ESE's works engine tuner

[wobbly]

And that 90mm rod and bearings survive at 30,000 rpm how?
Even a plain bearing with force fed oiling at 54.5mm stroke has thrown the rod thru the computer screen
at over twice the speeds we see now.

[ken seeber]

Fletto,

I'm in the dark as anyone.

Just thought that we'd add a bit of a reality check. The pics shows a schematic of the overall dimensions and hence constraints. This is based on scaling of the VM homologation drawings and the info from the CIK application.

Rightly or wrongly, we chucked in a piston of full skirt incorporating an oil scraper, pretty much as I described in my earlier post. So, while RicM4 has indicated a neat layout with some clever ideas utilizing a piston rod, I can't see that it could all fit within the overall dimensional envelope, ie the con rod eye passes well beyond the spacer plate.

As a final comment for the day, I wouldn’t be limited to thinking that the current norm of 2A, 2D and 1C passages (as suggested by the externals of the cast cylinder) are really that. There could be anything lurking within.

[husaberg]

And that 90mm rod and bearings survive at 30,000 rpm how?
Even a plain bearing with force fed oiling at 54.5mm stroke has thrown the rod thru the computer screen
at over twice the speeds we see now.

Pretty sure they never said the 30000 rpm was with a single 125 though or did they?
The Foul Stroke 250 MX with a roller big end and similar stroke and rod length achieves pretty close to the revs claimed for the ryger.
But then again I have never actually tachoed one, they sound horrible at MX all sitting they banging on and of the rev limiter on the start line

[Flettner]

Fletto,

I'm in the dark as anyone.

Just thought that we'd add a bit of a reality check. The pics shows a schematic of the overall dimensions and hence constraints. This is based on scaling of the VM homologation drawings and the info from the CIK application.

Rightly or wrongly, we chucked in a piston of full skirt incorporating an oil scraper, pretty much as I described in my earlier post. So, while RicM4 has indicated a neat layout with some clever ideas utilizing a piston rod, I can't see that it could all fit within the overall dimensional envelope, ie the con rod eye passes well beyond the spacer plate.

As a final comment for the day, I wouldn’t be limited to thinking that the current norm of 2A, 2D and 1C passages (as suggested by the externals of the cast cylinder) are really that. There could be anything lurking within.

Don't let reality get in the way of a good story

[wobbly]

The CRF250 has a stroke of 53.8 and revs to around 17K so yes the plain bearing pressure oiled crank is reliable at those rpm
exactly as I would expect.
But the Ryger concept has the same stoke near enough, and we believe its a plain bearing "mechanism " of some sort, but
yes ITS reliable at 30,000 rpm we have been told.
Not even remotely the same ballpark.

[husaberg]

The CRF250 has a stroke of 53.8 and revs to around 17K so yes the plain bearing pressure oiled crank is reliable at those rpm
exactly as I would expect.
But the Ryger concept has the same stoke near enough, and we believe its a plain bearing "mechanism " of some sort, but
yes ITS reliable at 30,000 rpm we have been told.
Not even remotely the same ballpark.

I am not sure that is what has been said. I seem to remember some speculation that 30000rpm could be achievable. But there were no claims that I seen that this was with a 54mm stroke and a single though.
I think Harry was pretty forthcoming on the Race hero's of yesteryear thread.

[Flettner]

Fletto,

I'm in the dark as anyone.

Just thought that we'd add a bit of a reality check. The pics shows a schematic of the overall dimensions and hence constraints. This is based on scaling of the VM homologation drawings and the info from the CIK application.

Rightly or wrongly, we chucked in a piston of full skirt incorporating an oil scraper, pretty much as I described in my earlier post. So, while RicM4 has indicated a neat layout with some clever ideas utilizing a piston rod, I can't see that it could all fit within the overall dimensional envelope, ie the con rod eye passes well beyond the spacer plate.

As a final comment for the day, I wouldn’t be limited to thinking that the current norm of 2A, 2D and 1C passages (as suggested by the externals of the cast cylinder) are really that. There could be anything lurking within.

Bet I could fit that all in, just saying I've fit my one in to a smaller space??? My prototype rod / crank / guide assembly that is
You of all people should know Ken, think boomerang

[RAW]

And that 90mm rod and bearings survive at 30,000 rpm how?
Even a plain bearing with force fed oiling at 54.5mm stroke has thrown the rod thru the computer screen
at over twice the speeds we see now.

What about the ignition Wobbly, a KZ curve & 30k rpm ?

