ESE's works engine tuner

[tdc211]

You are ignoring the huge hook on the A port front wall.The flow angle points right in front of the boost port.

not ignoring it, just thought it would be more radiused on top there

[Muhr]

...../..


338670


Below is a test I did on an RSA port setup (as close as I could), with a transfer intake speed at 350m/s for a time period of 0.002s

https://vimeo.com/287057635

[TZ350]

338732 338731

Well now we know. Water injection on a 2S may not be a good idea. B/E failed after a water leak allowed the motor to drink all the cooling water. Interesting that the vaporized copper thrust washer found its way everywhere including into the little end brg.

338733 338734

The lengths I had to goto to get a 6 speed gearbox, waste of time for Bucket racing, better off with a 5 speed and a wider power spread. The Kawasaki KE175 rotary valve is a winner. much larger than the old Suzuki one.

Waiting on a new special big end pin. Cross drilled for direct BE oiling. I am going to use a small peristaltic pump arranged to deliver a small amount of oil when the motor is running. The oil will be feed through the crank from the drive side end.

[F5 Dave]

Bear in mind Rob you race at one of the 2 dinkiest tracks in NZ. 6 speed Ruapuna no question but I'd say Kaitoke too.

[Frits Overmars]

Water injection on a 2S may not be a good idea. B/E failed after a water leak allowed the motor to drink all the cooling water.Drawing conclusions faster than Lucky Luke can draw his revolver? I'd rather say that a water leak on a 2S may not be a good idea. Better try it on a 4S :devil2:.
I wouldn't apply water injection either, but not for fear of leakage. Water injection can markedly improve power at low revs, but practice (with a close-ratio 6-speed gearbox) has shown that a good rider never needs to go that low.


The lengths I had to go to to get a 6 speed gearbox, waste of time for Bucket racing, better off with a 5 speed and a wider power spread.If your power band is both wide enough and strong enough, less gear changes will get you around a circuit quicker. That is especially true on kart tracks.


Waiting on a new special big end pin. Cross drilled for direct BE oiling. I am going to use a small peristaltic pump arranged to deliver a small amount of oil when the motor is running. The oil will be feed through the crank from the drive side end.Such a setup can increase big end life tenfold. Way to go!

[TZ350]

.
Yes, the cross drilled B/E was suggested by Flettner and he is helping me organise it.

[husaberg]

Drawing conclusions faster than Lucky Luke can draw his revolver? I'd rather say that a water leak on a 2S may not be a good idea. Better try it on a 4S.
I wouldn't apply water injection either, but not for fear of leakage. Water injection can markedly improve power at low revs, but practice (with a close-ratio 6-speed gearbox) has shown that a good rider never needs to go that low.

If your power band is both wide enough and strong enough, less gear changes will get you around a circuit quicker. That is especially true on kart tracks.

Such a setup can increase big end life tenfold. Way to go!

Which dovetails to my question in 1997/98 when unleaded was introduced into GP the crankshaft life of Hondas NSR500 was decreased from 1500 miles to 500 miles (nothing to do with the big bang to screamer either as it was all NSR500's)
Also that year there was a rash of seizures on all the makes of bikes not just the hondas
Does leaded fuel really provide more lubrication in a two stroke or was it just that the revs were raised that year to make up for the shortfall in compression or were the techs just not used to the differing characteristics of unleaded?

[Frits Overmars]

Which dovetails to my question in 1997/98 when unleaded was introduced into GP the crankshaft life of Hondas NSR500 was decreased from 1500 miles to 500 miles (nothing to do with the big bang to screamer either as it was all NSR500's)
Also that year there was a rash of seizures on all the makes of bikes not just the hondas
Does leaded fuel really provide more lubrication in a two stroke or was it just that the revs were raised that year to make up for the shortfall in compression or were the techs just not used to the differing characteristics of unleaded?https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130459870#post1130459870

[husaberg]

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130459870#post1130459870
Cheers It still doesnt explain the rash of seizures unless they were over run induced as well?
Interestingly Motocourse (Cameron i think) Mentioned that the Japanese knew with the leaded high octane fuel that they knew the engines comp ration was to high for peak power but they prefered it that way for higher low end and mid range performance the "overcompressed" engines offered. Doohan hated the unleaded engines and referred to the engines as "road bikes" rather than race bikes their after.

[wobbly]

The unleaded fuel reacted very differently to tuning and it took the engineers ( and Elf ) some time to find the optimum.
Less com, more advance and richer made the best power .,more so with the later Mits 31+ fuel blend , very rich mixtures were the norm.
Whereas early on the mindset was still,lean it down to go faster ,very wrong as it turned out.

[jonny quest]

As Wobbly mentioned richer jetting. Wasn't that around the time that riders were running out of fuel? Did they have to make larger tanks?

[TZ350]

338750

An engine that has all the bells and whistles would not be complete without a touch of Stealth Coat from Super Finishing Ltd.

If I can I am going to get the rotary valve blade and cover faces done too.

[wobbly]

Haha, Rob , if Dazz coated the pin ends you could true it without a hammer.

[TZ350]

Haha, Rob , if Dazz coated the pin ends you could true it without a hammer.

Thought of that and taped them off before he got hold of them. It sure is slippery shit. He says he can do the oil seal lips too.

Anyway I am waiting for the real be-spoke cross drilled pin to arrive, maybe latter next week.

[peewee]

anyone tried fitting complete ign system from one engine to another ? thinking of trying to fit a 250ktm system to my old 550. problem is my flywheel is mounted on the opposite side so i would have to rotate the stator in such a way to account for the opposite direction flywheel spin. i want a way to have programming capabilities and this seems the only way. im not even sure the flywheel taper would be the same bit its worth a look

[Michael Moore]

If you look around at

https://hpi.be/

they have a lot of information on rotor tapers that may let you ID what will or won't work on your bike. I think some ignitions are sensitive to the direction of rotation, you might be better off getting something meant for use on your bike rather than fighting to get something to work.

Jeff Henise has been making ignitions for various vintage bikes (CT-1 Yamaha, his F37 Kawasaki, CB160s) with the hpi parts and they seem to be very reliable and give good service.

cheers,
Michael

[190mech]

Ive installed a KX100 iggy system(LH side) on a Minarelli scooter(RH side),but I had to move the pickup(pulse) coil to get the proper 'phase' angle..It worked great then!I found the answer at this site;
http://www.sportdevices.com/ignition/ignition.htm
Hope this helps you move to the other side..:cool:

[Tim Ey]

Adapting ignitions with a single pickup on the outside is absolutely not an issue.
And that setup screams for an ignitech.
Pickup on the inside is not so easily.

The most challenging part is to machine the cone to suit if it does not fit.
But most modern bikes got the 1:5 taper so whilst having a few ignitions to choose from, that might be a swop as well.

@peewee
why dont you use the ignitech magneto lfs they offer in their shop?

[TZ350]

338754

An engine that has all the bells and whistles would not be complete without a touch of Stealth Coat from Super Finishing Ltd.

If I can I am going to get the rotary valve blade and cover faces done too.


Haha, Rob , if Dazz coated the pin ends you could true it without a hammer.

For sure .... :laugh:

338755

Dazz did the Rotary Valve parts and Piston for me. Real happy with that. Only issue is to clean out the gear box housing, don't want any of that slippery stuff in the clutch. Maybe time to go air cooled clutch so I can have all the engine and gearbox parts super finished and stealth coated. Big thanks to Super Finishing Ltd.

[wobbly]

As noted before most ignitions have the same 1:5 taper, just differing ID.
There are some ( very rare ) ignition modules that detect the trigger and power coil voltage peaks to prevent running backwards from a kick over misfire.
But no aftermarket CDI do this.
So all thats needed is to position the trigger correctly,most want the trailing edge of the lobe to pass the trigger pole center BTDC , this is called Base Advance.

[husaberg]

As noted before most ignitions have the same 1:5 taper, just differing ID.
There are some ( very rare ) ignition modules that detect the trigger and power coil voltage peaks to prevent running backwards from a kick over misfire.
But no aftermarket CDI do this.
So all thats needed is to position the trigger correctly,most want the trailing edge of the lobe to pass the trigger pole center BTDC , this is called Base Advance.

I have noticed quite a few Hondas have a long pip and what looks like a plain trigger pip on the flywheels whats the other pip on the flywheel for?
I had noticed TZ's Aprilia one the other day. With pips every few degrees.

[wobbly]

You only need multiple lobes ( usually with one missing ) to tell accurately a fuel injection ECU where the crank is located in relation to TDC.

[husaberg]

You only need multiple lobes ( usually with one missing ) to tell accurately a fuel injection ECU where the crank is located in relation to TDC.
Sorry it was the FZR250 rotor i gave to speedpro that had it
here is a pic of one note the small pip at 2 oclock maybe that is TDC?
338758

[tdc211]

Heres one for ya wob.

New 104cc .been playing on it.
No port sta. 27hp worth of transfer. In sim.
A port 120/B-119/ C 122 or something
High 1.35 case comp. . 29 ex tunnel exit . (Which is less area than a fully ported cylinder at 32mm)
A whole 14.3 comp/no sq. Pump gas. Ex port a whole 86,raduis to 85ish.subs 91. One single pv in main ex.
I havnt even ground on the ports on it yet.
I doubt sim will sim this high. Maybe cranking the combustion efficiency will get it up past 11-13% dyno hp. I am not sure. Havnt tried to get sim to match. I think the new tranfers and ex exit and pipe are the big reason

[peewee]

As noted before most ignitions have the same 1:5 taper, just differing ID.
There are some ( very rare ) ignition modules that detect the trigger and power coil voltage peaks to prevent running backwards from a kick over misfire.
But no aftermarket CDI do this.
So all thats needed is to position the trigger correctly,most want the trailing edge of the lobe to pass the trigger pole center BTDC , this is called Base Advance.

heres what im thinking and maybe im way off. from what ive read, nitro doesn't make as much power if it doesn't have enough spark lead. in top fuel cars I believe their rules only allow a certain max rpm and they limit it by retarding the spark. if I can fit a newer style flywheel and programable ign system to my bike then maybe I can find some free power by sorting out the spark curve. with the standard ign, if I try to advance the pickup trigger then it advances the whole curve respectively. I need to retard it alot in the beginning to get the engine started without fear of the dreaded kickback and breaking engine parts, then it can advance as needed once running

[katinas]

Interesting cylinder from Rotax Max EVO 2017 engine. Other photos about KR 250 and looks like cylinder trans A B ports interflow to one window.

[husaberg]

Interesting cylinder from Rotax Max EVO 2017 engine. Other photos about KR 250 and looks like cylinder trans A B ports interflow to one window.
Nice Kr Drawing here a a few Crankcase pics
338794338795338796

[katinas]

Early KR 250 version from Brno GP with rear cylinder exhaust around the engine.
And two cuts in fairing for air on Mang's KR at Imola 81'.

[lodgernz]

I've often wondered how accurate is the long-accepted mantra surrounding carburettors.
Forever, we have been told that the main jet only controls the last 1/4 of the throttle opening, as shown in this widely-published diagram and others similar.
338807

To satisfy my own curiosity, I stripped the 28mm genuine Keihin PWK that has been perfectly fuelling my 90 bucket racer for years.
I measured the needle jet very accurately at 2.60mm, and the needle diameter at 1mm increments from the point at which it is highest in the needle jet, i.e. at full throttle, to the throttle closed point.

Then I calculated the annular area between the needle and the jet at each 1mm from fully closed to fully open.
The main jet is a 140, so it has a CSA of 1.4776mm2.
The pilot jet is a 40, so its CSA is 0.0993mm2.

It seems to me that no matter how big the annular area is, the main jet, being the feed for the needle jet, must limit the fuel delivery to its own flow capability.

My calculations show that, when the throttle is open 13mm, not quite half throttle, the needle/jet annular area is 1.5080mm2.
Bearing mind that the main jet CSA is slightly less than this at 1.4776mm2, my conclusion is that the main jet actually controls fuelling from at least half throttle, despite the needle/jet annular area dramatically increasing with further throttle opening.
If I add in the pilot jet CSA to the calculations, the areas change but the 13mm limitation remains.

This doesn't seem to make sense. Is there some other secret fuel circuit that I'm missing, or is venturi action somehow massively variable throughout the opening?
I note that the needle jet tube has tiny holes in it, but these are in an area that is linked to the atmosphere in the bellmouth, so don't appear to be a fuel source.
Clearly the amount of fuel drawn through the jets by venturi action will increase as the air flow speed through the throat increases, but that doesn't explain why the needle/jet area continues to increase past the point where the main jet has apparent control.

Please discuss...

[wobbly]

If the emulsion tube has holes in it, then its a 4T carb.
These holes bend the fuel curve shape depending upon their height and diameter.
A 2T carb uses a shroud in the venturi , and this operates ,along with the main air corrector to change the fuel curve shape - away from simply getting richer as the airspeed rises.
What very few realize is that the fuel delivery at WOT - low rpm , is set by the tube/needle annulus area.
In any 2T tuned correctly such as the 125 karts ,I can remove the main completely,and on the dyno it will pull WOT from 7000 to around 12,000 ,then go rich.
If the needle/tube combination isnt correct ie too rich down low ,as well as a needle end too small ,it will hardly pull any load at all - let alone WOT.
I have recently done a test of varying the shroud height (2mm lower ), as this was a trick we used for years in Rotax classes where the jetting ( apart from the main ) is a tech item.
Lowering the shroud made those engines light up big time, but someone in Tech discovered what we were doing and got it banned.
But in the TM test I did ,a lower shroud just gave way higher egt as the rpm rose.
Rejetting the main to get the egt back, gave identical power,sadly.

