ESE's works engine tuner

[190mech]

Some of the Vespa tuners claim their 'special' cylinders use flat sided pistons to promote linking to increase crankcase pressure!I always tell them to read the ESE thread,but they never do...:facepalm:

[ken seeber]

Years gone by in the era of 100cc air cooled rotary valve, reed valve and piston port inlet kart engines, guys used to shorten the piston skirt on the exhaust side such that, at TDC, the crankcase was open to the exhaust, by a couple of mm. Never saw any dyno figures etc, but some felt it was gainful.

[jamathi]

Years gone by in the era of 100cc air cooled rotary valve, reed valve and piston port inlet kart engines, guys used to shorten the piston skirt on the exhaust side such that, at TDC, the crankcase was open to the exhaust, by a couple of mm. Never saw any dyno figures etc, but some felt it was gainful.

Of course I also tried this , it made surprisingly little difference, but there was certainly no power gain!

[Frits Overmars]

Years gone by in the era of 100cc air cooled rotary valve, reed valve and piston port inlet kart engines, guys used to shorten the piston skirt on the exhaust side such that, at TDC, the crankcase was open to the exhaust, by a couple of mm. Never saw any dyno figures etc, but some felt it was gainful.Yamaha even employed this scheme in a production machine; I think it was the RD400, but it was discontinued in their later models.

[katinas]

Yamaha even employed this scheme in a production machine; I think it was the RD400, but it was discontinued in their later models.
Tried this on Honda NS 250, at TDC exhaust connect with crankcase through cut 10x10mm on piston EX side skirt. Surprisingly at low and mid rpm nothing changes, but from 9000 to 13000 rpm power much softer.
Yamaha do the same on latest 2018 YZ 250, just open not main EX, but satellites when piston is at TDC ( add pic).
Maybe on RD400 and YZ 250 they tried to do more friendly engine character, but maybe not.

[peewee]

Tried this on Honda NS 250, at TDC exhaust connect with crankcase through cut 10x10mm on piston EX side skirt. Surprisingly at low and mid rpm nothing changes, but from 9000 to 13000 rpm power much softer.
Yamaha do the same on latest 2018 YZ 250, just open not main EX, but satellites when piston is at TDC ( add pic).
Maybe on RD400 and YZ 250 they tried to do more friendly engine character, but maybe not.

about 25yr ago ktm did that same thing on a dirtbike engine. im not sure if it was intentional or just a byproduct of using such a high wristpin

[F5 Dave]

Funny. Mike tried that when he sleeved down a RGV barrel and it was a bit rubbish, as piston too thin to cover bridged port. Everything better with a wider skirt piston.

[peewee]

I used 4203 rod.
Mark is taking the screw top piston one step further after I wised him up to a patented reverse L ring design that traps the
vertical leg and prevents bulging into large unbridged ports.
Our man on Two Stroke Stuffing is on the same path.

how much power could the rsa have if jan had a chance to try nonbulging rings ?

[wobbly]

60 Hp easy if simply removing the bridges on the 3 port.
But the transfers would need to be raised - as they are perfectly matched to the existing effective Blowdown STA.

[Flettner]

Raised? How much?
I've got a cylinder with a static ring, pinned.

Haven't tried it yet, intetesting to see how well this pinned piston ring works, are there any real world results yet?

[katinas]

Tested Suzuki RGV 250 1/2 engine with lower crankcase separator and flow directly to transfers, like tested on Honda NS.
Engine reaction from 0 to 8000 rpm very similar to NS ( clean burning at lower revs).
But from 8000 rpm, when power valve opens, engine stopped and only first gear overcome 8000-10000 rpm dip.
From 10000 to 12500 rpm nothing special from std.
Then made two 16 mm holes on separator sides to add pressure from crankcase and this immediately eliminate dip.
In normal mode, without separator, engine lost cleanliness at lover revs, but at higher goes better than with std piston.
So needed more tests, but as on NS engine work in a good way from first run , on RGV all things more complicated.
Would be interesting to try new separator with reed valves.

[katinas]

about 25yr ago ktm did that same thing on a dirtbike engine. im not sure if it was intentional or just a byproduct of using such a high wristpin


Maybe on Yamaha YZ 250, gains from higher cuts, overcome looses from opened EX satellites.
And very strange that piston intake side skirt legs is higher than B transfers windows lower edges, when piston is at TDC. This open B windows little more, but piston legs working in danger zone.
Patent EX communicating with A through piston https://patents.google.com/patent/US6591792B2/en?inventor=Toshihisa+Nemoto

Testing on Dyno, shows that rising side cuts as much as possible (without short cut with satellites) on std piston with KTM SX 65/85/125 add little hp. Last week on the new Husqvarna TC 65, just with modified std piston, power rise up 0,8 hp with the same mid (higher cuts 0,3 hp. rounded piston with sharp edge at C 0,5 hp.)
Its funny, some time ago, when we rising side cuts we thinking that it helps better flow from crankcase when piston is at BTC. Now we doing the same, but thinking that it add longer suction pulses to transfers ports when piston is at TDC. But this works on reed engine, on rotary opposite, as on Jan's engines cuts is much lower and did not open trans windows at all when piston is at TDC .

Add RGV Di piston at TDC

[wobbly]

Without doing a full sim analysis on the RSA 125 ( again ) with the new Exhaust width I have no idea what will be needed to
get the Blowdown and Transfer STA back into sync Neil.
The setup that Mark and Mr Stuffing are working on isnt " pinned " as such.
It is a reversed L Dykes ring , such that the vertical leg is trapped within the ring groove.
Its under a patent issued to Savice, the engine design consultancy company i worked for in China.

[Flettner]

thats a bit rich, China useing the patenting system.😆

[DoldGuy]

thats a bit rich, China useing the patenting system.😆

Now that’s funny!!!:2thumbsup

[DoldGuy]

Tried this on Honda NS 250, at TDC exhaust connect with crankcase through cut 10x10mm on piston EX side skirt. Surprisingly at low and mid rpm nothing changes, but from 9000 to 13000 rpm power much softer.
Yamaha do the same on latest 2018 YZ 250, just open not main EX, but satellites when piston is at TDC ( add pic).
Maybe on RD400 and YZ 250 they tried to do more friendly engine character, but maybe not.

Katinas,
Do you know if the satellites/sub ports open on the 2017 and earlier? It appears the 2018 received a new/different cylinder. I have been working on a cylinder that has the satellites/subs open like the YZ and have searched for a solution/piston to cover the ports at TDC, but my concerns over this might not be warranted.

[katinas]

Katinas,
Do you know if the satellites/sub ports open on the 2017 and earlier? It appears the 2018 received a new/different cylinder. I have been working on a cylinder that has the satellites/subs open like the YZ and have searched for a solution/piston to cover the ports at TDC, but my concerns over this might not be warranted.
Hi,
When Yamaha changed YZ 250 engine in 1999 ( piston from 68 to 66,4 mm ) looks like satellites was opened until now. We really surprised to see this, when changed the piston on the 2018 YZ 250 two moth ago.
Before 1999, with 68x68 mm engine, they use piston with extensions to cover satellites.

[Frits Overmars]

All MotoGP-races live on the internet: https://www.servus.com/tv/jetzt-live/ (German-spoken; Servus is a TV-station owned by Red Bull).

[peewee]

Hi,
When Yamaha changed YZ 250 engine in 1999 ( piston from 68 to 66,4 mm ) looks like satellites was opened until now. We really surprised to see this, when changed the piston on the 2018 YZ 250 two moth ago.
Before 1999, with 68x68 mm engine, they use piston with extensions to cover satellites.

you can probly just use the 250sx piston. that should cover the sub ports

[ken seeber]

BATTLE OF THE BULGE

Nope, not really, but the measured bulging of a ring with progressively increasing port chordal widths.
So, I made up a small mandrel and bored it to 54.0 and used a KZ standard style 1.0 * 2.20 Meteor piston ring. The mandrel was faced off on its underside and then grooved out so a vernier could measure the top of the ring between that and the flat. The pics tell the story really.

341764341766341767341768341769[
Then, with a fixed stop arrangement in the mill, the slot was progressively widened in 2 mm steps using an Ø8 mm cutter. Between each cut the ring height was measured, both externally with the verniers and, also using verniers, the inside diameter of the ring on an axis in line with the centre of the “port”.

To ensure consistency, the ring was always orientated in the same position and was pushed into place using a shouldered mandrel to place it into the centre of the port each time.
The zero bulge/reference point was set at the initial port width of 18 mm, based on the assumption that no bulging could ever be present at such a small chord width.
Results were the average of the internal and external measurements taken at each port width. If I was to do this again, I can think of better methods of measurement to eliminate the experimental variation that was present.

One can see the real action starts around the 70% port width.

341765

What does all this mean? Not sure in that these are just a series of measurements in a static test rig. If the grand plan is to have the widest port possible consistent with the ring not snagging, then the practical limit ultimately would have to be tested on an engine. Major influencing factors would be:
• The shape of the roof of the port
• The radius of the port between the roof and the sidewalls.

Another factor is gas pressure. As is well known, the gas pressure in the cylinder activates the sealing of the ring by providing a pressure force on the effective projected area of the ring. At the point of EPO, the gas pressure in the cylinder might be up to 5 bar, and this would certainly be enough to assist the outward bulging of the ring. But at this point, it is no big deal as the ring is in fresh air (exhaust gas really) . Assuming the ring passing over the floor of the exhaust port is also not an issue due to well rounded shape, the real issue would be the rising situation when the ring could snag on the roof of the port.

So, dunno if anyone has progressively widened a port to the point of destruction, but most figures I have seen are around 70 – 72% maximum.
Clearly at widths of 80% plus, destruction looks likely. Hence the need for some form of containment at the 100% level as proposed by Wob, Mark & old mate in 2 stroke stuffing. To me this is going to take a serious tolerancing & mfg exercise to make it work, but I hope it does.

The alternative to achieving more exhaust area is to add more ports than the current generic 3 port arrangement. To do this will most likely require an alternative scavenging arrangement and we all know what some of these are.

[Niels Abildgaard]

BATTLE OF THE BULGE


The alternative to achieving more exhaust area is to add more ports than the current generic 3 port arrangement. To do this will most likely require an alternative scavenging arrangement and we all know what some of these are.

Will this do?

https://i.imgur.com/Iz3tD97.jpg

[Flettner]

Will this do?

https://i.imgur.com/Iz3tD97.jpg

Niels, have put some thought into the transfer flow?

[Scubbo]

may aswell go 4 stroke :facepalm:

[Niels Abildgaard]

Niels, have put some thought into the transfer flow?

Lots of thinking.
My MZ had mikuni oil pump and that shall feed directly on the cam.
A reed valve inlet directly into the scavenge port belt will do until I get wiser.
Dreams of not much else.
To old for women, money and power.
When the sidevalve single has proved what a genious I still am,I will do a directcoupled V2 for aircrafs.
The pistons need not have same diameter.

https://i.imgur.com/kgeUWsJ.jpg

[husaberg]

......................<a href="https://imgflip.com/gif/3070p2"><img src="https://i.imgflip.com/3070p2.gif" title="made at imgflip.com"/></a><a href="https://imgflip.com/gif/3070qs"><img src="https://i.imgflip.com/3070qs.gif" title="made at imgflip.com"/></a><a href="https://imgflip.com/gif/30714i"><img src="https://i.imgflip.com/30714i.gif" title="made at imgflip.com"/></a><a href="https://imgflip.com/gif/30715c"><img src="https://i.imgflip.com/30715c.gif" title="made at imgflip.com"/></a>

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130226221#post1130226221

[oldjohnno]

http://www.oldengine.org/members/diesel/rootes-listerts3/TS37.jpg

[husaberg]

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

[Flettner]

Yes plenty of examples of uniflow scavenging.
There is an issue with transfer flow into the cylinder to get a clean fill, the gas doesn't necessarily go where the little arrows point.��

[peewee]

i made up some exh spigots. just alittle more work on the water jacketing at the side of the cyl and figure out some sort of water nipples near the exh exit. easiest for me would be some threaded weld on bungs then a brass 90* elbow screwed into the bung but that sharp 90* may not be the best for water flow. what do you guys think ? I kind of wanted to make the elbows removable but I haven't found anything other than the brass 90*. I guess i could probly make a bit of a radiused elbow with a bunch of pie cut tube welded together

[TZ350]

..... that sharp 90* may not be the best for water flow. what do you guys think ? I kind of wanted to make the elbows removable but I haven't found anything other than the brass 90*.

341776 https://www.jegs.com/i/Aeroquip/023/FBM4032/10002/-1 these bolt onto a nipple that is threaded into the engine block.

Expensive but light and come in all sorts of sizes and look the bees knees too.

[Sandokan]

i made up some exh spigots. just alittle more work on the water jacketing at the side of the cyl and figure out some sort of water nipples near the exh exit. easiest for me would be some threaded weld on bungs then a brass 90* elbow screwed into the bung but that sharp 90* may not be the best for water flow. what do you guys think ? I kind of wanted to make the elbows removable but I haven't found anything other than the brass 90*. I guess i could probly make a bit of a radiused elbow with a bunch of pie cut tube welded together

https://www.siliconhoses.com/search?q=silicone+hose+bends

[wobbly]

A welded on bung with a right angle 8mm hose tail on each spigot end going up to hose tails screwed into the triangle outlet
piece in the head will flow more than enough water imho.
Of more concern is the hopeless water flow regime from the factory.
You need to change it with all the cold water entering the cylinder in the middle at the rear.
Then using a lasercut "gasket " that forces all that flow to travel around each liner above the transfer tops.Then up into the head
at the front , flowing around the inserts and exiting the head cover at the rear highest point.
The trapped water at the highest point in the cylinder rear needs a couple of small bleed holes to allow air to escape into
the head.
Makes the system self bleeding , and uses the coldest water to cool the transfers.

[F5 Dave]

What, as opposed to a bucket with a 2 holed lid and a weak hose pushed in one and outlet in the other,?

If it was good enough for Kenny Roberts' 3rd uncle. . .:scooter:

[TZ350]

341783

I have been fighting a bit of a battle with the PesudoMAP sensor. The issue is that the PesudoMAP value drops away over 8,000 RPM or so as seen in the picture above (Yellow line). Currently my code can make a sensible reading every 8 deg at 13,000 RPM and with a bit of clever coding it could make a reading every 2 deg. 8 deg is good enough for the three high pressure readings I make at 15 deg intervals. 115, 130, 145 deg ATDC.

