ESE's works engine tuner

[FastFred]

.

Oil... Team ESE use 5% (20:1) in petrol and back in the day TZ's often ran as much as 8% (12:1)

Team ESE use 20:1 for a very practical reason. It is much easier and way more reliable to send someone down the road with a 1 liter pack of oil and a 20 liter drum and tell them to tip the oil in and fill the drum up. No mental arithmetic required, anyone can get it right. Mixing at the time of use is fraught with calculation errors and who can remember if that old tin of race gas has had oil put in or not. Ours are mixed at the time of filling and there is no raw fuel without oil on site, never had a problem yet.

[SwePatrick]

Man,, i´m the lazy bastard. *lol*
I haven´t flushed my methanolengine once, not a single time this summer.
No problems whatsoever.

Only thing i do is to empty bowl and let the bottom plug be off when it is at rest.
To get it well ventilated(free from moisture)

can it also be that my methanol supplier sells me fresh fuel and is one of the most pure methanols one can get hand of?
Dragracers must use this purity, if not they might not be ok in a fuel test.

[Carel H]

.

Oil... Team ESE use 5% (20:1) in petrol and back in the day TZ's often ran as much as 8% (12:1)

Team ESE use 20:1 for a very practical reason. 1 liter pack of oil and a 20 liter drum and tell them to tip the oil in and fill the drum up.

Isn't this 19:1 or am I missing something?

[Flettner]

Yes, I don't know, but I've never flushed my F9 running on E85 since 2008 when it first ran on the stuff. To be fair, one VMX season it ran a carburetor and petrol. Rider didn't want to be called out on EFI, I guess a good thing as he did win the season on it that year. And boy was it gutless, bloody skilled riders! (a young hotshot)
I have changed filters a few times though, both low pressure and high pressure filters.

[FastFred]

Oil... Team ESE use 5% (20:1) in petrol and back in the day TZ's often ran as much as 8% (12:1)

Team ESE use 20:1 for a very practical reason. It is much easier and way more reliable to send someone down the road with a 1 liter pack of oil and a 20 liter drum and tell them to tip the oil in and fill the drum up.
Isn't this 19:1 or am I missing something?

Yes you are missing the bit that I did not say, "fill the drum up with 20 liters of petrol" sorry should have said.

Carel have you got any pictures of your recent projects to post and talk about? Love to see them.

[wobbly]

If you make the assumption that 20:1 on petrol is the baseline then when using Methanol to get the same amount of oil entering the engine
per stroke you will only need 1/2 that ratio approx,as twice as much + fuel is being consumed with the same amount of air.

Regarding the ratio - with 20 L of fuel and 1 L of oil, that is strictly a ratio of 20:1, but you now have 21 L of mixture in total.

In the past I have always flushed the Methanol out of race engines by running them on a petrol/oil mix from a small container with a hose onto the carb.
As firstly if you dont the bowl ends up a white corroded mess, and secondly the remnant Methanol sits on the internal bearing surfaces happily absorbing water.
This moisture eventually will rust pit bearing races etc,and destruction soon follows.

[peewee]

As firstly if you dont the bowl ends up a white corroded mess, and secondly the remnant Methanol sits on the internal bearing surfaces happily absorbing water.
This moisture eventually will rust pit bearing races etc,and destruction soon follows.

this was my reasoning also but thinking past that, i have atleast a pound of epoxy on the transfer port walls trying to hold on for dear life. the less time the methanol is in the engine the less time it has to attack and break loose a epoxy chunk and send it to the piston top

[teriks]

i flush the engine and carb with petrol premix at the days end. no problems so far. i bet the reason some rc fuel uses 18% - 23% oil content is to maybe reduce the nitric acid accumulation inside the engine. thats the only thing i could think of
Well, the oil migration at 30+kRPM is quite fast, add to that plain big end bearings even on the best racing engines I bet there's a real need for huge amounts of oil.
As I said though, I haven't done any kind of experimenting with oil content, changing is simply not an option due to rules. -A good thing I think, there's enough to mess up any way, don't need to add exotic fuels to the mix. :)



can it also be that my methanol supplier sells me fresh fuel and is one of the most pure methanols one can get hand of?
Dragracers must use this purity, if not they might not be ok in a fuel test.
Unfortunately not, as Wob already mentioned, methanol absorbs moisture from the surroundings, so no matter how pure the methanol is to start with it will start absorbing water from the air as soon as the can is opened.

[Lightbulb]

If you cut back the oil on your F3D engine to around 17%, it will fail a big end on the rod if it runs lean at all.
Saw where a person did not mix the 80% methanol to the 20% oil correctly. Then failed an engine. Maybe if they
had mini needle rollers it may not be quite so bad. I still can't figure how they thought 170mls of oil was 20% of 1L.
Maybe they were going to mix up 1 pint of fuel and used a L flask and just stopped at the top. Don't know.

Neil

[SwePatrick]

Unfortunately not, as Wob already mentioned, methanol absorbs moisture from the surroundings, so no matter how pure the methanol is to start with it will start absorbing water from the air as soon as the can is opened.

I know,, thats why i keep my lids shut ;)
Still have no problems, come see for yourself,, i do not lie.

And one have to take in consideration, that peoples eager to be correct on the web always plays a role in this kind of discussions.

Somebody have 'heard/read' that someone had problems with something, and through many mouthes it adds expressions to make their statement.
And by that increases the problem that was a minor problem at first.

I also have worst case scenario i guess.
fueltank in almost 'pure' aluminium, and just ventilating the floatbowl between runs.
And still no problem.
The fuelpump i used thou had slightly bigger problems.
A mikuni copy. 70l/h
I had to clean that one out due to valves stopped working inside.
But other than that - no problems.
Not even slightly, can´t find any white oxid anywhere.

could it be that my fuel is very little exposed to air?
I run pressure from the pipe into the tank instead of fuelpump, works much better.
And tank isn´t 100% sealed so it blows out the air and replaces it with exhaustfumes.
My fueljugs are also closed at all times.
I use a siphonpump or what they are called to fill upp fueltank, always to the top.
It keeps fuel in jug away from unnecessery moisture.
And my fuel is pre-mixed in the jugs.

[lohring]

i flush the engine and carb with petrol premix at the days end. no problems so far. i bet the reason some rc fuel uses 18% - 23% oil content is to maybe reduce the nitric acid accumulation inside the engine. thats the only thing i could think of

The reasons RC racing engines use up to 20% oil with high castor content is protecting and sealing the ringless piston as well as oiling the plain big end bearing. Even engines with roller bearing big ends use a high oil content. Lower performance engines can use lower oil content and synthetic oils to reduce the mess.

RC airlpane engines running on mostly methanol can get away without running after run oil. RC boat engines' bearings fail immediately without a WD 40 flush and after run oil. I use ATF. Of course they run 60% nitro in a water environment.

RC boat gasoline engines do fine without after run oil. They still develop more power with more oil. I've dynoed engines with up to 10 oz of oil per gallon before power stops improving. Eight oz per gallon is standard.

Lohring Miller

[SwePatrick]

The reasons RC racing engines use up to 20% oil with high castor content is protecting and sealing the ringless piston as well as oiling the plain big end bearing.

Lohring Miller

I would say this is the reason to about 95% :)
If i would run 20% in my 211cc engine i would need to clean whole garage and ventilationsystem after a dynoday.

3% in my engine is good enough, it revs to about 14000rpm give or take.
And no remarkable wear.
Only that were worn was the wristpin, but i figure that was because i had no window in piston.
Need to cool it down with fresh oil mixture was my guess.
Std there´s a window in piston, so i milled one just recently.
Bought a new wristpin and bearing, so now i can fin an answer to that also.

Piston was almost like new, just the graphitecoating had worn off in certain places.
And in those places, really really soft rubbing from cylinderwall.
Still can see the marks from turning the piston really really clear.
Cylinderbore was also perfect.
Still round, and still schratches left from honing.(the deep ones were still there and the small ones that should bed in with pistonring was perfectly polished all the way around)

I ran engine for a couple of hours with heatcycling at first with 4% before start punishing it.

And it has got beaten really hard.
Almost 200 dynopulls as we speak.
And a whole raceweekend.

I never run it above 60c watertemp thou.

Rgds,

[Carel H]

Carel have you got any pictures of your recent projects to post and talk about? Love to see them.

For motorcycle related you can google "pictures", "harmsen motor" or even "harmsen rotax". Not recent, more historic. I was a great fan of Jamathi: "Beat the factories from a shed!".

After motorcycles I went back to industrial automation and what people hate most: electronics and software.

Most recent project is a motorized catflap for cats who believe in conspiracy theories (They are waiting for me on the other side!). I sold one to myself, having a conspiracy theory cat. Made possible with AMS contactless hall sensor chips. So this project includes a rotary sensor, a servo drive and a positioning system. Think TPS and power valve.

Applications don't matter, it's all about building blocks.

[Grumph]

I know,, thats why i keep my lids shut ;)
Still have no problems, come see for yourself,, i do not lie.

And one have to take in consideration, that peoples eager to be correct on the web always plays a role in this kind of discussions.

Somebody have 'heard/read' that someone had problems with something, and through many mouthes it adds expressions to make their statement.
And by that increases the problem that was a minor problem at first.

I also have worst case scenario i guess.
fueltank in almost 'pure' aluminium, and just ventilating the floatbowl between runs.
And still no problem.
The fuelpump i used thou had slightly bigger problems.
A mikuni copy. 70l/h
I had to clean that one out due to valves stopped working inside.
But other than that - no problems.
Not even slightly, can´t find any white oxid anywhere.

could it be that my fuel is very little exposed to air?
I run pressure from the pipe into the tank instead of fuelpump, works much better.
And tank isn´t 100% sealed so it blows out the air and replaces it with exhaustfumes.
My fueljugs are also closed at all times.
I use a siphonpump or what they are called to fill upp fueltank, always to the top.
It keeps fuel in jug away from unnecessery moisture.
And my fuel is pre-mixed in the jugs.

I think you've hit on a combination of factors that i've never experienced personally.
Aluminium fuel tanks I stopped using for methanol wherever possible as without regular cleaning they also turned into blocks of white corrosion...
But those were vented to atmosphere - and most of the speedway running here is done on cool evenings so condensation is a problem.
Undoubtedly using exhaust gas to pressurise the tank has had a beneficial effect chemically.

When methanol was legal here for bike roadracing I used to get asked to read plugs and assist with carb setup quite frequently. By the time they got to my local round of the Nationals, they'd usually done at least one or two other meetings and had opened tins of methanol with them. My first demonstration was always to use a water test kit on their fuel. That opened a lot of eyes as to just why they were having problems...

[Nath88]

Mini progress update on the ion sensing.
Got the engine running with the ion sensing circuit in place, maintaining 90V across the plug gap. The first bit of the signal is the coil ringing at ~20 kHz after spark. I think the ion current is imposed over the top of that. 2.5 volts amplitude over a 80k ohm measuring resistor gives a current of 31 microamps. H-D (feels bad to compare, but they also use ion sensing...) report about 30 microamps with 80V across the plug gap, so my numbers are in the ballpark.

Next up is to make some signal processing circuitry to turn it into a usable output. Probably a buffer amplifier, followed by some filtering, integrating the signal to find 'how much current has flowed in this cycle', then find the threshold value that indicates a misfire vs. fire.


https://www.youtube.com/watch?v=uonon9KuWhY

[lodgernz]

OK, here's the dyno result (thanks F5Dave) with my new Disc Valve setup on my NSR50, using the same 24mm carb and pipe etc. as with reeds.
The red line is with reeds, the blue line is with the RV.
As Wobbly predicted, closing at 80º has cost top end and over-rev. Surprising similarity with reeds through the mid-range though.

Next move is to cut the disc to get 85º closing, then, depending on that result, 90º closing. I think I'll leave the opening at 135º for now.
332256

[wobbly]

Way back when dyno testing the old Rotax twin at Zipkarts for Hines Superkart,I found that the closing timing of the RV is very
responsive to tiny changes.
The stock timing was 134/86 , and moving the closing out to 88 gave a big result in peak and overev power.
That engine only reved to 13400 max tho, and any more timing simply killed the upper midrange way more than it increased the topend.
Opening ended up at 138 as going any more made it all but impossible to jet correctly with a huge amount of standoff badly affecting the acceleration
both under dyno load and on the track.
So my advice is to cut the blade in only 2* increments at most.

[peewee]

swepatrick a few years ago i had honda that i only used petrol and castor. the engine never failed but i took it apart one day, i think to grind the ports alittle from what i recall. i was suprised to see rust on the iron bore and forming on the crank bearing races. i suspect the castor was attracting moisture. dont forget it might happen to you also

while im thinking of it, does anyone know of a shorty plug thats reasonably priced ? since adding a spacer under the cylinder i cant use a normal plug now. i been using the br9ecm like what some moderm ktm use but theyre 12usd plus freight and theyre only available in resistor type. the owners manual says i should use nonresistor and i already have 5k cap so should i be using nonresistor or what ? unless maybe i could find a non resistor cap somewhere. the cdi-coil is all one unit. electronic stuff isnt my specialty

[lodgernz]

Way back when dyno testing the old Rotax twin at Zipkarts for Hines Superkart,I found that the closing timing of the RV is very
responsive to tiny changes.
The stock timing was 134/86 , and moving the closing out to 88 gave a big result in peak and overev power.
That engine only reved to 13400 max tho, and any more timing simply killed the upper midrange way more than it increased the topend.
Opening ended up at 138 as going any more made it all but impossible to jet correctly with a huge amount of standoff badly affecting the acceleration
both under dyno load and on the track.
So my advice is to cut the blade in only 2* increments at most.

Thanks Wobbly, that's really good info. So, 2º it is then. I suspect there's possibly 2º variation in timing due to belt flex but hopefully consistent under load.

I was very pleased to see that the twisted belt arrangement was completely untroubled by several 14,000+ dyno pulls, including "blipped" down-changes.

[Grumph]

Thanks Wobbly, that's really good info. So, 2º it is then. I suspect there's possibly 2º variation in timing due to belt flex but hopefully consistent under load.

I was very pleased to see that the twisted belt arrangement was completely untroubled by several 14,000+ dyno pulls, including "blipped" down-changes.

Put a strobe on it to see how much the belt moves in use.
On an OHC setup it's horrifying but your little disc is much lower loads.

[Peter1962]

Happy birthday, Frits ! :drinknsin

[husaberg]

Put a strobe on it to see how much the belt moves in use.
On an OHC setup it's horrifying but your little disc is much lower loads.

Flettner has mentioned how this quirky wrinkle it could be very useful on a 2t.

Oh yeah happy birthday Frits, your present is under your bed.

[F5 Dave]

What I like is it gained between 9 & 10. Why?!?!. Also it used the same jetting as the reed valve. Was cool to see the belt in action. Like to see a way shorter inlet tract but packaging just doesn't allow.

[sidecar bob]

What I like is it gained between 9 & 10. Why?!?!. Also it used the same jetting as the reed valve. Was cool to see the belt in action. Like to see a way shorter inlet tract but packaging just doesn't allow.

Just loose the disc valve & belt. Apparently shit runs better without them.;)

[Flettner]

I don't know, but it would seem the sliding rotary valve GIB might be a good thing after all. It works for me. I wonder, what might happen if in conjunction with a variable valve housing, open a port on the opposite side of the crankcase when on the pipe. A 23 / 7 induction of sorts.
With TPI it just needs to be a hole.

[SwePatrick]

swepatrick a few years ago i had honda that i only used petrol and castor. the engine never failed but i took it apart one day, i think to grind the ports alittle from what i recall. i was suprised to see rust on the iron bore and forming on the crank bearing races. i suspect the castor was attracting moisture. dont forget it might happen to you also

while im thinking of it, does anyone know of a shorty plug thats reasonably priced ? since adding a spacer under the cylinder i cant use a normal plug now. i been using the br9ecm like what some moderm ktm use but theyre 12usd plus freight and theyre only available in resistor type. the owners manual says i should use nonresistor and i already have 5k cap so should i be using nonresistor or what ? unless maybe i could find a non resistor cap somewhere. the cdi-coil is all one unit. electronic stuff isnt my specialty

Yes, i know of castor and moisture, but it has never been a problem for me.
With petrol and castor i only got like 'syrup/caramel' coating after a while.

Are the answer laying right in front of me?
Is Shell advance racing m containing anticorrosion additives?

Reading in Shell´s pdf document they say 4% mixture is recommended for motorcycles.

Can it also be, the more oil the more problems?

[oldjohnno]

Yes, i know of castor and moisture, but it has never been a problem for me.
With petrol and castor i only got like 'syrup/caramel' coating after a while.