[lodgernz]

I'm confused. If the needle and needle jet annulus controls the flow from idle to WOT, what is the main jet for? And why is it not limiting the flow at the needle, since it is smaller in area?

[wobbly]

The combination of the annulus area and the flow restriction of the main , control the total fuel delivered only at higher rpm.
This is shown when using different combinations of needle end diameter and emulsion diameter.
Depending upon the WOT annulus the main can vary from a 132 all the way out to 185 and this will give the same peak egt.
The trick is to find an annulus area that gives the best low rpm WOT response - then choose a main that delivers the final peak egt required.
Of course I am talking 2T carbs here , the situation is very different without the venturi shroud.

[ken seeber]

Isn't it a simple matter of the Cd of the round hole in the main jet vs a very thin annular section of the needle within the needle jet?

[Frits Overmars]

I'm confused. If the needle and needle jet annulus controls the flow from idle to WOT, what is the main jet for? And why is it not limiting the flow at the needle, since it is smaller in area?The main jet controls fuel flow; the needle/needle jet gap may control the larger-volume fuel-air emulsion flow, depending on the type of carb.
A secondary aspect, as indicated by Ken Seeber, is the difference in boundary layers. The main jet just has an internal boundary layer that subtracts from the flow area. The needle jet has an internal boundary layer and the needle has an external boundary layer, that may or may not overlap, depending on whether the needle is centered in the needle jet.
Sideways movement of the needle in its jet causes a variation in effective flow area. That is why some carbs have a small spring pushing the needle sideways, so it is always in the same position in relation to the jet.
In the drawing below the needle could still move a little further to the right until it leans against the jet body, which would increase the effective flow area, or it could move further to the left, decreasing that area at first, and then decreasing it again.
338811

[husaberg]

If the emulsion tube has holes in it, then its a 4T carb.
These holes bend the fuel curve shape depending upon their height and diameter.

I dont agree with that Wob,I have seen a few factory carbs from Disc valve bikes that have had emulsion tubes on Mikunis
Ie (B) type for primary bleed needle jets.
http://www.psep.biz/images/fue-intake/MIKUNI%20NEEDLE%20JET.jpg
Pretty sure its in the Bell book as well?
338812338813
This site is worth a look for intakes and etc
http://kocherenterprises.com/wp-content/uploads/2017/11/fuel_and_intake.pdf
Alot looks sudco though

I seen someone was making needle jet blocks for Kehins PWK's the other day too
I have not seen these generally available like on a Mikuni it has replaceable needle jets
338814

https://gaming.youtube.com/watch?v=FCyW6Ads2kA
holey shit though the price...
https://www.mxsouth.com/stic-fuel-systems-stic-dvi-keihin-metering-block.htm
MX South Price:$495.00 USD

https://thumpertalk.com/forums/topic/1234222-stic-block-review-2006-cr250/
Interesting stuff with Mikuni needles and some differences in the PJ on the PWKs

[Muhr]

If the emulsion tube has holes in it, then its a 4T carb.

Rotax classes where the jetting ( apart from the main )

Is not the rotax classes you referring to running FN 266?

[Flettner]

any old carburetors😆

[Frits Overmars]

any old carburetors😆You could melt 'm and cast your own injector bodies.
338816

[wobbly]

And I agree with you as well.
There have been a very small number of factory jet setups that use the bleed type emulsion tubes on a 2T.
One model of Yamaha RD had this , and it is common practice to ditch that in favor of the next years jets that used the shroud , as
they respond " normally " to tuning , the bleed system was always near on impossible to get spot on.
But the vast majority of 2T setups use the shroud - the old story of the exception proves the rule.

The history of the Rotax is that they used the FN 4 stroke tube in the early model engine ( with a shroud as well ) then when the EVO kit was introduced the FN 266 was
dumped in favor of a " normal " DP 267 with a shroud - same setup as a KZ engines carb..
During the engines life various shrouds were introduced , and we mixed them up to get the best results ,but as I said Mr Tech finally got onto us and specific shroud heights are now fully specified.

[Flettner]

HaHa, a view inside that rubbish bin.😆

[lodgernz]

Interesting discussion, thanks to all. Some of it makes sense :o)

A quick question Wobbly: Do Lectron carbs have a shroud?

[wobbly]

No, Lectrons have no shroud nor do they have any air correction.
The fuel curve is set entirely by the flat on the needle , and its that system that gives them incredible fuel atomization.
I tested this something like 30 years ago , using what was then a real trick VHS tape camera.
Pulling air thru the carb on the flow bench ,I videoed a Mikuni Powerjet off a TZ and a 38 Lectron.
Playing it back in Slo Mo you could see huge globs of fuel slopping out of the emulsion tube on the Mik ,but a real fine mist exiting the Lectron.
I always believed that the later model carb, called Blue Magnum was better as it had an air corrector jet.
But when you dyno a Lectron using Lambda ,the A/F ratio is all but perfect the whole time once the needle and powerjet are set correctly.
A " perfectly tuned " Mikuni is all over the place.
Smart Carbs use the same tech , but have cracked the huge issue of varying mixture with altitude as well.
We tested a winning Quad at Pikes Peak ,and the A/F was at 12.8:1 at the bottom, and 12.8:1 at the top - I couldn't believe it.

[tdc211]

Been playing on the new 105.
33hp and honestiy it's the easiest /best curve
33hp i have done. Not even pushing any port numbe6rs on it yet. Only 85 degree main ex port and 90.5 subs. Runs on pump.

Now the question is why? Tried 4 pipes. One was best by far
Has a good ex tunnel. And the new tranfers make my modified tranfers look big and pathetic in shape.
Tranfer volume is extremly small. Smaller than my modified cylinders by quite a bit
I can tell it less short circuit by alot.

Maybe some of you can use the chord or % on ex to tranfers to compare. I Can tell you the stock cylinder sucks here!

[peewee]

just a observation here. appears the large inner wall tea cup radius is all but gone. wonder what affect that had

[tdc211]

They flow way more than sta says.
I know wob probably give me grief on that statement.
But sta is from 1996 blair book far as i know

[peewee]

Saturday I finally got to take the old shitter to one of the largest sand hills in the united states. im still amazed this thing is holding together and hasn't given me a single problem ever. starts right up in two kicks everytime, tranny shifts perfectly even though the gear ratios are some of the worst ive ever seen, which meens theres only three useable gears. spending time sorting out the fuel flow into the carb really paid off, there was definatly enough flow to go up the hill . burned through 4.4L nitro and 8.1L methanol. unfortunately im not a pro camera man so youll have to click the full screen button



https://youtu.be/q6iRQvDschI


https://youtu.be/1lexOnYmfYs

[husaberg]

No, Lectrons have no shroud nor do they have any air correction.
The fuel curve is set entirely by the flat on the needle , and its that system that gives them incredible fuel atomization.
I tested this something like 30 years ago , using what was then a real trick VHS tape camera.
Pulling air thru the carb on the flow bench ,I videoed a Mikuni Powerjet off a TZ and a 38 Lectron.
Playing it back in Slo Mo you could see huge globs of fuel slopping out of the emulsion tube on the Mik ,but a real fine mist exiting the Lectron.
I always believed that the later model carb, called Blue Magnum was better as it had an air corrector jet.
But when you dyno a Lectron using Lambda ,the A/F ratio is all but perfect the whole time once the needle and powerjet are set correctly.
A " perfectly tuned " Mikuni is all over the place.
Smart Carbs use the same tech , but have cracked the huge issue of varying mixture with altitude as well.
We tested a winning Quad at Pikes Peak ,and the A/F was at 12.8:1 at the bottom, and 12.8:1 at the top - I couldn't believe it.
Edmonson carbs
· 1968-1969: The Lake Injector prototype and final production model carburetor.
· 1970-1971: The Pos-A-Fuel prototype and final production model carburetor.
· 1971: The Pos-A-Fuel with remote float bowl production model carburetor.
· 1973-1974: The Lectron prototype and final production model carburetor.
· 1976-1977: The E.I. Prototype and final production model carburetor.
· 1978: The Blue Magnum production model carburetor.
· 1981-1982: The Qwik Silver prototype and production model carburetor.
· 1993: The Qwik Silver II production model carburetor (sold to Edelbrock)./size]

The red Edmonson story is here
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130160524#post1130160524

[Muhr]

The history of the Rotax is that they used the FN 4 stroke tube in the early model engine ( with a shroud as well ) then when the EVO kit was introduced the FN 266 was
dumped in favor of a " normal " DP 267 with a shroud - same setup as a KZ engines carb..
During the engines life various shrouds were introduced , and we mixed them up to get the best results ,but as I said Mr Tech finally got onto us and specific shroud heights are now fully specified.

At the time I ran around on euro challenge, modifications of the "shroud" were occurring, both shortening and even pulling up and twisting it a bit to adjust the emulsion air flow, like an air screw for main. the first time I saw that they checked it with a jig was in Angerville in 2011 after a qualifying if I remember correctly

[tdc211]

just a observation here. appears the large inner wall tea cup radius is all but gone. wonder what affect that had

Think as far as air flow thru a pjpe/duct. The new shape is superior. Not just the roof angles and inner radius, But the port floor ,by the bore as well.

[peewee]

Think as far as air flow thru a pjpe/duct. The new shape is superior. Not just the roof angles and inner radius, But the port floor ,by the bore as well.

oh the smaller vinamolds were better? i thought you meant the hogged out molds were better. misunderstanding

[tdc211]

oh the smaller vinamolds were better? i thought you meant the hogged out molds were better. misunderstanding


Yes. smaller is the new one. I have tried many attempts to make old cylinder better . But i never pushed the port floor angle as far as the new cylinder.

[husaberg]

I've often wondered how accurate is the long-accepted mantra surrounding carburettors.
Forever, we have been told that the main jet only controls the last 1/4 of the throttle opening, as shown in this widely-published diagram and others similar.
338807


This doesn't seem to make sense. Is there some other secret fuel circuit that I'm missing, or is venturi action somehow massively variable throughout the opening?
I note that the needle jet tube has tiny holes in it, but these are in an area that is linked to the atmosphere in the bellmouth, so don't appear to be a fuel source.
Clearly the amount of fuel drawn through the jets by venturi action will increase as the air flow speed through the throat increases, but that doesn't explain why the needle/jet area continues to increase past the point where the main jet has apparent control.

Please discuss...
The answer is the the fuel circuits as marked on many diagrams are not cut and dry like the diagram show them to be.
http://www.nightrider.com/bt30/images/jet2.jpghttps://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=314575&d=1439079622
they have massive overlaps in the area that they effect the carb size also has a dramatic effect on the fueling ie a smaller than ideal carb will readily enriches past peak revs While a bit too large carb one often doesn't.
Also other circuits effect the fueling as well as the shroud height does the stages of the needle tapper and the air control circuits effect areas hugely.
Thats without going into the volume and shape and length of the underside of the slide as well.

read through Robinson and Bell and have a look at cameron is the best i can say.
338829338830338831338832
most i can say to start with float level then the needle jet and get that right first.
Pretty sure its even in the first post of the thread :)
I posted a nice tuning from scratch a while back. but i cant find it.
But as wob said the Lectron style carbs dont have such wide overlapping circuits
Plus as Flet sdaid neither does EFI you can change the fueling at any point rev or throttle opening you whish

[lodgernz]

Thanks Husa. Good stuff as usual.

[TZ350]

.

Plus as Flettner said, EFI you can change the fueling at any point rev or throttle opening you wish

I just love EFI.

338833

Cross drilling my crank in preparation for the new be spoke crank pin and direct oiling for the big end. I cant wait to get this lot back together so I can get on with my EFI development. Very excited as the new Arduino based Speeduino EFI's CPU 2S software is coming along very nicely. Once it is up and running the next move will be pick and hold crankcase MAP reading.

338835 NSR110 dyno curve.

Power valve curves. below is my NSR110 power valve curve. I have no idea what they should look like.

338834 NSR110 PV curve.

Does anyone know what a PV curve should look like because I have made a better longer flatter fat torque curve with my 28hp air-cooled cylinder that was just a big gaping exhaust port without a power valve. And I expected the same sort of flat torque curve with the PV.

338837 air cooled dyno curve.

I have cracked 31hp with my air cooled but 28 proved more thermally reliable.

[F5 Dave]

Just finished prepping dinner for tomorrow TexMex.
It will marinade in fridge. Won't put it on till 10am.

This is what I'm listening to.


https://m.youtube.com/watch?v=6HJGIhpsN5Y

With big dirt bikes it is incredible how much influence the needle has. On the bucket I need just off idle to be real progressive to control the front. Then transition to mainjet in 0.5 seconds.

Just put an AS2 carb on the GasGas 300 replacing the AS1 with NEDJ needle. Hesus what a stella difference. You've got to take up this dirt bike thing just for an excuse to ride more 2 Strokes. Fanbloodytastic.




Come to me, I'll fill the hole
Why would I be lying
End fan, all planned out
Offering a wonderful
Peace of mind worth buying
Bow down last round up

I am wise and you don't know
A cloud is my home
Only some get in
Got a 'maginary friend

[DoldGuy]

TZ, I can not answer the complete curve, but know if you overlay the dyno with valve open versus valve closed, where they cross is where the valve should be open & prior to the two crossing should give you a good idea of when & how quickly to open.

[Muhr]

Been playing on the new 105.
33hp and honestiy it's the easiest /best curve
33hp i have done. Not even pushing any port numbe6rs on it yet. Only 85 degree main ex port and 90.5 subs. Runs on pump.