341782

So I put the oscilloscope on the crankcase pressure sensor tonight, purple line, yellow line is the ignition pulse. I wanted to see what sort of signal it produced and what it looked like compared to EnginMod's prediction. Pretty close I recon. The next move is to try and capture a trace at 12,000 rpm.

I have been having problems with the MAP value dropping away above 8,000 RPM and suspect either the pressure sensor is not keeping up or the speed of response from it is so slow that the indicated pressure peak moves away from my last measuring point at 145 deg ATDC.

341781

[peewee]

A welded on bung with a right angle 8mm hose tail on each spigot end going up to hose tails screwed into the triangle outlet
piece in the head will flow more than enough water imho.
Of more concern is the hopeless water flow regime from the factory.
You need to change it with all the cold water entering the cylinder in the middle at the rear.
Then using a lasercut "gasket " that forces all that flow to travel around each liner above the transfer tops.Then up into the head
at the front , flowing around the inserts and exiting the head cover at the rear highest point.
The trapped water at the highest point in the cylinder rear needs a couple of small bleed holes to allow air to escape into
the head.
Makes the system self bleeding , and uses the coldest water to cool the transfers.

thats great idea but with sqaushed cylinders its hard to have much water on that side. whats worse still is most of the water jacket is filled with weld to let the aux ports go to near bore center. ill do the best i can and that will have to be good enough:laugh:

[jonny quest]

Is there a thread with dyno pictures? I'm thinking of building a inertia rear wheel dyno that also will run off counter sprocket for an engine stand. Curious to what others have done.

TZ, can you slow down the sampling rate. Just for a test to view trace? Or is sensor itself just not fast enough? Would 2 sensors measuring same pressure and average be useful?

[husaberg]

Is there a thread with dyno pictures? I'm thinking of building a inertia rear wheel dyno that also will run off counter sprocket for an engine stand. Curious to what others have done.

TZ, can you slow down the sampling rate. Just for a test to view trace? Or is sensor itself just not fast enough? Would 2 sensors measuring same pressure and average be useful?

Yes...........
https://www.kiwibiker.co.nz/forums/showthread.php/178284-DIY-dyno
prob here also
https://www.kiwibiker.co.nz/forums/showthread.php/141672-YLR-Racing?highlight=dyno

there more but it must be in buried in other threads

if you look in wobbly's pic near the start there is a pic go to that post.
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130542420#post1130542420

[Carel H]

341782

So I put the oscilloscope on the crankcase pressure sensor tonight, purple line, yellow line is the ignition pulse. I wanted to see what sort of signal it produced and what it looked like compared to EnginMod's prediction. Pretty close I recon. The next move is to try and capture a trace at 12,000 rpm.

Looks like a slow sensor. 4000 rpm/min / 60 seconds = 66.6 rps (revolution per second). Scope shows 11 sample changes with the same increment/decrement in that period.
11 * 66.6 = 733 changes per second. (responsetime 1.4 msec). At 12000 rpm this will be ~4 samples per period.

There is no peak, just increment/decrement, so there is a dampening. I guess the swing will increase with decreasing rpm.

[TZ350]

341789


Looks like a slow sensor. 4000 rpm/min / 60 seconds = 66.6 rps (revolution per second). Scope shows 11 sample changes with the same increment/decrement in that period. 11 * 66.6 = 733 changes per second. (response-time 1.4 msec). At 12000 rpm this will be ~4 samples per period. There is no peak, just increment/decrement, so there is a dampening

Many thanks for your comments. I have no previous experience with this sort of pressure sensor so I was not sure what I was looking at. But sure was not expecting discreet steps, I was expecting a more analog signal from the pressure sensor. I have no trouble making software reads at the right time in the crank cycle but four distinct steps at 12,000 RPM from the pressure sensor may not be a very good representation of the pressure cycle in the crankcase.

Anyway if I can I will try and get a picture of what the pressure sensors output looks like at 12,000 rpm, this might take a night or two. And when I have a test setup that makes good traces then I can search/test for a sensor that better suites what I am trying to do.

[TZ350]

341791 Low RPM

341792 Higher RPM

I still have not been able to make a definitive trace at 12,000 rpm yet, Crap fuel mapping issues. But it is becoming obvious that I will need to take the high pressure reading at BDC and the low reading at TDC, so that is helpful to know.

[sispeed]

Hello. I'm building a Aprilia RS250 for Race use and I like to use spark plugs like the r7376. Original it is a BR10ECMIX and this one is a little bit shorter.
Do you know of any alternatives to the original type in R7376 Style with the thin ground electrode?
Thank you
Regards Siggi

[TZ350]

341796 341797

Engine Mods crankcase pressure simulation and a trace taken at much the same conditions. The trace is certainly recognizable from the simulation. Unfortunately the slow speed of the crankcase pressure sensor distorts the trace at higher RPM but I think that once I know that the trace is consistent and what its shape looks like I will be able to adjust my software to use it.

341798

As the RPM increases the number of pressure points decreases and I am sort of expecting that there will be 3 at 12,000 and maybe only 2 at 13,000 RPM. I think I will still be able to work with 2 so long as they are consistently the highest and lowest reading and always appear in the same place.

341799

Plan "B" is to use a Ceramic Piezo. These are very dynamic and give off a proportional voltage as long as the pressure on its face is changing. So it might give a fast and continuously analog signal. Anyway that is plan "B" if I need it.

[Carel H]

341796 341797

Engine Mods crankcase pressure simulation and a trace taken at much the same conditions. The trace is certainly recognizable from the simulation. Unfortunately the slow speed of the crankcase pressure sensor distorts the trace at higher RPM but I think that once I know that the trace is consistent and what its shape looks like I will be able to adjust my software to use it.

341798

As the RPM increases the number of pressure points decreases and I am sort of expecting that there will be 3 at 12,000 and maybe only 2 at 13,000 RPM. I think I will still be able to work with 2 so long as they are consistently the highest and lowest reading and always appear in the same place.

341799

Plan "B" is to use a Ceramic Piezo. These are very dynamic and give off a proportional voltage as long as the pressure on its face is changing. So it might give a fast and continuously analog signal. Anyway that is plan "B" if I need it.

I had a look on an MAP sensor, the functional block describes how it "slices" at 1khz and explains the not connected steps in your scope photos. The speed is there, but not the conversion speed. I already suspected it, there must be a conversion somewhere in the sensor.

Have a look at page 11, look at the A/D conversion, correction, D/A conversion, then look at your scope and see the handicapped potential.

https://www.infineon.com/dgdl/Infineon-KP214N2611-DS-v01_00-en.pdf?fileId=db3a30432ad629a6012af6ab37f00b3a

So an alternative is to work more near the component level with the Freescale MPX or Honeywell pressure sensors.
They convert pressure into an analog signal. Period.

Piezo transducers and pressure sensors are close family. But the piezos work at a resonant frequency and they need a very good designed housing to work properly. In my opinion a can of worms.

[Niels Abildgaard]

12000 rpm is 200 rps and with ten points per cycle to get reasonable measurements You are in 2kHz michrophone country.
Condenser michrophones can be very cheap and unlinear but that is not a problem here methink.

[katinas]

Hello. I'm building a Aprilia RS250 for Race use and I like to use spark plugs like the r7376. Original it is a BR10ECMIX and this one is a little bit shorter.
Do you know of any alternatives to the original type in R7376 Style with the thin ground electrode?
Thank you
Regards Siggi

Hi
Tested some different spark plugs on RGV 250 ( like RS 250 ), and looks like with standard angled spark plug head and std. ignition (SAPC 22D30, 23D00), non resistor plugs add some power.

Non resistor std. hex plugs
Denso IW06 ( iridium-platinum thin )
NGK R5184 ( gold palladium-platinum thin)
NGK R6061 ( nickel alloy- nickel alloy standard ground, but spacial conical inside shape and ground electrode position, maybe is very eligible for std, complicated, head with angled spark plug)

With modified straight plug position head and adjustable ignition ( ignitech, zeeltronic) on RGV/RS, resistor plugs like NGK R7376 or short R7282 with TRS 1225 cap. is very good.

With thin platinum ground electrode, on Denso is possible to adjust gap, NGK not.

[wobbly]

The R7376 is a "normal " insulator length plug ( and thus uses a cheap 5K plugcap ).
It has an iridium fine wire center electrode and a Platinum fine wire ground electrode.
This is identical to the Honda RS125/250 NGK plug R7282 in its nose configuration but the Honda version is a short insulator type.
The Honda plug is 4x the price and the special plugcap costs more than the plug.
Its also available with longer threaded body to enable use of an under plug deto sensor.
Is there no room for the longer/cheaper R7376.

[TZ350]

341801

Ok, not quite 12,000 RPM but it tells me everything I need to know. That the signal is consistent and instead of measuring at the theoretically correct crank angles I can allow for the delay in the sensor and measure the crankcase high pressure at BDC and the low pressure at TDC. Easy as.

[sispeed]

Hello Katinas and Wobbly. I managed, with a little fiddling, to install them.
So I think this should be fine.
Thanks for Reply and hints.
I have straight Head inserts but Std Ignition at the moment

Regards Siggi

[Flettner]

TM and I thank those that assisted in trying to stop KTM patenting TPI. It seems their application has been turned down by the patent office.

[DoldGuy]

TM and I thank those that assisted in trying to stop KTM patenting TPI. It seems their application has been turned down by the patent office.

Flettner, Do you know “Why” they were denied? If so, did your previous design, installed & working have an effect?

[Flettner]

Flettner, Do you know “Why” they were denied? If so, did your previous design, installed & working have an effect?

Beeing that KTM copied theTPI YZ, I think so.

[TZ350]

KTM patenting TPI. It seems their application has been turned down by the patent office.

Shit Hot .......... :2thumbsup

Now to make sure they can't steel the PesudoMAP concept and patent it, of seeing changes in airflow through a 2S motor by measuring the difference between high and low pressures in the crankcase.

I think Flettners idea of measuring the crankcase pressure was first published for the World Wide Web here on KiwiBiker.


Well actually it was Flettners original idea to measure the crankcase pressure at a set point. He suggested a sample and hold approach and tried it with a small rotating valve timed to the peak crankcase pressure. It showed promise on his 360. I am just trying to refine it a bit by using a small PLC.

[TZ350]

<iframe width="560" height="315" src="https://www.youtube.com/embed/xX6_LlXtt48" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>

Fuel Injected 500cc V4 two stroke Ronax Road Racer. http://www.ronax500.com/en/

For sensing mass air flow I think they are using a MAF sensor on the entry to a large airbox. Would love to know more if anyone has info.

<iframe width="560" height="315" src="https://www.youtube.com/embed/6qNcttBSw9Y" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>

<iframe width="560" height="315" src="https://www.youtube.com/embed/f9hJ13eq3qo" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>

[TZ350]

<iframe width="560" height="315" src="https://www.youtube.com/embed/kj9-6B3XPls" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>

Another fuel injected 500cc V4 twostroke. The Suter at the Isle of Man TT

<iframe width="560" height="315" src="https://www.youtube.com/embed/FRJy-DEsLjs" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>

<iframe width="560" height="315" src="https://www.youtube.com/embed/QCkwxTxvOeI" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>

[Niels Abildgaard]

Shit Hot .......... :2thumbsup

Now to make sure they can't steel the concept and patent it, of seeing changes in airflow through a 2S motor by measuring the difference between high and low pressures in the crankcase.

I think Flettners idea of measuring the crankcase pressure was first published for the World Wide Web here on KiwiBiker.

A better way is to measure airflow/velocity throuh a scavenge channel during the first half of the scavenge period,start fuel injection and calculate when to stop.
Measuring airflow 2kHz variation is piece of cake with hot wire anemometry.

[husaberg]

A better way is to measure airflow/velocity throuh a scavenge channel during the first half of the scavenge period,start fuel injection and calculate when to stop.
Measuring airflow 2kHz variation is piece of cake with hot wire anemometry.

it could also measure the same air flow more than once.

https://www.youtube.com/watch?v=KcNfci9OruU

[TZ350]

A better way is to measure airflow/velocity through a scavenge channel during the first half of the scavenge period,start fuel injection and calculate when to stop. Measuring airflow 2kHz variation is piece of cake with hot wire anemometry.

I would sure like to know more.

But there are some issues. As well as the air reversal issue Husaburg mentions. There is also the fire that comes back down the transfer ducts when the engine is over revved and at times the injection cycle is 80 - 90% of the crank cycle. The primary injectors duty cycle goes out to 80 - 90% before swapping to the secondrys which also may go out to 80 - 90% at peak load. In the "B" port the injector would squirt raw fuel over the hot wire but the idea could be made to work in the "A" ports. As an aside, the longer the injectors are on the better the motor seems to run. The motor seems to run best when the injectors are on for long enough to cover the whole of the transfer port open time.

341811

Hot wire. It is something worth thinking about, there may be a way to use it. I will look into it, thanks.

[Kiwiagbike]

Well that's most helpful and makes sense regarding jetting in respect to the CHT & EGT relationship.

[Norman]

Shit Hot .......... :2thumbsup

Now to make sure they can't steel the concept and patent it, of seeing changes in airflow through a 2S motor by measuring the difference between high and low pressures in the crankcase.

I think Flettners idea of measuring the crankcase pressure was first published for the World Wide Web here on KiwiBiker.

Look at the abstracts on the attached patents. You can find the docs by google the number. Patent text can include a lot of info and text, however, first claim is what counts the most and very important (1.) and then the rest of the claims. A patent engineer can help to possibly come around it if your design is close and the intent is to go market. It could perhaps cost a couple of $300-500 to get a first opinion. One of them is an application for US patent but i believe it already has a granted French patent.

[TZ350]

A patent engineer can help to possibly come around it if your design is close and the intent is to go market.

No, my intent is not to bring something to market but to publish as much detail as I can about a practicable working arrangement so that it is public knowledge and that way prevent someone else from locking up knowledge and slowing the development of a new era of two stroke development. I wanted to make anything useful I might find available to anybody who could use it.


Look at the abstracts on the attached patents. You can find the docs by google the number. Patent text can include a lot of info and text, however, first claim is what counts the most and very important (1.) and then the rest of the claims.

Thank you for the Patent's. It tells me a lot about where things are at currently.

