a full stop.

[Grumph]

Well I am confused because I think that is where I first seen them, Pretty sure the Hondas are the same?

don't know at what point or which model they changed. i do remember you could resleeve the 400 barrels out bigger - couple of Brit outfits would do it.

[Frits Overmars]

A reminder that the European convention for decimals is that a decimal place is a comma , not a full stop.You don't need to remind me, Twotempi. My original drawing had commas; I adapted it just for you guys. And may I remind you that the use of decimal commas is not a european, but a world-wide convention? But some people keep hanging on to the foot-pound-fortnight system and I was foolish enough to oblige.

[Frits Overmars]

313114313115 313113

[F5 Dave]

Really? `cause we arent too enamoured with the French (and their state sanctioned terrorist activities) here but I do like the SI system and Michelin tyres. I didn't know about the coma thing being that widespread.

[husaberg]

Really? `cause we arent too enamoured with the French (and their state sanctioned terrorist activities) here but I do like the SI system and Michelin tyres. I didn't know about the coma thing being that widespread.

Dave you are being unfair, they also gave us passable wines, taught us how to do amazing things with fried potatoes and a reason to protect our scrotums in Rugby.
On the plus side of the ledger they did produce this cheeky little number.
<iframe width="554" height="310" src="https://www.youtube.com/embed/CLKNuhDmfvQ?list=RDCLKNuhDmfvQ" frameborder="0" allowfullscreen></iframe>

[Frits Overmars]

...we arent too enamoured with the French (and their state sanctioned terrorist activities) here.... I didn't know about the coma thing being that widespread.I know what you mean regarding their interpretation of external affairs. And though their wines are OK, their cuisine is grossly overrated if you ask me.
Luckily the coma thing isn't that widespread, or we would all be asleep all day long :sleep:.

[ken seeber]

Northern hemisphere report #2
There is a little guy called Tony Bufalo that has created a replica Yamaha 250 V4, model RD05. Sounded great on the stand.
He made it all from pics. The major engine parts all from billet, not cast. Seemed to be combination of CNC and manual, all heavily blasted so it almost all looked like castings, even the cylinders. Took him 10 years.
Can be seen on http://www.spiritofspeed.eu/4/w-10/tony-s-marvel-a-rd05a-replica-home-made.html
Not to beat around the bush, I told him that Neil could fix him up with some Ryger kits, with the possibility of a bulk discount for four units. As to the yet to be invented 24/7 conversions of the disc valve inlets, I said he’d have to ask Neil direct. Hope that’s ok Neil?



313117313118313119313120313121

[Flettner]

Northern hemisphere report #2
There is a little guy called Tony Bufalo that has created a replica Yamaha 250 V4, model RD05. Sounded great on the stand.
He made it all from pics. The major engine parts all from billet, not cast. Seemed to be combination of CNC and manual, all heavily blasted so it almost all looked like castings, even the cylinders. Took him 10 years.
Can be seen on http://www.spiritofspeed.eu/4/w-10/tony-s-marvel-a-rd05a-replica-home-made.html
Not to beat around the bush, I told him that Neil could fix him up with some Ryger kits, with the possibility of a bulk discount for four units. As to the yet to be invented 24/7 conversions of the disc valve inlets, I said he’d have to ask Neil direct. Hope that’s ok Neil?



313117313118313119313120313121

Funny you should mention Ryger, I might have accidentaly bought some alloy plate and found a 34mm stroke fourstroke crank and some other associated parts assembled on the now extended prototype bench ready to whisk something up. Only way to know for sure is do it yourself.
Nice job of the Yamaha 250, how does it go?

[husaberg]

ryger.............................
http://www.kiwibiker.co.nz/forums/member.php/48608-ryger
313123313124

[twotempi]

You don't need to remind me, Twotempi. My original drawing had commas; I adapted it just for you guys. And may I remind you that the use of decimal commas is not a european, but a world-wide convention? But some people keep hanging on to the foot-pound-fortnight system and I was foolish enough to oblige.

Hi Frits

Did my physics in the MKS system. I thought that the comma was only european but only in every day usage. What do you guys use for scientific and mathematical subjects

Then I was "edgumicated" in the English ( Imperial ) system for engineering where everything was expressed in the most archane way possible. For example speed was "furlongs per fortnight". Don't get me started on links,chains,cables ( nothing to do with a motorcycle ) for length measurements or pecks,gills etc for volumes, or roods for area. Then we get short tons, long tons & metric tons ( tonnes ), kips for weights !!!!

You guys had it so so easy with the metric system. Interestingly the USA is by statute a metric country but only use imperial ( well- kind of ) in practice. :mellow::mellow::mellow:

[Flettner]

ryger.............................
http://www.kiwibiker.co.nz/forums/member.php/48608-ryger
313123313124

Opps, better be careful what we say, our secrets might get out:lol:
I guess what I really meant was - welcome, Harry, to our Forum and hope you are likely to post here.

[lodgernz]

You guys had it so so easy with the metric system. Interestingly the USA is by statute a metric country but only use imperial ( well- kind of ) in practice. :mellow::mellow::mellow:

The US has been trying to change to the metric sytem since 1893, but they cling to the furlong-hundredweight-fortnight system to stay in line with those world leaders Myanmar and Liberia who also use this wonderful system.
Hard to believe that the first country in the world to go to decimal currency is otherwise mired in such a weights and measures time-warp.
I fully expect the Trans-Pacific Partnership Agreement to mandate the use of the 16th century measurement system by all partners.

[m4r]

anybody heard of the "middle power flush (http://www.google.com/patents/DE102010056258A1?cl=en)", could the Ryger rely on this? except from using the crankcase and instead connecting the transfers directly to the Reed valve in BDC. Therefore the piston builds up higher to contain the connection ports. So the thick alloy plate is not only to block the transfers from the crankcase but also to compensate the increased piston height?

[Frits Overmars]

anybody heard of the "middle power flush (http://www.google.com/patents/DE102010056258A1?cl=en)"?I have now. Where's me aspirin? I'm lucky enough to have a fair amount of German, without which it would have been impossible to understand this piece of Denglish.
And enough of the original lingo shimmers through to conclude that the German version was not exactly faultless either. An hour wasted; what a start of my Saturday.

[breezy]

Hi Frits

Did my physics in the MKS system. I thought that the comma was only european but only in every day usage. What do you guys use for scientific and mathematical subjects

Then I was "edgumicated" in the English ( Imperial ) system for engineering where everything was expressed in the most archane way possible. For example speed was "furlongs per fortnight". Don't get me started on links,chains,cables ( nothing to do with a motorcycle ) for length measurements or pecks,gills etc for volumes, or roods for area. Then we get short tons, long tons & metric tons ( tonnes ), kips for weights !!!!

You guys had it so so easy with the metric system. Interestingly the USA is by statute a metric country but only use imperial ( well- kind of ) in practice. :mellow::mellow::mellow:

well when we" english" started the industrial revolution... :innocent:;)