Now the question is why? Tried 4 pipes. One was best by far
Has a good ex tunnel. And the new tranfers make my modified tranfers look big and pathetic in shape.
Tranfer volume is extremly small. Smaller than my modified cylinders by quite a bit
I can tell it less short circuit by alot.

Maybe some of you can use the chord or % on ex to tranfers to compare. I Can tell you the stock cylinder sucks here!

Would be interesting to see the dyno sheet from the different cylinders

[TZ350]

TZ, I can not answer the complete curve, but know if you overlay the dyno with valve open versus valve closed, where they cross is where the valve should be open & prior to the two crossing should give you a good idea of when & how quickly to open.

Great. Thanks, I will try that and see what it looks like.

[wobbly]

Its easy to set up a good baseline PV curve TeeZee.
But the place to start is to have a graph point at the beginning and end of the ramp with only one intermediate point.
Having a heap of points ( so you can make a " curve " ) slows down the ramp speed considerably.
You only need one point connected by two straight lines, so this can be two different slopes , opening fast - then slower , or visa versa.
Find the full open and closed volts, and also note the physical 1/2 height of the blade ( this is rarely 1/2 way between open and closed ).
Do a run with the blade held down, one at 1/2 height ,and one fully up.
Where each curve crosses is a point on the needed ramp curve.
If the blade is too low ,then opening it sooner will give more bottom end.
But in any case no way will it need to be fully up past peak Hp - as your sample shows..
Usually around 1500 rpm below - with "normal " Ex port timing.

[F5 Dave]

Thanks I need to get the 496 RZ back on the dyno now Ignitech PV control. Still have old RZ servo. Sounds ok but surprised the mV readings are pretty close between open and closed. Guess the computer doesn't care as long as it's consistent.

[TZ350]

Still have old RZ servo. Sounds ok but surprised the mV readings are pretty close between open and closed.

It looks like mine is about 800mV. 2.1V to 2.9V yes not that big a difference, our other engine is much the same...... must be right.... :scratch:

338847

[tdc211]

Would be interesting to see the dyno sheet from the different cylinders

I probably have 1000 charts over the years.
Most on old lap top

But i posted 34.5hp (my best peak)one before on here. With the old cylinder. Had epoxy tranfers. 20hp at 9000. 17.0 comp 790 pipe (520mm piston to diffuser)
117/118/119 Tranfers 82/86subs. 40hp worth of sta.
1.32 case comp = 34.5 on dyno and matched sim well at 88/89 combustion efficiency


Now i 790 pipe (560mm piston to diffuser) . 14.3 comp And specs i listed a few daya ago and With in 1hp of old set up. I am 33.4 as of now

Old cylinder. Even epoxied ,Hated 560mm p-d pipe. Seem to just want lots return pulse. Small stingers etc.

Old cylinder from ktm was 18hp at9000 and 14.5 comp .
And about 27hp. With the 11cc tranfers and shit A port hook

Those are dead honest #s from yrs of testing.

[wobbly]

If you have a small delta V then that means that the pulley ratio is wrong ( or the lever ratio actually pulling up the blade ).
You need a much bigger diameter on the PV shaft , so the servo rotates alot more.
With only a small delta and the 100mV hysteresis it will be very hard to get repeatable results.

[tdc211]

Would be interesting to see the dyno sheet from the different cylinders


Did you move A port away from main export and fill in bottom radius of main ex port in that cfd? Or is that just the transfers shape/volume?

[F5 Dave]

If you have a small delta V then that means that the pulley ratio is wrong ( or the lever ratio actually pulling up the blade ).
You need a much bigger diameter on the PV shaft , so the servo rotates alot more.
With only a small delta and the 100mV hysteresis it will be very hard to get repeatable results.
Hmm. Ok will put it on the bench and restart from scratch. I'm using presumably the same pulley as the 485 in example but readings are nearer 5v and not much delta.

[wobbly]

If its near 5V that just means the pulley position on the servo is near the end of the feedback pot.
Adjust the cables so you can move the pullet away from 5V.

[Muhr]

Those are dead honest #s from yrs of testing.


Did you move A port away from main export and fill in bottom radius of main ex port in that cfd? Or is that just the transfers shape/volume?

There is no mistrust about those numbers in any way, rather an interest in seeing how they perform over rpm. CFD I put up was a 100cc one with 150% neck (90 * from transfer port) area and the other with 200%, the same inner radius. In this case, the smaller area seems to do a better job on moving the charge towards the center of the cylinder

[SwePatrick]

When flowsimulating, are you simulating constant flow or flow with high pressure that gets lower as the piston moves further down the bore, and that actually gets below 1bar absolute at btdc?

I´d say constant flow is way off from what´s happing for real in the transfers.

[F5 Dave]

Hey, where's Adegnes our favourite Norwegian shed drinking scooter fiend these days?

[jamathi]

When flowsimulating, are you simulating constant flow or flow with high pressure that gets lower as the piston moves further down the bore, and that actually gets below 1bar absolute at btdc?

I´d say constant flow is way off from what´s happing for real in the transfers.

After years of flow testing I concluded that flow testing the transfers makes no sense.
More flow often means less power.
So we decided that power-testing was the best thing to do!

[Muhr]

When flowsimulating, are you simulating constant flow or flow with high pressure that gets lower as the piston moves further down the bore, and that actually gets below 1bar absolute at btdc?

I´d say constant flow is way off from what´s happing for real in the transfers.

I agree with its complexity to recreate this in the computer. There of my interest in the results TDC211 has. What I do is like a flow bench, but at significantly higher flow speeds, which is required for air to begin to vary in density.

[tdc211]

I agree with its complexity to recreate this in the computer. There of my interest in the results TDC211 has. What I do is like a flow bench, but at significantly higher flow speeds, which is required for air to begin to vary in density.

And what changes combustion efficeny?
The density?

[wobbly]

DEA use a pulsed flow bench, that effectively recreates the actual flow regime in the transfers .
This gives a much more accurate representation of reality and can be used reliably to predict power.
I met Yamaha's GP technical director in 2000 and he said that that they had just reached the stage where using the CNC Czech flow visualizer
they could accurately predict the power by being able to see and analyse the trapping and scavenging efficiency of the ports in a cylinder.
They had used it to develop the 250 ( title winning twin ) after years of not being even close in Hp , though that was also in part due to finally ditching the stupid oversquare bore size.

[oktrg500]

Hey, where's Adegnes our favourite Norwegian shed drinking scooter fiend these days?
https://www.youtube.com/results?sp=CAI%253D&search_query=two+stroke+stuffing

[dutchpower]

DEA use a pulsed flow bench, that effectively recreates the actual flow regime in the transfers .
This gives a much more accurate representation of reality and can be used reliably to predict power.
I met Yamaha's GP technical director in 2000 and he said that that they had just reached the stage where using the CNC Czech flow visualizer
they could accurately predict the power by being able to see and analyse the trapping and scavenging efficiency of the ports in a cylinder.
They had used it to develop the 250 ( title winning twin ) after years of not being even close in Hp , though that was also in part due to finally ditching the stupid oversquare bore size.

Anemometric bench

[jamathi]

DEA use a pulsed flow bench, that effectively recreates the actual flow regime in the transfers .
This gives a much more accurate representation of reality and can be used reliably to predict power.
I met Yamaha's GP technical director in 2000 and he said that that they had just reached the stage where using the CNC Czech flow visualizer
they could accurately predict the power by being able to see and analyse the trapping and scavenging efficiency of the ports in a cylinder.
They had used it to develop the 250 ( title winning twin ) after years of not being even close in Hp , though that was also in part due to finally ditching the stupid oversquare bore size.

Yamaha won the title because Guy Coulon, tech 3's chief mechanic, made copies of the Honda cylinders for their Yamaha's, without Czech flow visualizer. They also used a copy of the Aprilia fairing, offered to them by an ex-Aprilia aerodynamicist. We had such a Czech flow visualizer at Aprilia, it proved to be completely useless. DEA made his own, I don't know of any results.. The best pulsed flowbench is the engine itself....

[SwePatrick]

After years of flow testing I concluded that flow testing the transfers makes no sense.
More flow often means less power.
So we decided that power-testing was the best thing to do!

That´s exactly what my own logic says to me.
One cannot copy real world scenarios.

Pressure oscillation in crankhouse.
Backpressure from exhaust varies.
Piston moves and disturbes flow.
The ports are fully open on a fraction of a second.

And so on and so on.

I would say that an electrical engine that pulls the engine to test at different rpm´s, whole cranksystem with piston etc etc is about as close as you can get if you measure the air pumped through the cylinder.
But when adding spark,fuel and a pipe, all is changing as there comes a lot of new variables in the game.

So, dyno is by far the best.

[ken seeber]

The racetrack is the ultimate tool, the dyno being the second most representative. However there are lots of other tools eg EngMod, Frit’s FOS exhaust formula, Jante rigs, Gordon Blair’s CO2 single cycle rig, empirical guides for port areas, etc, etc. If DEA have success with their rig then for them they have a good tool to shorten dev’t costs and time…

Importantly, 2 hours and Jack Miller is off from P2…can’t wait.:clap:

[jamathi]

The racetrack is the ultimate tool, the dyno being the second most representative. However there are lots of other tools eg EngMod, Frit’s FOS exhaust formula, Jante rigs, Gordon Blair’s CO2 single cycle rig, empirical guides for port areas, etc, etc. If DEA have success with their rig then for them they have a good tool to shorten dev’t costs and time…

Importantly, 2 hours and Jack Miller is off from P2…can’t wait.:clap:

DEA is not going very well. they will probably transfer to Slovenia....

[Frits Overmars]

DEA is not going very well. they will probably transfer to Slovenia....It's already been done. Last week Andrea told me that he has now finished moving all his equipment, including his magnesium foundry, to Romania.
Italian tax legislation made it impossible for him to make a profit, so he felt forced to move out.

[SwePatrick]

The racetrack is the ultimate tool, the dyno being the second most representative.


Yeah,, only problem i ain´t got a track in my garage =)

[Peter1962]

It's already been done. Last week Andrea told me that he has now finished moving all his equipment, including his magnesium foundry, to Romania.
Italian tax legislation made it impossible for him to make a profit, so he felt forced to move out.

Will he still be active in contruction of 2 stroke competition engines ? The 125cc kart market seems to become a TM-only market...

[Frits Overmars]

Will he still be active in contruction of 2 stroke competition engines ? The 125cc kart market seems to become a TM-only market...Yes he will. And it's true that TM has a firm grip on the 125 cc shifter kart market, although DEA has a beautiful KZ125 engine; the only one in its class with a balance shaft and a coolant pump, while all other engines rely on a rear axle-driven pump that does nothing for engine cooling when you are gassing it on the start line.
338853338854338855338856

[schutten]

Will he still be active in contruction of 2 stroke competition engines ? The 125cc kart market seems to become a TM-only market...

But yesterday Patrik Hajek became FIA ​​Karting World Champion with a VORTEX engine.
Maybe more vortex from now on :P

[Muhr]

And what changes combustion efficeny?
The density?

What I can see in sim is that if you are flowing at higher speeds you can see that the smaller transfer is picking up speed further down in the transfer because of it seems to have a less tendency to choke as we approach the transfer port . You can begin to see it after about 0.0008 sec. On the left incompressible, right compressible, up speed and down pressure / density. If this would have any effect in reality then it should start to be clear after 10000 rpm

[jonny quest]

Were the edges of the intake ports leading into crankcase on RSW, RSA 125 contoured, or left sharp?

Clarify... the rotary valve port from the carb, where it ends in crankcase. Not the transfers.

[DaisyB]

Yes he will. And it's true that TM has a firm grip on the 125 cc shifter kart market, although DEA has a beautiful KZ125 engine; the only one in its class with a balance shaft and a coolant pump, while all other engines rely on a rear axle-driven pump that does nothing for engine cooling when you are gassing it on the start line.
338853338854338855338856

They make some rather splendid looking Vespa barrels as well!

[wobbly]

A Vortex won in the weekend, but it was a situation exactly like 250 GP with Aprilia, the fast TM guys keep taking each other out, or ruining each others points totals.
If you look at the lap times DeConto / TM qualified 17th due to a loose hose, that dumped water on the track that then ruined a lot of others times.
He was the fastest in the final going from 14 to 5th , if he had started top 4 it was an easy win..
DEA will never be a force in top level KZ racing , no matter how good the engines are technically, as you have 10 genuine factory supported TM drivers , tuned by Franco on the day.
Its a case of better / more data , better/more support at every championship round.

https://www.youtube.com/watch?v=Pv5s_n66W9Y

[jbiplane]

Does anyone have 3d or drawings of modern 50...70 cc 2-stroke cylinder? Going to produce by cnc milling.

Want to try out milled cylinders on high rpm boxers. Doing CFD optimization of boxer intaje after reed valve.
http://www.reaa.ru/yabbfiles/Attachments/Merger.jpg
I use stream divider (white area at the top) to cut and isolate incoming air of rotating cranckshaft.
May be same approach would be useful for one cylinder engines.