Some of the ideas are close to mine. Reading what they claim and based on my experience I doubt any of them have a working example. They leave out key important facts that are necessary to know for success. You would un-avoidably run into these issues if you try what they claim so I think they are just guessing.

The race is on to get the information out there as general knowledge before someone can lock it up.

[Norman]

No, my intent is not to bring something to market but to publish as much detail as I can about a practicable working arrangement so that it is public knowledge and that way prevent someone else from locking up knowledge and slowing the development of a new era of two stroke development. I wanted to make anything useful I might find available to anybody who could use it.



Thank you for the Patent's. It tells me a lot about where things are at currently.

Some of the ideas are close to mine. Reading what they claim and based on my experience I doubt any of them have a working example. They leave out key important facts that are necessary to know for success. You would un-avoidably run into these issues if you try what they claim so I think they are just guessing.

The race is on to get the information out there as general knowledge before someone can lock it up.


I am glad to hear that these are likely not to any problem for your hard efforts. I was just a bit worried for a moment.:sweatdrop

[TZ350]

.
They are good to see, it means people are still thinking about two strokes. :sunny:

[TZ350]

341823 Flettners YZ250 "B" port injection cylinder.

Actual video clip of the YZ being ridden, May 2013 ..... https://youtu.be/hOGZ5llowoU .... check out video's by <yt-formatted-string id="owner-name" class="style-scope ytd-video-owner-renderer" has-link-only_="" style="--yt-endpoint-color:var(--yt-channel-owner); --yt-endpoint-hover-color:var(--yt-channel-owner); font-size: 1.4rem; line-height: 1.6rem; color: rgb(0, 0, 0); font-family: Roboto, Arial, sans-serif;">GerbilGronk (https://www.youtube.com/channel/UCoYhqhrdK9On_IfKGD31hGA) on YouTube.</yt-formatted-string>

KTM first reveled their EFI bike in May 2017.

The first person I know of to post anything about "B" transfer port injection was Flettner.

When KTM saw it they told him they were going to do something more sophisticated but after messing about for a long while and wasting a lot of time they eventually adopted Flettners idea then the cheeky buggers tried to patent it as their own.

341822 341824

https://transmoto.com.au/ktm-two-strokes-engine-development/

https://dirtbiketest.com/fresh-dirt/two-stroke-fuel-injection-ktms-path-to-tpi/#E38d07FCRK6YAG4u.97


KTM patenting TPI. It seems their application has been turned down by the patent office.

[husaberg]

341823 Flettners YZ250 "B" port injection cylinder.

The first person I know of to post anything about "B" transfer port injection was Flettner.

When KTM saw it they told him they were going to do something more sophisticated but after messing about for a long while and wasting a lot of time they eventually adopted Flettners idea then the cheeky buggers tried to patent it as their own original idea.

341822 341824

https://transmoto.com.au/ktm-two-strokes-engine-development/

There is a better article than that it was Synject that did most of the work for KTM they were part owned by Orbitial.

Synject has been sold to a large US tech firm that does anti lock brakes etc.
https://dirtbiketest.com/fresh-dirt/two-stroke-fuel-injection-ktms-path-to-tpi/

[ken seeber]

341835341836

[Flettner]

Ken, you will have to trade it on a TM now😆.

[Flettner]

At least TM are good enough to send me one😆.

[Frits Overmars]

At least TM are good enough to send me one😆.I'm happy for you, Neil. By the way, how are TM-gearboxes?

[Flettner]

Haven't sampled it yet. Do they have a problem? It is just a 125, interestingly.

[Frits Overmars]

Haven't sampled it yet. Do they have a problem? It is just a 125, interestingly.I don't know about any problems. I was asking because you always seem to struggle finding Yamaha gearbox parts and I thought your Italian friends might have a solution.

[philou]

Vforce Reed valve on Honda Nx4. Breaks every 2 races. An idea ?

341850

[Haufen]

Vforce Reed valve on Honda Nx4. Breaks every 2 races. An idea ?

341850

turn the little metal bar which keeps the plates in place around (set stiffness from low to high).

[dtenney]

turn the little metal bar which keeps the plates in place around (set stiffness from low to high).
That is pretty ugly. It looks like something is not agreeing with the resin. I had heard that V-Force may have changed resin at somepoint over the last year or 2. We were having some problems with reed delamination/chipping about a year ago but nothing to the extent that you are seeing. Today we are still getting some chipping at the reed tips.....we are running methanol not gasoline.

[peewee]

wob you can see the cooling will be complete shit but since its not a road going petrol engine im not losing any sleep over it. with a small bit of grinding I got barely .5mm air gap between the cyl :woohoo:. just have to weld on the water bungs then off to the machinist and straighten out the decks

[peewee]

I found this yesterday but it gives some idea of how much flow is reduced with elbows in the cooling lines
https://www.ekwb.com/blog/do-angled-adapter-fittings-really-reduce-flow/

[Flettner]

That is pretty ugly. It looks like something is not agreeing with the resin. I had heard that V-Force may have changed resin at somepoint over the last year or 2. We were having some problems with reed delamination/chipping about a year ago but nothing to the extent that you are seeing. Today we are still getting some chipping at the reed tips.....we are running methanol not gasoline.

V force told me their reeds were not compatible with ethanol, perhaps its the same with methanol.
You need a steel rotary valve😆

[teriks]

V force told me their reeds were not compatible with ethanol, perhaps its the same with methanol.
You need a steel rotary valve��
Well, given that methanol is normally more aggressive than ethanol to epoxy resins, that's most likely true.

[Grumph]

Well, given that methanol is normally more aggressive than ethanol to epoxy resins, that's most likely true.

Drop one of your broken ones in some of your fuel mix. Post pics please.....

[peewee]

hey guys on the yami twin theres a small hose from the head to top of rad. im guessing this is a self air bleeder like the bleeder screw found on most other heads. what im not sure of is if its only purpose is just for the first time the system is filled and after that its useless. ?

[TZ350]

hey guys on the yami twin theres a small hose from the head to top of rad. im guessing this is a self air bleeder like the bleeder screw found on most other heads. what im not sure of is if its only purpose is just for the first time the system is filled and after that its useless. ?

I have something similar on my bike. It continuously runs a small amount of water from the head to the radiator and takes any evolved air/gas leakage with it. As well as being easy to bled the head, it Leaves me confidant I am not going to wind up with an air/gas pocket at the back of the head. It is a piece of mind thing.

[41juergen]

hey guys on the yami twin theres a small hose from the head to top of rad. im guessing this is a self air bleeder like the bleeder screw found on most other heads. what im not sure of is if its only purpose is just for the first time the system is filled and after that its useless. ?

And during cold start, when the thermostat is still closed, it might reduce a bit the water pressure when slightly reving up the engine...?

[jbiplane]

Thank you for the Patent's. It tells me a lot about where things are at currently.

Some of the ideas are close to mine. Reading what they claim and based on my experience I doubt any of them have a working example.
Stihl and Husqvarna both sucseed in fuel injection on disk saw STIHL TS 500i
This year they will start STIHL MS 500i
What ideas and algorithms used unclear. Both companies have few EFI related patents...
May be good idea reverse engineer one of those EFI ?

[F5 Dave]

So, . . What sort of throttle response is required on a saw?

[Grumph]

So, . . What sort of throttle response is required on a saw?

Suburbanite....Response should be at least equal to the best bikes, preferably better. With no flat spots or hesitancy.
Instant return to a steady idle is a prerequisite too.

[wobbly]

The VF2 was not designed for the NF4 , it was a CR125 part that also fitted the TM125MX.
But it made better power than the NF4 reeds and way better than the later VF3.
In the race bike the outers hit the case .
The petals are too thin , and the 1st mode resonance is too low for running to over 12,000 all day.
I got Tassinari to make special petals with biased carbon weave , that solved the issue running a TM125MX to 13,000 all day.

[jasonu]

So, . . What sort of throttle response is required on a saw?

Instant!!!

[TZ350]

341855


Stihl and Husqvarna both sucseed in fuel injection on disk saw STIHL TS 500i This year they will start STIHL MS 500i What ideas and algorithms used unclear. Both companies have few EFI related patents... May be good idea reverse engineer one of those EFI ?

I would love to know more about Stihl performance, peak torque rpm, bmep etc; and anything about Stil's EFI and how they arrange the injector(s).

My own experience has lead me to believe that you can successfully fuel inject any two stroke using the common Alpha-N topology. Unless the motor is heavily reliant on symbiotic pipe resonance for its power, like a Honda RS125 or Aprilia road racer. Because when you throttle off, the pipe resonance collapses and so does the airflow. Current 2S EFI systems don't cope well with dramatic changes in pipe suction.

Currently there is no proven method I know of that can detect this change of airflow in a high performance single cylinder racing two stroke. So you get very poor EFI throttle response with racing single cylinder two strokes that are producing more than 10 bar BMEP. Anything less than 10 bar BMEP should be relativly easy to fuel inject and get good throttle response. The lower the BMEP the easier it will be to fuel inject successfully. And because it's a time thing, over 9-10,000 rpm you will also need staged injection.

I expect exhaust pipe induced air flow does not change much in industrial two strokes, making it much easier to map the industrial 2S EFI for good throttle response.

[husaberg]

So, . . What sort of throttle response is required on a saw?

Hand in Your Kiwi Bloke id immediately. Anyone lucky enough to have ever seen Ron Hartill use one to carve stuff you would know what a Chainsaw can do.
http://stoppress.co.nz/media/VERSIONS/blog/2013/10/screen_shot_2013-10-17_at_4.37.28_pm_1200x1200.png
In the Bloke code its written Most blokes would rather lend out their wife than their Chainsaw.

They also need to work on any angle or way up, thats why they have a pumpercarb. Like a KT100S

[F5 Dave]

Well funnily enough I'm in turangi cleaning out dads Bach of 35 years. I've left behind a realatively new McCulloch chainsaw . I'd just rather use a lithium saw. Too scared of chainsaw.
As far as the Kiwi man card goes, tell them to turn up with 2 slick shod 50cc racers and see of they can beat me around any track despite my doting years
Good luck with that.

[husaberg]

Well funnily enough I'm in turangi cleaning out dads Bach of 35 years. I've left behind a realatively new McCulloch chainsaw . I'd just rather use a lithium saw. Too scared of chainsaw.
As far as the Kiwi man card goes, tell them to turn up with 2 slick shod 50cc racers and see of they can beat me around any track despite my doting years
Good luck with that.

Can you beat Av?:scratch:

[jbiplane]

So, . . What sort of throttle response is required on a saw?

Stihl report chain acceleration from 0 to 100km/h for amazing 0.25 seconds :)

[speedpro]

I don't know, but I suspect there will be a centrifugal clutch in there somewhere. So - engine revs to ??,000rpm and then clutch grabs. The engine doesn't pick up that fast, just the clutch.

[F5 Dave]

And further not what speed of acceleration but how controlled?

[F5 Dave]

Can you beat Av?:scratch:

I might have had a drink last night and been spouting bile.

If we can change the question to have I beaten Av before? Yes. When she was a kid. On occasion I've also beaten Jay and Sketchy and a whole raft of other teenagers (who grew up and would now wipe the floor with an old man).:laugh:

[TZ350]

Stihl report chain acceleration from 0 to 100km/h for amazing 0.25 seconds :)


I don't know, but I suspect there will be a centrifugal clutch in there somewhere. So - engine revs to ??,000rpm and then clutch grabs. The engine doesn't pick up that fast, just the clutch.

Agreed, it is all about the clutch. Idle speed is 2,500 rpm so the flywheel inertia at whatever speed the clutch takes up would accelerate the chain quite quickly. Still amazing though, and frightening.

[TZ350]

If we can change the question to have I beaten Av before? Yes. When she was a kid.

I have beaten Av before too, when I was chasing her and she fell off in the rain. I felt conflicting emotions about feeling pleased to have beaten a 13 year old girl who had just bounced along the track... :crazy:

[Frits Overmars]

I have beaten Av before too, when I was chasing her and she fell off in the rain. I felt conflicting emotions about feeling pleased to have beaten a 13 year old girl who had just bounced along the track... :crazy:I know the feeling. In my first 500cc race the guy I was chasing fell off and my first thought was: "One down, only about 20 to go".
My second thought, about one second later, was: "Shame on me, one shouldn't think that way".
I suppose many of us have experienced similar feelings. Or is it just my twisted brain?

[Carel H]

341855

Because when you throttle off, the pipe resonance collapses and so does the airflow. Current 2S EFI systems don't cope well with dramatic changes in pipe suction.

Currently there is no proven method I know of that can detect this change of airflow in a high performance single cylinder racing two stroke.

Throttle is also an input and the trigger off an event.

[speedpro]

That's a good point. What about the reverse of an accelerator pump, or acceleration enrichment in FI terminology? A timed "reduction" in the calculated fuel when TPS changes from very low value to some other value. Long enough to kick the pipe back into life without drowning the motor.
Factors would be:
Amount of reduction, in %
Duration of reduction, in seconds
Slope of reduction, determined by the above, or simply on & off.

[F5 Dave]

I have beaten Av before too, when I was chasing her and she fell off in the rain. I felt conflicting emotions about feeling pleased to have beaten a 13 year old girl who had just bounced along the track... :crazy:

It's a win Rob. I've beat Dennis on my 50 he on a fast 100. There might have been reasons but I feel they aren't important.

[Lurifax]

So, . . What sort of throttle response is required on a saw?

My experince with chainsaws and felling a tree that the chainsaw is either ON or OFF. You allways use full power and keep throttle wide as you are cutting the tree. A sharp chain is also a must, if you sharpen it wrong the cut will turn either side and then you are halving the tree...

[JanBros]

My experince with chainsaws and felling a tree that the chainsaw is either ON or OFF.

indeed, it doesn't need "instant response". it just needs to run great at WOT, it must have good idle and it must respond well to "quickly opening the throttle" . It never has to respond well at smoothly opening the throttle after having being run with closed throttle at at "slowly descending revs halfway the rev-range"
what it does very bad is (or "dangerous for the engine") is run wthe the throttle "in between" as their pumper carbs do not have something to regulate the mixture at "half throttle". IBEA makes pumper carb's that have a seperate adjustment for that.

[F5 Dave]

So chainsaw fuel injection may be not a relevant model to follow for the racing motorbicycle.

[Grumph]

So chainsaw fuel injection may be not a relevant model to follow for the racing motorbicycle.