[Grumph]

The CRF250 has a stroke of 53.8 and revs to around 17K so yes the plain bearing pressure oiled crank is reliable at those rpm
exactly as I would expect.
But the Ryger concept has the same stoke near enough, and we believe its a plain bearing "mechanism " of some sort, but
yes ITS reliable at 30,000 rpm we have been told.
Not even remotely the same ballpark.

There are certain differences though...the 4T with it's "coasting" stroke puts big load reversals into the rod and pins. The 2T is always under compression which should make a difference.
Not saying you're wrong, I don't have the computing power available to quantify it...

RAW - If I remember correctly, Honda found when going over 20,000 rpm with their multis that the ignition point became less important, almost irrelevant as long as it ran some advance. You'd wonder if, at those revs,the fire ever went out...glowplugs anyone ?

[husaberg]

There are certain differences though...the 4T with it's "coasting" stroke puts big load reversals into the rod and pins. The 2T is always under compression which should make a difference.
Not saying you're wrong, I don't have the computing power available to quantify it...

RAW - If I remember correctly, Honda found when going over 20,000 rpm with their multis that the ignition point became less important, almost irrelevant as long as it ran some advance. You'd wonder if, at those revs,the fire ever went out...glowplugs anyone ?

Octane became irrelevant at high revs. Not sure if the advance was though. Those early 4V Hondas needed plenty of advance initially anyway up to 50 degrees I think , due to the wide valve angles dictated by the air cooling they had causing the inefficient combustion chamber shape.

[Frits Overmars]

... if you add another pumping chamber below the plate communicating with the upper chamber when the piston reaches TDC controlled between the two chambers by a simple flat reed ala Flat plate RG50. Over 100% cylinder filling can be achieved, as the mixture will also be compressed twice.

So wouldn't it be better to add still another pumping chamber? Or ten of those?
If you let your lower chamber communicate with the upper chamber, the compressing chamber simply moves the mixture to the expanding chamber. One chamber breathing to or from another won't give you double-pumping action; it will only violate KISS. You can compress the mixture as many times as you want; it won't change the amount of mass that was initially inhaled.
Double-pumping requires each chamber to breathe from atmosphere and into a receiver, but this would be a clear violation of the 'no supercharging' rule found in most rulebooks.

Pretty sure RicM has posted here before or was it Pitlane?

RicM = Rick Maas; he is the Dutch guy who built the servo-controlled trombone pipe that I presented here some time ago.

[wobbly]

Frits has categorically said several times that the 125 kart engine makes 70 Hp @ 17K and revs to 30,000.
And he is a man I respect - who wont say what he isnt allowed to, but for sure I believe what he does actually say.
The homolgation application papers show the bore/stroke and rod length for that single cylinder 125 engine he
has been talking about.

That engine if it gets passed by the CIK it must run the homologated PVL analogue ignition with all but a straight line advance curve.
I have test bench graphs from PVL that show plenty of ignition power up to 20,000 so maybe its OK at another 10,000.
It must be as Frits has driven the thing at 30,000 in reality - havnt you been watching.

[husaberg]

So wouldn't it be better to add still another pumping chamber? Or ten of those?
You can compress the mixture as many times as you want; it won't change the amount of mass that was initially inhaled. If you let your lower chamber communicate with the upper chamber, the compressing chamber simply moves the mixture to the expanding chamber. One chamber breathing from another won't give you double-pumping action; it will only violate KISS.
Double-pumping requires each chamber to breathe from atmosphere and into a receiver, but this would be a clear violation of the 'no supercharging' rule found in most rulebooks.

RicM = Rick Maas; he is the Dutch guy who built the servo-controlled trombone pipe that I presented here some time ago.

The idea of the double pumping was more to allow continuous induction it would alternately breath through the upper and lower in turns . The crankcase does a similar thing on a two stroke.
In practice the under and over pumping would be pumping no more that the actual capacity of the cylinder wouldn't it? so technically legalish.
Regardless If the mixture was compressed, wouldn't it be able to flow faster buying valuable time.
Bugger the rules they are made by four stroke people anyway.

Thought the name rung a bell.............

[Frits Overmars]

Frits has categorically said several times that the 125 kart engine makes 70 Hp @ 17K and revs to 30,000.
And he is a man I respect - who wont say what he isnt allowed to, but for sure I believe what he does actually say. The homolgation application papers show the bore/stroke and rod length for that single cylinder 125 engine he has been talking about.
That engine if it gets passed by the CIK it must run the homologated PVL analogue ignition with all but a straight line advance curve.
I have test bench graphs from PVL that show plenty of ignition power up to 20,000 so maybe its OK at another 10,000.
It must be as Frits has driven the thing at 30,000 in reality - havnt you been watching.