Are the answer laying right in front of me?
Is Shell advance racing m containing anticorrosion additives?

Reading in Shell´s pdf document they say 4% mixture is recommended for motorcycles.

Can it also be, the more oil the more problems?

I use Shell M with methanol too and have never experienced any corrosion. But if I don't purge it I get a LOT of water collecting in the crankcase, especially in hot and humid weather. It may be less of a problem in a cold climate.

[oldjohnno]

Hypothetical question: if you had some sort of magic inlet valve that needed no space or drive mechanism, where would you put it? In other words if you had complete freedom in placing the intake port and passage, where would it be and in which direction would it be aimed?

[Lightbulb]

Years ago, one of the methanol suppliers used to add a small amount of acetone to their stock. It allowed it to blend with the oil a little better. In the model engines, adding a little bit of diethylether, or ether at about 1% also improved oil mix stability and also aided in the fuel mixture being consistent. ie a very stable needle valve setting. But storing for any time was a problem as the ether would easily diffuse out of the fuel.
Neil

[Frits Overmars]

Undoubtedly using exhaust gas to pressurise the tank has had a beneficial effect chemically.It's common practice in methanol-burning F3D model aeroplanes, but with one important restriction: the fuel is contained in a rubber bladder inside the tank.
The exhaust pressure works on the outside of the bladder, so exhaust gas and fuel never come into direct contact. Just as well, because the H2O-content of exhaust gas is quite a bit higher than the H2O-content of ambient air.


happy birthday Frits, your present is under your bed.Thanks Husa, but I'm not going to fall for that any more. For years I've been looking under my bed before I went to sleep, but there was never a pretty body there waiting for me.

[teriks]

Yes, i know of castor and moisture, but it has never been a problem for me.
With petrol and castor i only got like 'syrup/caramel' coating after a while.

Are the answer laying right in front of me?
Is Shell advance racing m containing anticorrosion additives?

Reading in Shell´s pdf document they say 4% mixture is recommended for motorcycles.

Can it also be, the more oil the more problems?
Well, I get away with leaving my engines as is after running too.

I guess I get away with it for a few reasons,
* The engine have no throttle and is stopped by cutting the fuel, so most (all?) of the methanol is gone.
* Even though the methanol is gone, there's still a generous amount of oil left providing corrosion protection. (Castor is actually quite good at preventing corrosion)
* Engines stored indoors in stable temperature.
* Location: We rarely get those extreme amounts of humidity here in Sweden.

Leave it for too long and the castor turns solid-ish though, now that shit is a pain to get rid of.. Good thing I have small stuff, so it can be avoided by a quick spray of Castrol DWF in the intake _before_ the castor has gone solid.

Anyway, if you don't have problems, just keep doing what you are doing.

[SwePatrick]

332259

Where´s the pumping displacement?

If taking a wild guess, the piston is 54mm
And the innerdiam of piston is about 40-45mm
It doesn´t leave much pumpingdisplacement to fill the cylinder.
So i would say it´s very much depending on the pipe.
Maybe it´s just rpm tuned area in pipe that isn´t that important.
It need the pipe as a pump to get it to breathe as far as i can see.

Without the pipe one can never reach 100% VE with that construction, noway!

[lodgernz]

What I like is it gained between 9 & 10. Why?!?!. Also it used the same jetting as the reed valve.

Might have been a hole in the reed curve rather than a bulge in the RV one?

[ken seeber]

332259

Where´s the pumping displacement?

If taking a wild guess, the piston is 54mm
And the innerdiam of piston is about 40-45mm
It doesn´t leave much pumpingdisplacement to fill the cylinder.
So i would say it´s very much depending on the pipe.
Maybe it´s just rpm tuned area in pipe that isn´t that important.
It need the pipe as a pump to get it to breathe as far as i can see.

Without the pipe one can never reach 100% VE with that construction, noway!

There is only one person to ask Patrick and he's not here.:weird:

[SwePatrick]

There is only one person to ask Patrick and he's not here.:weird:

Oh,, i´m sure he reads it thou ;)

[jamathi]

332259

Where´s the pumping displacement?

If taking a wild guess, the piston is 54mm
And the innerdiam of piston is about 40-45mm
It doesn´t leave much pumpingdisplacement to fill the cylinder.
So i would say it´s very much depending on the pipe.
Maybe it´s just rpm tuned area in pipe that isn´t that important.
It need the pipe as a pump to get it to breathe as far as i can see.

Without the pipe one can never reach 100% VE with that construction, noway!

Is anybody still believing in this project?
What about pumping losses....

[SwePatrick]

Yes.

Let´s say you pressurise the crankhouse about 20-1 to get some punch into the small flow there is.
Piston has to work against that whole stroke, and at the most important part of the stroke where there are no powerstroke it becomes tougher and tougher.

A BIG flywheel might overcome that.
but......

[jamathi]

Yes.

Let´s say you pressurise the crankhouse about 20-1 to get some punch into the small flow there is.
Piston has to work against that whole stroke, and at the most important part of the stroke where there are no powerstroke it becomes tougher and tougher.

A BIG flywheel might overcome that.
but......

Looks VERY promising indeed...
Getting better and better!

[Lightbulb]

Is anybody still believing in this project?
What about pumping losses....

I think the only pumping losses are those pumping money into the project are realising losses.

I am seriously thinking that if they really did have anything really substantial, it would be out by now and
be blistering track records everywhere. But that has not happened, sadly. We get strung along all the time
with little miss leading things, time and time again. We are suckers for new tech and most here have a true desire
to learn more about a very simple in principle engine. Crowd development may be the way to go. They got a patent
application in place, but still don't share anything. They set a track record against 4s renta karts and we are supposed to be impressed.
I have seen a one time picture from a tacho at like 28100 rpm. Then told it has passed 30 k more than once. But like any monsta
story, no video, or audio for that matter. 1900 rpm is a lot at that level. Look at a 6.5 cc methanol engine. Very difficult to go from 34k to 35k
rpm, and they want us to believe it can easily do 30k with a 125. Like some have said, very doubtful for any length of time, without super materials that
would put the engine price above 30k to get made.

[41juergen]

Can somebody help me: what is that material you use to do the molds of the transfers and were can one get that from?

[Peter1962]

Can somebody help me: what is that material you use to do the molds of the transfers and were can one get that from?

It's called Vinamold : http://www.mbfg.co.uk/vinamold/red-vinamould.html

[TZ350]

I knocked this up the other day.

It's just a prototype to test whether the twisted belt arrangement is capable of high revs.
To my surprise, it was untroubled by blips to 14,000RPM and sustained 12,000 for a few seconds.
Here's a video of it running: https://youtu.be/7Ffs1x145zw

332277

I set the timing to: Open 135º BTDC, Close 80º ATDC, but once assembled, I found it was 5º late (at both ends, obviously) so it ran a bit hairy. I can fix that of course. Main object was to prove the belt drive.

I have no idea whether this setup will provide more power, although I suspect it might produce a better mid-range curve.
I'd appreciate any comments or advice.
Dyno time needed...

https://youtu.be/7Ffs1x145zw


332276

OK, here's the dyno result (thanks F5Dave) with my new Disc Valve setup on my NSR50, using the same 24mm carb and pipe etc. as with reeds.
The red line is with reeds, the blue line is with the RV.As Wobbly predicted, closing at 80º has cost top end and over-rev. Surprising similarity with reeds through the mid-range though.Next move is to cut the disc to get 85º closing, then, depending on that result, 90º closing. I think I'll leave the opening at 135º for now.

Great effort, very impressed with the RV conversion. My favorite RV timing on the 125 is, inlet opens 145 BTDC and closes 85 ATDC. Opening is 145 std Suzuki timing for a GP125 and 135 for a GP100.

[TZ350]

Opening ended up at 138 as going any more made it all but impossible to jet correctly with a huge amount of standoff badly affecting the acceleration both under dyno load and on the track.

If the standoff was reduced and as jetting is not a problem with EFI.

Would it be a benefit to opening a RV inlet much earlier, or even before BDC like a 4T or is there some other limit?

Interested because with my bike running EFI for jetting and using the variable inlet area system that I have for suppressing the standoff I would be very interested in how much earlier people think the RV inlet opening timing could be usefully advanced too.

[TZ350]

332283

Preparing a new cylinder with a center injector port for fuel injection to the underside of the piston.

I have tried this before on the air cooled motor and found it made for very good fuel homogenization at low engine speeds and/or throttle opening. But abandoned it at the time because it did not give me what I wanted which was having the main high speed fuel injecting under the piston for piston cooling. The center arrangement did not work well for high speed high volume fueling.

But with water cooling the piston cooling problem is a non issue and previously the combination of injecting in the B transfers for power and under the piston for low speed has worked well in the air cooled motor so we will re visit that arrangement.

The new cylinder has been ported to increase the blowdown STA. I will test it on the dyno, hopefully next weekend and if its any good I will get the cylinder re plated.
332284332285

Bigger engines like 250's that only rev to 9,000 rpm or so can get away with only B port injectors but once you go past 10,000 rpm "Time" constraints mean you need staged injection and my experience has been, for a high revving 125, center injection for <8k and injection into the B ports for rpm and power work best.

I still have the problem of determining between on/off pipe and fueling below 20% throttle to overcome.

[TZ350]

332286

28 RWhp from a MC21 NSR250 cylinder with standard porting fitted to a Suzuki GP100 bottom end.

My ambition is hopefully a bit over 30 so I can catch up with those Team GPR boys and their 32 RWhp air cooled special.

332287

Very competitive Team GPR air cooled 125 with a hand made cylinder CNC machined out of billet.

[lodgernz]

Great effort, very impressed with the RV conversion. My favorite RV timing on the 125 is, inlet opens 145 BTDC and closes 85 ATDC. Opening is 145 std Suzuki timing for a GP125 and 135 for a GP100.

Thanks for that Rob, much more development to do though. Wow, that stock GP125 opening is really early, but I guess they don't rev much.

I suspect that with your EFI you can get away with ealier opening than suggested for a carburetted engine as the reduced intake air velocity would not have the repercussions for fuel flow that you get with a carb.
I'm only guessing really. Dyno will tell you.

[jamathi]

I think the only pumping losses are those pumping money into the project are realising losses.

I am seriously thinking that if they really did have anything really substantial, it would be out by now and
be blistering track records everywhere. But that has not happened, sadly. We get strung along all the time
with little miss leading things, time and time again. We are suckers for new tech and most here have a true desire
to learn more about a very simple in principle engine. Crowd development may be the way to go. They got a patent
application in place, but still don't share anything. They set a track record against 4s renta karts and we are supposed to be impressed.
I have seen a one time picture from a tacho at like 28100 rpm. Then told it has passed 30 k more than once. But like any monsta
story, no video, or audio for that matter. 1900 rpm is a lot at that level. Look at a 6.5 cc methanol engine. Very difficult to go from 34k to 35k
rpm, and they want us to believe it can easily do 30k with a 125. Like some have said, very doubtful for any length of time, without super materials that
would put the engine price above 30k to get made.

Those 'pumping in the money' must really be worried now.....
No races won, no engines sold, how will this end?
In a very bad way I think!

[jonny quest]

TZ350, we rev 250 4 strokes to 15,000rpm all day with a single injector in the throttle body. I'm comparing apples to oranges I know, but still... was shocked to think you need 3 injectors for 13k.

I'm also very interested to hear more of your findings in your NSR250 porting. You actually lost power by opening up the ears of the exhaust port? You're either transfer limited, or major short circuit going on A transfers to ex port. You may find it beneficial to "bowl" out ex port right after window.

[sidecar bob]

TZ350, we rev 250 4 strokes to 15,000rpm all day with a single injector in the throttle body. I'm comparing apples to oranges I know, but still... was shocked to think you need 3 injectors for 13k.
.

Applying some quite basic arithmetic, 13,000 rpm on a two stroke, equals roughly 26,000 rpm on a 4 stroke as regards injector cycles.
Maybe that goes some way to help explaining the anomaly.

[TZ350]

Applying some quite basic arithmetic, 13,000 rpm on a two stroke, equals roughly 26,000 rpm on a 4 stroke as regards injector cycles. Maybe that goes some way to help explaining the anomaly.

Absolutely


I'm also very interested to hear more of your findings in your NSR250 porting. You actually lost power by opening up the ears of the exhaust port? You're either transfer limited, or major short circuit going on A transfers to ex port. You may find it beneficial to "bowl" out ex port right after window.

Yes my first effort at porting the NSR cylinder lost power. And I think you are right about the reasons. I tried leveling the top of the exhaust port off by eye but totally stuffed up the exhaust port timing, got something like Ex opens 74 ATDC and to get the timing anywhere sensible I trimmed 2mm of the bottom of the barrel. The Ex was then 78.5 atdc and trans 122. To get the trans back to 113 I angled the A's up at 25 deg and the B's at 15 but the whole thing was a shambles.

So I started again.

332289


TZ350, we rev 250 4 strokes to 15,000rpm all day with a single injector in the throttle body. I'm comparing apples to oranges I know, but still... was shocked to think you need 3 injectors for 13k.

Yes, three physical injectors but there are actually only two "logical" injectors, one big one small. The two "physical" injectors in the B ports are there for symmetry of fuel distribution and are fired together as one Logical injector. I use three physical 124g/min injectors but the EFI CPU sees only two logical injectors, a 124g/min slow speed injector and one 248g/min high speed injector.

But it is not about injector size but time available to get the injecting done. If you only have half the time, then you need an injector twice the size to get the job done. And you need a small one for tune-ability when there is plenty of time like <9k 2T rpm (equivalent to 18k 4T rpm) and a much bigger one to deliver much the same amount of fuel when time is getting short like above 10k.

The reason you can't use the big injector for slow running is because an injector must be turned on for a minimum amount of time to get it completely open and controllable. And a big injector just spills to much uncontrolled fuel while it is opening for idling speeds and small throttle opening.

15,000 4T maxed out rpm "Time" for an injection cycle is just about where my 2T is starting to come on the pipe and get going. A 4T has twice as much time to get things done so only needs an injector half the size of a 2T, ie something about the size of my slow running injector.

It is "Time" not injector size that is the real issue with EFI.


... a single injector in the throttle body.

Another issue with 2T EFI and throttle body injection is that unlike a carburetor which adds fuel to the air stream all the time, regardless of whether the air is being sucked in or blown back out of the crankcase ie fuel standoff.

A fuel injector squirts fuel in discreet blobs. And is just as likely to add all the fuel to the air stream as its blown back out as it is to the air stream being sucked in. So there could easily be rpm patches where you could wind up with little fuel at all in the crankcase.

This is less of a problem with transfer port injection. Where the bulk of the fuel is concentrated in the transfer duct and not the inlet tract where it can be more easily ejected. And will be one of the reasons why 2T EFI can show improved fuel efficiency over a carburetor.

And another reason for injecting into the B transfers is that the bulk of charge short circuiting happens from the A ports and if there is little fuel in the short circuiting air then the motor is cleaner and more fuel efficient. Another win over the carburetor which would have loaded all the crankcase air with fuel.

With a carburetor all blow back and short circuiting air loses fuel and pollutes the environment, with 2T EFI not so much as the air lost has little fuel in it.

[husaberg]

TZ350, we rev 250 4 strokes to 15,000rpm all day with a single injector in the throttle body. I'm comparing apples to oranges I know, but still... was shocked to think you need 3 injectors for 13k.

I'm also very interested to hear more of your findings in your NSR250 porting. You actually lost power by opening up the ears of the exhaust port? You're either transfer limited, or major short circuit going on A transfers to ex port. You may find it beneficial to "bowl" out ex port right after window.
AS well as what Bob and Rob have mentioned
Four stroke 4 cylinder maps have pretty basic requiements four stroke twins are a lot more fussy two stroke are a less forgiving again

[guyhockley]

Hope this link works, as it's from an email subscription, but it should go to a page from Dirt Rider magazine reviewing the EFI strokers from Husky and KTM.
http://links.mkt3362.com/servlet/MailView?ms=MzAyMjYzOTcS1&r=MTMzNzExMjYwNzU4S0&j=MTEwMjAxOTkwNgS2&mt=1&rt=0

[jellert]

I have seen a one time picture from a tacho at like 28100 rpm. Then told it has passed 30 k more than once. But like any monsta
story, no video, or audio for that matter.

Maybe they had the tacho in 4 stroke mode and they are too deep into the rabbit hole to admit it now :scratch:

[Greg85]

RSW and RSA ducts were the same.
Roof angles did not change since 1995
The RSA cylinder had improved cooling.