Depends if you count the X games bikes as racers....The abilty to run inverted and through extreme G loadings is certainly required there...
And from what I've seen, midrange control isn't an issue, LOL.

[wobbly]

When was the last time you powered into a tree cut at full throttle, backed right off with the chain still moving , then went back to 1/3 throttle
and expected it to react smoothly , such that your boots didnt loose grip with the ground .
The real issue though is that the so called " box " muffler reacts nothing like a tuned pipe during these transient response phases.

[SwePatrick]

V force told me their reeds were not compatible with ethanol, perhaps its the same with methanol.
You need a steel rotary valve😆

Newer V-force reeds sold lately is like rubberpetals when using them with methanol, no good.

[peewee]

if you want good reeds for methanol and nitro go to this place carbontech.com

[lohring]

We've built a lot of model boat racing 26 cc engines that started life on weedeaters. Like chain saws they run pumper carbs, can mufflers, and are either on or off in stock form. We want a tuned pipe engine with almost twice the power that can be throttled a little and idles well. A typical running start involves a slow speed approach to the line with a quick transition to full throttle. A lot of engines will die despite heavier flywheels and carb pop off tuning. Bored out stock carbs don't help with the pressure signal to the diaphragm either. We've even blocked passages with super glue in a Tillison carb to get a rich enough low speed mixture and a lean enough full throttle mixture.

I keep thinking that someone will build a simple fuel injection system that can be easily adjusted to overcome these issues. Even throttle body injection should be better. Probably cost keeps manufacturers from developing injection over carbs. I keep following the more sophisticated injection systems worked on here for hints. Meanwhile YS model pattern engines (https://www.centralhobbies.com/ysparts.php?id=43) run a very simple injection system with CD ignition.

Lohring Miller

[husaberg]

We've built a lot of model boat racing 26 cc engines that started life on weedeaters. Like chain saws they run pumper carbs, can mufflers, and are either on or off in stock form. We want a tuned pipe engine with almost twice the power that can be throttled a little and idles well. A typical running start involves a slow speed approach to the line with a quick transition to full throttle. A lot of engines will die despite heavier flywheels and carb pop off tuning. Bored out stock carbs don't help with the pressure signal to the diaphragm either. We've even blocked passages with super glue in a Tillison carb to get a rich enough low speed mixture and a lean enough full throttle mixture.

I keep thinking that someone will build a simple fuel injection system that can be easily adjusted to overcome these issues. Even throttle body injection should be better. Probably cost keeps manufacturers from developing injection over carbs. I keep following the more sophisticated injection systems worked on here for hints. Meanwhile YS model pattern engines (https://www.centralhobbies.com/ysparts.php?id=43) run a very simple injection system with CD ignition.

Lohring Miller

Lohring i posted a while ago mirco fuel injection stuff a university student was selling Pico or something.
https://www.popularmechanics.com/cars/hybrid-electric/a9263/the-20-device-to-replace-dirty-carburetors-15682450/
https://www.fastcompany.com/3004342/picospray-aims-fraction-emissions-fraction-cost
http://spark.annarborusa.org/features/Nov14Feature2.aspx

[TZ350]

<iframe width="560" height="315" src="https://www.youtube.com/embed/utakS4p3NOE" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

.................

[lohring]

Lohring i posted a while ago mirco fuel injection stuff a university student was selling Pico or something.
https://www.popularmechanics.com/cars/hybrid-electric/a9263/the-20-device-to-replace-dirty-carburetors-15682450/
https://www.fastcompany.com/3004342/picospray-aims-fraction-emissions-fraction-cost
http://spark.annarborusa.org/features/Nov14Feature2.aspx

Very interesting, but can you actually buy a unit? Their web site is under construction. I'll see if their email works.

Lohring Miller

[jasonu]

It's a win Rob. I've beat Dennis on my 50 he on a fast 100. There might have been reasons but I feel they aren't important.

Did he loan you a crank seal???<_<

[jasonu]

So chainsaw fuel injection may be not a relevant model to follow for the racing motorbicycle.

and I thought my Husky 460 Rancher was the business...
https://www.youtube.com/watch?v=so2N2PAtzgs

[Flettner]

Not a lot of feathering the throttle there.

[F5 Dave]

Did he loan you a crank seal???<_<

Pretty sure I replaced that. Or bought you a beer.

Or drank one in your honour. It's a fuzzy reality at best.

[Pursang]

Because when you throttle off, the pipe resonance collapses and so does the airflow. Current 2S EFI systems don't cope well with dramatic changes in pipe suction.

Currently there is no proven method I know of that can detect this change of airflow in a high performance single cylinder racing two stroke.

Because when you throttle off, the airflow collapses and so does the pipe resonance.

How about an unrestricted reed valve at the inlet, control the airflow (engine speed, rates of accel & decel) with metered fuel delivery and maintain pipe pressure & temp for instant response by throttling the chamber outlet. Forget about asking it what it really wants, instead, just tell it what you want it to do! ....:psst:

Cheers, Daryl.

[Frits Overmars]

How about an unrestricted reed valve at the inlet, control the airflow (engine speed, rates of accel & decel) with metered fuel delivery and maintain pipe pressure & temp for instant response by throttling the chamber outlet. Forget about asking it what it really wants, instead, just tell it what you want it to do!I think you just invented the Diesel Daryl.

[Pursang]

I think you just invented the Diesel Daryl.

The unrestricted inlet and the exhaust brake are Dieselly...:rolleyes:
The ability to out compression brake 4-strokes is a bonus, plus a great new 'noise' to frighten the horses.

The rest is still Otto.
There might be a couple of cycles of (potentially) exhaust contaminated or lean mixture on transition back to accelerate mode.
The FI could perhaps inject a little extra fuel initially, to manage this. (Just like an accell pump does)
A retarded spark or two and the rich mixture might quickly put some heat & pressure back into the pipe, to fire it up again.
The stinger throttle should not be direct by cable to the twist grip. It will really need its own control circuit monitoring things like:
Throttle position, RPM, pipe temp & pressure, brake activation & pressure , decell rate (G force) etc. (A fart by wire system).

Cheers, Daryl.

[lohring]

Exhaust throttles were once common in model boat race engines. The throttle was usually located at the beginning of the header. Sticking and leakage were problems. Recently stinger throttles were also tried. They seem to be equally effective without the header throttle problems. Users claimed that the throttle response was better than with conventional carbs. These engines run alcohol based high nitro (60+%) fuels so the exhaust temperatures are low. As far as I know they haven't been tried on gasoline engines.

Lohring Miller

341886341885341887

[Pursang]

Thank you for your interesting input Lohring.

I'm pleased to know that i'm not just 'brain farting' into the wind.

Cheers, Daryl

[flyincat]

TZ350 - this is probably a totally dumb idea, but what about using a pressure signal from the intake or exhaust to control fuel flow by manipulating the fuel pressure regulator? The collapse of resonance would reduce intake vacuum and reduce pipe pressure. If you could feed that pressure event to the regulator, wouldn't it help add another dimension to the fuel mapping? Of course, these would be average pressures so some sort of buffering would be needed to apply the average pressure to the regulator. Although it wouldn't be a complete solution, it might help some problem areas of the EFI tuning.

[TZ350]

TZ350 - what about using a pressure signal from the intake or exhaust to control fuel flow by manipulating the fuel pressure regulator?

That is not a bad idea.

It turns out that the collapse of pipe resonance allows the intake, crankcase and average pipe pressure to all increase to near atmospheric (0.95 bar or so). When the pipe is resonating well everything is at a lower working pressure (0.8 bar or thereabouts). The two stroke inlet manifold situation is totally different to a four stroke. When the pipe is not resonating and sucking air through the motor atmospheric pressure flows back in via the exhaust stinger and any other hole it can find. Piston pumping on a high performance two stroke (or any 2S) is virtually non existent compared to a four stroke.

[Pursang]

Piston pumping on a high performance two stroke (or any 2S) is virtually non existent compared to a four stroke.

OK, I see that with regard to braking. :facepalm: 2S is just compressing and expanding 'gas' above the exhaust port.
No matter what the actual pressure, the effect is pretty neutral.

A compression release on a 2S is effective because the compression work is lost, not returned.

In a 4S engine on overrun, the pressure is lost out the exhaust valve.
Probably even more effective as a brake with an open throttle and the ignition killed.

Cheers, Daryl

[TZ350]

341902

My plan is to measure the difference between the highest and lowest pressure in the crankcase each cycle and use the difference between these readings as an indication of relative changes in airflow through the motor. The more air, the bigger the difference.

Following pointers from other people, I have found that the pressure sensor transmits the pressure reading in discreet 1 ms steps, ie; every ms it transmits the current value for 1 ms. I thought it was going to be a continuous analog signal but nope, I was wrong about that. 1 ms steps it is, not sure but this might be quite a common approach.

341900

Checking with a scope near maximum rpm I am able to see a distinct high and low pressure reading for each crank cycle, so good to go with my plan.

Because the pressure transducer and TPS have relativly high output resistances I need to use an OP AMP voltage follower to supply enough current quickly enough to charge the capacitors in the analog input of the EFI's CPU for the CPU to read.

The EFI CPU reads an analog signal by allowing the analog voltage to charge a capacitor up and the CPU then times how long it takes to discharge. These capacitors have very little forward resistance so the signal source also needs to have little forward resistance to be able to charge the capacitor up in the time available. TPS's and MAP sensors don't, they have relativly high forward resistances and low current so I will need something like an OP Amp to follow the sensors signal voltage and output a low resistance high current signal to the CPU.

341901

My first efforts with an Op Amp were a bust. It took me a while to find out that an OP Amp has limitations. It is unable to completely swing to the extremes of the supply voltage. So a 0 to 5 Volt power supply is not good enough for a 0 to 5 Volt analog output. To get a zero Volt signal out you need a negative supply rail to the OP Amp. I have been able to find some tricky little DC DC converters that take +5V and converts the output to -5V so now using the bikes 12Volt system I will be able to jack up a -5V to + 12V supply for the Op Amp and get a good 0V to 5V analog signal out. Hopefully get to bench test this over the week end.

This is Buckets, you take a simple idea like EFI, leap in boots and all, find out how complicated it is to implement then learn a shit load along the way trying to make it work....... :D .... Love It.

[lohring]

Lohring i posted a while ago mirco fuel injection stuff a university student was selling Pico or something.
https://www.popularmechanics.com/cars/hybrid-electric/a9263/the-20-device-to-replace-dirty-carburetors-15682450/
https://www.fastcompany.com/3004342/picospray-aims-fraction-emissions-fraction-cost
http://spark.annarborusa.org/features/Nov14Feature2.aspx

Website under construction, no phone, no reply to email; I think they are not in business. I've checked out several other small two stroke throttle body injection systems as well. So far, no luck. I suspect they don't offer enough advantage over carbs and are higher cost.

The small IC engines are also in danger of being replaced with battery electric systems. That's pretty much happened in the under 15 cc model engine area and is creeping into even larger sizes as battery costs and weights go down. We'll see what happens with larger, low weight, high power applications.

Lohring Miller

[husaberg]

Website under construction, no phone, no reply to email; I think they are not in business. I've checked out several other small two stroke throttle body injection systems as well. So far, no luck. I suspect they don't offer enough advantage over carbs and are higher cost.

The small IC engines are also in danger of being replaced with battery electric systems. That's pretty much happened in the under 15 cc model engine area and is creeping into even larger sizes as battery costs and weights go down. We'll see what happens with larger, low weight, high power applications.

Lohring Miller

Battery weight stays the same regardless of charge where as fuel weight diminishes as fuel load decreases thus increasing range and performance.
Electric for planes doesn't make sense a lot of sense. unless you are talking servicing costs.

He had a lot of publicity. Shame.

[Carel H]

341902

My first efforts with an Op Amp were a bust. It took me a while to find out that an OP Amp has limitations. It is unable to completely swing to the extremes of the supply voltage. So a 0 to 5 Volt power supply is not good enough for a 0 to 5 Volt analog output. To get a zero Volt signal out you need a negative supply rail to the OP Amp.

Sounds like LM741. Try something like LM224. Single supply, nearly full swing. Full does not exist.

Trimpots for understanding amplification.
Study RC filters for frequency response.
And then: noise, what spoils it all.

Analog, when you thought you knew it all. Not.

[TZ350]

341908341909 160 mph in full flight down the hill and drum brakes, check out those battered and un muffled expansion chambers.

Team ESE was Bucket racing at Hampton Downs last Sunday where I meet up with Peter who was racing his FXR150. He rode air cooled Yamaha's at the IoM in the late 60's.

Maybe at only 160 mph down the hill the bikes were not quite as fast as the latest 200 mph super bikes of today but the pilots were just as brave. Real brave men who rode the flexi fliers back in the day and pushed them to their limits just like todays road warriors do. Back in the day they were getting them airborne over Ballaugh Bridge too. https://youtu.be/rpVABjI9-3w

<iframe width="560" height="315" src="https://www.youtube.com/embed/iRWp9rhfS_0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>

[TZ350]

Sounds like LM741. Try something like LM224. Single supply, nearly full swing. Full does not exist.

Trimpots for understanding amplification.
Study RC filters for frequency response.
And then: noise, what spoils it all.

Analog, when you thought you knew it all. Not.

Yes LM741, thanks for the heads up about LM224's and the suggested study. Being a newbee to this electronics stuff the suggestions are very helpful.

[Pursang]

This is Buckets, you take a simple idea like EFI, leap in boots and all, find out how complicated it is to implement then learn a shit load along the way trying to make it work....... :D .... Love It.

We Love that you Love it TZ. Your intelligent & persistent dedication and selfless sharing of your project is inspirational.:2thumbsup

cheers, Daryl.

[husaberg]

Can someone post the stud spacings on a RGV 250

I have a feeling its 90mm front and rear and 85mm between

[lohring]

Battery weight stays the same regardless of charge where as fuel weight diminishes as fuel load decreases thus increasing range and performance.
Electric for planes doesn't make sense a lot of sense. unless you are talking servicing costs.

He had a lot of publicity. Shame.

I'm talking about model boats and airplanes. My conversions don't weigh much more than the IC versions, but have considerably more power. I agree about full size planes that need to have significant flight time. However, electric trainers (https://electrek.co/2018/04/27/all-electric-trainer-plane-airworthiness-certification-faa-us/) have enough endurance for that job and cost a lot less to operate.