[karter444]

Hi Wobbly
I have just pulled the insert out of the head for the first time and was expecting it to be a tap fit with an o,ring around the plug thread boss , but obviously found it to be a press fit with the insert shape the same as the head shape . As no water flows around the insert, heat transfer relies on the interference fit between the insert and head . Do you think that this is the best way to run or do you modify the head and insert to allow water flow directly over the insert .I had a mate who couldnt remove the plug because the insert was turning , but it didnt seem to detonate or run hot with minimal contact between the head and insert but only ran it like that for one meeting .
cheers Richard

[wobbly]

The B is a different animal to the C as far as heat path is concerned.The way a B is set up you cant do what is required - that is to cool the area above the squish
and the area around the plug threads , but have the chamber itself alot hotter..
The stock C has one little trick , that is a small recess behind the main part of the combustion chamber - this means an air gap to the water cooled cover alloy.
Im not going to show you how I do it , as its being tested for the D model now, but with slots and drillings you can get the parts cool that need to be , but maintain the hotter chamber surface.
The biggest fuckup is of course having the squish spigoted down inside the cylinder 3.4mm , with a layer of chrome around it , and miles from cooling water.
Fix that and you are 1/2 way there.

[karter444]

The B is a different animal to the C as far as heat path is concerned.The way a B is set up you cant do what is required - that is to cool the area above the squish
and the area around the plug threads , but have the chamber itself alot hotter..
The stock C has one little trick , that is a small recess behind the main part of the combustion chamber - this means an air gap to the water cooled cover alloy.
Im not going to show you how I do it , as its being tested for the D model now, but with slots and drillings you can get the parts cool that need to be , but maintain the hotter chamber surface.
The biggest fuckup is of course having the squish spigoted down inside the cylinder 3.4mm , with a layer of chrome around it , and miles from cooling water.
Fix that and you are 1/2 way there.

Thanks Wobbly for the reply , having looked at pictures online i can see the obvious difference between the B and C insert , it appears that the C insert has water flow completely around it for cooling . A couple of questions regarding this
.Does the C head and insert fit straight on the B
barrel .
Am i correct in assuming the only way to get rid of the 3.4.mm spigot is to machine /grind 3.4 mm off the top of the barrel and machine a new insert to suit .
Is the design you have for the D basically the C head and insert modified to limit or eliminate coolant flow over the chamber surface but keeping
squish and plug threads cool
cheers Richard

[wobbly]

Yes , a C top end will bolt straight onto a B.
Yes machining off the top of the cylinder eliminates alot of the deto issues and allows alot leaner jetting.
Yes I have modified a C head cover and CNC machined a new insert that keeps the squish and plug cool , but allows the back side of the chamber to run hotter..
No, the C insert does not have water all around it although as you say, it looks like it does.

[karter444]

Yes , a C top end will bolt straight onto a B.
Yes machining off the top of the cylinder eliminates alot of the deto issues and allows alot leaner jetting.
Yes I have modified a C head cover and CNC machined a new insert that keeps the squish and plug cool , but allows the back side of the chamber to run hotter..
No, the C insert does not have water all around it although as you say, it looks like it does.

Thanks for the reply
cheers Richard

[husaberg]

Yes, they definitely did much better than Yamaha and Suzuki!

It would, until you need to split the cases. I'd rather glue the spacer to the cylinder. But I'd never weld it.

Scan rsw/rsa aprilia

Frits Jan or and other Euros Dutch power etc....


Are you familiar with Albert Siegers i can only find that he raced in the 70s with (Maybe)RG500 and TZ's.
Also do you know anything of Wout Rijn
I believe they were both Dutch?

[jamathi]

Frits Jan or and other Euros Dutch power etc....


Are you familiar with Albert Siegers i can only find that he raced in the 70s with (Maybe)RG500 and TZ's.
Also do you know anything of Wout Rijn
I believe they were both Dutch?

Albert Siegers is a good friend of mine.
Never knew Wout Rijn...

[husaberg]

Albert Siegers is a good friend of mine.
Never knew Wout Rijn...
Cheers Jan

(Pm sent)

[jamathi]

Were the edges of the intake ports leading into crankcase on RSW, RSA 125 contoured, or left sharp?

Clarify... the rotary valve port from the carb, where it ends in crankcase. Not the transfers.

In the RSA it was left sharp, the RSW was contoured

[dutchpower]

Mechanic from jumping Jack

[TZ350]

.
I ran some simulated crankcase pressure traces with the minimum in the middle because I wanted to see if there was anything useful there that I could use for my EFI efforts.

I was expecting the crankcase pressure to be low at Idle. But to my surprise the crankcase pressure remains relativly high. So how does the motor slow down to an idle with all that air/fuel to burn. :confused: my guess is, it can't be air/fuel but pollution.

338962 338963 338964

The peak on the left looks like air that went into the crankcase then bounced out again, as it does. Or maybe, exhaust gases back flowing down the transfers into the crankcase.

Pollution from the exhaust may explain why the minimum crankcase pressure can be the highest and much the same at idle and low RPM whatever the throttle position.

Exhaust pollution in the crankcase may also explain why the motor idles when the throttle is near shut in spite of the average crankcase pressure being the highest, much higher than at WOT.

A 4S motor has a throttle plate with an inlet tract attached to a fairly good piston pump so its inlet MAP is low at idle and high at WOT.

A 2S also has a throttle plate but its inlet tract is attached to something that acts more like a pulse jet engine than a pump.

A 2S crankcase MAP is high at idle and lower at WOT. So MAP behavior for a 2S is quite different to what we are used to from a 4S.

338965

The yellow line is a crankcase pressure MAP data log I took when the bike was on the dyno and it tends to support the notion that the crankcase pressure is relativly high at idle and low rpm and the average drops at higher throttle openings. The crankcase MAP at idle is very close to ambient air pressure. White line is TPS and Brown is RPM.

Looking for the peak crankcase pressure had already been suggested by Flettner. So for 2S EFI my current thinking is to expand on that and take the difference between the minimum crankcase pressure seen in the middle of the simulated graphs and the maximum that is seen on the right hand side where the piston is compressing the actual air that was trapped in the crankcase and using the difference as an air flow indicator.

To me this difference seems to give the best indication of mass air flow. With the difference at 65% being about 0.33 bar, 15% 0.20 bar and 5% 0.15 bar at a rough guess.

If we do something like MAP = (Max - Min) * 3

Then 65% on the pipe would be 0.99 bar
And 15% on the pipe would be 0.60 bar
And 5% on the pipe would be 0.45 bar

They Look like useful traditional 4S MAP values to me and something that a EFI CPU can use and off the pipe situations would easily show up as a lower MAP values.

[TZ350]

.
Like most people I guess, I just assumed that a 2S crankcases pressure behaved like a 4S inlet manifold. Low pressure when the throttle was closed and high when the throttle is open. But for a 2S that is not true, in fact its the complete reverse and another example of the mistake of trying to apply 4S thinking to a 2S.

[lodgernz]

Anyone tried Pyro Putty 1000 before?
http://www.aremco.com/ceramic-metallic-pastes/
Just bought some, approx $100AUD for a kit which makes about 250ml. Going to try it in the exhaust duct and AUX EX ports to test different shapes before welding/replating. Fingers crossed it holds together long enough to get some decent dyno runs in.


I used it to lower the Aux ports on a Rotax 257 for sprint kart use.
Worked fine.
But the issue with filling the main duct with it means the ceramic putty will be a first class insulator - the retained charge will overheat
and you will loose power.
No matter how good the " shape " may be.

Wobbly, do you think this would be OK for transfers? I'm finding DevCon a bit unreliable.

[F5 Dave]

Was that the issue on Sunday?
Cleanliness is next to Godliness (trying to work a suitable joke in there, work in progress).
Also centre punch marks to give something to key onto.

Presumably some engines with less blowdown will fire hotter and longer ex gasses down the transfers.

[lodgernz]

Was that the issue on Sunday?
Cleanliness is next to Godliness (trying to work a suitable joke in there, work in progress).
Also centre punch marks to give something to key onto.

Presumably some engines with less blowdown will fire hotter and longer ex gasses down the transfers.

No. The issue on Sunday was 6-month-old fuel. Both normally reliable engines detoed their pistons to death.
Very embarrassed.

The issue I'm having with DevCon is getting it to cure. No matter how accurately I measure the quantities, and provide appropriate recommended curing temperatures, it remains sticky and able to be dug out.
Maybe past its best by date, but everything I've read says there's no shelf life limit.

[F5 Dave]

There was a chap doing 4 stroke inlets with JB Weld. I've got a few tubes if you want to try it. Seems fine. Can get singles at Mitre10.

[diesel pig]

Maybe past its best by date, but everything I've read says there's no shelf life limit.

I was on the Devcon site the other night and I am pretty sure it said Devcon F had no shelf life limit if unopened but once opened it would last about 3 years.
How long has it been since you opened your lot?

[husaberg]

According to the figures JB welds adhesive strength is lower.
http://iedaddy.com/2011/09/many-uses-of-j-b-weld-but-is-devcon-is-better/

if the devcon is going off properly thats more likely the issue imo.

highest temp stuff i have seen
https://www.aremco.com/ceramic-metallic-pastes/

[lodgernz]

I was on the Devcon site the other night and I am pretty sure it said Devcon F had no shelf life limit if unopened but once opened it would last about 3 years.
How long has it been since you opened your lot?

Probably about 3 years. Bugger.

[Flettner]

.
Like most people I guess, I just assumed that a 2S crankcases pressure behaved like a 4S inlet manifold. Low pressure when the throttle was closed and high when the throttle is open. But for a 2S that is not true, in fact its the complete reverse and another example of the mistake of trying to apply 4S thinking to a 2S.

A discovery of significance and no one seems to notice😎
Keep up the good work, I'm watching.

[jonny quest]

Awesome stuff TZ350. I had about 5 things to rationalize, then I remembered you're rotary valve... would it be similar in case reed scenario? I started thinking too much and I hypothesized too many things that made sense then didn't make sense, lol. Great work. I'm going to have to re read your posts multiple times

[TZ350]

Awesome stuff TZ350. I had about 5 things to rationalize, then I remembered you're rotary valve... would it be similar in case reed scenario?

I have not checked but I expect so, rotary valve, 24/7, reed, case reed or piston port would all have the same crankcase pressure scenarios. If anyone wanted to, they could use something like EngMod2T to check.

The lowest crankcase pressure is with the piston at TDC, and that makes sense.
The highest crankcase pressure is with the piston about 140 ATDC, sort of makes sense too.

At 140 ATDC the inlet is closed and the transfers and exhaust port are open. Some mixture is flowing out the transfers but not fast enough for all of it to escape before the piston gives the remaining mixture in the crankcase a hurry up.

The pipe should be starting to suck real hard around that point too, so you have a real push pull situation accelerating the transfer of fresh charge into the cylinder.

If the pipe is not sucking that hard you will have a higher residual pressure left in the crankcase. That explains why at idle and low throttle at low revs the crankcase pressure is higher than when the throttle is wide open and the motor is singing on the pipe. With high crankcase pressure exhaust gas pollution explains why when the throttle is closed the motor slows down to an idle.

At idle the motor is running on a very small amount of fresh air mixed with a lot of pollution that has back flowed from the exhaust. I am not sure if the crankcase is full of pollution or its full of clean mixture and only a small amount is being transferred to a cylinder full of un scavenged pollution, maybe a bit of both so the story is not completely told yet.

But one thing is for sure, the crankcase pressure is higher at idle and low throttle than it is at wide open throttle with the motor making real power.

338968

[breezy]

I have not checked but I expect so, rotary valve, 24/7, reed, case reed or piston port would all have the same crankcase pressure scenarios. If anyone wanted to, they could use something like EngMod2T to check.

The lowest crankcase pressure is with the piston at TDC, and that makes sense.
The highest crankcase pressure is with the piston about 140 ATDC, sort of makes sense too.

At 140 ATDC the inlet is closed and the transfers and exhaust port are open. Some mixture is flowing out the transfers but not fast enough for all of it to escape before the piston gives the remaining mixture in the crankcase a hurry up.

The pipe should be starting to suck real hard around that point too, so you have a real push pull situation accelerating the transfer of fresh charge into the cylinder.

If the pipe is not sucking that hard you will have a higher residual pressure left in the crankcase. That explains why at idle and low throttle at low revs the crankcase pressure is higher than when the throttle is wide open and the motor is singing on the pipe. With high crankcase pressure exhaust gas pollution explains why when the throttle is closed the motor slows down to an idle.

At idle the motor is running on a very small amount of fresh air mixed with a lot of pollution that has back flowed from the exhaust. I am not sure if the crankcase is full of pollution or its full of clean mixture and only a small amount is being transferred to a cylinder full of un scavenged pollution, maybe a bit of both so the story is not completely told yet.

But one thing is for sure, the crankcase pressure is higher at idle and low throttle than it is at wide open throttle with the motor making real power.

338968

TZ, I Think you already new this, but being told and seeing it for yourself is two different things. Seeing this information for me helps to realise the the significance of blow down , flow reversal ,lower and wide transfer ports, poor idling at low rpm, exhaust function taking over from engine pumping as rpm increases.:niceone:

[dutchpower]

But one thing is for sure, the crankcase pressure is higher at idle and low throttle than it is at wide open throttle with the motor making real power.

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[dutchpower]

But one thing is for sure, the crankcase pressure is higher at idle and low throttle than it is at wide open throttle with the motor making real power.

338968[/QUOTE]

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[jonny quest]

So, when a 2stroke comes "on pipe" is it the crankcase having a clean mixture versus a polluted mixture in crankcase?

[TZ350]

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

High crankcase pressure at idle and lower at WOT. Takes a bit of getting your head around but it is all laid out with pictures in the original post.


I ran some simulated crankcase pressure traces with the minimum in the middle because I wanted to see if there was anything useful there that I could use for my EFI efforts. I was expecting the crankcase pressure to be low at Idle. But to my surprise the crankcase pressure remains relatively high. So how does the motor slow down to an idle with all that air/fuel to burn. :confused: my guess is, it can't be air/fuel but pollution.