Hello mr jan, you say that the transfer times have been unchanged so that means that it was the right compromise debit, pressure, opening time? How to find this flow balance, pressure? Is what the transfer flow corresponds to The intake capacity? is what the port transfers match the pipe pulses? thank you

[wobbly]

If you look at the STA numbers of an Aprilia cylinder it appears that the transfers are way ahead of the Exhaust as far as power making capability.
But if you look at the reality of the Exhaust Cd, with its huge radius on the top edge, that effectively begins to open above 200* duration with the port
roof itself down at 196* then it becomes clear that all the work done by hand in the R&D dept to match the Blowdown flow numbers with the transfers
gave a highly synergistic scenario.
Raising the transfers lost power - as did lowering them.
And the scavenging pattern along with the timings had been optimized quite early on.
The same with the Aux ports - any higher or wider lost power.
All dimensions being tested on the dyno and the best results kept in production - a slow to achieve, but highly accurate method for gaining GP winning power.

[jamathi]

Maybe they had the tacho in 4 stroke mode and they are too deep into the rabbit hole to admit it now :scratch:

HAHA, probably....

[WilDun]

....... a page from Dirt Rider magazine reviewing the EFI strokers from Husky and KTM.

Guy, our Neil (Flettner) has had a Kawasaki Bighorn operating successfully on fuel injection for yonks, we are proud of him for his perseverance in achieving that!

update:- also TZ is into it big time as well! - very forward thinking.... us Kiwis! :msn-wink:

[TZ350]

332295332294

Cylinder and under piston injector slot done.

So if I can get the engine back together during the week it is looking hopeful for a dyno run next weekend.

[TZ350]

Because someone asked.

There are three physical injectors but there are actually only two "logical" injectors, one big one small.

The two "physical" injectors in the B ports are there for symmetry of fuel distribution and are fired together as one Logical injector.

I use three physical 124g/min injectors but the EFI CPU sees only two logical injectors, a 124g/min slow speed injector and one 248g/min high speed injector.

In broad terms, because there is much the same amount of air consumed per revolution. Both 124 and 248 injectors deliver the same amount of fuel per revolution.

332298

Both 124 and 248 injectors deliver much the same amount of fuel per revolution.

Because the lower speed 124g/min injector has 10ms to do the job.

And because the higher speed 248g/min injector only has 5ms to do the job it needs to be twice as big.

Time available dictates the injector sizes.

[Frits Overmars]

If the standoff was reduced and as jetting is not a problem with EFI would it be a benefit to opening a RV inlet much earlier, or even before BDC like a 4T or is there some other limit? Interested because with my bike running EFI for jetting and using the variable inlet area system that I have for suppressing the standoff I would be very interested in how much earlier people think the RV inlet opening timing could be usefully advanced too.If a clear suction signal to the carburetter is no longer needed, you could start opening the RV at about 20° after BDC at max.torque rpm, assuming sufficient transfer angle.area, and even earlier at lower rpm's.
Opening the RV as soon as the crankcase pressure has dropped to the same value as the pressure upstream of the RV, will prevent the case pressure from dropping much further, which would slow down and eventually reverse the transfer flow.

[wax]

Hey guys thanks in advance for your thoughts
Im working on a new head for our vintage skis and I have finished the drawing except for the combustion chamber shape.
From the reading on here from people who are clearly in the know I will be using a toroid shape chamber. My question however is there a magic number when it comes to squish band ratio.
Or what is the effect on the power of having the squish band ratio to much or to little.
Please note im not talking about clearance its the ratio of squish to combustion chamber I am after.
Cheers

[wobbly]

Squish width is dependent upon how much piston clearance you have.
I have found that a calculated MSV of 38M/Sec gives the beat result in most cases.
To achieve this number you start with the clearance and keep increasing the width until the velocity is correct.
What is your bore/stroke/clearance/com.

[wax]

Squish width is dependent upon how much piston clearance you have.
I have found that a calculated MSV of 38M/Sec gives the beat result in most cases.
To achieve this number you start with the clearance and keep increasing the width until the velocity is correct.
What is your bore/stroke/clearance/com.

Thanks Wobbly
my bore is 75mm
The stroke is 60mm
My projected squish clearance is .9 mm
The engine will rev to about 7500

[wobbly]

With those numbers I get 57% SAR = 13mm wide.

The effect of excessive MSV is that in effect the added chamber turbulence is the same as adding advance,the result being lack of overev.
The excess volume trapped in the squish also burns too late in the cycle to create as much power as the energy could do if it was done correctly.

[lodgernz]

With those numbers I get 57% SAR = 13mm wide.

The effect of excessive MSV is that in effect the added chamber turbulence is the same as adding advance,the result being lack of overev.
The excess volume trapped in the squish also burns too late in the cycle to create as much power as the energy could do if it was done correctly.

Interesting. That sounds like there's a formula. True Wobbly? Or are you simming it?

[wobbly]

There are plenty of calculators available on line, but the best rule is to drop the clearance to the point that the piston will just clip the head
when overeved, thus the clearance will be zero in effect.
In that big bore short stroke ski engine only reving to 7500, the safe limit would for sure be closer to 0.8 mm, and then the width can be reduced to around 10mm.
This gives the same MSV, but way less mixture is trapped and not contributing to making power.

[F5 Dave]

So knowing nothing is skis one would expect over-rev would be king. I'd guess single gear and you have several props maybe adjust final drive so it matches what that prop can turn at without cavitating. But with it all being a guess how rough it will be having over-rev would make it more tolerant.

[wax]

There are plenty of calculators available on line, but the best rule is to drop the clearance to the point that the piston will just clip the head
when overeved, thus the clearance will be zero in effect.
In that big bore short stroke ski engine only reving to 7500, the safe limit would for sure be closer to 0.8 mm, and then the width can be reduced to around 10mm.
This gives the same MSV, but way less mixture is trapped and not contributing to making power.
Thanks alot wobbly. i really appreciate it

[JanBros]

Hey guys thanks in advance for your thoughts
Im working on a new head for our vintage skis and I have finished the drawing except for the combustion chamber shape.
From the reading on here from people who are clearly in the know I will be using a toroid shape chamber. My question however is there a magic number when it comes to squish band ratio.
Or what is the effect on the power of having the squish band ratio to much or to little.
Please note im not talking about clearance its the ratio of squish to combustion chamber I am after.
Cheers

no exhangeable combustion chambers? seems like a missed opportuniy.
I made one for a KR1S :

http://kr-1s.co.uk/forum/viewtopic.php?f=2&t=11307

[wax]

no exhangeable combustion chambers? seems like a missed opportuniy.
I made one for a KR1S :

http://kr-1s.co.uk/forum/viewtopic.php?f=2&t=11307
It looks great
Whats the crush you ran on the domes to make them seal properly

[wax]

Ok well this is the combustion chamber finished
Thoughts and constructive criticism is most welcomed

[Frits Overmars]

RSW and RSA ducts were the same. Roof angles did not change since 1995.What did change, were the leading directional angles of the A-transfers. Aiming them more away from the exhaust port proved beneficial.
332308


... it becomes clear that all the work done by hand in the R&D dept to match the Blowdown flow numbers with the transfers gave a highly synergistic scenario.That hand work in the Aprilia Racing Dept. included modifying every dimension of every port in 0,25 mm steps over a 10 year period; not something you are likely to equal by yourself during a winter season... It would take the likes of Honda to put in a similar effort. But Honda could not manage.
So in a way you might say that it was Jan Thiel who drove Honda to ban two-strokes from GP racing :devil2:.


There are plenty of calculators available on line, but the best rule is to drop the clearance to the point that the piston will just clip the head when overeved, thus the clearance will be zero in effect.Indeed, there are a lot of Mean Squish Velocity calculators available on the internet, but I haven't yet seen a single one that takes the dynamic stretch of a high-revving engine into account, and it makes a lot of difference whether your squish clareance is 0,6 mm or 0,06 mm. As a rule of thumb that stretch will be about 0,1% of the stroke, assuming that your crankshaft is sound. I agree with Wobbly: reduce the squish clearance until you are going to suspect that the piston may be kissing the head. Then there will be zero clearance and zero mixture in the squish band. And you won't get detonation if there is nothing there to detonate :rolleyes:.

[wax]

What did change, were the leading directional angles of the A-transfers. Aiming them more away from the exhaust port proved beneficial.
332308

That hand work in the Aprilia Racing Dept. included modifying every dimension of every port in 0,25 mm steps over a 10 year period; not something you are likely to equal by yourself during a winter season... It would take the likes of Honda to put in a similar effort. But Honda could not manage.
So in a way you might say that it was Jan Thiel who drove Honda to ban two-strokes from GP racing :devil2:.

Indeed, there are a lot of Mean Squish Velocity calculators available on the internet, but I haven't yet seen a single one that takes the dynamic stretch of a high-revving engine into account, and it makes a lot of difference whether your squish clareance is 0,6 mm or 0,06 mm. As a rule of thumb that stretch will be about 0,1% of the stroke, assuming that your crankshaft is sound. I agree with Wobbly: reduce the squish clearance until you are going to suspect that the piston may be kissing the head. Then then will be zero clearance and zero volume in the squish band. And you won't get detonation if there is nothing there to detonate :rolleyes:.
Thanks Frits
I have told people about that before. That the squish being at zero at high rpm and they say it causes deto. I always reply " whats going to deto"
I have set the head for .9 of a mm in clearance and my eyes are about to fall out of my head from to many hours drawing hahaha.

[lohring]

As a rule of thumb that stretch will be about 0,1% of the stroke, assuming that your crankshaft is sound. I agree with Wobbly: reduce the squish clearance until you are going to suspect that the piston may be kissing the head. Then there will be zero clearance and zero mixture in the squish band. And you won't get detonation if there is nothing there to detonate :rolleyes:.

We did that test on a 26 cc racing engine that developed peak power at around 18,000 to 19,000 rpm. We ran the over rev to 23,000 rpm and found that the piston hit the head button with .05 mm clearance. since the stroke was 28 mm that's about .2% of the stroke.

The engine had 4 main ball bearings and caged needle bearings on both ends of the rod. The big end bearing may have had its clearance increased a little to help it live.

Lohring Miller

[Frits Overmars]

Experience will of course overrule rules-of-thumb, Lohring.
I've witnessed Kreidler engines with reputedly stiff crankshafts, but with angular contact bearings, that needed at least 0,7 mm clearance for their 39,7 mm stroke;
I've also tested Rotax engines with a 54,5 mm stroke and 0,4 mm squish clearance, that merrily revved past 14000 rpm without the piston touching the head.

[JanBros]

Whats the crush you ran on the domes to make them seal properly

what do you mean by crush ?

all sealing is done by viton O-rings

[Greg85]

If you look at the STA numbers of an Aprilia cylinder it appears that the transfers are way ahead of the Exhaust as far as power making capability.
But if you look at the reality of the Exhaust Cd, with its huge radius on the top edge, that effectively begins to open above 200* duration with the port
roof itself down at 196* then it becomes clear that all the work done by hand in the R&D dept to match the Blowdown flow numbers with the transfers
gave a highly synergistic scenario.
Raising the transfers lost power - as did lowering them.
And the scavenging pattern along with the timings had been optimized quite early on.
The same with the Aux ports - any higher or wider lost power.
All dimensions being tested on the dyno and the best results kept in production - a slow to achieve, but highly accurate method for gaining GP winning power.

Thank you for your explanation wobbly, thanks frits for pictures fos scavenging, ok now I know there is no miracle a lot of research has to do in this area and as said frits it will take me more than 1 winter hahaha ...

[wax]

what do you mean by crush ?

all sealing is done by viton O-rings
I know how it's sealed we run those style heads all the time on Jetskis. But you have to have a certain amount of crush on them other wise the domes spin when you are removing or fitting the spark plugs

[seattle smitty]

I was wondering about that, too (I machined my own head for a 250cc Konig outboard back in the Pleistocene Era, but was too dumb to think of anything like inserts). If I were to do another, I would think that the insert should stand a little proud (like maybe .002"/0.05mm ??) of the outer housing's mating surface . . . which of course would depend on if it goes on over a gasket (and then how much does the gasket crush?). I didn't know the sled guys were already doing this. I can and would make the outer part (need some terminology here!!) hell-for-stout to minimize flexing, but would still suppose that the insert ought to protrude just a little.

I have looked at your 8-page link, JanBros, but if this info was there, I missed it.

[wobbly]

Yes, if you have inserted domes you need to have the outer flange sitting proud of the cover by around 0.03 to 0.05mm.
If they are made flush they eventually start to fret and then bounce up and down.
Unless of course the hold down bolts go thru the domes flange,but even in this case TM have the domes sitting up,and use a big O ring around the
outer water jacket with a shallow groove giving plenty of crush depth.
In any scenario the outer cover should be used to provide clamping force on the area around the plug threads - Jan told me of a situation where a new insert design
made alot less power, and he tracked it down to the combustion chamber flexing upward,reducing the com.
In the head shown, the small flat area outside the plug body within the chamber needs to be wider, or it will overheat.
Show us a section across the head so I can see if water is getting close enough to the plug threads.

[wax]

Ok here it is, i understand what your saying about the water cooling on the plug up in the cooling jacket area
your also telling me to make the area around the plug a larger diameter.
I can see there is no way that there is getting enough cooling.
I have the sides of the combustion chamber alot more vertical than in your instance, is this an issue ?
I think im going to owe you a bottle of muesli or what ever grain your drink lol.
Im thinking about making the head as a removable dome now. its not that much work and lot easier to machine in the software than afterwards

[wobbly]

The angle into the bowl is not very critical, I have used angled sides as well as a radius that ended almost vertical - depends upon the chamber geometry
needed to get the volume correct.
Just make sure, as I said before to clamp the outer flange, and use the water jacket cover to support the plug sealing face ( the step with an Oring in my section view).

[wax]

yes i saw that in your drawing and i have a heap of room to allow me to clamp the face down on the head.
hanks for that
Back to the drawing board literally hahaha
Thanks Wobbly

[lodgernz]

Just an aside: Did anyone notice that the British 50cc acu freetech championship was just won by an RG50, in the original frame?

[FastFred]

Did anyone notice that the British 50cc acu freetech championship was just won by an RG50, in the original frame?

Yes, and we have one or two here........ :yes:

[F5 Dave]

Ya what? Was Marquez riding it? To them an RG is an exotic (post classic) import and Derbi or RS common.

[jasonu]

Ya what? Was Marquez riding it? To them an RG is an exotic (post classic) import and Derbi or RS common.

Maybe it was running that bridged exhaust port cylinder Chris Pickett made...

[lodgernz]

Ya what? Was Marquez riding it? To them an RG is an exotic (post classic) import and Derbi or RS common.

Hudson Kennaugh riding.
https://www.facebook.com/hudson.kennaugh.1?fref=gc
Scroll down a few posts until you see photos of a red and green number 50. There are videos of the race there too.

[Nath88]

For anyone interested, I did some further testing on the ion sensing system, choking the inlet to induce a misfire... I expected the measured ion current to drop to zero like it does with a four stroke... of course it doesn't! I think because the exhaust gas isn't purged from the cylinder every cycle like in the four stroke, the ions from the combustion are still there for the next cycle, whether there's fire or not, which seems obvious now. Nothing is ever clear cut with the two stroke cycle.

So next step will be to make a circuit to capture the pressure peak each cycle, then feed it into the ECU for datalogging, I should be able to detect misfire with that method.

[TZ350]

I did some further testing on the ion sensing system, choking the inlet to induce a misfire... I expected the measured ion current to drop to zero like it does with a four stroke... of course it doesn't! I think because the exhaust gas isn't purged from the cylinder every cycle like in the four stroke, the ions from the combustion are still there for the next cycle, whether there's fire or not, which seems obvious now.

Very Interesting.


Nothing is ever clear cut with the two stroke cycle.

I know your pain........ :laugh:


So next step will be to make a circuit to capture the pressure peak each cycle, then feed it into the ECU for datalogging, I should be able to detect misfire with that method.

I am following this with a great deal of interest, thank you for your work and sharing the results.

[SwePatrick]

New goals and challenges, winter is long in Sweden.
Summers testing went ok, but with a nagging thought, to heavy or lack of power.
I dynoed in the end when sorted out the fuel distribution 75.54hp/13280rpm and 41.6Nm/12310rpm(peak),38.8Nm at 10500rpm. (calculated crank)
Never tested it on track with that power, it was supposed to be a test now in september, but my girlfriend celebrates her 50th birthday exactly that day, one of those days one should stay at home i guess ;)

So, why not start with winterplans early instead?

332313

Turbo got capacity of ~280hp on 4stroke engines.
About half or a little bit more than half on twostrokes.