Lohring Miller

[katinas]

Can someone post the stud spacings on a RGV 250

I have a feeling its 90mm front and rear and 85mm between

Hi,

Yes, 90mm at front and at rear, but 82mm between.

[lodgernz]

team ese was bucket racing at hampton downs last sunday where i meet up with peter who was racing his fxr150. He rode air cooled yamaha's at the iom in the late 60's.



mgp 1969, tt 1970.

[guyhockley]

Don't know if it will work in NZ, but there's nearly ten hours of video from last week's NW200. No 2 strokes, though, sadly...

https://www.bbc.co.uk/sport/live/northern-ireland/48187693

[TZ350]

341915

Got my LM741 Voltage follower Op Amp working. For now I am using two 9V batteries for the + and - Voltages. If it works sorting out the unstable readings from the TPS then I will setup something more permanent with a DC-DC Positive - Negative Voltage converter. One's for Arduino and RaspberryPie's are cheap as chips.

341916 I have a couple of these tiny reverse voltage modules on order. Just the thing for my job.

341917 If you need a bit of positive/negative power there is lots of different versions of converters available from AliExpress.

[TZ350]

341918 Arduino Nano mini computer.

People have asked me why I have been positing this electrical/electronics stuff. Well these little computers and their associated devices like realays and PWM servo control and stepper motors means we can do some things much more easily that were not so possible before like:-

341919 Flettners idea of changing the rotatory valve timing on the fly.

341920 Frits's idea of opening the stinger when in over rev to reduce detonation caused by running out of Ex blow down time area.

341921 My idea of splitting the inlet into two channels and at low rpm closing one side off for better low end torque and carburation.

https://youtu.be/FeB9O6rtLXQ .... https://youtu.be/ar8YST2TYjQ

341922 The famous plenum idea could be developed to stay in resonance thereby greatly increasing power.

https://youtu.be/YxiEo8cgopg .... https://youtu.be/p4ef-WUO1Qs

341923 The expansion chamber pressure bleed was very effective at improving low end torque and carburation too.

These little computer chips and associated bits are so affordable they open up a lot of tuning possibilities and can be run from 12Volts or a small battery.

On the dyno the split inlet tract and chamber bleed both improved low end torgue and carburation. The plenum chamber was ride able and we took it around the track a few times but the biggest most exciting thing about it was there was a definite torque bulge when the plenum came into resonance. On the dyno the torque bulge was dramatic and if we could keep it in sync with the motor I think we could have something very effective.

If I get the EFI thing beat then I am coming back to these ideas that have shown real promise and going to incorporate them and have a little Arduino Nano control them all.

[TZ350]

<iframe width="560" height="315" src="https://www.youtube.com/embed/Cz2eUzmqEkQ" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>

Classic ........

<iframe width="560" height="315" src="https://www.youtube.com/embed/PlQx9eaKZ_w" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Crosby ........

<iframe width="560" height="315" src="https://www.youtube.com/embed/XpER8wWqDLo" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>

[Carel H]

People have asked me why I have been positing this electrical/electronics stuff. .

They took their time! Everybody hates electronics.

Another idea: servo controlled needle. Left rocker controls the needle.
The drawing shows the open and closed positions, so use a little fantasy.

[Frits Overmars]

Another idea: servo controlled needle.Been there, seen that, built by my mate Martijn Stehouwer (wwwe.emot.nl). Still, I'd prefer to go the whole way: a decent two-stroke injection system.
341936

[Carel H]

Been there, seen that, built by my mate Martijn Stehouwer (wwwe.emot.nl). Still, I'd prefer to go the whole way: a decent two-stroke injection system.


Concurrent ideas, different layout. There is always someone with the same idea. My drawing is from 2009.

It's a way to further develop a carburettor. These crude early last century fysic devices seem to have a large bandwith.

I also think that a "decent two stroke injection system" is possible, but my calculator says that a "decent high rpm two stroke injection system" is uncharted territory where time becomes a limitation.

[TZ350]

I'd prefer to go the whole way: a decent two-stroke injection system.

Me Too .....


I also think that a "decent two stroke injection system" is possible, but my calculator says that a "decent high rpm two stroke injection system" is uncharted territory where time becomes a limitation.

Definitely ....

341941 Big RPM means 341940 Increasingly limited time to get things done. At 15,000 rpm every thing has to happen in 4 ms.

An injector can take 2 ms to open and 0,5 ms to close so 1,5 ms at 15,000 rpm is not a lot of time to deliver a controlled amount of fuel.

At 15,000 plus rpm one might get away with alternating between two big second stage injectors. So that there is much more time for the controlled squirt to happen on one cycle and the opening and closing plus rest to happen on the alternate cycle. That way you might be able to get a controlled 3 ms squirt at 20,000 rpm.

For 13,000 rpm I run two staged TPI, transfer port injection. At 6,500 rpm my small injector is running at 6 ms and at 13,000 rpm the large injector is at 3 ms to deliver much the same amount of fuel in half the time.

[Flettner]

I see KTM have a 150 cc TPI out now, by all accounts is better than the carburetor previous.

[TZ350]

I see KTM have a 150 cc TPI out now, by all accounts is better than the carburetor previous.

Looks like Flettners original method of TPI is now being used successfully by KTM on their smaller bikes.

I have been unable to find any power/rpm specs for the KTM150, so not sure if they have ventured into the dark zone above 10,000 rpm / 10 bar bmep yet.

[TZ350]

Looks like the 2018 KTM 150 carburetor version runs in the dark zone so I guess we can assume the EFI version does too.

341943 https://thumpertalk.com/forums/topic/1251977-2018-sx150-dyno-results/

The Thumpertalk page talks about dyno testing a 2018 KTM SX150 but the dyno graphs are headed SX125, so not sure whats happening here.

341944 https://thumpertalk.com/forums/topic/1281939-19-sx-150-dyno-time/

Correct labels on this one. Looks like the 2019 EFI KTM 150 is well and truly running in the dark zone. ...... They must have solved the issues I am grappling with.

Flettners original TPI idea and KTM's commercialization of it. NZ brains and European money. High performance EFI two strokes ....:drinknsin

[monkeyfumi]

For the EFI application the cylinder features two lateral domes which hold the fuel injectors that supply fuel to the rear transfer ports. The downstream injection guarantees excellent atomization of the fuel with the upstreaming air. Thus, the loss of unburnt fuel is minimal, resulting in less emissions, a more efficient combustion and reduced fuel consumption. A small tube in the back of the cylinder is connected with an intake pressure sensor, which supplies pressure data to the control unit.

From here

https://www.ktm.com/en/enduro/150-exc-tpi/engine-exhaust

[koenich]

Not sure how the situation is in the US, but I imagine quite similar - the previous EXC models had not near the power delivery of a SX model in Europe.

[F5 Dave]

Looks like the 2018 KTM 150 carburetor version runs in the dark zone so I guess we can assume the EFI version does too.

341943 https://thumpertalk.com/forums/topic/1251977-2018-sx150-dyno-results/

The Thumpertalk page talks about dyno testing a 2018 KTM SX150 but the dyno graphs are headed SX125, so not sure whats happening here.

341944 https://thumpertalk.com/forums/topic/1281939-19-sx-150-dyno-time/

Correct labels on this one. Looks like the 2019 EFI KTM 150 is well and truly running in the dark zone. ...... They must have solved the issues I am grappling with.

Flettners original TPI idea and KTM's commercialization of it. NZ brains and European money. High performance EFI two strokes ....:drinknsin

Yeah last curve blie line it says STIC. That's an aftermarket needlejet tower for Keihin carb.

[husaberg]

Looks like the 2018 KTM 150 carburetor version runs in the dark zone so I guess we can assume the EFI version does too.

341943 https://thumpertalk.com/forums/topic/1251977-2018-sx150-dyno-results/

The Thumpertalk page talks about dyno testing a 2018 KTM SX150 but the dyno graphs are headed SX125, so not sure whats happening here.

341944 https://thumpertalk.com/forums/topic/1281939-19-sx-150-dyno-time/

Correct labels on this one. Looks like the 2019 EFI KTM 150 is well and truly running in the dark zone. ...... They must have solved the issues I am grappling with.

Flettners original TPI idea and KTM's commercialization of it. NZ brains and European money. High performance EFI two strokes ....:drinknsin
.......................

The Challenges: Initially, the TPI engines experienced flameouts because the exhaust pressure wave demanded a more sophisticated EMS that could perfectly manage fuel metering. When these refinements to the EMS were finally sorted, KTM knew they were onto a winner. And they promptly slapped an international patent on the TPI technology. A lot of sceptics said that, in principle, KTM would never be able to develop a fuel-injection system for two-strokes that would perform consistently well in all conditions. For example, when you ride through a creek that suddenly makes the exhaust pipe much cooler – a situation that a carburettor bike is ‘naïve’ to – then you need to find a way to override the information that the TPI bike’s EMS is receiving to ensure it continues to run properly. That’s just one example of the complexity and challenges that came with developing the TPI system’s mapping. But the TPI system was by far the best solution when it came to meeting KTM’s primary design objectives – which were to keep the power characteristics, feel and exhaust note of the TPI models as close as possible to the carburetted engines.
https://transmoto.com.au/ktms-two-stroke-efi-how-it-evolved/

[Flettner]

KTM's patent has been denied, they didn't invent it.

[husaberg]

KTM's patent has been denied, they didn't invent it.

I thought they were referring to the specific ECU they used which they didnt invent or even develop either:laugh:

[FastFred]

.
Flettner was the original inventor and the first to demonstrate a working ride-able TPI transfer port injected two stroke.

[FastFred]

.

""Initially, the TPI engines experienced flameouts because the exhaust pressure wave demanded a more sophisticated EMS that could perfectly manage fuel metering.""

Looks a lot like the issues TZ350 has faced with his project.


A small tube in the back of the cylinder is connected with an intake pressure sensor, which supplies pressure data to the control unit. https://www.ktm.com/en/enduro/150-exc-tpi/engine-exhaust

Also looks a lot like the solution Flettner proposed and TZ350 has been working on.

TZ350's idea is to measure the crankcase high and low pressure and use the changes in the difference between them as a measure of the changes in air flow through the motor. Air flow being greatly influenced by the action of the pipe.

[husaberg]

.


Looks a lot like the issues TZ350 has faced with his project.



Also looks a lot like the solution Flettner proposed and TZ350 has been working on.

TZ350's idea is to measure the crankcase high and low pressure and use the changes in the difference between them as a measure of the changes in air flow through the motor. Air flow being greatly influenced by the action of the pipe.

Maybe its more important to simply know if its a high or low value rather than what the value actually is.That would solve the speed limitations of the current electronics.
Or maybe reading every 2 or 4th revolution for the crankcase is actually enough?

[jbiplane]

Me Too .....
...
At 15,000 plus rpm one might get away with alternating between two big second stage injectors.


Stihl and Husqvarna smootly meter correct ammount or fuel in crankcase neglecting high rpm. Their ugly crankshafts smashed fuel drops better than nozzles.

I had as well small 3w UAV engine with EF* It have simple fuel pump with 2 microscopic gears. ECU regulate pump rpm. Worked perfectly.

Both solutions dont required high presure pumps, pressure regulators, numerous tubes and sensors.

For me adopting of cars EFI to small 2-strokes sometimes looks like fitting saddle on a cow :)

[TZ350]

For me adopting of cars EFI to small 2-strokes sometimes looks like fitting saddle on a cow :)

When Regina Mayer couldn't have a horse, the 15-year-old saddle trained a cow called Luna. https://caveviews.blogs.com/cave_news/2011/04/a-15-year-old-german-girl-saddle-trained-her-cow-luna.html

341945

A very clever cowgirl ...... :laugh: ..... if you have a passion, you do what you have to do.

[wobbly]

TeeZee , the comment about ignoring the absolute value , just measure the delta between high and low values is a valid one.
This was the beakthru used in Dr Longdills thesis I supervised at AK Uni where he used two fibre optic detectors in the combustion
chamber to measure two differing wavelengths of flame colour.
The difference in the two intesities was not affected by the absolute values , and this was used to measure the burning flames A/F ratio and correct
the output of the injection ECU.
It fixed the issue of " sooting " on the detector surfaces changing the values of light intensity measurements.
The system worked perfectly , but ultimately needed another input to correct the erroneous colour information that occured during detonation events.

[Grumph]

Stihl and Husqvarna smootly meter correct ammount or fuel in crankcase neglecting high rpm. Their ugly crankshafts smashed fuel drops better than nozzles.

I had as well small 3w UAV engine with EF* It have simple fuel pump with 2 microscopic gears. ECU regulate pump rpm. Worked perfectly.

Both solutions dont required high presure pumps, pressure regulators, numerous tubes and sensors.

That sounds a lot like Hilborn injection with the pump speed/output electronically regulated. I'm assuming from your description it's constant flow ?

[TZ350]

TeeZee , the comment about ignoring the absolute value , just measure the delta between high and low values is a valid one.

Yes, it is my intention to only measure the delta between high and low, then multiply it by a simple correction factor to increase its magnitude to something similar to what a regular four stroke MAP value would be.

That way I can use regular common after market four stroke type EFI CPU units and mapping. It has taken a bit of work to figure out how to do this, not quite there yet but I feel I am closing in on it.

[TZ350]

341948

On my GP/NSR110 3 times Delta crankcase pressure roughly equals the MAP reading you would expect to see from a four stroke's inlet manifold.

341950

This is an actual scope reading at about 11,500 rpm of a MAP sensor reading the crankcase pressure of my GP/NSR110. The yellow spikes are the ignition trigger pulses.

The purple steps are the sensors output each milli second. The sensor outputs its last (averaged??) reading every milli second for a milli second, hence the steps.

It is easy to see that the low pressure is around TDC and the high pressure at BDC as seen by this pressure sensor. I think processing delay shifts the timing from reality a bit. But that is not a problem as it is consistent.

My mission is to capture the readings with my Arduino Nano, process them and then pass a pseudo MAP reading to the EFI's CPU.

The Arduino Nano can easily take the two readings required every cycle, in fact it takes three high and three low and picks the best. Then averages them over ten readings, finds the delta and multiplies it by 3 and finally outputs it as an analog pseudo MAP reading. I have successfully simulated the fluctuating crankcase pressure and tested the pseudo MAP software on the scope to 15,000 rpm.

Technically simple to do but it is just taking me a bit of time to achieve it in reality on my bike.