Thanks Wob. What's your poison?
You're quite right about the ignition. In fact the Ryger prototype has been running all year with the CIK-homologated fixed-advance PVL ignition.

[husaberg]

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

Don't bother deciphering that patent; it's not the Ryger-patent. The Ryger engine is much simpler.

Thank god, finally a remark that I can comment on without violating the Ryger non-disclosure agreement.
Yes, you could employ an additional reed. But why would you? The 24/7 valve itself is a reed; how much simpler do you want things to be?

Husa, here is a rule of thumb: a racing two-stroke consumes about 7 cc fuel per hp per minute (the Ryger engine consumes considerably less).

Ken, you might want to review your correlation as the RSA produces its 54 hp @ 13,000 not 12,000 rpm.

I'm happy to say that patent http://worldwide.espacenet.com/publicationDetails/mosaics? is not the Ryger patent. And I agree: it's far too complicated.
Must hurry now, couldn't even find the time to read your whole post, Ken. I'll get back to you if there is anyting that I am allowed to comment on.

It would certainly put the RG-trannie to the test. 280 hp, that's 50 horses more than what the current 1000 cc MotoGP bikes have, with all their electronic gizmos, meant to keep their riders on the track and out of hospital.

Like a regular 125 cc kart engine, until you rev it through the ceiling. Lovely sound!

Attachment 312440 Attachment 312441
Yep, this is the cylinder, and here is what Harry Ryger wrote:

Your idea looks rather simple compared to some suggestions I've seen here. But your pumping cylinder is moved by crankcase pressure alone, right?
It may function at 3.000 rpm, but the Ryger revs past 30.000 if you keep your foot down (which I did the first time I gave it some throttle, because I expected 125 cc kart-like acceleration, not the rocket launch I got) .

Yep.
Here are two links showing the standard VM 125-engine.

VM 125 M 02/B catalogue: http://www.vmmotor.com/www/vmmotor/f...5-m02-beng.pdf

VM homologation: http://mach1motorsport.files.wordpre...ogering-vm.pdf

I didn't count them but I estimate that in the Ryger engine 98% of these parts are used unmodified, including the cylinder head.

Asked and answered, Your Honour: http://www.kiwibiker.co.nz/forums/sh...post1130868700

I can envisage a free piston engine surrounded by coils, acting as a generator and driving an electromotor. But that's for next month.

I'm not at liberty to answer that.

Not necessarily. For example, a piece breaking off the piston skirt will not do the rpm much good, generally.
Joking apart, a while back I would have answered that the attainable rpm in a two-stroke is limited by the time.areas, not by piston speed or mass.
But that was BR (Before Ryger).

Whole pistons have been made from pressed carbon (the kind that carbon brushes are made of). Mahle experimented quite a bit with them, mainly for TDI engines, but they made some two-stroke pistons as well. They are self-lubricating and will withstand very high temperatures, but they are not much lighter than light-alloy pistons because they require thicker skirt walls, and their high crown temperature will provoke detonation, which makes them unsuitable for anything but diesels.
Attachment 312538

You made my day, Jan; you fell for it 38 years after the fact. That magazine was MOTO 73, of which I was the technical editor (and test rider, and photographer, and translator, and I also made the coffee occasionally, but somehow we managed to become the biggest motorcycle magazine in the Netherlands and Belgium).
The TVPS (Top Valve Piston System) was our 1977 April Fool's joke!

I intended to read all the pages you posted before giving an answer, but I stopped reading after "Let it be assumed that the conditions of heat transfer, flow resistance and flow dynamics are not significantly influenced by skip cycling". Yeah, right. That may be true in engines that solely depend on a scavenging pump. But ours don't; they depend on exhaust resonance. And when you skip just one combustion cycle, the dynamics collapse and so does the next scavenging event. And the next. And the next, until eventually there is enough mixture in the cylinder for successful ignition again.

That's the way I operate too, Neil. Who wants to be rich? I'm happy each time one of my wild ideas actually works.
The Ryger situation is an exception because there is more involved than just my own ideas.

Too bad I wasn't aware of your intentions Jan; I would have been happy to play ball. But don't feel bad about the bouncing PM. I blocked PMs on all public forums; forums absorb far too much of my time as it is, every day.