I want more power on the wheel then bike´s wet weight.
Much easier and cheaper to build power than loose weight ;)

I´m building an small compact draw through carb setup, no intercooler needed when running on methanol, thereby one can concentrate on not loosing as much response.
I´m using an modified gnarly pipe as the pulses tends to get more intense when higher density(and higher temp on boost) in the exhausts, i have also tuned it further down in rpm´s to get more power early to leave the line with, when turbo is pumping it will have power upwards in rpm´s anyway.

Rgds.

[JanBros]

But you have to have a certain amount of crush on them other wise the domes spin when you are removing or fitting the spark plugs

ok, now I understand.
yes, there is a little crush, but I also make a small cut-out in the insert, and in the head I bolt a small stainless steel bolt. it's head fits the cut-out and stops the insert from turning round.

you can see the bolt on the right side at 6 o clock, and the cut out between 3 and 4 o clock.

http://users.telenet.be/jannemie/CNC/P1040679.JPG

[katinas]

Very interesting 1972

https://www.google.com/patents/US3805750

[husaberg]

Very interesting 1972

https://www.google.com/patents/US3805750

Hope it doesn't mention the patent holders name:wacko:

[guyhockley]

Just an aside: Did anyone notice that the British 50cc acu freetech championship was just won by an RG50, in the original frame?
I THINK he won the road-based class, but, fair-play, that's still a 20 year old bike beating Aprilia RS50s, Derbi GPRs etc.

[Neal]

I THINK he won the road-based class, but, fair-play, that's still a 20 year old bike beating Aprilia RS50s, Derbi GPRs etc.

And the racer is as skinny as a jockey and won a few championships in his career .

[dark art]

I THINK he won the road-based class, but, fair-play, that's still a 20 year old bike beating Aprilia RS50s, Derbi GPRs etc.

Those newer aprilias and derbis are greatly overweighted, that may be the reason why is so dificult to get dry or wet weight figures online. Some time ago I read those are around 130 or 140kg.

[F5 Dave]

my RG50 I got down to 59.5kg on the kart scales with empty tank but ready to go. There were perhaps afew mods, but standard frame (well started as one.). OK maybe many many obsessive hours weighing every item.

And yes, the bike weighed 20kilos less than me.

[Frits Overmars]

Those newer aprilias and derbis are greatly overweighted, that may be the reason why is so dificult to get dry or wet weight figures online. Some time ago I read those are around 130 or 140kg.They are overweight alright, but not that much. Sounds like you read the total weight of bike+rider.

[mike schmidt]

W. Tenney (Bill Tenney) Very sharp engineer / powerboat racer. Won a ton of championships and set a bunch of worlds records. 1930's thru early 1960's. Knew more about nitro in two stokes than everyone on this board combined. His son David is on here and has the fastest 125 hydro in the US. Just won the US National Championship.

Michael

[Nath88]

Turbo got capacity of ~280hp on 4stroke engines.
About half or a little bit more than half on twostrokes.


Turbo is an excellent idea. What makes you say the capacity will be about half? For the same power the airflow will be similar for 2 strokes or 4?



I´m using an modified gnarly pipe as the pulses tends to get more intense when higher density(and higher temp on boost) in the exhausts, i have also tuned it further down in rpm´s to get more power early to leave the line with, when turbo is pumping it will have power upwards in rpm´s anyway.


Before and after dyno will be very interesting. I always thought it would only be effective in the resonant range of the pipe, and just amplify the pipe effect. But it would be nice if it extended the power range.

[dark art]

They are overweight alright, but not that much. Sounds like you read the total weight of bike+rider.

Back in the day, had the old model with steel frame, single sided swing arm and was acceptable, maybe 90/95kg stock. The Al frame model they use in UK might be around 90-100kg when new. Newer models, seem to be the same bike as the RS4 125 4stroke but with a 50cc engine.:second:
No listed weights anywhere, someone must know someone who ones one :laugh:

http://www.aprilia.com/en_EN/models/motorbikes/road/rs4/

[SwePatrick]

Turbo is an excellent idea. What makes you say the capacity will be about half? For the same power the airflow will be similar for 2 strokes or 4?



Before and after dyno will be very interesting. I always thought it would only be effective in the resonant range of the pipe, and just amplify the pipe effect. But it would be nice if it extended the power range.

It´s a small rule of thumb here in Sweden when turbocharging snowmobiles, use a turbo with twice the capacity then you aim for, i actually dunno why but having a clue.
You blow out boost through exhaust.
Even thou i try to balance the pressureratios and it isn´t blowing out boost, i´ll just have the bonus of extra capacity ;)

Yes it´ll boost the pipe´s area, but 'after' the pipe as in my case having whole lot durations it´ll keep on filling the cylinder but with less effect of the pipe ofcourse.
One has to see what the pipe actually does.
It increases the VE with the pumping in a certain area.
This is also what the turbo does, but in a bigger area.
The pipe i use should have a long 'overrev' from what i have measured, the end cone/baffle is 'wild' 8 degree for example, this often let´s a small engine rev to the skies but with less power ofcourse.
If my ideas work, my powercurve will be looking quite odd for a twostroke.
Kind of a wide ayers rock with falling torque curve instead.
As long as i get my 100hp to the wheel somewhere in the usable rpm area i´m happy.

Started the bike the other day, no silencer *yuck*
Sounded like it didn´t give a damn about the fact it sat a turbo in the end of the pipe.
Same throttlerepsonse as before maybe even better as pipe tunes at lower rpm.
Looked at the turbo and it seemed to spin hard, couldn´t hear any boost thou.

I´m waiting for silencer to show up before i can evaluate some more, i got neighbors sadly enough *lol*

Rgds.

[katinas]

W. Tenney (Bill Tenney) Very sharp engineer / powerboat racer. Won a ton of championships and set a bunch of worlds records. 1930's thru early 1960's. Knew more about nitro in two stokes than everyone on this board combined. His son David is on here and has the fastest 125 hydro in the US. Just won the US National Championship.

Michael

Thanks, and looks like he was very romantic person

https://www.google.com/patents/US2612749

[dtenney]

I see a couple of my fathers patents have shown up on this thread. It was interesting growing up in the Tenney house. Rather than talking sports or politics, we discussed 2 cycle engines. He had many patents in 3 disciplines.....2 cycle engines, Pulse jet engines and fog generation. During WW-2 my father was stationed at Curtis-Wright field in Dayton, Ohio. While there, the airbase received some parts from a V-1 Buzz bomb engine and my father was given the task of building a US version....which he did successfully.

Post the war he sold a model pulse jet engine under the Dynajet brand name. As you would imagine the demand for tis type of product is not too large. At the same time my father figured out that you could actually use the Pulse jet engine to create fog...fog that could be used for carrying insecticides and for a smoke screen. Building pulsejet based foggers and engine powered foggers became a primary business for 40 plus years.

In addition, to building foggers my father was extremely active in boat racing. In the late 50"s he began importing the British Anzani race motor to the US. These motors, running megaphones and up to 40-50 percent nitro were monsters in their day. The test tank for the outboards was outside of the kitchen of our family home. You can imagine the noise. It is a good thing that we lived in the country.

In addition to foggers, my fathers other main line of business was 2 cycle R&D work. The "eye brow" port patents referred to above are an example of that. To showcase the effectiveness of the ports, my father built a single cylinder engine where the "eye brow" ports could be opened and closed manually on the dyno. The results were dramatic. He spent many years defending his "eye brow" patent versus the big Japanese companies, but the amount of legal resources they had simply dwarfed the legal resources he cold muster. Thus, in the end the patent was sold to Yamaha for a relatively small sum of money.

Lesson learned...patents are nice but are very hard to defend.

It is great to see that this web site is helping to keep 2 cycle engines relevant in todays world. The content of this thread is amazing.

In the US I race boats where we use 2 cycle engines and the only rules are bore and stroke based. This is a great play ground for those that like to develop and race 2 cycle engines. Special thanks to Guiseppe Rossi and Carlo Verona(VRP) for helping to keep our sport of Pro(Alky) boat racing alive. They build engines that dominate the sport today.

[Frits Overmars]

https://www.google.com/patents/US2612749I was pleasantly surprised to see how mr. Tenney controlled flow direction in his pulse jet. Looks familiar :msn-wink:.
https://www.kiwibiker.co.nz/forums/showthread.php/171300-Oddball-engines-and-prototypes?p=1130985512#post1130985512

[katinas]

I see a couple of my fathers patents have shown up on this thread. It was interesting growing up in the Tenney house. Rather than talking sports or politics, we discussed 2 cycle engines. He had many patents in 3 disciplines.....2 cycle engines, Pulse jet engines and fog generation. During WW-2 my father was stationed at Curtis-Wright field in Dayton, Ohio. While there, the airbase received some parts from a V-1 Buzz bomb engine and my father was given the task of building a US version....which he did successfully.

Post the war he sold a model pulse jet engine under the Dynajet brand name. As you would imagine the demand for tis type of product is not too large. At the same time my father figured out that you could actually use the Pulse jet engine to create fog...fog that could be used for carrying insecticides and for a smoke screen. Building pulsejet based foggers and engine powered foggers became a primary business for 40 plus years.

In addition, to building foggers my father was extremely active in boat racing. In the late 50"s he began importing the British Anzani race motor to the US. These motors, running megaphones and up to 40-50 percent nitro were monsters in their day. The test tank for the outboards was outside of the kitchen of our family home. You can imagine the noise. It is a good thing that we lived in the country.

In addition to foggers, my fathers other main line of business was 2 cycle R&D work. The "eye brow" port patents referred to above are an example of that. To showcase the effectiveness of the ports, my father built a single cylinder engine where the "eye brow" ports could be opened and closed manually on the dyno. The results were dramatic. He spent many years defending his "eye brow" patent versus the big Japanese companies, but the amount of legal resources they had simply dwarfed the legal resources he cold muster. Thus, in the end the patent was sold to Yamaha for a relatively small sum of money.

Lesson learned...patents are nice but are very hard to defend.

It is great to see that this web site is helping to keep 2 cycle engines relevant in todays world. The content of this thread is amazing.

In the US I race boats where we use 2 cycle engines and the only rules are bore and stroke based. This is a great play ground for those that like to develop and race 2 cycle engines. Special thanks to Guiseppe Rossi and Carlo Verona(VRP) for helping to keep our sport of Pro(Alky) boat racing alive. They build engines that dominate the sport today.

I read your story six times, and briefly moved to those times. So interesting and informative.
Thank you very much.

[F5 Dave]

Real world Ryger dabbled and part time Time Lord. Your powers are impressive Katrina's.

[Lightbulb]

I see a couple of my fathers patents have shown up on this thread. It was interesting growing up in the Tenney house. Rather than talking sports or politics, we discussed 2 cycle engines. He had many patents in 3 disciplines.....2 cycle engines, Pulse jet engines and fog generation. During WW-2 my father was stationed at Curtis-Wright field in Dayton, Ohio. While there, the airbase received some parts from a V-1 Buzz bomb engine and my father was given the task of building a US version....which he did successfully.

Post the war he sold a model pulse jet engine under the Dynajet brand name. As you would imagine the demand for tis type of product is not too large. At the same time my father figured out that you could actually use the Pulse jet engine to create fog...fog that could be used for carrying insecticides and for a smoke screen. Building pulsejet based foggers and engine powered foggers became a primary business for 40 plus years.

In addition, to building foggers my father was extremely active in boat racing. In the late 50"s he began importing the British Anzani race motor to the US. These motors, running megaphones and up to 40-50 percent nitro were monsters in their day. The test tank for the outboards was outside of the kitchen of our family home. You can imagine the noise. It is a good thing that we lived in the country.

In addition to foggers, my fathers other main line of business was 2 cycle R&D work. The "eye brow" port patents referred to above are an example of that. To showcase the effectiveness of the ports, my father built a single cylinder engine where the "eye brow" ports could be opened and closed manually on the dyno. The results were dramatic. He spent many years defending his "eye brow" patent versus the big Japanese companies, but the amount of legal resources they had simply dwarfed the legal resources he cold muster. Thus, in the end the patent was sold to Yamaha for a relatively small sum of money.

Lesson learned...patents are nice but are very hard to defend.

It is great to see that this web site is helping to keep 2 cycle engines relevant in todays world. The content of this thread is amazing.

In the US I race boats where we use 2 cycle engines and the only rules are bore and stroke based. This is a great play ground for those that like to develop and race 2 cycle engines. Special thanks to Guiseppe Rossi and Carlo Verona(VRP) for helping to keep our sport of Pro(Alky) boat racing alive. They build engines that dominate the sport today.

Did you turn up at a model speed plane meeting in Dayton Ohio with a pulsejet on the back of a trailer and did a demo of the fog machine unit that your family used to make. At the same competition, they were flying the Dynajet pulse jet speed models. This was back in like 05 or 06 or some where around that time frame.
Neil Lickfold

[lohring]

I fondly remember Dynajet control line speed models in my youth (1950s). The definitely rivaled the megaphone exhaust outboards' noise.

Lohring Miller

[F5 Dave]

I remember my Dad talking about control line planes. My uncle had one with the engine slightly offset but moved into rc as it evolved. Was too young to remember much.

Sound like an efficient way of killing bystanders .

[TZ350]

332347

As a kid I don't remember seeing one fly but I do remember being fascinated by talk about them and how they worked.

[peewee]

I remember my Dad talking about control line planes. My uncle had one with the engine slightly offset but moved into rc as it evolved. Was too young to remember much.

Sound like an efficient way of killing bystanders .

as a kid i had a control line plane with small cox engine. it must of been some 30yrs ago. i vaguely remember it using some kind of fuel from a small metal can like a liquor flask. to start it, it seemed like there was a spring on the back side of the prop and you would put the hook of the spring on one of the blades and turn it backwards to wind the spring. once you let go it spun the engine forward and would start

[lodgernz]

On my 50 engine, now fitted with a disc valve inlet, the transfers open at 114º ATDC, which means they close at 114º BTDC. My disc valve opens at 135º BTDC, so there is only a tiny window of 21º where the negative pulse from the exhaust diffusers can communicate directly with the carb.
We usually target this negative pulse to coincide roughly around BDC at peak power revs, so presumably this negative pulse, reflecting through the transfers, adds to the negative pressure caused by the rising piston to significantly reduce the crankcase pressure BEFORE the RV opens, so that when it does open, there is a burst of flow through the carb, which then quickly reduces to just the flow caused by the still-rising piston as the transfer ports close. I would have thought this uneven flow could cause difficulties with carburetion, compared with a reed setup that presumably allows a more consistent gas flow, starting as soon as the negative crankcase pressure is sufficient to open the reeds.

It seems to me then, that the additional flow through the carb resulting from the tuned exhaust should be longer in a reed engine, with less fluctuation than in an RV engine, so why does a disk valve generally enable more power?
Is that initial burst of flow through the carb actually beneficial rather than problematic?
Or is the better power perhaps more to do with better control of the closing point of the inlet offered by an RV?

So many questions, so little time...

[Ocean1]

I remember my Dad talking about control line planes. My uncle had one with the engine slightly offset but moved into rc as it evolved. Was too young to remember much.

Sound like an efficient way of killing bystanders .

A friend of the old man's went the same way, very early on, he was a bit of a radio boffin anyway and he got the old man to make servos for his projects.

I remember standing in the middle of the airstrip at Frankton while he run a new 1:32 scale Lancaster, (seriously) up and down the runway. He wasn't planning an actual flight, just a control test, but things looked so good. Last seen still climbing up towards the Remarkables.

"Can't we go find it, dad?"

"No son, shutup and get in the car."

[F5 Dave]

Hahahaha, oh dear!

Like the first flight of my Christmas pull to launch plane. It went a lot further than I thought. Shouldn't have aimed in the trees direction. Never seen again.

And the first flight of my rc plane 20 years later when I should have known better, but I blame my wife who gets excited as a Labrador and just wanted to see it fly, - launched the plane away from me instead of towards. Arrgh, it'll get out of range. Um, quick, turn thinks brain. Bang. More enormous pine trees:laugh:

[lohring]

I flew control line a lot with some friends before I went away to high school. We attended the AMA Nationals in 1957 and 1958. They were held at navy air stations and we were really impressed at being treated like we were navy airmen in the barracks and chow hall. My friend was 4th in junior combat (an event where you cut the streamer off the tail of your opponent). He destroyed the three planes I designed so we had to build a new plane over night for the fly off. My control line speed planes were less impressive.

Lohring Miller

[katinas]

Bruce Anstey wins Lightweight TT, new record on Honda RS 250. Interesting for RS airbox intake on right side.

[Frits Overmars]

Interesting for RS airbox intake on right side.I can hardly imagine that this small rectangle is the only airbox intake. With such a small cross flow area the necessary flow velocity will nearly always be higher than the bike's riding speed. It would mean that the engine has to pull its air through the intake, rather than experiencing some useful ram air pressure.
The only remaining advantage would be that it receives air that hasn't gone through the radiator. But the same would be true for a bigger air intake...