I think KTM have got it sorted and are doing something similar on their latest EFI 2S bikes.


A small tube in the back of the cylinder is connected with an intake pressure sensor, which supplies pressure data to the control unit. .... https://www.ktm.com/en/enduro/150-exc-tpi/engine-exhaust

[Flettner]

I think so, you might find KTM are spying here. KTM were certainly awear of my work documented on TSM.

[TZ350]

<yt-formatted-string force-default-style="" class="style-scope ytd-video-primary-info-renderer"><iframe width="560" height="315" src="https://www.youtube.com/embed/8k8hJWKIVNs" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>

Kenny Roberts and the Indy Mile (2009) riding the TZ750 powered Flat Tracker.</yt-formatted-string>

[peewee]

I think so, you might find KTM are spying here. KTM were certainly awear of my work documented on TSM.

if theyre spying then what name could they be using? or they dont sign up at all. some time ago i told the big chief around here to atleast make the photos invisible to anonomous guests or somebody could spy easily with no name

[obelsik]

Long time lurker on this most excellent place (No I dont work for KTM, I live in Auckland and drive a YZ250 ;-)).

The GET replacement EFI box for the the KTM TPI models also includes a "race" option where the injectors are moved to a new manifold mounted between throttle body and reeds.
This video suggets this improves low end power which is crucial for hard enduro:
https://www.youtube.com/watch?v=_cNscr4E3GU


Then we have this, which is also suggesting dual mounted injectors mounted at the throttle body:
https://www.youtube.com/watch?v=DMLqtKqHt9U
Two Stroke Performance does mention that it does miss with big throttle openings and low loads which makes it unsuitable for motocross where you need to blip the trottle in the air.

[F5 Dave]

I also don't work for KTM but if they were to send me a regular significant enticement I would gladly sell out all the ideas I come across here.:psst:

[Note to Forum members: Dont worry- of course I wouldn't]:niceone:

[Note to KTM: Yes I will].:shifty:

[TZ350]

The GET replacement EFI box for the the KTM TPI models also includes a "race" option where the injectors are moved to a new manifold mounted between throttle body and reeds. ... https://www.youtube.com/watch?v=_cNscr4E3GU

Then we have this, which is also suggesting dual mounted injectors mounted at the throttle body: ... https://www.youtube.com/watch?v=DMLqtKqHt9U (https://www.youtube.com/watch?v=DMLqtKqHt9U)


341954 341955 341956

Yep, it looks like there is already an aftermarket re programmable ECU with new maps that can be changed for the EFI KTM's. Maybe a good thing. Looks like high performance 2S EFI is going to be a real thing.

[oldjohnno]

Stihl and Husqvarna smootly meter correct ammount or fuel in crankcase neglecting high rpm. Their ugly crankshafts smashed fuel drops better than nozzles...

That's interesting - some time ago I was thinking about injecting fuel (methanol) up against the underside of the piston crown as a way of improving piston cooling. But I wasn't convinced the fuel would be sufficiently atomized and wondered whether the loss of cooling in the intake tract would cost power. I'm still tempted to give it a run on the dyno.

[lohring]

341954 341955 341956

Yep, it looks like there is already an aftermarket re programmable ECU with new maps that can be changed for the EFI KTM's. Maybe a good thing. Looks like high performance 2S EFI is going to be a real thing.


$900 seems a little steep and is out of my price range.

Lohring Miller

[TZ350]

$900 seems a little steep and is out of my price range. Lohring Miller

Yes, agreed. It is why I hope to post a proven working example that makes it easy/cheaper to do for ourselves.

I don't think KTM are using anything too fancy themselves and I wanted to stick with what was affordable for DIY.

Automotive sensors can be picked up cheap on the Net.

The Speeduino EFI CPU's firmware code is free and open source so you can modify it to suit your needs.... https://speeduino.com/wiki/index.php/Compiling_and_Installing_Firmware#Installation_-_Easy_Method

TunerStudio for adjusting the Speeduino's mapping, the basic version is free.... http://www.tunerstudio.com/index.php/tuner-studio

The Speeduino Shield DIY naked board for the Arduino Mega is cheap and they can also be brought fully made up.... https://speeduino.com/forum/app.php/page/buy

The Arduino Mega itself is relativly inexpensive.... https://www.amazon.com/ARDUINO-MEGA-2560-REV3-A000067/dp/B0046AMGW0

The Arduino Nano is cheap .... https://www.amazon.com/OSOYOO-Arduino-ATMEGA328P-Microcontroller-Without/dp/B00UACD13Q

So Inexpensive, Cheap or Free. As a DIY project I hope others might try 2S EFI too. And for the sake of my pocket I am keen to keep this affordable.

[TZ350]

341970 Air Cooled and Fuel Injected Suzuki GP125

A series of EFI dyno runs taken at different throttle positions on my old air cooled 125. I had spent a lot of time mapping the Alpha-N fuel injection table. Alpha-N only looks at TPS and RPM and for each cell on the table you map an engine "Load" value that is used by the CPU to determine how much fuel to inject at that particular point, every time, nothing changes. This worked well for anything above 45% throttle position but it is not a flexible fueling system. More suited to drag racing than road racing.

I got the Alpha-N mapping fairly good and even rode the bike like that a few times and towards the end, sort of successfully but throttle control coming out of corners was not so sweet.

The current plan is to use Alpha-N above 45% TP and VE, volumetric efficiency below 45%. VE looks at engine volumetric efficiency vis manifold absolute pressure (MAP). That way fueling can be variable in response to the airflow changes induced by the pipe.

This way I can have the best of both worlds. Alpha-N which has proved reliable and very tune-able when the motor is on song and responsive variable fueling at lower throttle openings.

Combining the two mapping typologies, Alpha-N and VE should be relativly easy with the Arduino Nano pseudo MAP system. Below 45% I make the output variable and above I make it fixed at atmospheric.

[TZ350]

341972 Throttle held full open, TPS signal jerky green line.

Two steps forward, one step backwards. Fixed a couple of things and then ran into this issue. A wobbly TPS signal. Hold the throttle full open and steady and the TPS signal jumps all over the place. Most noticeable when revs get up and it starts coming up on the power. I will have to sort this before I can progress to mapping the fuel table and seeing if the pseudo map simulator works like I hoped.

Finaly seem to have sorted this (hopefully), simple really, tightened up all the terminals, who would have thought ...... :crazy:

[TZ350]

That's interesting - some time ago I was thinking about injecting fuel (methanol) up against the underside of the piston crown as a way of improving piston cooling. But I wasn't convinced the fuel would be sufficiently atomized and wondered whether the loss of cooling in the intake tract would cost power. I'm still tempted to give it a run on the dyno.

I think squirting under the piston to aid piston cooling is a great idea. I tried that, although I was not able to get enough upwards angle to impinge directly on the under side of the piston crown I do think that the evaporating fuel mist helped with piston cooling. It certainly helped with fuel evaporation and smooth running. I even thought of locating the injector in the bottom of the crankcase so it had a straight shot at the underside of the piston.

At low speeds just injecting under the piston worked well but at higher loads I had to also inject in the B ports just to be able to get enough fuel in there. I was also worried about loss of power due to the loss of inlet cooling but in the end I did not notice any power difference to carburation. In fact I made a little more power with injecting. Probably because I was able to more accurately adjust the fuel curve.

341974341975341976341973

[JanBros]

341970 Air Cooled and Fuel Injected Suzuki GP125
This way I can have the best of both worlds. Alpha-N which has proved reliable and very tune-able when the motor is on song and responsive variable fueling at lower throttle openings.

Combining the two mapping typologies, Alpha-N and VE should be relativly easy with the Arduino Nano pseudo MAP system. Below 45% I make the output variable and above I make it fixed at atmospheric.

shouldn't the ideal point for switching be the rpm at which the pipe begins to work, and not throttle opening ?

comming out of a corner with throttle at 60% within the pipe rpm surely needs different variables than below the pipe's rpm I would thinck ?
Or are you solely looking at it from a racers pov, i.e. you are not supposed to leave the working range of the pipe ?

[jbiplane]

That sounds a lot like Hilborn injection with the pump speed/output electronically regulated. I'm assuming from your description it's constant flow ?

Probably this patent close to reality. Cannot be sure.
https://patents.google.com/patent/US9534528B2/en

[TZ350]

shouldn't the ideal point for switching be the rpm at which the pipe begins to work, and not throttle opening ? coming out of a corner with throttle at 60% within the pipe rpm surely needs different variables than below the pipe's rpm I would think ? Or are you solely looking at it from a racers pov, i.e. you are not supposed to leave the working range of the pipe ?

Interestingly Alpha-N works well at all throttle settings below the rpm where the pipe works but I guess not a surprise as air flow there is consistent.

So you are right, confining the VE table to less than 45% TPS and only in the RPM range where the pipe is expected to be working should be the aim. Because that is the area where airflow is variable.

In my experience if the motor is firing, then above 45% the airflow becomes increasingly consistent within the full range of rpm and Alpha-N can do the job very well.

Agreed, I will probably need to use both TP position and "RPM" to select the switch point between Alpha-N and VE. Just to limit VE only to the lower TP, say less than 45% TPS at higher RPM where the pipe is working. Every where else can be Alpha-N.

[TZ350]

.
Had the bike back on the dyno again today. Simulated the blast up the straight, roll off the power and gently back on again. Like you would negotiating a corner. I did this a few times at the sort of rpm you would be using on the track.

It showed real responsiveness and actually looks like it is working. Mapping is a bit crude and the motor needs some maintenance. So I will strip the motor and spruce everything up then get onto mapping the fueling properly.

Anyway it looks very much like the Delta Crankcase pressure idea is the answer to keeping track of changes in airflow through a single cylinder high performance two stroke EFI motor.

KTM, we worked out how it is done and successfully tested it. Now the world knows the secret to fuel injecting a high performance two stroke, (EFI 2S) too.

KTM's disapproval of our work ...... 342019

[TZ350]

I have been trying to figure out a way of determining the relative air flow through my 2T motor.

From previous experience we know mass air flow meters don't work and that using the Ecotrons MAP sensor to measure the pressure in the crankcase or pipe just wound up with an average that slightly reduced below ambient as the motor came onto the pipe and flow through the motor increased.

I tried measuring the residual pressure pulse in the cylinder just before exhaust port opening. That worked well but did not tell me anything meaningful about air flow and fuelling requirements. Only whether the motor had fired or not. The best I could do with that information was to arbitrarily reduce fuel on the next cycle.

335751

My new line of thinking is to use a pressure sensor and an Arduino to determine the difference between the maximum and minimum crankcase pressure each cycle and feed this value as a MAP signal to the Ecotrons EFI CPU for processing. I am picking this difference in pressures will be a good indication of mass air flow and therefor fuelling required.

335754 335753 Dyno runs taken in reducing 10% throttle position steps.

If the pressure difference idea works then I might be able to use the Volumetric efficiency VE map with the Ecotrons EFI system for the troublesome area below the 20% TPS region and the Alpha-N map for power. From experience I know that Alphan-N works well above 20% TPS.

Determining an indication of the mass air flow by finding the difference between maximum crankcase pressure as the piston descends and the minimum pressure as the pipe sucks the air/fuel mixture from the crankcase. This pressure difference must say something about the mass air flow and therefor the fuelling required, and I am guessing the pressure differential will follow the torque curve.

Hopefully, anyway if this does not work, there is always booze .... :drinkup:

March 17/2018 This is my original post where I first talked about looking at Delta crankcase pressure as a way of tracking air flow changes through a two stroke motor. Hopefully it predates any of KTM's efforts at Patenting the concept. Like Flettners "B" Port injection, it would be good to be able to keep it all out in the public domain and available for anyone to use.


A couple of other threads that are worth looking at if 2S EFI is your thing.

https://www.kiwibiker.co.nz/forums/showthread.php/185773-Speeduino-2T-EFI-Project

https://www.kiwibiker.co.nz/forums/showthread.php/159112-Ecotrons-Engine-Management/page15

[Frits Overmars]

Maybe not the place for it, I take the liberty of posting it here anyway:
342020

[TZ350]

.
Happy Birthday Jan...... :D

[husaberg]

342021 342022As above Jan thanks.......

[wobbly]

Frits , this is for sure the place to say Happy Birthday to the man that has been, and always will be the biggest inspiration
to us " young fella's " in the world of 2S tuning.
I salute you Jan Thiel , and hope you have a happy day with your family and friends.

[peewee]

happy bday jan. for sure you are a inspiration to me and I think all your work is excellent :drinknsin


got a bit more done guys. all the water piping is mostly complete but I haven't a clue what im doing so who knows if its any where near correct :laugh:. found some 9.5mm id elbows for the cyl and the Y and T, i made myself. weld a small bung on the rad top for the self bleeder hose is all that remains of the cooling system. machine the cyl decks flat and size the bore to the piston next week then ill be grinding the ports within two weeks im hoping :headbang:

[Pursang]

Happy Birthday Jan.

Re: KTM TPI, here is what the exhaust looks like.
https://s3.amazonaws.com/WEBPOSTS/KIWI+ESE/2019+KTM+250+EXC+TPI+chamber.jpg

I assume the extended parallel header is to keep up the heat and pressure to deal with the CAT.

Cheers, Daryl

[TZ350]

.
Thanks for the picture of the pipe, some interesting features. A cat converter?

[TZ350]

342035

This is how I would setup the EFI fueling using the delta crankcase pressure concept.

The Red area below 45% TPS and in the RPM area where the pipe is working I would setup the fueling for VE volumetric efficiency. MAP vis RPM.

Every where else in the Green area I would setup fueling as Alpha-N. TPS vis RPM.

And in the Purple area below the RPM where the pipe works and TPS = 0% the MAP value needs to be set at 0.2 - 0.4 bar. This is necessary because when the pipe is not sucking strongly the crankcase pressure rises to someplace close to 0.8 - 0.9 bar of dirty air. This happens because the pipe is not drawing airflow through the motor and atmospheric pressure and stale exhaust gasses flow back into the crankcase raising the pressure there and in the inlet tract.

The motor can idle with a crankcase full of dirty air because some fresh air/fuel makes its way through the smog and randomly finds its way into the cylinder. At idle the cylinder has some fresh air and a lot of smog.

[ken seeber]

Not too sure which KTM model Daryl is looking at, but the 300 EXC TPI has no sensor of any sort on the exhaust pipe. The only "air flow" inferring sensor is a MAP sensor that is tapped into the cylinder's C port.