I didn't do 30k in 6th gear Ken; not on the stretch of road you saw in the picture. There were protruding manhole covers in the middle, leaving a useful width of one kart width plus maybe 30 cm.
Re the catch can filter: I am not even at liberty to confirm that it is a catch can filter, but I will admit that it is a filter. Satisfied? Didn't think so. Nice try though .

Are you thinking bread crumbs or 36-24-36? In the latter case I can sympathize with you.

I've said this before: it's not up to me to decide which questions regarding the Ryger engine I can or cannot answer.

We're on the same page Husa. The Rygers amazing power and its willingness to rev are not even its main strong points. Its fuel economy and clean exhaust are.
But the environmental climate is not favourable for two-strokes.
Several dutch cities are contemplating a ban on small two-strokes because they are big polluters. Which is true because these 50 cc mopeds and scooters are limited to 25 or 40 kmh. They are not allowed to produce anything like decent power, so their combustion is mediocre.
The logical error is of course that vehicles should be banned if they pollute, not because they are chinese, or orange, or two-strokes. But try telling that to a politician.
The only thing they understand is what the public wants to hear. They don't want to see 'clean' and 'two-stroke' in the same sentence.

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

(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).

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 .
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.

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 .

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.

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

No need to die first in order to become a spiritual father, Breezy. Harry Ryger is alive and kickin' the two-stroke community.

Your 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.

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.

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.

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.

When Facebook announced they would disrespect all privacy rules as of 01-01-2015, I stopped logging in, so I haven't got a clue what is going on there nowadays.
I do know that avoiding facebook saves me over an hour, every day, so I do not intend to go back there.
Who wrote the lines you are quoting? If it was Harry Ryger, you can take his word. And yes, the power, the revs and the emission values are all from the same engine.

Could you let us know what those are, before I answer that I'm not at liberty to answer?

I know what you mean Yow Ling. I felt exactly the same until I got some hands-on experience with the Ryger.

I know the feeling Neil. I'm very glad to be involved with the Ryger engine, but it has also made me very reluctant about everything I thought I knew about two-strokes.

You're right Jonny. I'm able to answer that. But I'm not allowed to.

Could you say how the underside of the piston would shut the exhaust port off at any position, Neil?
We did some playing around with this type of piston too, but it's no good for a two-stroke.
Attachment 313705

Let alone the things you are about to find out about people in R&D departments. They don't change tyres. None of them (in the glory days when Aprilia was ruling the roost in the 125 and 250 cc classes, there were not 100 but 150 people working in R&D).
Taking care of the tyres was the responsibility of the racing teams, that were completely separate from the R&D dept. And they didn't change tyres either; they just dropped the wheels at the Dunlop, Michelin or Bridgestone service trucks, went for a glass of Lambrusco a cup of coffee, and picked them up again.

When I first heard the numbers, I was very sceptical. When I first got acquainted with the engine, this was my reaction:
http://www.kiwibiker.co.nz/forums/sh...post1130866554
There was no need (but a huge desire) to double-check the feeling of that first ride.

You may have to farm out some of the work, but you will be able to keep using most of your current parts.


Are you pulling my leg Ken? When I wrote 'everything I thought I knew about two-strokes', I meant two-strokes. Is there any other kind?
I think I know what you wish to hear. The laws of physics haven't changed but I am beginning to realize that I neglected some aspects of the gas dynamics in an engine as being unimportant, until Harry Ryger showed what can still be found there. I'd really love to be more specific, but that will have to wait until I get the green light.

I happened to notice this addition to your original post, Neil. Normally I would have missed it. And I hate missing things, so from my point of view it would have been safer to put it in a new post instead of adding it to a post that I already thought I'd seen. Come to think of it: God knows how many valuable additions I've already missed because I usually don't go back to 'old' posts.
That Husqvarna video of yours reminds me of a Stihl patent ( http://www.google.com/patents/US6415...roke+OR+engine ) wherein scavenging is also taken care of by air only, after which the fuel-air mixture is transferred. But I don't see any similarities with the Ryger engine.

I never planned to control the exhaust ports. We talked about controlling the transfer ports here (via the 'commas') but once Flettner showed an interest, I thankfully turned my mind to other (Ryger) things.

It may be just my suspicious mind, but do I feel a hand on my leg again?

It starts like any other kart engine. You get a push, you knock the shift lever into second gear and off you go. And I don't need to tell you that any conventional two-stroke is started with the help of a positive mechanical displacer for the incoming gas or air: the crankcase pump. That's all I can say right now.