[katinas]

I can hardly imagine that this small rectangle is the only airbox intake. With such a small cross flow area the necessary flow velocity will nearly always be higher than the bike's riding speed. It would mean that the engine has to pull its air through the intake, rather than experiencing some useful ram air pressure.
The only remaining advantage would be that it receives air that hasn't gone through the radiator. But the same would be true for a bigger air intake...

I did not find another picture, but maybe same intake is located on left side. Last year they won with nose style intake

[TZ350]

Bruce Anstey wins Lightweight TT, new record on Honda RS 250.

Great to see a Kiwi doing well on a 2T at the Island.

Neels sent me this link, very interesting read if your into DIY EFI.

https://klr650.net/forums/showthread.php?t=108393

Got my bike back together ready for the dyno but unfortunately I will be away for work in the South for a week or so. Maybe get to the dyno in two weeks time, fingers crossed.

[koenich]

Bruce Anstey wins Lightweight TT, new record on Honda RS 250. Interesting for RS airbox intake on right side.
that little thing is a GoPro Session I think...

[speedpro]

Those who are a little older may remember Bruce on his TZ here in NZ. Hill climb up Mt Vic was going good untill he highsided it or what about dicing with Robert Holden who was on the Bob Brown Ducati at Masterton. Pretty sure he was National champ on it at least one year as well. Or, not so motorcycle related, eating all the chocolate biscuits at DynoTech every time he visited, which was every day.

[chrisc]

When modelling a reed setup in DAT2T, how do I reasonably estimate the maximum tip displacement when there isn't a stopper plate?
Carbon 0.3mm reeds, vforce 4 sided block, 8 petals/reed block ports.

[katinas]

that little thing is a GoPro Session I think...

Yes, I am wrong, this is GoPro. Thanks

[F5 Dave]

Those who are a little older may remember Bruce on his TZ here in NZ. Hill climb up Mt Vic was going good untill he highsided it or what about dicing with Robert Holden who was on the Bob Brown Ducati at Masterton. Pretty sure he was National champ on it at least one year as well. Or, not so motorcycle related, eating all the chocolate biscuits at DynoTech every time he visited, which was every day.
I was talking to Chris when Bruce showed up on his mountain bike on one wheel. Slowed down, Tapped him on the shoulder with the front tyre and off again.

[teriks]

as a kid i had a control line plane with small cox engine. it must of been some 30yrs ago. i vaguely remember it using some kind of fuel from a small metal can like a liquor flask. to start it, it seemed like there was a spring on the back side of the prop and you would put the hook of the spring on one of the blades and turn it backwards to wind the spring. once you let go it spun the engine forward and would start
Perhaps it made more of an impression than you remember given your choice of username here. ;)

Cox Peewee:
http://www.mh-aerotools.de/airfoils/images/cox_peewee_rc.jpg

[TZ350]

332386332387

Ages ago to increase the airflow through a class legal 24m carb I came up with the idea of a 24mm venturi section in a 24mm carb that had been bored oversize. The idea was that the larger front section acted like a flow straightener and by eliminating turbulence it would allow the venturi to pass more air. Whether it really worked like that I don't know but it did allow Team ESE to make much more power with the old air cooled 125's than people thought possible for the class.

332384

Recently on an inspired whim I brought an old Kilt pumper carb from Ebay Japan. And found it had a larger bore with a 24mm venturi at the engine end, just like my modified carb.

332383332385

The 24mm venture can be seen at the engine end of the Kilt carb. Seeing that Kilt have also done this leaves me feeling really vindicated and in good company.

It is not everyday that you find one of your original clever ideas was also one of the big boys tuning secrets... :banana:

332389

Kilt make real flash pumper carbs for Kart racing.

[dark art]

. Seeing that Kilt have also done this leaves me feeling really vindicated and in good company.


Maybe pumper carbs are less sensitive to ventury speed to attaind good metering?

[guyhockley]

Great to see a Kiwi doing well on a 2T at the Island.
Mr Anstey is looking pretty good for the super bike race, too. Did a 125+mph on the YZR500. Possibly fastest ever 2 stroke lap?

[wobbly]

REED BLOCK MODELLING.
The front page of STA numbers gives you a recommended tip lift based on the petal length.
If you run the intake traces and see the reeds going spastic,ie wild changes in lift cycle to cycle, then the petal is too thin and hitting the ( virtual ) stop.

[chrisc]

Thanks Wobbly. This prompted me to more clearly read the help section on inlet modelling in DAT2T which has helped a lot. I also revisited a bunch of the posts you've done on reed valves before which helped some more.

I'm obviously modelling something wrong somewhere because I can't seem to get much predicted reed tip lift which is killing power in the sim. If I reduce the reed thickness from 0.3mm carbon to 0.25mm carbon the tip lift increases significantly and so does predicted power. I would have thought 2x narrow 0.3mm thick carbon reeds on each face would be plenty flexible enough.

[wobbly]

What is peak Hp rpm, and what is the reed 1st mode frequency rpm.

[2T Institute]

On my 50 engine, now fitted with a disc valve inlet, the transfers open at 114º ATDC, which means they close at 114º BTDC. My disc valve opens at 135º BTDC, so there is only a tiny window of 21º where the negative pulse from the exhaust diffusers can communicate directly with the carb.
We usually target this negative pulse to coincide roughly around BDC at peak power revs, so presumably this negative pulse, reflecting through the transfers, adds to the negative pressure caused by the rising piston to significantly reduce the crankcase pressure BEFORE the RV opens, so that when it does open, there is a burst of flow through the carb, which then quickly reduces to just the flow caused by the still-rising piston as the transfer ports close. I would have thought this uneven flow could cause difficulties with carburetion, compared with a reed setup that presumably allows a more consistent gas flow, starting as soon as the negative crankcase pressure is sufficient to open the reeds.

It seems to me then, that the additional flow through the carb resulting from the tuned exhaust should be longer in a reed engine, with less fluctuation than in an RV engine, so why does a disk valve generally enable more power?
Is that initial burst of flow through the carb actually beneficial rather than problematic?
Or is the better power perhaps more to do with better control of the closing point of the inlet offered by an RV?

So many questions, so little time...

There isnt any need for the diffuser to influence the carb at BDC, there isn't enough time for intake charge to go from the carb to the combustion chamber by the time the transfers shut. The low pressure in the diffuser at bdc is beneficial because thats where the transfers are fully open, pressure flows from high to low and if the lowest pressure is in the diffuser at bdc charge in the transfer ducts and just under that in the cases will want to go toward the diffuser.
Case pressure won't start to drop rapidly until the transfers shut. with reed engines the reed is the restriction a rotary has no restriction which is why a really well designed stuffer combined with petal thickness/width is so beneficial, so the inertia of the intake charge will keep the reed open for longer.

[chrisc]

What is peak Hp rpm, and what is the reed 1st mode frequency rpm.

14,000rpm, 28,218rpm when using 0.3mm thick reeds

EDIT: Screenshot of the reedblock except I just noticed I'd left 0.25mm reeds in
332397

[wobbly]

Something seriously wrong there then.
The reed 1st resonance should be around 11 to 12,000 for peak at 14,000.

[Lightbulb]

332386332387

Ages ago to increase the airflow through a class legal 24m carb I came up with the idea of a 24mm venturi section in a 24mm carb that had been bored oversize. The idea was that the larger front section acted like a flow straightener and by eliminating turbulence it would allow the venturi to pass more air. Whether it really worked like that I don't know but it did allow Team ESE to make much more power with the old air cooled 125's than people thought possible for the class.

332384

Recently on an inspired whim I brought an old Kilt pumper carb from Ebay Japan. And found it had a larger bore with a 24mm venturi at the engine end, just like my modified carb.

332383332385

The 24mm venture can be seen at the engine end of the Kilt carb. Seeing that Kilt have also done this leaves me feeling really vindicated and in good company.

It is not everyday that you find one of your original clever ideas was also one of the big boys tuning secrets... :banana:

332389

Kilt make real flash pumper carbs for Kart racing.

My experience of venturi for a restricted class, is to have the venturi point a s far forward as possible, with almost the longest possible total venturi length that the rules allow. Often with a restricted class is a plenum volume as well.
Neil

[schutten]

Thanks for info.
I´m just sold to the stability of PVL, solid like a tank, never fails.(well, not yet)
And the curve seems to fit my engine just perfectly now after activating the exhaustports.(had them locked open before).
I have a perfect flat torque powerband that´s about 3500rpm wide.

And by that i want to give the PVL 458/4000 some more chances.
I dunno, but i ordered some silver sparkplugs just to minimize losses in spark.
Maybe a pluglead with silvercore could help also.
Dunno if even exists thou.

Rgds.
Patrick


The PVL coil is a CDI and coil in one, and there are no different winding ratios available.
One magnet on the rotor supplies the power to the CDI the other activates the trigger.
There are various stator windings available,and the more turns ( like 4000 ) the greater the retard available but less " power " at the plug.
I got 5000 turn coils made years ago ( no plastic covering ) to use on Banshee quads as the kick start hardly turns the thing over and the high ratio
winding gives a fatter spark at kickover ( also more retard as a bonus ).
But anything other than a pretty much stock engine and the plugs would misfire at higher rpm.
The kart stators are the lowest number of turns ( 50 ohms ) and have no trouble at all with high speed high power engines, but that has a useless dead straight ( flat ) line ignition curve.
They do run best with no resistance, in the cap or the plug, but sadly there are no trick rare earth plugs available with no internal resistance - that would be the best case scenario.

Edit - TM sell a Brisk plug with no resistance that does work well with the PVL - part on box is L08S Silver 1827


@Wobbly

Many drivers use here the NGK R7282 plug with the NGK TRS1233A plug cap, this is a total resistance off ~9 kohm.
TM advice no resistance in cap or plug,what are the pros and cons Of this combi, s ?

[JanBros]

regarding squish : it is agreed that a minimum of 1% of stroke is safe. I suppose this is the limit for "normal revving engines" - by that I mean for example +/- 14;500 for a square 125?)

but what can be considered safe for an engine that hit's only about half it's "normal max rpm" ? talking about my Sky-MX (39x41.4) moped : tuned for max power at 7.500-8.000 rpm, and I don't think at a race it will ever reach 9.000, so that's about only half of the "normal max rpm" for 50cc.

Is my simple thinking correct that a squish of 0.4mm is over-safe and that 0.2mm would be ok (very simple thinking : half rpm's, half stretching/bending, half squish needed) ?

[lohring]

Our solution was to drop the head button in small increments until marks appeared on it from piston strikes. Then we increased the clearance a little. Of course that's easier to do on a 34 mm bore cylinder.

Lohring Miller

[SwePatrick]

regarding squish : it is agreed that a minimum of 1% of stroke is safe. I suppose this is the limit for "normal revving engines" - by that I mean for example +/- 14;500 for a square 125?)

but what can be considered safe for an engine that hit's only about half it's "normal max rpm" ? talking about my Sky-MX (39x41.4) moped : tuned for max power at 7.500-8.000 rpm, and I don't think at a race it will ever reach 9.000, so that's about only half of the "normal max rpm" for 50cc.

Is my simple thinking correct that a squish of 0.4mm is over-safe and that 0.2mm would be ok (very simple thinking : half rpm's, half stretching/bending, half squish needed) ?

Don´t take the 1% rule as certain.
I have 61mm stroke and piston touches the head with 0.8mm.
I run at this point 1mm and can rev upp against 14000 without touching.

137mm rod 61mm stroke and 66.4mm bore.

Rgds

[JanBros]

isn't your engine 211 cc (and a dragbike) ? and wouldn't it be fair to say that a 211cc revving to 14.000 is slightly outside the "normal max revving" capabilities ?

[SwePatrick]

Oh yes it is. ;)

But i just mentioned it so one can se that 1% doesn´t need to be the complete truth.

[wobbly]

Schutten - the combination of plug and cap with 9K Ohms is what is needed for a digital ignition to reduce the bad RF created by the coil voltage "ringing ".
In the PVL analogue setup this is not necessary at all as there is no digital control of the ignition curve.
All the testing I have done with PVL shows that a " better " spark is gained by using cheaper,non rare earth plugs, with no internal resistor, as well as simple clip on caps.
All the latest rare earth plugs have internal resistance,and good results are had with these ( like the NGK shorty type ) and the ridiculously expensive matching cap,but that only
works on the kart type straight line PVL version.
Much cheaper is to use a R7376 with a clip on cap and this gives the same performance for 1/3 the cost.

[SwePatrick]

How about those bosch silver plugs?

[wobbly]

Never seen Bosch silver - only Brisk, that is what TM sell.
But those have a silver center electrode, not a rare earth ground strap, thus only half the advantage of less voltage requirement and less shrouding.

[TZ350]

.

Just so us 2T boys know what we are up against.

332407332408

Some time ago Richban and the GPR boys dropped in for a dyno session. Richbans FXR150 pulled 23.9rwHp (red line) which was pretty impressive. The blue line is my air cooled 125 2T, being air cooled it would lose its edge after two or three laps.

332409

I think this is the 20th Team GPR bike and I expect they may have improved the power output a whole lot more, they are looking dangerous.

You have to admire those GPR bikes.

[TZ350]

332411

I was traveling in the South Island this week and made the pilgrimage out to Grumps place. Where he was working on his latest project, the twin cylinder 150 made from cutting down a four cylinder engine and crank.

332410332412

Even though the original four cylinder motor looks quite bulky it is much lighter than I thought. The half crank is very light and the primary drive and gearbox is much lighter than comparable FXR150 parts.

But the best part is that the twins RPM ceiling is about 18,000 rpm while the FXR150 is about 12,000. There is big performance possibilities in that extra 6,000.

[TZ350]

.

The two stroke team need to get busy........ or the four stroke boys are going to give us the 4T salute.... :motu:

[mr bucketracer]

.

Just so us 2T boys know what we are up against.

332407332408

Some time ago Richban and the GPR boys dropped in for a dyno session. Richbans FXR150 pulled 23.9rwHp (red line) which was pretty impressive. The blue line is my air cooled 125 2T, being air cooled it would lose its edge after two or three laps.

332409

I think this is the 20th Team GPR bike and I expect they may have improved the power output a whole lot more, they are looking dangerous.

You have to admire those GPR bikes.thats rob , hope to have good results , got to get me a tread mill to fix me lol

[WilDun]

Just as an interested onlooker I'm a little intrigued by Grumph's "2/4" and was wondering if he is intending it to be a 180deg or a 360deg crank. ie is he using the inner journals (360deg) or what?
I seem to remember Speedpro trying something similar.

[Grumph]

thats rob , hope to have good results , got to get me a tread mill to fix me lol

Ha - I've got skinny kids lining up to ride mine...

Will - have a look on the thread here "The sensible twin" - all is explained.

[oldjohnno]

Groundbreaking new ignition module from Bosch:


https://www.youtube.com/watch?v=0ZR0FX1_icg

[SwePatrick]

Never seen Bosch silver - only Brisk, that is what TM sell.
But those have a silver center electrode, not a rare earth ground strap, thus only half the advantage of less voltage requirement and less shrouding.

Search Bosch F2cs on google.
just like an ordinary plug but with silver centercore and no resistor.
I have a couple at home, but haven´t tested them yet as i started fooling around with turbo ;)

Rgds.


https://http2.mlstatic.com/bujia-bosch-electrodo-plata-f2cs-competicion-14-milla-nitro-D_NQ_NP_18880-MLA20162314372_092014-F.jpg

[TZ350]

332413

Bosch F2cs

https://www.boschsparkplugs.net/learning-center/article/225/heat-range-conversion-chart

https://www.briskracing.com/heat-range-cross-reference-table

332414 NGK

[WilDun]

Will - have a look on the thread here "The sensible twin" - all is explained.

Thanks Grumph, I checked it out last night (went through it all quite quickly but will do it more thoroughly soon), I am a bit too focused on my 3 bucket forums and didn't know that thread existed! - so my question regarding 180 deg and 360 deg is answered. I think the Honda 125 racer twins of the sixties were 180 deg.

Sorry guys, back to two stroke business!

[shnaggs]

Maybe this has been talked about before, but why did the RSW Aux Ex ports not utilize a power valve? Was this for a reason, or was there just not enough room, or did packaging not allow such a design? Reason I ask is because I thought Wobbly mentioned about how having the Aux Ex ports opening before the main port was not ideal. In the case of the RSW, with the power valve down, the Aux Ex ports were opening before the main exhaust.