342036

[Peter1962]

Happy birthday, Jan.

Nog veel gezonde jaren toegewenst.
Maak er een fijne dag van samen met je familie

[katinas]

Happy birthday Jan.

Add photo from my school days czech magazine Svet Motor, with nice little two stroke bikes from 1974 Brno GP.

[Pursang]

Not too sure which KTM model Daryl is looking at....


The seller says this is a 2019 EXC 250 TPI. Bought new for a project and not used.
Has O2 sensor & Cat Converter. Probably from a Euro model.

Cheers, Daryl

[Pursang]

TM's approach to 2T FI

https://scontent.fbne5-1.fna.fbcdn.net/v/t1.0-9/61528097_1688260384610865_1648853651629801472_n.jp g?_nc_cat=106&_nc_ht=scontent.fbne5-1.fna&oh=95c392f425e6bfc3bf4fb5a33267878a&oe=5D859C15

https://scontent.fbne5-1.fna.fbcdn.net/v/t1.0-9/61613355_1688260371277533_7241672880939859968_n.jp g?_nc_cat=105&_nc_ht=scontent.fbne5-1.fna&oh=873031570d57c1f57c0aef3d12b45faf&oe=5D5CF0E9

From their Facebook page" https://www.facebook.com/TMRacingNederland/photos/pcb.1688260681277502/1688260364610867/?type=3&theater

[F5 Dave]

2 head outlets. Hadn't actually seen that.

GasGas ships with a Cat pipe in some countries along with an offroad pipe. I tried one. Would hardly get out of it's own way. I wouldn't have bought it if I'd ridden it with that pipe.
They've (if picture is new ktm) gone further still with sensor and queer header.

[husaberg]

Not too sure which KTM model Daryl is looking at, but the 300 EXC TPI has no sensor of any sort on the exhaust pipe. The only "air flow" inferring sensor is a MAP sensor that is tapped into the cylinder's C port.

342036

Parts fiche has it Ken on the Euro but not on the US model but i might have had the wrong id

its a Std KTM lambda as used on 4ts
exceedingly expensive.
342038

[wobbly]

Always great to see pics of things you have never seen.The pipe is " designed " with virtually no diffuser effect , thus drawing very little excess
mixture from the cylinder - maybe to help with hydrocarbon emmissions .
Honda had twin head outlets years ago - to feed twin radiators , and I notice that the TM has 3 yellow wires from the alternator , obvously
they need 3 phase to get enough power to run the injection system.
And big reps to TeeZee , mate you have gone done something original and published the results , fukin awsome.
Give it a new name - like TPI or Wobbly Duct , soon everyone will be calling the new idea yours - Worldwidefamewithnopay.

[TZ350]

And big reps to TeeZee , mate you have gone done something original and published the results , fukin awsome.

Thanks Wobbly. ...... Hmmmm I nead help with a name for it. Anyone got some ideas? .... :laugh:

[F5 Dave]

I did try at lunchtime but didn't get past DeltaSquirt .

[rtechracing]

I am sorry if my post ends up in the wrong topic but I am all new on this forum......:confused:
I have a 750 triple on my inertia dyno and can`t get rid of the HP/torque drop before powerband. Has anyone seen it before and have experience what can cause this? I have done more or less all in regards to jetting, altering ignition, etc.

[TZ350]

.
Certainly the right place to ask.

My guess is, that at 129 hp its not unexpected, the dip is the result of the pipe being out of phase with the engines exhaust port timing at that rpm point. It gets worse the more effective the pipe is and/or more tuned the engine is. The trick is to reduce the pipes effectiveness at the dip point, an VTEC chamber or maybe a chamber pressure bled.


Looks like an atac valve.
They are just a chamber about the same size as the engines cylinder, and a butterfly valve.
They do work on increasing low end power as long as they are mounted close to the exhaust port.
They have been used in various incariations on Honda CR NS and MVX as well as the BSL500 and Cagivas.
http://i.ebayimg.com/00/s/NzY4WDEwMjQ=/z/BrAAAOSwT5tWNI~~/$_35.JPG

https://www.youtube.com/watch?v=zVY4PJP5WDg
Suzuki and Kawasaki have also used more compicated variations of exhaust chambers.

the this is how they work
note the butterfly is mounted 90' away from how it is pictured here
https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=320342&d=1457837142https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=307620&d=1420439122
This was Farmakens DIY effort (maybe not its a twin lol)
https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=307606&d=1420439042https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=307605&d=1420439042
https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=307608&d=1420439042

Hopefully others will explain it better. And anyway, a Kawasaki H2, I am really really jealous ...... :D

[rtechracing]

Well, we use to do 151HP without the drop before pipe but then we were forced to change engineblock, resleeve all cylinders and do new porting. We increased ex duration slightly according to recommandation we got.....
With this new set up we have so far 141HP but still with the drop before pipe.....

[TZ350]

.

"search term" site:https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?

The power dip issue has been talked about on the ESE thread before. Try the google "site" option. You should be able to turn up some interesting stuff.

[rtechracing]

Thanks a lot.
Sorry, I am not sure what you mean by google "site" option? Something on the forum?

[TZ350]

.
342040

On the Google search bar, put the term "site:" in front of the KiwiBikers Bucket URL.

The Google "site:" option can be used to limit your search to any site on the internet that you are interested in.

[Pursang]

Couple more pics of the TM 300 Fi engine

This one shows the innovative injector positioning, the finned alternator cover and the starter motor
https://s3.amazonaws.com/WEBPOSTS/KIWI+ESE/300Fi2S-a.jpg

And another bit of electrical consumption...exhaust power valve.
https://s3.amazonaws.com/WEBPOSTS/KIWI+ESE/300Fi2S-5.jpg

Cheers, Daryl.

[TZ350]

I did try at lunchtime but didn't get past DeltaSquirt .

DeltaMAP .... maybe . :)

[Frits Overmars]

I have a 750 triple on my inertia dyno and can`t get rid of the HP/torque drop before powerband. Has anyone seen it before and have experience what can cause this?We've all seen it, and TZ350 gave a perfect explanation. The simplest thing to try is give the engine a fistful of ignition advance, like 30* before TDC, in the problem area. But make sure the ignition timing is back to normal (somewhere around 16* bTDC) in the powerband.

[rtechracing]

Thanks Frits
Just a bit strange, before rebuild, resleeve, etc. we didn`t have the drop and had 151HP on the dyno. Now there is a huge drop and we do 141HP.
We increased ex duration from 200 to 204 and was aiming for more HP at 9500, we had 151 at 8900 rpm.
So with more ex duration I would expect lack at the bottom but perhaps a bit more in the top. Transfer are 130 pipe TL is the same.
EGT in header is 520 C so a bit cold.....
Ignition in the problem area is 30* and doesn`t affect the drop very much....
Attached are dyno of before and after rebuild.

[jonny quest]

Is this H2 a drag bike?

200ex is very high. 204 is ouch.

Anything over 196 is a band aid and more thought needs to be done on cylinders.

What kind of dyno? Yours? Is tire slip an issue?

[rtechracing]

Yes, it is a dragbike
Yes, it is my dyno. I have made the dyno myself, using software from Performance Trends.
No, tire slip is not an issue.
As I said, we used to have 200* and was recommended 204* more as an area issue more then duration to gain more HP. Peak rpm should be adjusted by the pipe.
To be honest I am also sceptic about 200* + duration but perhaps Frits can make a comment on that.

[Haufen]

Yes, it is a dragbike

Well then, why worry?

The only time you will be possibly driving through the torque dip range will be getting to the racing line and then back to the starting line.
However, from the shape of the two curves, it seems like there are some things significantly different between the setup before the rebuild and now.

For sure, a lot can be learned If you take the painful route of finding the differences and take your time to find out the impact of every single one of them.

[Frits Overmars]

Just a bit strange, before rebuild, resleeve, etc. we didn`t have the drop and had 151HP on the dyno. Now there is a huge drop and we do 141HP. We increased ex duration from 200 to 204 and was aiming for more HP at 9500, we had 151 at 8900 rpm. So with more ex duration I would expect lack at the bottom but perhaps a bit more in the top. Transfer are 130 pipe TL is the same.You were obviously right about expecting lack at the bottom. That you got less top end power instead of more is not too surprising. I used to own a couple of Kawa H2s, and both the blowdown angle.area of the single exhaust port and the angle.area of the four flat transfers left a lot to be desired (and the top-hat combustion chamber shape was sh*t as well).
Maximum power at 8900 rpm is not bad at all, but the engine will definitely run out of breath above that, even if you raise the exhaust timing to 204*. This may increase the blowdown angle.area but it does nothing for the transfer angle.area. And what about the inlet side? You'd need 48mm carbs for the revs you're aiming at...
Moreover, raising the exhaust timing moves it further away from the 190* that is optimal for wave superposition and it provides stronger initial pulses that are more capable of messing everything up at around 2/3 of the maximum torque rpm. I'd say: don't be too greedy and go back to max.power @ 8900 rpm.

[SwePatrick]

So,, we?ve been dynoing a little.
And, Before dynosession i just set the powerjets one turn richer and the needles a couple of turns leaner, this due to it was very rich, and really rich on lower throttleopenings.

And with no adjustments on ignition(ignitech) it pulled 71.31hp on the fourth pull.
There are more to come, but we were happy at this point and didn?t want to push it while we were 'high on life' ;)

Btw, Methanol ofcourse ;)

https://www.youtube.com/watch?v=c3AlzA15Zw0

[Flettner]

https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.sticsupertorque.com/about.html&ved=2ahUKEwj5mMmc8NHiAhVH_XMBHQ9tAsIQFjAAegQIBBAB&usg=AOvVaw2XMK67wzNxc_qcqTH6T9jb
What is this shit? Rendered down snakes?

[sispeed]

WOW you put Quantum Physics in your bike if you use it.
I think it has something to do with cold fusion :gob:

[Frits Overmars]

https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.sticsupertorque.com/about.html&ved=2ahUKEwj5mMmc8NHiAhVH_XMBHQ9tAsIQFjAAegQIBBAB&usg=AOvVaw2XMK67wzNxc_qcqTH6T9jb
What is this shit? Rendered down snakes?That's enough hot air for a BIG balloon :killingme.
342050

[peewee]

So,, we?ve been dynoing a little.
And, Before dynosession i just set the powerjets one turn richer and the needles a couple of turns leaner, this due to it was very rich, and really rich on lower throttleopenings.

And with no adjustments on ignition(ignitech) it pulled 71.31hp on the fourth pull.
There are more to come, but we were happy at this point and didn?t want to push it while we were 'high on life' ;)

Btw, Methanol ofcourse ;)

https://www.youtube.com/watch?v=c3AlzA15Zw0

do you have a chance to try nitro 30% ?

[Pursang]

DeltaMAP .... maybe . :)

Perhaps a descriptive name with a really memorable acronym, one that a major Corp is unlikely to appropriate.

Crankcase Resolution of Airflow & Pressure.

Parameters Of Oscillating Pressure.

Pressure Evaluating Numerically Iterated Simulation.

Measurements Inferring Localised Flow.

Mass Airflow States Tabulated Under Repeated Base And Top Exhalations.


All kidding aside... Great Work Tee Zee..:2thumbsup
Cheers, Daryl

[TZ350]

.
I admire the effort. They are certainly all memorable ...... :D

[TZ350]

Perhaps a descriptive name with a really memorable acronym, one that a major Corp is unlikely to appropriate.

Crankcase Resolution of Airflow & Pressure.

Parameters Of Oscillating Pressure.

Pressure Evaluating Numerically Iterated Simulation.

Measurements Inferring Localised Flow.

Mass Airflow States Tabulated Under Repeated Base And Top Exhalations.


All kidding aside... Great Work Tee Zee..:2thumbsup
Cheers, Daryl

The acronyms are certainly memorable ....... Thanks .... :laugh:

[F5 Dave]

https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.sticsupertorque.com/about.html&ved=2ahUKEwj5mMmc8NHiAhVH_XMBHQ9tAsIQFjAAegQIBBAB&usg=AOvVaw2XMK67wzNxc_qcqTH6T9jb
What is this shit? Rendered down snakes?
Only the Mercans can write that style of marketing blumph.

Of the product itself, the very real benefit is the humble but bloody useable PWK wears its needle jet and its non replaceable. A replacement block with new jet is a way to fix an ailing carb.

As far as being an improvement over stock I have no idea, but there's a few people raving about them on the dirt forums having done multiple bikes. Maybe there's something in it.

But I won't be trying one out of interest as damn they are expensive.

[Haufen]

I'd rather get one of these:

342051

[wobbly]

The H2 may be experiencing the age old issue of overscavenging.
The pointers are the resleeve - were the A port front walls exactly the same backsweep angle before and after ?
And second - the low egt , a real big givaway you are dragging A/F mixture straight out the Ex duct from the front transfers.
These old engines for sure need more rearward angle on the A port as soon as you start using an efficient ( fat ) diffuser , and the
flat/non staggered timing edges are crap as Frits said.

[rtechracing]

Thanks Wobbly
So you mean it is not a problem with 204* ex duration?
The exhaust side wall of the a-port is way more rearward aimed now then before resleeve. Before it was more aimed against center of bore now it is against boost ports (it is reed)
The transfers are 22/10/50 but not staggered, before resleeve they were more "old school" 10/5/50
The pipe is not fat diffuser pipes, they are typical old slim design. The previous owner of the bike use to have fat pipes but never got them to work.
The egt was actually not any hotter before the resleeve

[jasonu]

Thanks Wobbly
So you mean it is not a problem with 204* ex duration?
The exhaust side wall of the a-port is way more rearward aimed now then before resleeve. Before it was more aimed against center of bore now it is against boost ports (it is reed)
The transfers are 22/10/50 but not staggered, before resleeve they were more "old school" 10/5/50
The pipe is not fat diffuser pipes, they are typical old slim design. The previous owner of the bike use to have fat pipes but never got them to work.
The egt was actually not any hotter before the resleeve

How about some pictures?

[TZ350]

.
Yes, we all love to see pictures of other peoples projects.:yes::yes:

[Peter1962]

Couple more pics of the TM 300 Fi engine



And another bit of electrical consumption...exhaust power valve.
https://s3.amazonaws.com/WEBPOSTS/KIWI+ESE/300Fi2S-5.jpg

Cheers, Daryl.