[TZ350]

So, when a 2stroke comes "on pipe" is it the crankcase having a clean mixture versus a polluted mixture in crankcase?

"On the Pipe" the air is cleaner and the pressure in the crankcase is lower because the pipe is sucking the crankcase down faster than the inlet can re fill it at WOT.

At idle the crankcase pressure is higher, everything has a higher average pressure, inlet, crankcase and pipe. They are all near ambient air pressure.

The engine idles on closed throttle because there is only a small mass of air/fuel passing through the crankcase.

I suspect the crankcase may be highly polluted by back flowing poorly purged combustion products but not entirely sure about that point.

[Vannik]

I suspect the crankcase may be highly polluted by back flowing poorly purged combustion products but not entirely sure about that point.

The software gives you the purity at the entrance and exit of each transfer passage as well as the purity in the crankcase and inlet port.

[Flettner]

run this pressure trace without a pipe, what do you see?
Or perhaps a short stub.

[TZ350]

The software gives you the purity at the entrance and exit of each transfer passage as well as the purity in the crankcase and inlet port.

Good point. I will have a look.

[tdc211]

Just use splash zone in tranfers/Ebay.
Its marine green epoxy. Same shit prostock eng use
In USA for ever. Its not coming out of tranfers. If you preheat a touch and post heat more
.

Now I have mucked up a lot of tranfers.
That being said. On one particular cylinder I was close to ktm new 105 cylinder. In the mid . But I didn't know why. It definitely was the volume/outside and inner radius . And pipe I had on. Everything! Even with not great corner radius in export. Not just one roof angle or something.
It is a whole! You make them 1/2 moon shape and the roof/floor angles just part of that shape. I am convinced this ups the combustion efficiency. I use a feeler gauge . Snip end some. Bend 1/3 to desired root angle . Like a Mason trowel and put the roof angles in as splash zone kinda thick. Then I take a popsicle stick hit on the disk sander at one end (thin) and do the inner/out. and the popstick kinda bends with the radius I am trying to make.
That's after grinding out shit inner 1st.
Then no choice but mold it. To see what you have.
I built the best 105 I ever have. (Which I charged way less $ than my epoxy cylinder 105, cause it was a lot easier) And guy thinks I charged him
To much. I hate mx.

On a side note 10 or 20 degree roof means nothing unless tranfers work. Been there tried that. And transfer blip on blue page in sim is way higher now after the change in combustion efficiency. Trapping is good to.

Here's another thing. I ground out stock floor on one cylinder.
It had a good inner and 25 epoxy roof or so. As soon as that 1/2 moon was ground in the floor. Under the sink the streams where absolutely junk with aggressive floor angle. You make floor straight,streams back to a normal.
So the roof and outer wall is vital here to straighten the streams out with aggressive floor angle. Or the volume.
Idk length a big part to am sure. But I rather be to small than to big.

New cylinder in pic

[TZ350]

.
The straight lines represent the Crankcase purity.

338992 6,000 rpm. crankcase and cylinder similar to each other at 77-97% for the different throttle openings.

338991 9,000 rpm. peak torque and greatest variation in cyl purity 20-98% but CC much closer at 85-98%

338990 12,000 rpm. peak power and crankcase 88-99% Cly 46-99%

So at idle and low speed the crankcase is at its most polluted but not as much as I expected.

At idle only a small trickle of fresh charge is entering the crankcase and although the average pressure in the crankcase is high only a matching trickle of fresh mixture can be moving out the other side to the cylinder because the average pressure is equally high throughout the whole system.

[breezy]

The software gives you the purity at the entrance and exit of each transfer passage as well as the purity in the crankcase and inlet port.

how is the software able to calculate this? what sort of info is required?:scratch:

[dutchpower]

Just use splash zone in tranfers/Ebay.
Its marine green epoxy. Same shit prostock eng use
In USA for ever. Its not coming out of tranfers. If you preheat a touch and post heat more
.

Now I have mucked up a lot of tranfers.
That being said. On one particular cylinder I was close to ktm new 105 cylinder. In the mid . But I didn't know why. It definitely was the volume/outside and inner radius . And pipe I had on. Everything! Even with not great corner radius in export. Not just one roof angle or something.
It is a whole! You make them 1/2 moon shape and the roof/floor angles just part of that shape. I am convinced this ups the combustion efficiency. I use a feeler gauge . Snip end some. Bend 1/3 to desired root angle . Like a Mason trowel and put the roof angles in as splash zone kinda thick. Then I take a popsicle stick hit on the disk sander at one end (thin) and do the inner/out. and the popstick kinda bends with the radius I am trying to make.
That's after grinding out shit inner 1st.
Then no choice but mold it. To see what you have.
I built the best 105 I ever have. (Which I charged way less $ than my epoxy cylinder 105, cause it was a lot easier) And guy thinks I charged him
To much. I hate mx.

On a side note 10 or 20 degree roof means nothing unless tranfers work. Been there tried that. And transfer blip on blue page in sim is way higher now after the change in combustion efficiency. Trapping is good to.

Here's another thing. I ground out stock floor on one cylinder.
It had a good inner and 25 epoxy roof or so. As soon as that 1/2 moon was ground in the floor. Under the sink the streams where absolutely junk with aggressive floor angle. You make floor straight,streams back to a normal.
So the roof and outer wall is vital here to straighten the streams out with aggressive floor angle. Or the volume.
Idk length a big part to am sure. But I rather be to small than to big.

New cylinder in pic

The volume

[teriks]

"On the Pipe" the air is cleaner and the pressure in the crankcase is lower because the pipe is sucking the crankcase down faster than the inlet can re fill it at WOT.

At idle the crankcase pressure is higher, everything has a higher average pressure, inlet, crankcase and pipe. They are all near ambient air pressure.

The engine idles on closed throttle because there is only a small mass of air/fuel passing through the crankcase.

I suspect the crankcase may be highly polluted by back flowing poorly purged combustion products but not entirely sure about that point.
Are you sure that the average pipe pressure with the throttle closed and at "on the pipe rpm's" are lower than at idle rpms?
I would have guessed about the same, close to ambient. All the rest I tend to agree with.

For sure at WOT, the average pipe pressure increase with power.
Not too surprising given the restriction at the stinger, and also the reason we can use pipe pressure to assist in fuel metering in F3D (or just about any RC related two-strokes).
I don't have a throttle on any of my models, but a quick run @ WOT and a few different RPMs with the pressure transducer in the center of the belly section below:
338996
I doubt that such a signal would be very useful for your injection experiments though.
Perhaps the variation is way too small to be meaningful at smaller throttle openings,
and there should also be a bit delay building the pressure so would be bloody difficult regulating cycle to cycle I guess.

[tdc211]

The volume

Double post.

[tdc211]

The volume

Yes I agree.. Less volume at the floor with a aggressive floor angle. Your sort of taking volume from the floor and putting it on outer radius so it can swoop in. And keep streams strong.
The new 105 has the most aggressive floor angle and least amount of volume I have seen

[Nath88]

338996


I assume 33000rpm is close to resonance teriks? What happens past peak?
I still think the pressure rise after EPO is a great indicator of the following suction pulse (pipe boost effect in general) and therefore next cycle fueling. It worked really well when I tested it, but my ECU couldn't adjust for the delay by RPM vs. crank angle. So it only worked around the RPM range I had it adjusted for. Also the piezo disc I used was too big, so the signal output was huge and it quickly destroyed itself.

Just need to find a few hundred bucks to get the YZ cylinder plated before I can get it running again and continue testing.

[TZ350]

"On the Pipe" the air is cleaner and the pressure in the crankcase is lower because the pipe is sucking the crankcase down faster than the inlet can re fill it at WOT.
At idle the crankcase pressure is higher, everything has a higher average pressure, inlet, crankcase and pipe. They are all near ambient air pressure.
The engine idles on closed throttle because there is only a small mass of air/fuel passing through the crankcase.
I suspect the crankcase may be highly polluted by back flowing poorly purged combustion products but not entirely sure about that point.

Are you sure that the average pipe pressure with the throttle closed and at "on the pipe rpm's" are lower than at idle rpms?
I would have guessed about the same, close to ambient. All the rest I tend to agree with. For sure at WOT, the average pipe pressure increase with power.

No, I was looking at the crankcase pressures, although I did look at the pipe some time ago and what you say about it makes sense.

I would love to know more about your pressure transducer. It sounds like something I could use if its affordable.

[TZ350]

So, when a 2stroke comes "on pipe" is it the crankcase having a clean mixture versus a polluted mixture in crankcase?

Yes, 98% clean mixture at WOT and 9,000 rpm, 15% polluted with only 85% purity at minimum throttle and 9,000 rpm according to this simulation of my engine.

338998

[teriks]

I assume 33000rpm is close to resonance teriks? What happens past peak?
I still think the pressure rise after EPO is a great indicator of the following suction pulse (pipe boost effect in general) and therefore next cycle fueling. It worked really well when I tested it, but my ECU couldn't adjust for the delay by RPM vs. crank angle. So it only worked around the RPM range I had it adjusted for. Also the piezo disc I used was too big, so the signal output was huge and it quickly destroyed itself.

Just need to find a few hundred bucks to get the YZ cylinder plated before I can get it running again and continue testing.
Yes, 33kRPM is close to peak power, will do another run to show past peak later.
-Dont have access to the sim here.

For sure measuring the pulse close to the port at EPO would give better data. I also like the idea posted earlier where you sample combustion pressure thru the cylinder wall right before EPO. But as seen from your and TZ's work there seems to be no simple, cheap and robust method.. yet.


No, I was looking at the crankcase pressures, although I did look at the pipe some time ago and what you say about it makes sense.

I would love to know more about your pressure transducer. It sounds like something I could use if its affordable. Unfortunately the data was from the sim.
As far as real world stuff you are miles ahead already with your carbs, not to mention your injection systems.
We have a very crude form of carb where a simple needle acts as main jet, and the fuel tank, vented to the pipe belly, can be compared to the float bowl. No electronics, varying fuel level in the "bowl", and not even a throttle.. still works surprisingly well.

[Muhr]

Yes, 98% clean mixture at WOT and 9,000 rpm, 15% polluted with only 85% purity at minimum throttle and 9,000 rpm according to this simulation of my engine.




Hello tz
I have a bit of a difficulty understand what you have for value of the y axis in the graph?
As I understand this is the crankcase?

[Vannik]

Hello tz
I have a bit of a difficulty understand what you have for value of the y axis in the graph?
As I understand this is the crankcase?

1.0 is 100% pure air,
0.0 is 100% burnt gas.

[DoldGuy]

Interesting injector placement....


https://patentimages.storage.googleapis.com/9c/ca/9a/12945ca97f4209/US20180023528A1.pdf

[TZ350]

Interesting injector placement.... https://patentimages.storage.googleapis.com/9c/ca/9a/12945ca97f4209/US20180023528A1.pdf

I think with 2S EFI they should forget trying to look like a carburetor. Just my opinion.

Trying to mimic a carburetor is unlikely to work well everywhere because the air flows all the time and the fuel is injected in discreet amounts so homogeneous mixture can be a problem. In extreme situations most of the fuel could be in the bit of air that disappears down the exhaust or gets blown back out of the inlet.

339004

Although it does look great and it allows for staged injection so it could be spun faster than 10,000 rpm and make real power at WOT.

What I would very much like to know, is how do they account for the changes in air flow that occurs when the pipe is working or not.

There are two situations.

RPM + TPS and Pipe working, and engine making power.

Same

RPM + TPS but Pipe not working, different air flow, less fuel required, how do they see that? This is where I am stuck with my own project.

[Muhr]

1.0 is 100% pure air,
0.0 is 100% burnt gas.

Thanks Vannik

Then I think I understand! The red and dark blue etc are simulated values ​​from the combustion chamber or somewhere nearby

[tdc211]

My cylinder purity not good in sim on new 105. Like 93-94%..
With or without combustion %, set on higher %.
So I assume my purity is higher in real life.
Which I think a lot of this comes back to the new tranfers.

[ceci]

I think with 2S EFI they should forget trying to look like a carburetor. Just my opinion.

Trying to mimic a carburetor is unlikely to work well everywhere because the air flows all the time and the fuel is injected in discreet amounts so homogeneous mixture can be a problem. In extreme situations most of the fuel could be in the bit of air that disappears down the exhaust or gets blown back out of the inlet.

339004

Although it does look great and it allows for staged injection so it could be spun faster than 10,000 rpm and make real power at WOT.

What I would very much like to know, is how do they account for the changes in air flow that occurs when the pipe is working or not.

There are two situations.

RPM + TPS and Pipe working, and engine making power.

Same

RPM + TPS but Pipe not working, different air flow, less fuel required, how do they see that? This is where I am stuck with my own project.

Another mark more than to regressed (KTM first), direct injection to the cylinder, has to inject into the crankcase

[ceci]

Another mark more than to regressed (KTM first), direct injection to the cylinder, has to inject into the crankcase

bimota also backed down

[teriks]

I assume 33000rpm is close to resonance teriks? What happens past peak?.
Not too many data points, but for sure the average pressure drops after peak power.
339010

[husaberg]

I think with 2S EFI they should forget trying to look like a carburetor. Just my opinion.

Trying to mimic a carburetor is unlikely to work well everywhere because the air flows all the time and the fuel is injected in discreet amounts so homogeneous mixture can be a problem. In extreme situations most of the fuel could be in the bit of air that disappears down the exhaust or gets blown back out of the inlet.