Now comes the kicker... So I was fumbling around on engmod. I utilized the RSW exhaust parameters on my profiled MX ktm 125. Obviously this was not optimised, with a massive dip down low, so I added power valves to the Aux Ex ports. Well, that didnt work so well. So I kept fiddling and could not get them to work. So i got rid of them, but lowered the main powervalve... and kept lowering it, and so on. Well now I'm in no mans land with how low the main power valve is, but engmod is showing heaps low end!!! So my question is, why did this occur, and is this at all believable? And if so...then maybe having those huge Aux Ex ports doing much of the work till later on in the rev range might be beneficial??? Just FYI I could not replicate this type of low end with a more conservative 3 port configuration, and messing around with the powervalves, soooo is there something to this???

I'm sure Wobbly, Frits or Jan will be by to school me on this :facepalm:

[wobbly]

Having all 3 of the Ex ports closed by a PV in effect reduces the blowdown to virtually nil.
This works OK in a MX situation, where the engine is used well off the pipe and the low PV setting reduces the really bad effect of the pipe being way to short for the rpm.
In a roadrace engine the combination of the open Aux port with the PV down in the main port, allows a usable amount of blowdown at the lower end of the powerband.
Then the PV is lifted over a fairly wide band of rpm, giving a much wider powerband ,in the range that is used on track.
The Aprilia, and many other engines using this setup,they dont have the PV all up until about 1000 rpm before peak power.

[F5 Dave]

332386332387

Ages ago to increase the airflow through a class legal 24m carb I came up with the idea of a 24mm venturi section in a 24mm carb that had been bored oversize. The idea was that the larger front section acted like a flow straightener and by eliminating turbulence it would allow the venturi to pass more air. Whether it really worked like that I don't know but it did allow Team ESE to make much more power with the old air cooled 125's than people thought possible for the class.

. . .
Hey Rob, this will become topical for the TF as a future mod. I had figured on doing a taper from the back of the carb. Had you tried that and dyno'd to then come up with the bore from the front approach?
Pity you are off site presently.

[Grumph]

Hey Rob, this will become topical for the TF as a future mod. I had figured on doing a taper from the back of the carb. Had you tried that and dyno'd to then come up with the bore from the front approach?
Pity you are off site presently.

Talking to him about this when he was here. He's now confident of getting mid to high 20's HP with parallel bore carbs.
When I did kev's big MB I put a venturi on the engine side of the slide - reducing the 29mm flatslide to the regulated 24mm.
Never tried it with a straight 24 or 29 but taking it down to 24 didn't seen to slow it up any...

[TZ350]

I had figured on doing a taper from the back of the carb. Had you tried that and dyno'd to then come up with the bore from the front approach?

332420

24mm at the very front of the carb and taper bored out to 30mm at the engine end of the carb.

332421

30mm with 24mm venturi at the engine side. Both worked but I don't have dyno results with back to back tests comparing these carbs but I did like working with the 24mm venturi on the engine side best and it would be my pick.

The venturi could be cut in half so that the carb measured 24mm at the rear and the pressure recovery part became part of the rubber manifold. If you do that make the carb side 24mm and the pressure recovery side 25mm. The small 0.5mm step is an enormous help in aligning the flow and avoiding any sharp disruptive edges facing the high velocity air stream. The small step does not seem to affect anything.

Remember someone asked MNZ for clarification on where a carb should be measured and they said at the engine end, total crap but there you go.

[F5 Dave]

Thanks Rob but that picture confusels me. It looks like a 28mm with an insert.

I'd kinda made the inlet rubber about 30mm and the TF inlet needs some space as it separates into the inlet port and crankcase reed.

I could fill that area with Devcon some.

Maybe I need a rethink.

[TZ350]

Thanks Rob but that picture confusels me. It looks like a 28mm with an insert.

AHhhh yes your right. That is a 28, should have been a 24mm OKO bored out to 30 with a 24mm insert, anyway the principle is the same and I found the 24mm venturi at the engine end was better to work with jetting wise than having the 24mm at the front of the carb.

Grumph mentioned that I was of the mind that I could make good hp with an ordinary 24, mid 20's at least, or even 30. I think that 24, 28, 32,34 or 38 won't give any more power in the engines we run because the real (or bigger) problems are elsewhere, like the transfers and exhaust flow coefficient.

Anyway Team ESE are making a 100 and another two 110's with 24mm inlet tract so I guess we will know for sure soon enough.

[F5 Dave]

Yeah,? The RG 50 with a dreadfully compromised transfer arrangement (opps, like the TF) worked better with 28 than 26 or 24 from same family.

Certainly easier to bore from the front than taper from the back.

[TZ350]

332433332434

Some of the different carburetor configurations I have tried.

332432332431

36mm EI flat slide smoothbore with a 24mm insert, this one worked well but I didn't have enough needles to get it working perfectly.

332430

A 28 and a 38 with 24mm inserts. Surprisingly the 38 worked very well but would stumble if you grabbed a big handfull of throttle quickly so maybe not so suitable. After optimising the jetting the 38 didn't make any more power than the 28. The 38 flowed more air on the test bench though.

After trying a few different sized carbs it seemed like 32-34mm would be about the size that would work well without stumbling on a big handful of throttle.

332429

By far and away my favorite was the humble 24mm OKO bored out to 30 with a small section at the engine end left at 24 and shaped into the front part of a venturi. OKO carbs machine very nicely and don't crush easily like the pot metal ones do

[TZ350]

Yeah,? The RG 50 with a dreadfully compromised transfer arrangement (opps, like the TF) worked better with 28 than 26 or 24 from same family.

The better performance from the bigger carb may not be because it can pass more air but because the fuelling curve is more appropriate for the amount of air the motor is consuming.

A 28 on a 50 seems really out there, but whatever works best is what works best, whatever it is ..... :niceone:

[Frits Overmars]

The better performance from the bigger carb may not be because it can pass more air but because the fuelling curve is more appropriate for the amount of air the motor is consuming.True, and the same goes for smaller carbs, different pipes, heads, etc, etc. One should re-optimize carburation and ignition timing after every change, before jumping to conclusions.


A 28 on a 50 seems really out there
whatever works best is what works best, whatever it is ..... :niceone:I would call a 28 mm carb on a 50 cc engine average. I've seen 50s doing quite well with a 34 mm carb, although I admit that seems rather big even to me.
But your second remark is pure gold. I often use it when questioned about jet sizes: 'if the engine feels happiest with a 678 jet, fit a 678'.

[F5 Dave]

Thanks Rob, that is what we'll try then. Esp as I got him to buy a 24 oko. We'll run it std first and then machine it.

I had considered taper boring it at the rear as shown in your early picture, could also be combined with front bore so centre section where the needle is as 24. But that leaves a nasty transition at the slide.

I am still a bit uncertain as to if you bored it right through surely the emulsion tube would lose it's seat. Where I've bored carbs before you offset to only lick this area, but 30mm this would not be possible. OK I'm confused again.

[TZ350]

I am still a bit uncertain as to if you bored it right through surely the emulsion tube would lose it's seat. Where I've bored carbs before you offset to only lick this area, but 30mm this would not be possible. OK I'm confused again.

The OKO is easy to hold and does not crush like softer carbs made from pot metal.

332438

The rib around the bell mouth fits neatly into the grove in the chuck jaws.

This is a 24 bored out to 30mm. It was bored parallel straight through and had a small 24mm section pressed back into the engine end. Next time I would machine it so it had a short (5mm) venturi shaped section of the original 24mm bore left. The original OKO has no venturi at the slide, it is parallel straight through.

332437

With the 24 bored out to 30mm there is still some sealing area for the slide, (blue line). Being parallel bored there is no venturi section at the slide. The sharp edges facing the wind were radiused (yellow line) they were worked until they felt smooth when sliding a finger down the bore and the needle and pilot jet holes still had enough seat area left (black line).

332439

Adding a tube to the air correction jet hole moves it's intake out into high pressure air so it is not suffocated by the partial vacuum back in the bellmouth.

[F5 Dave]

Wow ok. Guess the original was based on the 28 pwk so beloved by me and RZ owners worldwide

Thanks for the pics. So you bored right through then right like 60mm in, flared in to 24mm. Then presumably out to create a venturi?

What's the torrent bit in left air intake?

[TZ350]

So you bored right through then right like 60mm in, flared in to 24mm. Then presumably out to create a venturi?

Yes but the venturi bit was a separate bit pressed in and only the front half at that. The pressure recovery (flared out) part is in the rubber manifold.

332440

Cut at the yellow line, carb on the left, manifold part on the right. Keep the larger parallel part in the front of the carb as long as possible. If I make anymore I intend leaving a 5mm or so section of the original 24mm bore at the engine end of the carb for forming the front part of the venturi.

332443

This is a complete venturi pressed into a carb but if you are machining a venturi into the end of the OKO carb you can make only the front part in the carb, the other part can be a separate part in the manifold.

You could of course just press a complete venturi section into the carb. The venturi bit does not have to be formed from the original carb casting to be a 24mm equivalent but it does make a neater job and retains some of the original OKO manufacturers 24mm bore and the bush lawyers would be pushing it up hill trying to argue with that.

[F5 Dave]

So why didn't I start off with a 28mm pwk?

[TZ350]

So why didn't I start off with a 28mm pwk?

Because the OKO has a neat little "24" on the side.

[F5 Dave]

I can probably punch that in with my punch set. 39mm pwk off my based into the mix?

[TZ350]

I can probably punch that in with my punch set. 39mm pwk off my based into the mix?

Well it is "Buckets" everything is on the table, or is it called "thinking outside the box".........:devil2:

[Frits Overmars]

..........
332448

[Lightbulb]

Happy Fathers Day to all the Kiwi Bikers out there. Ride hard and return home safely.

[TZ350]

For anyone wondering what this 24 thing is about, its a class restriction, F4 2T's over 104cc are restricted to a 24mm carb.


So why didn't I start off with a 28mm pwk?

You certainly could have if you have one, and I would, but a 30mm OKO special flows more air than a 28mm Keihin.

The reason I use 24mm OKO's and partly bore them out to 30mm for the Team ESE bikes is that they are cheaper than a 28mm Keihin, readily available, clearly labeled "24" on the side for all to see, machine better and don't crush in the lathe easily like the pot metal Keihin or Mikuni do.

Also having some of the original 24mm bore left in the engine end of the OKO meets MNZ's carburetor measurement for size clarification.

Starting with a 24mm OKO helps to silence the sideline and armchair critics and other amature legal beagles who so often label anything they have not thought of or are using themselves or plain just don't understand, as "not Legal" or "against the spirit", all the while conveniently forgetting that cleverness and thinking outside the box is the very essence of Bucket racing.

But my reasons don't have to be your reasons..... :msn-wink:

[Grumph]

For anyone wondering what this 24 thing is about, its a class restriction, F4 2T's over 104cc are restricted to a 24mm carb.

Starting with a 24mm OKO helps to silence the sideline and armchair critics and other amature legal beagles who so often label anything they have not thought of themselves or are using or plain just don't understand as, "not Legal" or "against the spirit", all the while conveniently forgetting that cleverness and thinking outside the box is the very essence of Bucket racing.

But my reasons don't have to be your reasons..... :msn-wink:

I quite deliberately left the 29mm marking on the carb on Kevs bike. There were a lot of rumours about how big capacity it was and I was trying to tempt someone into a protest...Bit sorry now it didn't happen, LOL.

[Yow Ling]

I quite deliberately left the 29mm marking on the carb on Kevs bike. There were a lot of rumours about how big capacity it was and I was trying to tempt someone into a protest...Bit sorry now it didn't happen, LOL.

I dont recall a single protest in Chch buckets in the last 15 years, that doesnt mean there is no reason for them as i have seen plenty of evidence that not everyone plays by the rules, the score is still zero

[jamathi]

Having all 3 of the Ex ports closed by a PV in effect reduces the blowdown to virtually nil.
This works OK in a MX situation, where the engine is used well off the pipe and the low PV setting reduces the really bad effect of the pipe being way to short for the rpm.
In a roadrace engine the combination of the open Aux port with the PV down in the main port, allows a usable amount of blowdown at the lower end of the powerband.
Then the PV is lifted over a fairly wide band of rpm, giving a much wider powerband ,in the range that is used on track.
The Aprilia, and many other engines using this setup,they dont have the PV all up until about 1000 rpm before peak power.

Yes Wobbly, exactly!
By the way, did you already test the ceramic coated exhaust duct?
And what was the result?
Is there any news about TM's 'uncooled' exhaust duct?

Regards, Jan

[Grumph]

I dont recall a single protest in Chch buckets in the last 15 years, that doesnt mean there is no reason for them as i have seen plenty of evidence that not everyone plays by the rules, the score is still zero

Levels has a nice big scrutineering shed....how do you feel about stripping the first three in the BoB ?

Back in the 90's we stripped the whole field of 250 production - with some amusing results....

[Yow Ling]

Levels has a nice big scrutineering shed....how do you feel about stripping the first three in the BoB ?

Back in the 90's we stripped the whole field of 250 production - with some amusing results....

Wouldnt worry me, but then Im not entering this year. Up to Cams to do what they want. Wouldnt hurt, bit expensive for the FXRs to reassemble

[F5 Dave]

My MB wouldn't raise many eyebrows except for the triple exhaust port and rather conservative timings,. But full story would take more than a strip down.

[wobbly]

Hi Jan, I have been flat out building test pipes for TM, as well as doing the record breaking 350cc Pre 81 Land Speed Project at Bonneville.
Thus I have not been able to remove the test cylinder from the dyno to get it coated.
Franco is way too secretive to tell me I think, if his non cooled duct was a failure or not.
But i will ask, as soon I have a result to show him - wont be long.
I had originally been obsessed with getting over 50 Hp along with plenty of overev power, but the 30mm carb seems to prevent any real
extra peak power.One pipe made 49.6 and had 6 more at 14500, but on track that was barely faster.
So I have been hard at work trying to get more front side power, ie going up to the peak.
Here is where I am at now, and building/dynoing this pipe today.

[Nath88]

the 30mm carb seems to prevent any real extra peak power

If the carb is restricting airflow, could you use an additional volume in the intake after the carb to reduce the peak velocity through the carb but increase the average velocity?
Maybe a helmholtz resonator tuned to the peak, with a valve so it doesn't affect the rest of the range.

[F5 Dave]

Rob
We'll the TF inlet is a mess anyway with piston port and then a big hole in the floor for the reed.

I needed to fill in the manifold I'm using so made up this taper. It's hardly a shallow taper but will do as a stopgap and maybe be the 2nd trailing part of venturi.

[SwePatrick]

First stumbeling tests with turbo.
Fueling issues.
Need to revert to gasoline i guess.
If idling for a long time, i figure the fuel(methanol) drops out of airstream and then when hitting throttle the engines takes a big gulp.
One can fix this with heating the inlet manifold, but heck,, the engine isn´t warm yet, nothing to heat it up with(coolant water)
Leaning out the jet don´t work, yes it runs nicer, for a while... but after some revving the engine runs out of control and need bigger jet to idle at lower rpm´s.
Gasoline doesn´t have this issues, well a little but not this big.
However, in posted video i got it to run(not letting it idle) and it made 0.4bar boost(5.9psi) just holding the throttle(end of video)
I later leaned it out a bit and got a whole 1bar boost(14.7psi)
But i never got response from idle good.
I´ll switch to gasoline for a test.
I can use methanol for cooling later on if needed(meth/water injection).
I dunno if you can hear it, in the end when boost hits it revs up a little bit more(12800rpm).
Before that the pipe 'keeps' it on ~12000rpm

Rgds



https://youtu.be/fI7WN82qTkU

[mr bucketracer]

First stumbeling tests with turbo.
Fueling issues.
Need to revert to gasoline i guess.
If idling for a long time, i figure the fuel(methanol) drops out of airstream and then when hitting throttle the engines takes a big gulp.
One can fix this with heating the inlet manifold, but heck,, the engine isn´t warm yet, nothing to heat it up with(coolant water)
Leaning out the jet don´t work, yes it runs nicer, for a while... but after some revving the engine runs out of control and need bigger jet to idle at lower rpm´s.
Gasoline doesn´t have this issues, well a little but not this big.
However, in posted video i got it to run(not letting it idle) and it made 0.4bar boost(5.9psi) just holding the throttle(end of video)
I later leaned it out a bit and got a whole 1bar boost(14.7psi)
But i never got response from idle good.
I´ll switch to gasoline for a test.
I can use methanol for cooling later on if needed(meth/water injection).
I dunno if you can hear it, in the end when boost hits it revs up a little bit more(12800rpm).
Before that the pipe 'keeps' it on ~12000rpm

Rgds



https://youtu.be/fI7WN82qTkUis the engine fuel injected?