That is the most interesting part of the new TM 300 : till 2018 they had a servo + cable operated power valve and now a custom made system without cables, which should be more reliable. And now that KTM has a balance shaft, they have it too. Good thing !
Unfortunately, it still is a copy of the honda CR250 2002-2007. It still has the typical honda exhaust... :(

[wobbly]

The problem with the H2 is probably quite complex in that you are dealing with a mix of old and new ideas, along with increased blowdown
capability gained by lifting the main Ex port.
The problem with the high Ex duration is that this increases the time available ( and the efficiency due to higher opening pressure ratio )
for the diffuser to overscavenge the A port.
You then combine this with " modern " duct exit angles , but these new angles are derived from ports that always have alot of stagger.
Be it normal or reversed.
Thus we have an orphan scavenging system that has no history of long development by many tuners finding out , most importantly, what
not to do.
Sorry but I really cant logic my way thru the changes and recommend what to actually do to fix it - as its a real left field tangent.

[Pursang]

The Classical Performance/Development Curve. .:yes:

https://s3.amazonaws.com/WEBPOSTS/KIWI+ESE/Performance+Development.jpg

Cheers, Daryl.

[DoldGuy]

https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.sticsupertorque.com/about.html&ved=2ahUKEwj5mMmc8NHiAhVH_XMBHQ9tAsIQFjAAegQIBBAB&usg=AOvVaw2XMK67wzNxc_qcqTH6T9jb
What is this shit? Rendered down snakes?

George Boswell is the man behind this, I can not (yet) confirm this does or doesn?t work, but many seasoned users have given it very good reviews. I have seen his original design back about 1995 & it was very impressive the way the bikes ran and sounded.

Here is a picture of his original design that I found on the web.

[Frits Overmars]

Yep, the quantum physics wormholes are clearly visible. This must be the best thing since sliced bread. Maybe even better :whistle:

[F5 Dave]

Oh gawd, that looks silly.

The current product looks like the Keihin metering block and simply replaces that. Typically running larger jets I think the emulsion tube feed is altered.

[DoldGuy]

Not endorsing the product, but IF this is a true example, then gain in HP per dollar spent is a bargain.

[wobbly]

The new metering block is really just an expensive way of changing the main air correction system from a primary only
( that is using an extended emulsion tube nozzle ) to also using a normal 4T type with air entering holes along the emulsion tubes
length.
This can have the effect of reducing the atomised fuel droplet size , and thus improving the fuel curve.
Easy to see what its doing due to the big increase in main jet needed.
But I cant help thinking the same effect could be had by a different ratio of nozzle length - shorter = progresively richer , along with
a bigger air corrector ( be it a jet or simply a drilling in the casting ) that by adding more air at larger flow rates offsets the nozzle effect
as well as improving atomisation ( still not as good as the old Lectron ).

[F5 Dave]

Tuned carb looks pretty good.

[TZ350]

The Classical Performance/Development Curve. .:yes:

https://s3.amazonaws.com/WEBPOSTS/KIWI+ESE/Performance+Development.jpg

Cheers, Daryl.

Absolutely ..... :)

[shnaggs]

I tried the metering block in a 19 KTM 125. netted about .5hp at peak and overrev. Surely the gains they are claiming can be had when up against stock jets etc. horribly rich from the factory. This is one of my gripes about these types of comparisons, at least jet the bike first for best power and then throw on the metering block...block heads!

[lucf]

Thanks Frits
Just a bit strange, before rebuild, resleeve, etc. we didn`t have the drop and had 151HP on the dyno. Now there is a huge drop and we do 141HP.
We increased ex duration from 200 to 204 and was aiming for more HP at 9500, we had 151 at 8900 rpm.
So with more ex duration I would expect lack at the bottom but perhaps a bit more in the top. Transfer are 130 pipe TL is the same.
EGT in header is 520 C so a bit cold.....
Ignition in the problem area is 30* and doesn`t affect the drop very much....
Attached are dyno of before and after rebuild.

No supprise at all, when you don't calculate.
When knowing the 2t tuning history from the beginning and specially from 1960 to 2007 and than asking yourself "why it took so long, almost 50 years", than you should know what is wrong in your engine.
So calculating with the right data is the only right way to keep a 2 stroke in the right balance at every tuning level.

[shnaggs]

quick question for Wobbly or Frits....or anyone else who knows.

In regards to the exhaust duct outlet ratio of 75% of window area. What if we have a raised port floor? Does the % rule remain the same? If we raise the port floor, than the window area obviously decreases, but should we take that into account when determining the outlet size? Just seems that if we do, than the whole duct area seems rather small, but I guess thats good for velocity.

[rtechracing]

Lucf:
Please explain, I am not sure I understand what you mean?..

[wobbly]

This time Luc you are dead correct , but doing the port time area calculations still has no effect on the scavenging system.
The blowdown and transfer STA could be perfecly matched , but as I said before having an oddball transfer setup with modern axial angles combined
with old fashioned flat opening angles , has no history of development to go by.
Thinking about it further I am tending to believe that the higher Ex timing is the culprit in that it combines two effects that are killing the power
due to overscavenging.
The high timing gives more pressure ratio when the port opens , making the diffuser more efficient , and then it naturally has more time/area
for the diffuser to pull out more mixture around BDC.

[wobbly]

The 75% area guideline was developed on alot of sample engines including several with the port floor raised ( by only 3mm though ).
But the guiding principle was the duct exit velocity approaching 0.8 Mach , above or below this power was generaly less.
Thus the only way to get the exit area on the money is to place the Ex transducer in EngMod at the duct exit length and check the
Mach and the Hp resulting from this

[lucf]

This time Luc you are dead correct , but doing the port time area calculations still has no effect on the scavenging system.
The blowdown and transfer STA could be perfecly matched , but as I said before having an oddball transfer setup with modern axial angles combined
with old fashioned flat opening angles , has no history of development to go by.
Thinking about it further I am tending to believe that the higher Ex timing is the culprit in that it combines two effects that are killing the power
due to overscavenging.
The high timing gives more pressure ratio when the port opens , making the diffuser more efficient , and then it naturally has more time/area
for the diffuser to pull out more mixture around BDC.

Not only this time Wobb, I always tell the truth !!
May be not the full about Ryger, but that story has still not ended, before I can do so.

You talk about details, and a good calculation can be made with only the headlines.
All little details of you can be calculated after that.

I don't use and don't need EngMot2t, I use my own, which has been develloped over a periode of about 15 years.
And I do not intend to give my program or details, away after my treatment in the past.
On FB only my friends can read my notes, with much more information.

[rtechracing]

This time Luc you are dead correct , but doing the port time area calculations still has no effect on the scavenging system.
The blowdown and transfer STA could be perfecly matched , but as I said before having an oddball transfer setup with modern axial angles combined
with old fashioned flat opening angles , has no history of development to go by.
Thinking about it further I am tending to believe that the higher Ex timing is the culprit in that it combines two effects that are killing the power
due to overscavenging.
The high timing gives more pressure ratio when the port opens , making the diffuser more efficient , and then it naturally has more time/area
for the diffuser to pull out more mixture around BDC.

Wobbly you are correct, time areas are calculated. The blowdown and transfer STA are matched (Transfer slightly over to sort of compensate for poor design port ducts) I am also aware that it combines old and new way of thinking but my opinion is that if you never try something new you will never achieve anything, only a copy of what everybody else do. Yes, it will give me some good punches in the face but a good way to learn.

I think I will back of 2* degrees on ex duration, stagger transfer opening, try to hook the a-port even more and then back on the dyno.

You think a possible cause is that the axial angles has increased flow quite some and in combination with a more effective diffuser due to higher ex duration is making it overscavenge??

[lucf]

Wobbly you are correct, time areas are calculated. The blowdown and transfer STA are matched (Transfer slightly over to sort of compensate for poor design port ducts) I am also aware that it combines old and new way of thinking but my opinion is that if you never try something new you will never achieve anything, only a copy of what everybody else do. Yes, it will give me some good punches in the face but a good way to learn.

I think I will back of 2* degrees on ex duration, stagger transfer opening, try to hook the a-port even more and then back on the dyno.

You think a possible cause is that the axial angles has increased flow quite some and in combination with a more effective diffuser due to higher ex duration is making it overscavenge??

rtechracing,
with a right calculation, you never get punches in the face.
all knowledge is already in the way of calculating.

[husaberg]

with a right calculation, you never get punches in the face.
all knowledge is already in the way of calculating.
https://media.balls.ie/uploads/2013/12/ali.gif
125cc 70HP and 30,000rpm plus 80% less emissions.:jerry:

Are you suggesting your calculator is better than Mr Thiels Dyno proven results and multiple GP wins and championships.
As i would suggest your own calculator has some history of excreting waste fluids.
Maybe luc you might be better served not to ascribe yourself as being part of the fountain of knowledge, when you have so often and so publicly spouted swamp water.
Or are you going to admit now that the Ryger was foolishly over-hyped to the point of spreading falsehoods by yourself.
its either one of three things Luc. you either lied, or you were wrong, or you both lied about it and was wrong.

[Flettner]

HaHa I wondered how long it would take. 😆😆😆
It's going to take a long time to live that one down.

[peewee]

Wobbly you are correct, time areas are calculated. The blowdown and transfer STA are matched (Transfer slightly over to sort of compensate for poor design port ducts) I am also aware that it combines old and new way of thinking but my opinion is that if you never try something new you will never achieve anything, only a copy of what everybody else do. Yes, it will give me some good punches in the face but a good way to learn.

I think I will back of 2* degrees on ex duration, stagger transfer opening, try to hook the a-port even more and then back on the dyno.

You think a possible cause is that the axial angles has increased flow quite some and in combination with a more effective diffuser due to higher ex duration is making it overscavenge??

i dont know how much time you want to invest in your engine but many things can be changed if you have acess to a welding machine. epoxy is also a valuable tool for making changes, like those flat roofs and radial angles

not to long ago i learned you have to take care with high exp ports, unless you have close ratio 8spd gearbox :laugh:. ive had better luck with lower-wider ports but my transmission are just three or four useable gears

also about angling the a port more rearward. it may be worth putting a radius wall if you can ,rather than sharp hooks. if you angle it to much rearward it may reduce the flow width however

[koenich]

HaHa I wondered how long it would take. 😆😆😆
he was too busy padding himself on the shoulder and supervising the production of 200 engines/month :tugger:

342074

just stay away from this beautiful place luc.

[Peter1962]

125cc 70HP and 30,000rpm plus 80% less emissions.:jerry:

[IMG]http://rygerengine.com/wp-content/uploads/est-test.jpghttp://i.imgur.com/X8IsktE.png

Are you suggesting your calculator is better than Mr Thiels Dyno proven results and multiple GP wins and championships.
As i would suggest your own calculator has some history of excreting waste fluids.
Maybe luc you might be better served not to ascribe yourself as being part of the fountain of knowledge, when you have so often and so publicly spouted swamp water.
Or are you going to admit now that the Ryger was foolishly over-hyped to the point of spreading falsehoods by yourself.
its either one of three things Luc. you either lied, or you were wrong, or you both lied about it and was wrong.



I hope Luc's rather unexpected tentative at Ryger-necromancing on the forum will not succeed.

https://jokideo.com/wp-content/uploads/2012/09/255547_388561131217027_708501230_n.jpg

[husaberg]

I am sorry if my post ends up in the wrong topic but I am all new on this forum......:confused:
I have a 750 triple on my inertia dyno and can`t get rid of the HP/torque drop before powerband. Has anyone seen it before and have experience what can cause this? I have done more or less all in regards to jetting, altering ignition, etc.

Neat stuff i would look at what Kawasaki did with the later racing models.
342078342079
From what i understand the H2 was designed as a 650 then stretched out to a 65 even for the time the transfer width is small.
One of the ways ito atempt to mitigate this limitation is to angle and overlap the transfers as done with Suzuki and here with the works KR750
Or to go to 4 or 6 transfer port.

If your class rules allow it i would use a snowmobile engine and transmission

[lucf]

Are you suggesting your calculator is better than Mr Thiels Dyno proven results and multiple GP wins and championships.
As i would suggest your own calculator has some history of excreting waste fluids.
Maybe luc you might be better served not to ascribe yourself as being part of the fountain of knowledge, when you have so often and so publicly spouted swamp water.
Or are you going to admit now that the Ryger was foolishly over-hyped to the point of spreading falsehoods by yourself.
its either one of three things Luc. you either lied, or you were wrong, or you both lied about it and was wrong.



My calculations are exactly the same as the Aprillia RSA.
And if you were one of my 23.000 folowers on YouTube or Facebook, than you could have read that many times.
Even stronger !! Since 2008 "my calculations are based on the Aprillia RSA" exept for one thing.
Jan was not free to choose his own exhaustpipe and he knows that I did correct that.

Beside everyone here should know what I wrote about calculate the Ryger principle.
And if you forgot, than read it back, for I don't want to repeat it every time again and again, because people cannot read well or had a bad memory.
Which is often followed by the same not smart suggestions as above and also shows a very bad insight in what realy happend inside a 2stroke engine.

A graph which is basic for my calculations:
https://www.facebook.com/photo.php?fbid=10203245604219984&set=a.1992436069636&type=3&theater

More about my calculatios:
https://www.facebook.com/luc.foekema/media_set?set=a.1992436069636&type=1&needsRefresh=true




Not only this time Wobb, I always tell the truth !!
May be not the full about Ryger, but that story has still not ended, before I can do so.

You talk about details, and a good calculation can be made with only the headlines.
All little details of you can be calculated after that.

I don't use and don't need EngMot2t and Neels kow why I use my own, which has been develloped over a periode of about 15 years.
And I do not intend to give my program or details, away after my treatment in the past.
On FB only my friends can read my notes, with much more information.


Wobb,
I'm still waiting on your reply !

[nitro2tfx]

I think I will back of 2* degrees on ex duration, stagger transfer opening, try to hook the a-port even more and then back on the dyno.



As exhaust duration increases to excessive levels, the magnitude of the return pulse has to increase quite a bit just to fill the cylinder to the same level as before, let alone fill it better. Basically the return pulse pressure can't be made big enough to stuff the same amount of AF mixture in the now smaller space (due to later closing). Though the exhaust opens earlier it is incapable of making the return pulse as big as it needs to be for the late closing, especially with slim pipes etc.