339004

Although it does look great and it allows for staged injection so it could be spun faster than 10,000 rpm and make real power at WOT.

What I would very much like to know, is how do they account for the changes in air flow that occurs when the pipe is working or not.

There are two situations.

RPM + TPS and Pipe working, and engine making power.

Same

RPM + TPS but Pipe not working, different air flow, less fuel required, how do they see that? This is where I am stuck with my own project.

I think they mimic it as it works.
I dont think its a co-incidence that if you plot the fuel flow of a carb against a engines power graph that they are the same shape.
One advantage a carb has is its immediate response to changes in airflow.
This has to be built into a 2t injection system from the get go as 4ts are much more forgiving as they are less time constrained and have lesser speed requirements.
that being said i think for it to work great in your situation on petrol it needs tiny injectors in multiple stages and extremely fast processing speeds.
These have only really became affordable and available in the last few years.
The work around for these current constraints with current tech as i see it is using very high injector pressures and multiole fast responding small injectors.
I think the timing of the injection sequence is the most important thing in regards to reducing emissions rather then getting the right amount of fuel ad a given rpm /load etc.
Flets transfer injection seems to be the go.

[Flettner]

intetesting, some spy photos I've just seen of TM's secret test enduro bike, (next years model? Im not sure its that secret if I got to see them��) but clearly seen on the side of the cylinder is TPI B port lugs to accept injectors, Same as KTM and the YZ250 TPI.
I did dangle the advantages of the Mk2 TPI in front of TM but they seemed not intetested.
Yes a modified version of the TPI is the answer, more power, better fuel economy.
But just like the original TPI system no one is interested, untill, suddenly, they are. I intend to have some fun with this next design before, 'suddenly they are'.

[husaberg]

its a bit late for april fools.
https://latestmxvideos.com/index.php/2018/09/21/honda-announces-cr500/

this has been floating about for a while now along with its injected and accompanied by a 125 and 250.

https://latestmxvideos.com/index.php/2017/08/10/honda-announced-2-stroke-comeback-for-2019/

I think its a pipe dream myself

[TZ350]

One advantage a carb has is its immediate response to changes in airflow. This has to be built into a 2t injection system from the get go.

Injector and CPU speed are good enough now and it is easy to build in immediate response to changes in airflow if you can see the changes clearly. Which is something I cant do yet and suspect nobody else can either, especially above 10,000 rpm and 10 bar BMEP. Like you say, being able to read the airflow situation is the key to successful two stroke EFI.

[husaberg]

Injector and CPU speed are good enough now and it is easy to build in immediate response to changes in airflow if you can see the changes clearly. Which is something I cant do yet and suspect nobody else can either, especially above 10,000 rpm and 10 bar BMEP. Like you say, being able to read the airflow situation is the key to successful two stroke EFI.
When i say injector speed and CPU speed i are meaning to get the injector timing screwed down to make the emissions tiny as with DI yet still be drive-able with similar response as a carb. Plus decent HP.
CPU might be there but i dont think the common injector are.
I cant remember what Cagiva and Honda were using but the pressure was huge.
he looks 180PSI..............
Honda no idea but i think they had to go with mechanical pump like Cagiva did so likely a lot as well
I should note that F1 race car also use mechanical pumps running i presume huge pressures
I know bosch do a 200 bar and a 500 bar version for something
i GUESS THE 500 BAR ONE IS dI
http://www.bosch-motorsport.de/content/downloads/Products/9007209798077963.html#teaser
http://www.formula1-dictionary.net/direct_injection.html

[TZ350]

339012

500 bar or 7,000 psi more or less. I have had a bit to do with this sort of pressure but it would be interesting to know how they use this in motor sport. Continuous injection on a turbo/supercharged diesel tractor pull motor maybe. Pretty Impressive. Certainly you could use that sort of pressure for two stroke DI.

<iframe width="560" height="315" src="https://www.youtube.com/embed/noduC7hjQyc" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen=""></iframe>

[husaberg]

500 bar or 7,000 psi more or less. I have had a bit to do with this sort of pressure but it would be interesting to know how they use this in motor sport. Continuous injection on a turbo/supercharged diesel tractor pull motor maybe. Pretty Impressive. Certainly you could use that sort of pressure for two stroke DI.



no idea but it came up when i googled F1 fuel injection pump
i dont folow f1 so i dont even know know f1 rules now dictate it must be D1 single injector.

[Peter1962]

intetesting, some spy photos I've just seen of TM's secret test enduro bike, (next years model? Im not sure its that secret if I got to see them��) but clearly seen on the side of the cylinder is TPI B port lugs to accept injectors, Same as KTM and the YZ250 TPI.
I did dangle the advantages of the Mk2 TPI in front of TM but they seemed not intetested.
Yes a modified version of the TPI is the answer, more power, better fuel economy.
But just like the original TPI system no one is interested, untill, suddenly, they are. I intend to have some fun with this next design before, 'suddenly they are'.

The French magazine 'Moto Verte' has a list of the new items on the 2019 TM 250 2stroke engines. New engine with counter balander, with electric starter, with new electronic powervalve system without cables. In it's enduro trim they are gonna sell it with a carb till 31/12/18 and in 2019 with fuel injection. In it's MX trim, no injection however. They follow the route taken by KTM and it's cousin Husqvarna.
https://moto-station.com/moto-verte/actu/nouveaute-ce-qui-change-sur-les-tm-racing-2019/403106

[teriks]

Injector and CPU speed are good enough now and it is easy to build in immediate response to changes in airflow if you can see the changes clearly. Which is something I cant do yet and suspect nobody else can either, especially above 10,000 rpm and 10 bar BMEP. Like you say, being able to read the airflow situation is the key to successful two stroke EFI.
Perhaps you could check if BRC would like to share information, seems they had an EFI attempt going but abandoned it due to lack of market.

From Facebook:
"We intended this to be a simple bolt-on conversion, so we wanted it to mimic carbs. We timed the injection pulse with the disc valve opening... Slightly before if I'm not mistaken. We weren't too sure if the carbon discs would have sufficient lubrication if we injected inside the cases or cylinder. It worked VERY well, but the development stopped due to a shrinking market for the BRC engine in the USA. Other countries wouldn't allow EFI."

Seems to work alright on the dyno at least.


https://www.youtube.com/watch?v=dNat9ZwWbq8

https://www.facebook.com/brcracingcanada/

[Nath88]

Not too many data points, but for sure the average pressure drops after peak power.
339010

Looks like a great indicator. Could be used for real time flow indication with the right transducer. Piezo could work here for sure, I just need to make one that works, preferably directly attached to the pipe.

Multiplier fuel table based on the exhaust pressure pulse value. Easy!

A more basic/robust system could have a table for amount of misfire cycles based on TPS and RPM (to skip or reduce injector duration when misfire is likely), then have the feedback from a transducer (ie; did it fire or not) as learning feedback for the table.

[Flettner]

The French magazine 'Moto Verte' has a list of the new items on the 2019 TM 250 2stroke engines. New engine with counter balander, with electric starter, with new electronic powervalve system without cables. In it's enduro trim they are gonna sell it with a carb till 31/12/18 and in 2019 with fuel injection. In it's MX trim, no injection however. They follow the route taken by KTM and it's cousin Husqvarna.
https://moto-station.com/moto-verte/actu/nouveaute-ce-qui-change-sur-les-tm-racing-2019/403106

It will interesting to see how KTM handle this.
Being as they claim they invented TPI and patented it.
Real interesting.

[husaberg]

Perhaps you could check if BRC would like to share information, seems they had an EFI attempt going but abandoned it due to lack of market.

From Facebook:
"We intended this to be a simple bolt-on conversion, so we wanted it to mimic carbs. We timed the injection pulse with the disc valve opening... Slightly before if I'm not mistaken. We weren't too sure if the carbon discs would have sufficient lubrication if we injected inside the cases or cylinder. It worked VERY well, but the development stopped due to a shrinking market for the BRC engine in the USA. Other countries wouldn't allow EFI."

Seems to work alright on the dyno at least.


https://www.facebook.com/brcracingcanada/
Riley wrote about it on Pitlane in about the first or second part.
From memory he said something along the lines of we decided to map it as if it was a carb with the same fuel curve ie they superimposed the fuel graph for a carb and set the map to replicate it.
they had great results with the feel ie not twitchy response by making the fueling less than perfect so it behaved like a carb would have.
I think most of the initial work was done on a single cylinder 125cc test mule.

[ken seeber]

Just some brute hp..

https://www.youtube.com/watch?v=7d3MtfgMalU

[TZ350]

Perhaps you could check if BRC would like to share information, seems they had an EFI attempt going but abandoned it due to lack of market.

From Facebook:
"We intended this to be a simple bolt-on conversion, so we wanted it to mimic carbs. We timed the injection pulse with the disc valve opening... Slightly before if I'm not mistaken. We weren't too sure if the carbon discs would have sufficient lubrication if we injected inside the cases or cylinder. It worked VERY well, but the development stopped due to a shrinking market for the BRC engine in the USA. Other countries wouldn't allow EFI."

Seems to work alright on the dyno at least.


https://www.youtube.com/watch?v=dNat9ZwWbq8

https://www.facebook.com/brcracingcanada/


Yes BRC may be worth a re visit but the first time I came across them I realized they were doing nothing on the dyno that I couldn't my self. You will see that they don't let the rev's drop off the pipe and with only one logical injector (two physical injectors firing alternately) I don't think they could have achieved on track drivability.

Over 10,000 rpm there is no escaping the need for staged injection, a small primary and a much bigger secondary. Its an inescapable physical requirement dictated by the time available. And for 10+ bar BMEP you also need to be able to see the changes in air flow when the pipe is working or not, because the motor is very dependent on the pipe for its power. They were also using the Alpha-N methodology and that does not take account of changes in airflow, it is totally a TPS vis RPM thing and half the time you are on the pipe and the AN map is right and half the time you are off the pipe and the AN map would be wrong and over fueling.

I don't think they did it, maybe I am wrong, can anyone post an on board video clip of a EFI BRC on the track.





Husa put me onto this post in PitLane http://translate.google.co.nz/translate?hl=en&sl=fr&u=http://www.pit-lane.biz/t839p15-technique-2-tempset-l-injection&prev=search

It talks about split injection where a injector fires every second revolution, it may be the way forward. Husa reminded me that he had suggested it to me before ...

Gentlemen,

2 years ago I did an Indirect EFI project on a 125cc Disk Valve Kart Racing Engine. I used a Vortex FC engine which produced 49HP carbureted. With our EFI, it made 55HP!!! The engine was very easy to start and the tuning was very simple. Here is how I did it:

Rather than attach sensors to figure out the everything for me, I went with information that was known to me. I have been tuning Del'Lorto carbs for years and have used their needle charts along with various softwares that calculate Comparative MainJet Sizes at 10% throttle increments. I used this information to calculate an initial map for the injectors. I did a test on the carbureted version at each throttle position to note the EGT that was giving the correct performance. Once running with the EFI i tried to tune it to achieve the same EGT numbers as the carbureted version.

In total I ran for 3 hours on the dyno and ended up with 10% more power everywhere!

The only sensors I used were Throttle Position, Engine RPM, Crank Angle, and Water Temp for initial start up enrichment.

How did I get an injector to fire every cycle at 15000 rpm?????? I didnt! What I did is used a Janvey 41mm butterfly throttle body with 2 injectors on the engine side of the butterfly. That way when the throttle is closed, fuel still feeds the engine to lubricate it like a Pilot Jet would do. To get 15000 RPM, I had each injector firing at alternating engine revolutions. Thereby the injectors were seeing 7500 pulse at 15000rpm of engine speed. I tricked them into thinking this was a 2 cylinder 4 cycle engine firing in Tandem.

In total I spent $1600.00 in componentry to validate my "Simple EFI" idea! I will be doing more tests this winter and will be track testing in the spring. We are workind on the miimum battery requirements and packaging.

I used 2.5 Bar of pressure and will be testing more. I chose a disk valve engine for the symetrical inlet timing. I used a valve the opened at 137 degrees BTDC and closed at 87 degrees ATDC. I started firing the injector 10 degrees earlier on the opening and stopped the injector 10 degrees after the valve closed.

Upon engine disassembly it was noted that the lubraction seemed to be better dispersed thru-out the engine (only an observation). The engine would start at less than 800 rpm of crank speed and would instantly accept full throttle load from 1200 rpm and up!

The only hurdle I see to over come is the packaging.

I am confident that my way of giving the ECU the MAP rather than having the ECU calculate the map is why I was successful. We have tuned by EGT for years and continue to see the relevance when using EFI in correlation to EGT. The increase power came by better fuel atomization. It stands to reason due to the limited time "Tuning" the system that even more power gains are to be realized with more work and data collection/analysis.

I am posting this information so more people will try this simple method and post their results here. I hope you all find the success that I did.

http://translate.google.co.nz/translate?hl=en&sl=fr&u=http://www.pit-lane.biz/t839p15-technique-2-tempset-l-injection&prev=search

[dutchpower]

My cylinder purity not good in sim on new 105. Like 93-94%..
With or without combustion %, set on higher %.
So I assume my purity is higher in real life.
Which I think a lot of this comes back to the new tranfers.

Got this on max power

[teriks]

Riley wrote about it on Pitlane in about the first or second part.
From memory he said something along the lines of we decided to map it as if it was a carb with the same fuel curve ie they superimposed the fuel graph for a carb and set the map to replicate it.
they had great results with the feel ie not twitchy response by making the fueling less than perfect so it behaved like a carb would have.
I think most of the initial work was done on a single cylinder 125cc test mule.