[TZ350]

I needed to fill in the manifold I'm using so made up this taper. It's hardly a shallow taper but will do as a stopgap and maybe be the 2nd trailing part of venturi.

That looks the business......

332485

[SwePatrick]

is the engine fuel injected?

No, simple Mikuni VM44 as it is in video.
But with added powerjet and 'ufo' plate.
And high flow floatvalve.

Rgds

[wobbly]

The problem with the 30mm carb on the KZ engine is that the inlet is as short as it possibly can be, and it is connected to a reed
that is capable of over 50 Hp.
Thus no room for any divergent duct.
The current setup has alot of area infill from the stuffer, keeping the area pretty constant right up to the petal curtain area.
I am trying all manner of test shapes using 3D printed inserts with various wings and guides,as the best power is had using very soft top petals
along with stiff lowers.
This biases the flow upward toward the transfer duct entries.

[monkeyfumi]

What material are you printing in for petrol resistance Wobbly?

[wobbly]

The best material I have found so far is ABS,that has then been vapor blasted to seal the surface.Cheap to.
But i have a Nylon one coming to try as well.
This is fine for testing, but if I was to use it long term then I believe the simplest way would be to spray paint the surface with a 2 pot epoxy
like automotive clearcoat - havnt looked into it in detail yet.

[OopsClunkThud]

I've found Nylon holds up quite well around the carb, been playing with 3D printed bells on Vespas for some time.

http://members.modernvespa.net/oopsclunkthud/uploads/img_1494_41102.png

[jamathi]

I've found Nylon holds up quite well around the carb, been playing with 3D printed bells on Vespas for some time.

http://members.modernvespa.net/oopsclunkthud/uploads/img_1494_41102.png


Yes Wobbly, exactly!
By the way, did you already test the ceramic coated exhaust duct?
And what was the result?
Is there any news about TM's 'uncooled' exhaust duct?

Regards, Jan

News from the Netherlands:

A Ryger has finally been tested on the same track with a TM.
The TM was just 2.5 seconds a lap quicker..
And the time between gear changes was notably longer.
Power was estimated at about 32HP by a very well known witness, against the 45HP of a TM.
So we'll have to wait some years more for further development......
They still have to try an uncooled exhaust duct, and a shorter connecting rod of 65mm
Maybe HCCI was not working?

The scrapheap might get tired of waiting!!!
That would not be a big surprise to anyone....
Might be that the one who pays wanted to see a reality test!
Finally.

[shnaggs]

Having all 3 of the Ex ports closed by a PV in effect reduces the blowdown to virtually nil.
This works OK in a MX situation, where the engine is used well off the pipe and the low PV setting reduces the really bad effect of the pipe being way to short for the rpm.
In a roadrace engine the combination of the open Aux port with the PV down in the main port, allows a usable amount of blowdown at the lower end of the powerband.
Then the PV is lifted over a fairly wide band of rpm, giving a much wider powerband ,in the range that is used on track.
The Aprilia, and many other engines using this setup,they dont have the PV all up until about 1000 rpm before peak power.

Thanks Wobbly for the explanation. I know it is difficult to change PV closing amounts, especially with a guillotine style vavle, but have you, Jan or Frits messed around with different closing amounts with Aux ports full open?

[wobbly]

Re PV closing.This is easy to test on a dyno.
To setup a PV curve I always do a run with it locked down, at mid position, and then fully up.
Join the Hp points and you have the opening ramp shape.
But then I lock it down , varying the height 0.5mm at a time.
This gives you the best full down point, that gives highest power at the lowest rpm you want to use on track.
This of course can be achieved bu opening the PV early with the servo, but its alot more long term accurate to have a physical
down stop.

[markRD]

News from the Netherlands:

A Ryger has finally been tested on the same track with a TM.
The TM was just 2.5 seconds a lap quicker..
And the time between gear changes was notably longer.
Power was estimated at about 32HP by a very well known witness, against the 45HP of a TM.
So we'll have to wait some years more for further development......
They still have to try an uncooled exhaust duct, and a shorter connecting rod of 65mm
Maybe HCCI was not working?

The scrapheap might get tired of waiting!!!
That would not be a big surprise to anyone....
Might be that the one who pays wanted to see a reality test!
Finally.


Dear Jan,


Can I ask where this was? The track where they supposedly have posted a new track record? Who tested it and are there any videos or articles about it? Did you speak with Aalt Toersen about this engine, or maybe Luc Foekema?

I am intreged by the whole secretive atmosphere around this engine.

[wobbly]

There are no Ryger secrets.
Its in black and white , it makes 70 Hp and spins to 30,000 rpm.
And dont bother to question Luc, as he will go running back to his dyno ( sorry computer screen ) and make up a new graph that proves we all are a bunch
of bastards who dare to doubt the reality of everything he says.

[WilDun]

I am in the happy position of knowing sweet FA about it, so I'll just sit here and enjoy watching it, knowing that it will either blossom into something big, or collapse into a black hole - either way, I must say that it's going to be great entertainment! :yes:

[F5 Dave]

If you want to be lied to for entertainment just find the loudest mouth at the pub and go talk to them. The other people who were being inflicted will gladly slink off to the toilet and never reappear.

[jamathi]

Dear Jan,


Can I ask where this was? The track where they supposedly have posted a new track record? Who tested it and are there any videos or articles about it? Did you speak with Aalt Toersen about this engine, or maybe Luc Foekema?

I am intreged by the whole secretive atmosphere around this engine.

The track record was set at Eefde, a very short track for rental karts where no KZ's are allowed....
At a more 'normal' track the Ryger was 2.5 seconds a lap slower than a TM, on the same day.
As far as I know Aalt Toersen has abandoned 50cc Ryger development.
Reported power was 13HP, which is really hopeless....
The 125 Ryger power was estimated at about 32HP by a very competent person watching the test.
In line with the 50cc's result.
The main reason for secrecy seems to be that they don't want people to know how bad this engine really is.
Because they have 50 of them they are wanting to sell, which will be very difficult.
But maybe they can give them away for free, to curious people!
It's based on the way of thinking of around 1950......
Useless and complicated.
Luc called me, and Wobbly, 'so called experts'
So we are not on friendly terms anymore....

A black hole it will be!

[Grumph]

There must be at least 50 public and private museums around the world who'd want one...

But not at the asking price.

[jasonu]

There must be at least 50 public and private museums around the world who'd want one...

.

What for? Paperweights or fancy door stops.

[jamathi]

There must be at least 50 public and private museums around the world who'd want one...

But not at the asking price.

With luck about one third of TM price.....

[SwePatrick]

I read rygerteam were amazed of the poweroutput and they couldn´t understand were the power came from, from the beginning.

I´ll tell you guys from where it came: BAD CALIBRATED DYNO! :brick: :facepalm::gob::eek5::sick:
I can easily manipulate my own dyno with just adding more inertia in software.
With that the dyno reports amazing power.

And not seeing that if you are unaware of the calibratiing fault you will start looking for explanations.
Those explanations often seem to be 'out of this world', and they have to be.
There´s no other way of explaining their gains.
In fact they are only fooling themselves.
And have been swollowing the whole bait they start to 'sell the story'.

Then reallife results is mediocre and bites them back.
But it´s to late to revert because that questions their knowledge.
So they are building smoke and mirrors.... :yes:

Rgds
Patrick

[sb07]

There are no Ryger secrets.
Its in black and white , it makes 70 Hp and spins to 30,000 rpm.
And dont bother to question Luc, as he will go running back to his dyno ( sorry computer screen ) and make up a new graph that proves we all are a bunch
of bastards who dare to doubt the reality of everything he says.

I think Luc will not write on this forum for a while :laugh:

[jamathi]

I read rygerteam were amazed of the poweroutput and they couldn´t understand were the power came from, from the beginning.

I´ll tell you guys from where it came: BAD CALIBRATED DYNO! :brick: :facepalm::gob::eek5::sick:
I can easily manipulate my own dyno with just adding more inertia in software.
With that the dyno reports amazing power.

And not seeing that if you are unaware of the calibratiing fault you will start looking for explanations.
Those explanations often seem to be 'out of this world', and they have to be.
There´s no other way of explaining their gains.
In fact they are only fooling themselves.
And have been swollowing the whole bait they start to 'sell the story'.

Then reallife results is mediocre and bites them back.
But it´s to late to revert because that questions their knowledge.
So they are building smoke and mirrors.... :yes:

Rgds
Patrick

They did not even have a dyno when they claimed 70HP.
Power was calculated on a computer.
Later they got a dyno, and the results were not as expected.....
They thought the dyno was at fault, and wanted to send it back to the manufacturer!
But obviously the fault is in the engine.....

[oldjohnno]

I read rygerteam were amazed of the poweroutput and they couldn´t understand were the power came from, from the beginning.

I´ll tell you guys from where it came: BAD CALIBRATED DYNO! :brick: :facepalm::gob::eek5::sick:
I can easily manipulate my own dyno with just adding more inertia in software.
With that the dyno reports amazing power.

And not seeing that if you are unaware of the calibratiing fault you will start looking for explanations.
Those explanations often seem to be 'out of this world', and they have to be.
There´s no other way of explaining their gains.
In fact they are only fooling themselves.
And have been swollowing the whole bait they start to 'sell the story'...



Reminds me of the old Bourke engine, similar in many ways to the Ryger, not just functionally but in its failure to live up to promises. A very interesting and entertaining tale of the Bourke here. (http://www.niquette.com/books/sophmag/bourke.htm)

[jamathi]

I think Luc will not write on this forum for a while :laugh:

Maybe Harry Gerrits has finally understood he has been misled by Luc.
Convinced by e real track test.....
2.5 seconds a lap is quite some difference!

[husaberg]

Maybe Harry Gerrits has finally understood he has been misled by Luc.
Convinced by e real track test.....
2.5 seconds a lap is quite some difference!

You are naughty Mr Thiel
If you don't watch out Luc with abuse you as well about giving out Harry unspokens name, citing some imaginary private message he claims to have sent you asking it not to be revealed as well.:shit:
Mabye in the test session where the Ryger was slower than the TM it was on account of not using a Official RYGER stopwatch.

[jamathi]

You are naughty Mr Thiel
If you don't watch out Luc with abuse you as well about giving out Harry unspokens name, citing some imaginary private message he claims to have sent you asking it not to be revealed as well.:shit:
Mabye in the test session where the Ryger was slower than the TM it was on account of not using a Official RYGER stopwatch.

I do NOT mean to be naughty to anyone, ever, Husaberg.
Most people who know me personally will confirm this I think.
But I don't like lies, and people misleading others...
Your remark about the stopwatch could be right!

[SwePatrick]

They did not even have a dyno when they claimed 70HP.
Power was calculated on a computer.
Later they got a dyno, and the results were not as expected.....
They thought the dyno was at fault, and wanted to send it back to the manufacturer!
But obviously the fault is in the engine.....

Just change my word 'dyno' to 'software'.
Then all is correct again. :)

[JanBros]

figured the Ryger out. Luc is right : you have to think outside the box and than it's all very obvious.
The Ryger is not based on thermodynamics, but on the dead-horse principle :

http://1.bp.blogspot.com/-Lg6ButPVD2M/T_HWUlVnznI/AAAAAAAAAYg/mO4EFAub6NE/s1600/the+dead+horse+theory.jpg

[TZ350]

332511

The Ecotrons EFI Alpha-N map load increases in 16 steps. So some time ago I used a flow meter to find the 16 TPS positions that equated to 16 even increases in airflow.

The curve followed this throttle plate curve I found on the net. I guess the offset is due to my curve starting at a slightly open position for the idle air.

332512

Interesting that 50% of airflow happens at 20% TP throttle position. The green shaded area is the area I am having most trouble with getting the engine response with the EFI Alpha-N map right.

332513

A series of dyno runs from 100% throttle down to the 20% green line. Also interesting that 50% air did not make 50% power. I don't understand that, I would have expected 50% air would equal 50% power.

The areas below 20% throttle represent a very small area on this collection of graphs but I have found it to be a huge problem on the track with throttle response. They also represent half the steps on the Alpha-N map.

When everyone knows big power is at WOT who would have thought that so much importance was in that first bit of barely opening the throttle.

[SwePatrick]

332513

A series of dyno runs from 100% throttle down to the 20% green line. Also interesting that 50% air did not make 50% power. I don't understand that, I would have expected 50% air would equal 50% power.


There are always losses in friction and heat transportation so the curve of powergain is seldom equal to air usage.

[husaberg]

332511

The Ecotrons EFI Alpha-N map load increases in 16 steps. So some time ago I used a flow meter to find the 16 TPS positions that equated to 16 even increases in airflow.

The curve followed this throttle plate curve I found on the net. I guess the offset is due to my curve starting at a slightly open position for the idle air.

332512

Interesting that 50% of airflow happens at 20% TP throttle position. The green shaded area is the area I am having most trouble with getting the engine response with the EFI Alpha-N map right.

332513

A series of dyno runs from 100% throttle down to 20% green line. Also interesting that 50% air did not make 50% power. I don't understand that, I would have expected 50% would equal 50% power.

The areas below 20% throttle represent a very small area on this collection of graphs but are a huge problem on the track with throttle response. They also represent half the steps on the map.

Who would have thought that so much importance was in that first bit of barely opening the throttle.

Back when programmable EFI was in its infancy they used to save room and data and more importantly time, by using the multiple smaller steps only in problem areas if that makes sense.
ie they did a basic map much like a 4 circuit carb pilot, cutaway, needle, main.
then used the rest of the 16 steps to full in the areas where it stumbled
smaller engines and single and twins and rotaries were far less forgiving then 4 and 8's.
I remember Riley Will saying something on Pitlane about someone (Aprilia i think) basically plotting the flow of a carb and then recreating it with the efi, to get rid of the twitchiness.

[ken seeber]

Didn't old mate Harold Bartol in the early days of injection use a carb for all low end / transitional operation and then just use the injector to fulfil the main jet operational areas? I guess this was cos the computing /software /hardware at that time didn't have the resolution & speed to match the "analogue" nature of the carb.

[lucf]

Maybe Harry Gerrits has finally understood he has been misled by Luc.
Convinced by e real track test.....
2.5 seconds a lap is quite some difference!


Yes Jan, that is really quite some difference.

But what you don't seem to know from your reliable witness is:
that the Ryger was almost 2,5 sec quicker than the TM KZ10c special.

So the opposite of your very well known "reliable witness"

And it was driven on the track of Pottendijk at Emmen last sunday Sept 3th, 2017
So make your witness known, because someone likes to change the real story.

[Greg85]

Yes Jan, that is really quite some difference.

But what you don't seem to know from your reliable witness is:
that the Ryger was almost 2,5 sec quicker than the TM KZ10c special.

So the opposite of your very well known "reliable witness"

And it was driven on the track of Pottendijk at Emmen last sunday Sept 3th, 2017
So make your witness known, because someone likes to change the real story.

hello mr Lucf, i think if your engine is 2.5 s faster than the tmkz10c special, you do not think everyone would have one for this weekend for the world cup has wackersdorf? the best way to prove it is to take a down to the free track is if it is significantly faster you would be millionaire in 1 week ...

[shnaggs]

Re PV closing.This is easy to test on a dyno.
To setup a PV curve I always do a run with it locked down, at mid position, and then fully up.
Join the Hp points and you have the opening ramp shape.
But then I lock it down , varying the height 0.5mm at a time.
This gives you the best full down point, that gives highest power at the lowest rpm you want to use on track.
This of course can be achieved bu opening the PV early with the servo, but its alot more long term accurate to have a physical
down stop.

Thanks Wobbly! I greatly appreciate the feedback.

Could you please tell me how YOU create a fuel and ignition curve in Engmod? Do you start with a straight IGN/Fuel map and then adjust looking at the TUBmax, then run a turbulent model? Or do you have to have a close IGN and fuel curve already before you can run a turbulent model? I've been trying it multiple ways and the power is generally the same, but my TUBmax values differ from one to the other, along with MaxDeg, but both hit deto quite a lot in the sim. For instance I'm playing around with the RSW engine, with the pieces that have been posted throughout this forum, but I am missing both the engine file and the IGN file. I've guessed on the engine file, but i'm trying to create an IGN file and not having a lot of luck...but I'm learning a lot along the way! Thanks!

[lucf]

hello mr Lucf, i think if your engine is 2.5 s faster than the tmkz10c special, you do not think everyone would have one for this weekend for the world cup has wackersdorf? the best way to prove it is to take a down to the free track is if it is significantly faster you would be millionaire in 1 week ...

Yes Greg, we know you are right !

[F5 Dave]

And it could fly!