I don't think the non-disclosure agreement applies here, but a normal chat between friends also deserves some privacy, so I won't give any details, but Harry intends to supply his own engines. He's not in it for the money, he's just a guy with a passion for two-strokes, just like yours truly.

Not on me, Neil.
The flywheel is the critical part. I can't remember which steel it was made out of, but the flywheel and both shaft stubs were made out of one lump. No holes, no shrink or press fits, no welding or glueing. The centrifugal tension concentrates on the center and if there is a hole there, you lose 50% of the permissible tension.


Some more pictures of the dyno:
Attachment 313816 Attachment 313815


True. Measuring with test props will you give just one point of the power curve per measurement; your engine will be worn out before the curve is completed.

Pressure measuring gives you the pressure at a given distance from the exhaust port, at a given point in time. With pressure waves coming and going in both directions, chances are that you are measuring maximum or minimum wave superposition values, or anything in between, which will only teach you to dedicate your time and energy to other aspects of the engine.

Engine size does not figure in resonance phasing. The MB40 engine has 190°/130° timing, like you would expect from any decent two-stroke.

I don't recall the rotary inlet timing of the hollow crankshaft shown below but it will probably be something like 140°/60°. That may seem tame and it is; this is not a high-revving engine . It doesn't exceed 35000 rpm and then the mean piston speed is only 23 m/s. Compare that to 26,3 m/s for an Aprilia RSA (or 54 m/s for a Ryger).
Anyway, I feel that this kind of shaft rotary inlet for model engines is a fashion thing more than anything else; I wouldn't be surprised if simple piston port induction would perform better (it would certainly flow better).
Attachment 313817

Good thinking Peewee. All hell broke loose here because of the Ryger homologation confirmation so I can't find the time to write a decent explanation, but here is a picture of the RSA's A-duct geometry where you can see the inner and outer radii and the coordinates of their centers.
Attachment 314338

The international homologation for the 125 cc Ryger kart engine was accepted yesterday. The Federation Internationale de l'Automobile typically needs six weeks to put their paperwork online,
but I will try to make the complete document available later this week.

yeah right they should switch to electric powered karts with solar charging then. From the ppm values I saw from the ryger engine, it is not as good as a four stroke, yet, let alone a four stroke with catalytic converter. (If a four stroke can be anything like "good", that is.)



By the way, thanks for the above explanation, I got it now. On the VHM website I saw a combustion chamber which was nicely shaped to follow the piston dome with the radiused edge. But that was a design which protrudes into the bore. So I think I can now safely try radiusing, too. Before I saw that picture, I was always afraid that the outside of the dome might distort and provoke detonation.


And with quite a fine mesh, too! Sometimes I miss all the tools I once had at my disposal. Did they use 3D CFD at Aprilia? Personally, I don't think that's necessary in race engine development, but it sure is a nice help in visualizing the scavenging (and, more importantly, visualizing the differences in scavenging between two variants).

Ryger production is running in high gear in order to meet the CIK regulations.
Attachment 314432Attachment 314433

Love the idea. And if you compare the size of a Ryger two-stroke single with a Moto3 foul-stroke engine, you can imagine how beautifully compact that V6 could be.
And imagine the sound of it! Bernie Ecclestone has been complaining about the lack of audio attraction in the present F1 turbo engines. An unsilenced Ryger V6 revving to your heart's desire could easily make that complaint go away.
Attachment 314586 Attachment 314587

You could make the financial aspect of the non-disclosure agreement go away. But that is not what it's about. I gave my word, simple as that.
Maybe you could spend your money trying to make Ecclestone see the error of his ways when he said "no two-strokes in F1".

don't you love it when you can use the same text twice Wob?

Thanks Wob. What's your poison?
You're quite right about the ignition. In fact the Ryger prototype has been running all year with the CIK-homologated fixed-advance PVL ignition.

Frits has categorically said several times that the 125 kart engine makes 70 Hp @ 17K and revs to 30,000.
And he is a man I respect - who wont say what he isnt allowed to, but for sure I believe what he does actually say.
The homolgation application papers show the bore/stroke and rod length for that single cylinder 125 engine he
has been talking about.

That engine if it gets passed by the CIK it must run the homologated PVL analogue ignition with all but a straight line advance curve.
I have test bench graphs from PVL that show plenty of ignition power up to 20,000 so maybe its OK at another 10,000.
It must be as Frits has driven the thing at 30,000 in reality - havnt you been watching.

Whoops Wob i indeed missed where Frits said it revved to 30000 when he drove it.
but i have bolded it and the 54ms.