Yes BRC may be worth a re visit but the first time I came across them I realized they were doing nothing on the dyno that I couldn't my self. You will see that they don't let the rev's drop off the pipe and with only one logical injector (two physical injectors firing alternately) I don't think they could have achieved on track drivability.

Over 10,000 rpm there is no escaping the need for staged injection, a small primary and a much bigger secondary. Its an inescapable physical requirement dictated by the time available. And for 10+ bar BMEP you also need to be able to see the changes in air flow when the pipe is working or not, because the motor is very dependent on the pipe for its power. They were also using the Alpha-N methodology and that does not take account of changes in airflow, it is totally a TPS vis RPM thing and half the time you are on the pipe and the AN map is right and half the time you are off the pipe and the AN map would be wrong and over fueling.

I don't think they did it, maybe I am wrong, can anyone post an on board video clip of a EFI BRC on the track.
So much for thinking I found something new on the net, then its old news at ESE, so old I had forgot I read about it here first.. :)
They did have a connection of some kind on the pipe belly in that video thoug, but your most likely correct. Could have been O2, or even pressure to control the power valves. -didnt look closely enough to tell. Oh well..


Just some brute hp..

https://www.youtube.com/watch?v=7d3MtfgMalU
Yeah, I have been following that development on FB, thats how I stumbled on the EFI stuff above.
Very impressive kit, but way too much power for my skill level...

[teriks]

Looks like a great indicator. Could be used for real time flow indication with the right transducer. Piezo could work here for sure, I just need to make one that works, preferably directly attached to the pipe.

Yes, at least for WOT. Might be useless at small throttle openings, or not...

The rest of your post is more TZ territory than mine, I enjoy reading the discussion but have nothing to contribute in the electronics department :)


Multiplier fuel table based on the exhaust pressure pulse value. Easy!

A more basic/robust system could have a table for amount of misfire cycles based on TPS and RPM (to skip or reduce injector duration when misfire is likely), then have the feedback from a transducer (ie; did it fire or not) as learning feedback for the table.

[tdc211]

Got this on max power

that says 85cc, maybe you changed the bore size in sim.
I am sure I don't have to tell you everything that changes when you bore it.

[husaberg]

It will interesting to see how KTM handle this.
Being as they claim they invented TPI and patented it.
Real interesting.
I am all for bringing in the Red Bull ambassadors for questioning.
https://image.shutterstock.com/image-photo/indianapolis-august-26-grid-girls-260nw-84886870.jpg

[Flettner]

I am all for bringing in the Red Bull ambassadors for questioning.
https://image.shutterstock.com/image-photo/indianapolis-august-26-grid-girls-260nw-84886870.jpg

Ha ha love it.

[husaberg]

Ha ha love it.
Nice site with nice bit on Mr Jan Thiel
http://www.classic50racingclub.co.uk/jamathi.html

http://www.classic50racingclub.co.uk/image/2/1/1/6/6/2116680/00969992.jpghttp://www.classic50racingclub.co.uk/image/2/1/1/6/6/2116680/00970036.jpg

[TZ350]

.339032

Simplified drawing of the pressure cycle in a two stroke crankcase. The low pressure is typically at TDC and the Maximum pressure is typically 140 deg ATDC this is much the same for all typical two strokes. The average pressure is high, about 0.8 bar at WOT and near 1 bar at idle.

The difference in height between the maximum and minimum pressures changes with air flow, more air, the bigger the difference.

The plan is to use this difference to see the changes when the engine is on the pipe or not.

The changes are subtle enough to be used as a MAP value in the traditional 4S sense.

[Flettner]

Probably what KTM are doing.

[Frits Overmars]

Nice site with nice bit on Mr Jan Thiel
http://www.classic50racingclub.co.uk/jamathi.htmlNot the best article on Jan Thiel I've ever read. I won't go into all of it; I'll leave that to Jan if he thinks it's worth it. Just one detail: Jan was born on 3 June 1940.

[husaberg]

Not the best article on Jan Thiel I've ever read. I won't go into all of it; I'll leave that to Jan if he thinks it's worth it. Just one detail: Jan was born on 3 June 1940.
I haven't read it yet, I only found it looking for pics of RC115 brakes.

https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=339025&d=1538002398

[F5 Dave]

Axially mounted? How old fashioned!

[JanBros]

Axially mounted? How old fashioned!

look good, they are radial and were ahead of their time :laugh:

[jonny quest]

.339032

Simplified drawing of the pressure cycle in a two stroke crankcase. The low pressure is typically at TDC and the Maximum pressure is typically 140 deg ATDC this is much the same for all typical two strokes. The average pressure is high, about 0.8 bar at WOT and near 1 bar at idle.

The difference in height between the maximum and minimum pressures changes with air flow, more air, the bigger the difference.

The plan is to use this difference to see the changes when the engine is on the pipe or not.

The changes are subtle enough to be used as a MAP value in the traditional 4S sense.

So the pipe is pulling .2bar out of crankcase

[F5 Dave]

look good, they are radial and were ahead of their time :laugh:

Ahh crap I got hung up seeing a mount on one side and my head said if they were on either side they would be radial but of course they are.
Kinda spoiled the joke now.

[husaberg]

Ahh crap I got hung up seeing a mount on one side and my head said if they were on either side they would be radial but of course they are.
Kinda spoiled the joke now.
If it makes you feel better the tires are cross ply.

[TZ350]

So the pipe is pulling .2bar out of crankcase

It looks complicated, a lot of the lowest crankcase pressure is after the inlet has opened, the exhaust port has closed and TDC so the rising piston is playing a part too.

339046

[Frits Overmars]

The lowest crankcase pressure is around TDC so the rising piston must be playing a part too.This way of reasoning could block your brain, TeeZee. The part played by the piston is quite weak compared to what the Helmholtz resonance is capable of.
For example, at low revs you can experience blowback while the piston is still rising, just because the Helmholtz frequency is too high for the inlet angle/rpm combination.

[TZ350]

This way of reasoning could block your brain, TeeZee. The part played by the piston is quite weak compared to what the Helmholtz resonance is capable of.
For example, at low revs you can experience blowback while the piston is still rising, just because the Helmholtz frequency is too high for the inlet angle/rpm combination.

Yep, it's a complicated dance.

[husaberg]

.

Simplified drawing of the pressure cycle in a two stroke crankcase. The low pressure is typically at TDC and the Maximum pressure is typically 140 deg ATDC this is much the same for all typical two strokes. The average pressure is high, about 0.8 bar at WOT and near 1 bar at idle.

The difference in height between the maximum and minimum pressures changes with air flow, more air, the bigger the difference.

The plan is to use this difference to see the changes when the engine is on the pipe or not.

The changes are subtle enough to be used as a MAP value in the traditional 4S sense.
Isnt it more important to see the difference between deceleration and acceleration.
I say this as isn't the issue with fueling related to over run performance vs acceleration fuel mapping?

[crbbt]

whom as seen this?


https://www.youtube.com/watch?v=YEaE6BHyjzg

[Frits Overmars]

whom as seen this?I have :D.
https://www.facebook.com/groups/671081149638729/?multi_permalinks=1900230753390423&comment_id=1900302073383291&notif_id=1537969431040020&notif_t=feedback_reaction_generic

[crbbt]

any dramas with the thread stretching?

[Frits Overmars]

any dramas with the thread stretching?Not at all. Mark used brute force to destroy one of his pistons to the extent that the piston pin was torn out of its holes, but the thread remained impeccable.
I have pictures but I'm not sure I'm at liberty to post them.

[F5 Dave]

I do note he puts the cast piston in backwards. . . Not that I'll cast too many stones since my last brain fart.:lol:
So what stops it rotating? I was thinking it must be heavier but he claims significantly lighter. Won't do farcebook maybe there is answers there.

[husaberg]

I do note he puts the cast piston in backwards. . . Not that I'll cast too many stones since my last brain fart.:lol:
So what stops it rotating? I was thinking it must be heavier but he claims significantly lighter. Won't do farcebook maybe there is answers there.
its helt by two pins i think y he mentions them in the video
i was thinking same thing about weight only potential difference i see in mass is shorter piston pin?

[Flettner]

https://register.dpma.de/DPMAregister/pat/PatSchrifteneinsicht?docId=DE102017102792A1

Does this link work?
KTM have indeed filed for a patent on the TPI system, above is the link.
Fabio from Power CDI found it for me, he suggests it would be a gross injustice if this patent went ahead and I do agree. How will this affect TM for example?
Personally no skin off my nose as I have no financial horse in this race but bugger KTM.

[TZ350]

.
I have expressed my concerns to the Patent Office, this is where you go to bring things to the German Patent Offices attention:-

https://www.dpma.de/english/our_office/contact/

KTM is trying to Patent knowledge that has been in the public domain for some time and this method they wish to make their own is not their original idea or intellectual property.

DE 10 2017 102 792 A1 2018.08.16DE 10 2017 102 792 A1 2018.08.16

If this matters to you I am happy to provide details.

[crbbt]

Not at all. Mark used brute force to destroy one of his pistons to the extent that the piston pin was torn out of its holes, but the thread remained impeccable.
I have pictures but I'm not sure I'm at liberty to post them.

Fair enough Frits.

I am guessing that the piece holding the piston pin isn't torqued overly tight and it's the locking pins achieving both anti rotation of the piston plus stopping the two piece moving independently (at TDC and BDC)

anyway cool concept. hopefully he makes some 125 pistons!

[Haufen]

.
I have expressed my concerns to the Patent Office, this is where you go to bring things to the German Patent Offices attention:-

https://www.dpma.de/english/our_office/contact/

KTM is trying to Patent knowledge that has been in the public domain for some time and this method they wish to make their own is not their original idea or intellectual property.

DE 10 2017 102 792 A1 2018.08.16DE 10 2017 102 792 A1 2018.08.16

If this matters to you I am happy to provide details.


https://register.dpma.de/DPMAregister/pat/PatSchrifteneinsicht?docId=DE102017102792A1
Does this link work?
KTM have indeed filed for a patent on the TPI system, above is the link.
Fabio from Power CDI found it for me, he suggests it would be a gross injustice if this patent went ahead and I do agree. How will this affect TM for example?
Personally no skin off my nose as I have no financial horse in this race but bugger KTM.

In this application for patent (not a patent, yet), KTM wants to patent an operating strategy for a two-stroke engine.

In a nutshell, their first two claims are:

on a two-stroke engine with transfer port injection mostly against the flow direction of the air, using at least one cylinder with two injectors per cylinder each, they use only one injector at a first load range and both injectors at a second load range. (claim 1) When they use one injector, they switch between left and right injector in an alternating manner. (claim 2).

Is this what you did, too? And did you publish it? And did you publish it before Feb 13th 2017?
If your answer is 3x yes, then you could officially complain and in the final patent KTM will have to drop every claim that has been verified as not invented by KTM (usually, some claims remain anyway, but these may not always be worth the effort holding a patent for the manufacturers).

In case you need help translating or filing the complaint etc. let me know.

[Haufen]

Just found out they filed for worldwide (WO) patent, too. Not just german (DE). Unfortunately, the patent is still in german language.

If you choose to complain, then complain against the worldwide patent.

https://register.dpma.de/DPMAregister/pat/PatSchrifteneinsicht?docId=WO002018146251A1&page=1&dpi=300&lang=de&full=true

[ceci]

[url]https://register.dpma.de/DPMAregister/pat/PatSchrifteneinsicht?docId=DE102017102792A1[

Personally no skin off my nose as I have no financial horse in this race but bugger KTM.


If your invention you want to leave free, you do not have to worry.
The other brands that want to use it are those that have to fight and those if they have economic resources such as KTM

[TZ350]

In this application for patent (not a patent, yet), KTM wants to patent an operating strategy for a two-stroke engine.

In a nutshell, their first two claims are:

on a two-stroke engine with transfer port injection mostly against the flow direction of the air, using at least one cylinder with two injectors per cylinder each, they use only one injector at a first load range and both injectors at a second load range. (claim 1) When they use one injector, they switch between left and right injector in an alternating manner. (claim 2).

Is this what you did, too? And did you publish it? And did you publish it before Feb 13th 2017?
If your answer is 3x yes, then you could officially complain and in the final patent KTM will have to drop every claim that has been verified as not invented by KTM (usually, some claims remain anyway, but these may not always be worth the effort holding a patent for the manufacturers).

In case you need help translating or filing the complaint etc. let me know.

Thank you for clarifying what the patient application is for. Looks like claim 1, the position of the injectors is not their original idea but claim 2, alternating the injectors for low load and firing them together at higher load is a novel approach.


If you choose to complain, then complain against the worldwide patent.

https://register.dpma.de/DPMAregister/pat/PatSchrifteneinsicht?docId=WO002018146251A1&page=1&dpi=300&lang=de&full=true

Great, Thanks.

[Norman]

I think that KTM could be on some thin ice here. Given that it is known before Feb 13th 2017 that the concept is working with both injectors in use at the same time, as KTM describe in Claim 1 for the high load, it could very well be that the idea using only one injector at the time, during low load, does not have enough additional technical height to be regarded as inventive enough for granting the patent. It could be argued that a person skilled in the art, would be able to forsee a possible advantage to use the injectors in an alternating sequence during low load, even though it has not been described before Feb 13th 2017. If that is the case, it is very doubtful if the patent will be granted in the end.
And, If Claim 1 is not accepted as being novel, the subsequent claims 2,3... which refers to Claim 1 will not be granted either.

By sending in the patent application it can (at least from KTMs perspective) give some hesitation to others looking for to use the idea, or something close. Let's hope the Patent Authorities takes a look at it soon.