Thought you weren't coming back. We missed you. . , no, wait. The other one.

[wobbly]

Bartol used an injector in the KTM to add fuel when the engine was overeved into a corner on nil throttle.
This being one area a carb cannot do what is needed.
At all other TPS setups the carb worked perfectly, so full injection was deemed unnecessary complication.

[peewee]

We ran 40% nitro in this engine. It definitely stopped as soon as the plug burned off. The ground strap was a little hard on the piston on the way out the exhaust. On 15% nitro it ran fine.

Lohring Miller

332121

do you have any advice about using nitro in a 2t ? I have 1gal nitro and 5gal methanol so I can mix my own percentage. my tank fuel valve flows 1gal (3.7L) per minute which is plenty im sure. this weekend ill figure how much fuel is passing through the carb float valve. my plan is to start with a low mix like 10% or even 5% and get it running well then go alittle higher to 15 or so. maybe even 20 but I don't want to put the cart in front of the horse just yet.

anyways I been using #9 and #10 heat range plugs with straight methanol. would 10 be a good choice for what im doing or even colder ? typically I been just using standard electrode. im guessing this should do fine ? i haven't yet installed any instant fuel cut off valve incase it should run away but im hoping that doesn't happen

the other thing i was wondering is spark lead. is it best to start with a setting that worked well on petrol and advance it in small increments as needed ?

heres something interesting that i found in a article and i wonder how truthful it is. maybe you could comment on it ? thnx for any help

Remember that the air/fuel ratio (AFR) we commonly refer to is pounds of air to pounds of fuel: feathers to lead. Weight, not volume. The AFR for alcohol: ~5:1. The AFR for 100% nitro: ~1.3:1.

If you saw a graph of the specific gravity change of the fuel (weight) for 0 through 100% nitro and also the AFR required for 0-100%, the lines would cross at about 33%.

From 0% to 33%, the change in the specific gravity of the fuel rises quicker than the change in the required AFR. The fuel is getting heavier QUICKLY at low percentages so you get more pounds per minute for the same air flow. The required AFR is not much different than straight alcohol. You actually have to go leaner to hit the optimal AFR you need.

After 33%, the AFR is changing quicker than the density of the fuel - more fuel is required to make up the difference. If you calculated it all out for 15%, you will see you have to lean the mixture from the optimal alcohol jet. This is probably why many people who run 20% say they don't see much of a gain in performance. They are way way way too rich and cancelling much of the benefit.

[SwePatrick]

If deciding to run on nitro, start pig rich!
Up to 20% it behaves quite normal, almost like methanol alone.
But getting upwards in blend things happen.
And when it starts releasing it´s own oxygen things happen fast, really fast.

One could run an electric powervalve controlled by exhaustheat to get full benefit of nitro.
Running cold it won´t produce any power.
Running hot and lean will produce aluminiumcoating in pipe *lol*

Find that sweetspot when it starts burning wild and add fuel at that point.
Make the stinger bigger(more power more diam on stinger)

One could take fuel directly from fuel line if running electric powerjet, no need to interference with carbs own fuel.

[SwePatrick]

The problem with the 30mm carb on the KZ engine is that the inlet is as short as it possibly can be, and it is connected to a reed
that is capable of over 50 Hp.
Thus no room for any divergent duct.
The current setup has alot of area infill from the stuffer, keeping the area pretty constant right up to the petal curtain area.
I am trying all manner of test shapes using 3D printed inserts with various wings and guides,as the best power is had using very soft top petals
along with stiff lowers.
This biases the flow upward toward the transfer duct entries.

Even though they aren´t allowed in karting.
Have you been comparing classifeid reed against V-forve 3 in dyno?

Do V-force stand up to the task?

Rgds

[wobbly]

I have used a VeeForce 4 from a Banshee - more power everywhere,except very top end in a motor used in an open class with a 34mm carb from a Rotax Max..
But big issues with petal ends chipping.

[SwePatrick]

Nice.

And i got the same problems both with boyesen and v-force.
It slams the petals hard so they chip.
Best results with modded std kawasaki reed.

Thanks for info =)

[jamathi]

I have used a VeeForce 4 from a Banshee - more power everywhere,except very top end in a motor used in an open class with a 34mm carb from a Rotax Max..
But big issues with petal ends chipping.

Hi Wobbly, did you already hear about the Ryger's 'success' in Holland.
It was only 2.5 seconds a lap SLOWER than a TM......
On a track with a lap time of about 35 seconds.
Now they are celebrating.
Sales can start now......
Anyone?

[sb07]

Yes Jan, that is really quite some difference.

But what you don't seem to know from your reliable witness is:
that the Ryger was almost 2,5 sec quicker than the TM KZ10c special.

So the opposite of your very well known "reliable witness"

And it was driven on the track of Pottendijk at Emmen last sunday Sept 3th, 2017
So make your witness known, because someone likes to change the real story.

you insist?
stop ... ryger is slow ...
is a continuous... bla bla bla...
I'm on the track every week ...
Ryger is famous only on the internet, only on forums :brick: no one is fear!!!
On the track everyone is talking about TM, Modena, Vortex ... iron with cocones !!!

[SwePatrick]

Is there a misunderstanding here?
If someone beat me with almost 2.5s it means they have beaten me with almost 2.5s =)
like 2.4x seconds.

[lohring]

My experience with nitro in ignition engines was in a series of tests to prove that simply changing the fuel in our 26 cc race engines wouldn't significantly help the power. The picture was from a very brief test series where we tried glow ignition. Since the plugs didn't hold up we ran spark ignition with good results on lower nitro ratios. In both test series no attempt was made to optimize the compression, ignition, or pipe for the fuel. We ran the same setup as for gasoline except for the mixture.

As model glow ignition engine racers, we had methanol fuel with various nitro percentages between 15% and 60% and with 20% synthetic/castor oil. The tests in the series in the .pdf below ran 8 oz. of oil per gallon. As you can see there was very little difference when you allowed for the precision of our inertial dyno. All the graphs are an average of 3 identical runs.

Lohring Miller

332521332522

[mitch meyer]

I have used a VeeForce 4 from a Banshee - more power everywhere,except very top end in a motor used in an open class with a 34mm carb from a Rotax Max..
But big issues with petal ends chipping.

I have had same problem with chipping on die cut reed petals. I coated the top edge and side edge of petals with West System epoxy and this cured most of the problem. 250cc methanol outboard at 13 to 14000 RPM. It might be worth a try.

[wobbly]

Yes Jan,the proof would have been that several Rygers would have been on track this week practicing for the
biggest KZ race of the year in Germany.
There are two NZ racers there,so I have follower the session times - not a Ryger on the board.

Re reed petal chipping,I have "fixed " this by carefully sanding the edges with 600 wet and dry,and putting a generous radius on the outer corners.
This works well in SKUSA CR125 as well as KZ class, but the hard plastic cage on the VeeForce is super critical on petal frequency, too soft and they shatter.
I will try the epoxy idea - is it a 2 pot you simply paint on ? maybe good for petrol protection of 3D printed plastic reed stuffer inserts as well.
Its not available here, could you PM me re getting some sent over to NZ.
cheers
Wob

[Lightbulb]

My experience with nitro in ignition engines was in a series of tests to prove that simply changing the fuel in our 26 cc race engines wouldn't significantly help the power. The picture was from a very brief test series where we tried glow ignition. Since the plugs didn't hold up we ran spark ignition with good results on lower nitro ratios. In both test series no attempt was made to optimize the compression, ignition, or pipe for the fuel. We ran the same setup as for gasoline except for the mixture.

As model glow ignition engine racers, we had methanol fuel with various nitro percentages between 15% and 60% and with 20% synthetic/castor oil. The tests in the series in the .pdf below ran 8 oz. of oil per gallon. As you can see there was very little difference when you allowed for the precision of our inertial dyno. All the graphs are an average of 3 identical runs.

Lohring Miller

332521332522

Some years ago, we tried to make a full tuned pipe engine for model boats that was to use a fuel with a minimum of 50% nitromethane. The supplied test engine did not use a proper full pipe , while it did make really good power, we could get as much power with a full pipe and 10% nitro fuel on the supplied engine. I built one up to run the 50% nitro. When it was close to running right, produced too much heat and melted holes in the piston every time or collapsed the crown. These were glow engines. My conclusion was with the heat being generated that the piston was not capable of dissipating that energy to the liner walls. It was water cooled head only. The bottom of the case was cold, but the area around the transfer ports was warmer than normal. For the very short time that it ran, the power output was very substantial. It was increase in power in the order of 30% with the 50% fuel over the 10% fuel. If the engine only needed to run for less than 6 seconds it will be great like a scale drag race car. We just tested with propellers and the power increase in general is the 3 of the rpm change.

[husaberg]

Yes Jan, that is really quite some difference.

But what you don't seem to know from your reliable witness is:
that the Ryger was almost 2,5 sec quicker than the TM KZ10c special.

So the opposite of your very well known "reliable witness"

And it was driven on the track of Pottendijk at Emmen last sunday Sept 3th, 2017
So make your witness known, because someone likes to change the real story.


https://youtu.be/ARxty_36JA8?t=25s

[jamathi]

https://youtu.be/ARxty_36JA8?t=25s

I will not give you his name, but he was the most capable person present.
So you will know who I mean!
And please stop telling fairy tales....
LOOSING 2.5 seconds a lap on a 35seconds track is ridiculous, not just very bad....
No 70 HP, not even 66, but about 33-35!
Who will buy such a piece of shit?
Not even the scrapheap will be happy with them...

[husaberg]

I will not give you his name, but he was the most capable person present.
So you will know who I mean!
And please stop telling fairy tales....
LOOSING 2.5 seconds a lap on a 35seconds track is ridiculous, not just very bad....
No 70 HP, not even 66, but about 33-35!
Who will buy such a piece of shit?
Not even the scrapheap will be happy with them...
i think you replied to the wrong person Jan.
I agree totally though, hence the Trump reference.

[jamathi]

i think you replied to the wrong person Jan.
I agree totally though, hence the Trump reference.

Sorry for my mistake Husaberg....

[wobbly]

I still dont get it at all - every track has a timing system.
If the Ryger was fast you would have to believe the very first thing to happen was a screen shot of the fastest lap to be posted online,even
if only to tell all of us here to " shut the fuck up ".
But no,the fast laps against a TM are about as proven as the bullshit dyno printouts.

[Greg85]

I still dont get it at all - every track has a timing system.
If the Ryger was fast you would have to believe the very first thing to happen was a screen shot of the fastest lap to be posted online,even
if only to tell all of us here to " shut the fuck up ".
But no,the fast laps against a TM are about as proven as the bullshit dyno printouts.

wobbly as i said lucf to the previous post if its engine would be performing is faster than the best current engine (tmkz10c) at present time there would be engines rygers at the world cup kz wackersdorf ...

[peewee]

was surprised how heavy this stuff is when I lifted the container. about 1.13kg for every 1L / 9.5lb per 1gal

[jamathi]

I still dont get it at all - every track has a timing system.
If the Ryger was fast you would have to believe the very first thing to happen was a screen shot of the fastest lap to be posted online,even
if only to tell all of us here to " shut the fuck up ".
But no,the fast laps against a TM are about as proven as the bullshit dyno printouts.

I am curious how it will sell.
At about 2000 Euro MORE than a TM.....
But now finally it lasts for more than 1.5 minutes.
The fantastic result of 2 years of development!!!
How can they be happy at being ONLY 2.5 seconds slower than a TM?

[peewee]

Some years ago, we tried to make a full tuned pipe engine for model boats that was to use a fuel with a minimum of 50% nitromethane. The supplied test engine did not use a proper full pipe , while it did make really good power, we could get as much power with a full pipe and 10% nitro fuel on the supplied engine. I built one up to run the 50% nitro. When it was close to running right, produced too much heat and melted holes in the piston every time or collapsed the crown. These were glow engines. My conclusion was with the heat being generated that the piston was not capable of dissipating that energy to the liner walls. It was water cooled head only. The bottom of the case was cold, but the area around the transfer ports was warmer than normal. For the very short time that it ran, the power output was very substantial. It was increase in power in the order of 30% with the 50% fuel over the 10% fuel. If the engine only needed to run for less than 6 seconds it will be great like a scale drag race car. We just tested with propellers and the power increase in general is the 3 of the rpm change.

were you mixing by volume or weight ? since this is my first time messing with nitro i been doing as much research as i can. from what ive read, if you mix say 20% volume its likely to really be more like 25% by weight. must have something to do with the differences in specific gravity i guess.

tonight i removed the bowl to see what float valve ive got. its 3.3mm main inlet hole with three 1mm secondary inlet holes. combined with the oversized float bowl it was sufficient on methanol. i talked to lectron about it and theyre sending me a different one with 6 secondary inlets just to be on the safe side.

the rest ill just learn as i go. ive got #10 plug installed. the spark curve i have no idea what it looks like so ill adjust it in small increments as needed. kind of sucks when you dont have a dyno to see whats really happening :facepalm:

[husaberg]

I am curious how it will sell.
At about 2000 Euro MORE than a TM.....
But now finally it lasts for more than 1.5 minutes.
The fantastic result of 2 years of development!!!
How can they be happy at being ONLY 2.5 seconds slower than a TM?

I muse that with such a small "crankcase" that to produce effective TM beating power it would have to rev to 30000RPM
Maybe this is the source of the RYGER tales of massive rev potential and HP someone plugged the figures into a sim software and never considered that this might not be feasible in reality.
Maybe the Ryger at one time did at one stage beat a tm around a track by a couple of seconds. You never know it might have been a pro driver with a Ryger against a rank amateur on his first drive on a tm.
It may end up with Ryger team claiming that due to its reduced pollution potential of the Ryger they should have a handicap much like 4ts enjoyed in motogp and MX.

[TZ350]

332543

Well I got to try my new nicely ported NSR cylinder. The workmanship of the last porting effort was a bit disappointing and I was not convinced by the results. Disappointingly my first effort only made 31hp. 31 is that as good as it was going to get or was it being held back by poor workmanship???? I was hoping for more than 31 on the new cylinder.

332545 332544

The good news is that today's tests confirmed that for off pipe slow speed fueling, under piston injection gives much better results and was noticeably better than crankcase injection.



I'm also very interested to hear more of your findings in your NSR250 porting. You actually lost power by opening up the ears of the exhaust port?

On my second attempt. I was very happy with my workmanship opening the ears up on this new ported cylinder to make it look more like a RS cylinder. But after hours of work on the dyno getting the PV right and ignition and fueling spot on it also did not make more than 31hp, Red line.

Inlet is 240 duration and both cylinders ported and std are 200 Ex duration and 132 Transfer duration.

The Blue line is a standard NSR cylinder with its droopy down exhaust port and the modified one, Red line had the top of the exhaust port leveled off for more blowdown time area. At this point I think the standard cylinder would give better on track results.

332546


You're either transfer limited, or major short circuit going on A transfers to export. You may find it beneficial to "bowl" out ex port right after window.

I will take your advice about "bowling" out the exhaust port. Also what you say about the short circuiting from the "A"s now that the cylinders have been ported makes sense. Engmod tells me that the transfers have enough transfer time area.

A Honda RS125 makes 40-43 hp. Because both my ported cylinders topped out at 31hp I suspect a common link and think that it might be that the exhaust nozzle I am using is going sonic and choking. I will look here first because that is easiest.

Jonny if you have been working with NSR cylinders I would love to know more about what you have tried and the results.

[peewee]

332543

Well I got to try my new nicely ported NSR cylinder. The workmanship of the last porting effort was a bit disappointing and I was not convinced by the results. Disappointingly my first effort only made 31hp. 31 is that as good as it was going to get or was it being held back by poor workmanship???? I was hoping for more than 31 on the new cylinder.

332545 332544

The good news is that today's tests confirmed that for off pipe slow speed fueling, under piston injection gives much better results and was noticeably better than crankcase injection.




I was very happy with my workmanship opening the ears up on my new ported cylinder to make it look more like a RS cylinder. But after hours of work on the dyno getting the PV right and ignition and fueling spot on it also did not make more than 31hp, Red line. The Blue line is a standard NSR cylinder. At this point I think the standard cylinder would give better results.

332546



I will take your advice about "bowling" out the exhaust port. I also suspect that the exhaust nozzle is going sonic and choking.

Jonny if you have been working with NSR cylinders I would love to know more about what you have done and the results.

sounds like your bridged exh is doing far better than mine. made it about 10min and the rings were chewed up on the front side :laugh:. roof must of been too flat and wide I suppose. about the bowling, there was a ase paper about it around here somewhere

[Frits Overmars]

You may find it beneficial to "bowl" out ex port right after window.Is this what you call 'bowling' Jonny?
332547