All in all I think it is more likely this patent will be rejected than accepted. But for this, I do think it is important what TZ350 did, making Authorities aware of what Flettner has done before.



In this application for patent (not a patent, yet), KTM wants to patent an operating strategy for a two-stroke engine.

In a nutshell, their first two claims are:

on a two-stroke engine with transfer port injection mostly against the flow direction of the air, using at least one cylinder with two injectors per cylinder each, they use only one injector at a first load range and both injectors at a second load range. (claim 1) When they use one injector, they switch between left and right injector in an alternating manner. (claim 2).

Is this what you did, too? And did you publish it? And did you publish it before Feb 13th 2017?
If your answer is 3x yes, then you could officially complain and in the final patent KTM will have to drop every claim that has been verified as not invented by KTM (usually, some claims remain anyway, but these may not always be worth the effort holding a patent for the manufacturers).

In case you need help translating or filing the complaint etc. let me know.

[TZ350]

.
2015 ... BRC EFI 250 twin supercart dyno demo https://youtu.be/dNat9ZwWbq8

BRC used two injectors and alternated between them in a manner similar to KTM's Patent application.

Links sent to me by Husaburg.

http://www.twostrokemotocross.com/fo...?topic=5482.30 (http://www.twostrokemotocross.com/forum/index.php?topic=5482.30)
he showed pics earlier of the kawasaki
http://www.twostrokemotocross.com/fo...p?topic=4884.0 (http://www.twostrokemotocross.com/forum/index.php?topic=4884.0)

https://www.kiwibiker.co.nz/forums/s...post1130571193 (https://www.kiwibiker.co.nz/forums/showthread.php/158975-Yamaha-YZ-250-EFI?p=1130571193#post1130571193)

One link shows the YZ injectors and in another a very dirty well used YZ that demonstrates the system works.

339054339055

Both the EFI Kawasaki and EFI Yamaha YZ250 were dyno tested on Team ESE's Dynojet in March 2010. Obviously the concept and bikes were well known before then, I just don't have dates and links, but others might.

To protect Flettners idea of improving 2S's and keeping the concept available as open source for better 2S development by any manufacturer wanting to explore 2S EFI.

It is important for as many people as possible to send info to places that talk about KTM's so called novel idea and to the Patent Office. Trade journalists and the Patent Office can't be expected to do all the heavy lifting on their own discovering what else was out there before KTM.


If you choose to complain, then complain against the worldwide patent.

https://register.dpma.de/DPMAregister/pat/PatSchrifteneinsicht?docId=WO002018146251A1&page=1&dpi=300&lang=de&full=true

KTM's German Patent Application number:- DE 10 2017 102 792 A1 2018.08.16DE 10 2017 102 792 A1 2018.08.16

I need other peoples help with this, I need people to discover links and send them to the Patent Office. Thanks.

[husaberg]

.
2015 ... BRC EFI 250 twin supercart dyno demo https://youtu.be/dNat9ZwWbq8

BRC used two injectors and alternated between them in a manner similar to KTM's Patent application.

Links sent to me by Husaburg.

http://www.twostrokemotocross.com/fo...?topic=5482.30 (http://www.twostrokemotocross.com/forum/index.php?topic=5482.30)
he showed pics earlier of the kawasaki
http://www.twostrokemotocross.com/fo...p?topic=4884.0 (http://www.twostrokemotocross.com/forum/index.php?topic=4884.0)

https://www.kiwibiker.co.nz/forums/s...post1130571193 (https://www.kiwibiker.co.nz/forums/showthread.php/158975-Yamaha-YZ-250-EFI?p=1130571193#post1130571193)

One link shows the YZ injectors and in another a very dirty well used YZ that demonstrates the system works.

339054339055

Both the EFI Kawasaki and EFI Yamaha YZ250 were dyno tested on Team ESE's Dynojet in March 2010. Obviously the concept and bikes were well known before then, I just don't have dates and links, but others might.

To protect Flettners idea of improving 2S's and keeping the concept available as open source for better 2S development by any manufacturer wanting to explore 2S EFI.

It is important for as many people as possible to send info to places that talk about KTM's so called novel idea and to the Patent Office. Trade journalists and the Patent Office can't be expected to do all the heavy lifting on their own discovering what else was out there before KTM.



KTM's German Patent Application number:- DE 10 2017 102 792 A1 2018.08.16DE 10 2017 102 792 A1 2018.08.16

I need other peoples help with this, I need people to discover links and send them to the Patent Office. Thanks.
As far as i know flets Big Horn has been TPI since 2008.

he posted this here in 2013
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130521181#post1130521181

first pic of big horn on ese
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130526946#post1130526946

description
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130527017#post1130527017

some more
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130531409#post1130531409

plus here
https://www.rotaryforum.com/forum/kit-makers-manufacturers/rotor-flight-dynamics-dominator/43509-autoflight-700-twin


https://youtu.be/hOGZ5llowoU

here
http://www.blackwoodyamaha.co.nz/news/local/yz250-fuel-injection-project-happening-here-blackwood-yamaha

[OopsClunkThud]

The EFF has had success in overturning/preventing patents where prior art exists. Mostly in software, but this may be one they could take.

https://www.eff.org/patent-busting

[Greg85]

A Vortex won in the weekend, but it was a situation exactly like 250 GP with Aprilia, the fast TM guys keep taking each other out, or ruining each others points totals.
If you look at the lap times DeConto / TM qualified 17th due to a loose hose, that dumped water on the track that then ruined a lot of others times.
He was the fastest in the final going from 14 to 5th , if he had started top 4 it was an easy win..
DEA will never be a force in top level KZ racing , no matter how good the engines are technically, as you have 10 genuine factory supported TM drivers , tuned by Franco on the day.
Its a case of better / more data , better/more support at every championship round.

https://www.youtube.com/watch?v=Pv5s_n66W9Y

hello wobbly indeed the franco drudi engines works really well in particular that of paolo de conto I was there in genk too bad for the collar not tightened it would have won this final... what is impressive is the number of karts that come to test the carburation at franco they must manage well because having so many engines to adjust the carburation must not be easy in any case the setup carburetor sounds good, soon the tm kz-r1 by franco-wobbly

[TZ350]

.
Making progress with the new direct oil to the big end crank. As soon as I can get the motor back together I can get on with my EFI work again, looking forward to that

339104

Got the oil holes lined up Ok. Brass Oil feed quill on the right. Crank trued up to within 0.0005"

339103

Healthy 1.5mm clearance each side in the cases.

[TZ350]

.

I have received a reply, looks like fax is the best way to contact the Patent Office with information re KTM's patent application. Basically the Patent Office has to have it in writing.



Thank you for your e-mail. We do not forward your inquiry to the file.

Please send your third party indications (Sec. 43 German Patent Act)


via post (Deutsches Patent- und Markenamt, 80297 München)

and/or


fax (+49 89 2195 - 2221)

To the file number. This is the only way to manage your concerns legally effective and quickly.

[husaberg]

.
Making progress with the new direct oil to the big end crank. As soon as I can get the motor back together I can get on with my EFI work again, looking forward to that

339104


I see you kept the back cut step transition in the Std Kawasaki inlet.
Does this version of the GP110 have the straight cut primary or did you not end up using it?

[shnaggs]

What Aluminum is best to use for a head insert? I see that VHM states they have a special aluminum, could be just marketing , but I was thinking of using 7075 aluminum, would this work or is there a better aluminum for the job?

[katinas]

What Aluminum is best to use for a head insert? I see that VHM states they have a special aluminum, could be just marketing , but I was thinking of using 7075 aluminum, would this work or is there a better aluminum for the job?

Would be better Al-Cu alloys - 2618, 2024, 2014. 2618- less thermal expansion and better thermal conductivity.

[wobbly]

2024 alloy is technically the go ( good temp strength ) but as long as the insert is carefully designed ( thick enough ) and has the dome retained by the cover
then 6061 works perfectly.

[Muhr]

What Aluminum is best to use for a head insert?

https://www.makeitfrom.com/compare/2024-AlCu4Mg1-3.1355-2L97-A92024-Aluminum/7075-AlZn5.5MgCu-3.4365-2L95-A97075-Aluminum

[Flettner]

And so it begins, KTM's patent application has stirred up other European manufactures. I don't think TPI will be patentable from what I hear, there is certainly some opposition to KTM's shenanigans.

[TZ350]

I see you kept the back cut step transition in the Std Kawasaki inlet. Does this version of the GP110 have the straight cut primary or did you not end up using it?

Yes standard Kawasaki KE rotary valve cover.

339111 339112

And straight cut gears cobbled together from a Honda Monkey Bike and GN clutch inner and cover for normal clutch springs instead of the difficult to fit GP ones with pins. See, easy as.

[wobbly]

I have seen several 7075 inserts crack , it seems to work harden under cyclic thermal of stress loads.

[TZ350]

.

After 30 plus years, a track currently used by Karts, Roller Bladders, Auckland Uni Engineering School and Buckets the Council closes Mt Wellington so they can make more money off the land as a container park.

Spontaneous race around the town square, got about 3 laps in before the council sent their noddy down to see what was going on.

https://www.facebook.com/leader.of.the.guise/videos/10160834104070632/

After race prize giving and media attention.

339115

[Michael Moore]

Would be better Al-Cu alloys - 2618, 2024, 2014. 2618- less thermal expansion and better thermal conductivity.

Matweb seems to disagree on 2024 vs 6061 (they didn't have the same temp range listed for CTE as for 6061)

2024-T6 CTE linear 23.8 µm/m-°C @Temperature 20.0 - 200 °C
2024 thermal conductivity 151 W/m-K

6061-T6 23.6 µm/m-°C @Temperature 20.0 - 100 °C
6061 thermal conductivity 167 W/m-K

Even if CTE is a wash 6061 seems to be better at conducting heat.

In Volume 2 of his series John Bradley mentions that the 2xxx and 7xxx series may have more corrosion issues and should be clear anodized to protect them. He also says that 2024 is much better than 7075 for fatigue resistance, and 7075 T6 can have a problem with fast fracture failure.

6061-T6 is similar in properties to 356-T6 casting alloy that might be used to make a cast head, perhaps it is good enough? It is certainly readily available, at least in the USA.

cheers,
Michael

[Flettner]

.

After 30 plus years, a track currently used by Karts, Roller Bladders, Auckland Uni Engineering School and Buckets the Council closes Mt Wellington so they can make more money off the land as a container park.

Spontaneous race around the town square, got about 3 laps in before the council sent their noddy down to see what was going on.

https://www.facebook.com/leader.of.the.guise/videos/10160834104070632/

After race prize giving and media attention.

339115

Cool, I thought the after race function might invole police.
Good effort.

[Lightbulb]

2024 is the best material for heads for model engines. While 6061 and other alloys do work, the heads that use taper seating glow plugs, or heads that have contra pistons in them, ie diesels, all other alloys fail very early on. While the 2024 lasts the longest. Even 2014 doe not last as well as 2024.
Like wobbly said, 2024 is hard to beat.
Neil

[wobbly]

Ha, Ha , here we have the classic catch 22 ,why do we think chamber thermal conductivity is an asset ?
We have the wank yanks going on about " cool Head " technology as tho its the last word in performance enhancement.
But no , reality is a little more subtle.
We want to keep as much heat of combustion contained within the expanding gas above the piston.
Having a great heat path into the water via the insert dome surface is counter productive to this basic concept.
To the point that ceramic coating just the chamber - makes more power.
BUT , we want to pull heat out of the squish band boundary layer, to prevent spontaneous combustion of the trapped end gases ie detonation caused by free radical formation.
Thus I now believe that clever concepts to separate the chamber cooling rate , from the squish heat transfer path is a key process to be considering.
I have the answer to this conundrum , but NDA restraints limit what i can say at this time.
Suffice to say - insert materiel properties is the last issue of real concern.

[shnaggs]

Ha, Ha , here we have the classic catch 22 ,why do we think chamber thermal conductivity is an asset ?
We have the wank yanks going on about " cool Head " technology as tho its the last word in performance enhancement.
But no , reality is a little more subtle.
We want to keep as much heat of combustion contained within the expanding gas above the piston.
Having a great heat path into the water via the insert dome surface is counter productive to this basic concept.
To the point that ceramic coating just the chamber - makes more power.
BUT , we want to pull heat out of the squish band boundary layer, to prevent spontaneous combustion of the trapped end gases ie detonation caused by free radical formation.
Thus I now believe that clever concepts to separate the chamber cooling rate , from the squish heat transfer path is a key process to be considering.
I have the answer to this conundrum , but NDA restraints limit what i can say at this time.
Suffice to say - insert materiel properties is the last issue of real concern.


2024 is the best material for heads for model engines. While 6061 and other alloys do work, the heads that use taper seating glow plugs, or heads that have contra pistons in them, ie diesels, all other alloys fail very early on. While the 2024 lasts the longest. Even 2014 doe not last as well as 2024.
Like wobbly said, 2024 is hard to beat.
Neil


Matweb seems to disagree on 2024 vs 6061 (they didn't have the same temp range listed for CTE as for 6061)

2024-T6 CTE linear 23.8 µm/m-°C @Temperature 20.0 - 200 °C
2024 thermal conductivity 151 W/m-K

6061-T6 23.6 µm/m-°C @Temperature 20.0 - 100 °C
6061 thermal conductivity 167 W/m-K

Even if CTE is a wash 6061 seems to be better at conducting heat.

In Volume 2 of his series John Bradley mentions that the 2xxx and 7xxx series may have more corrosion issues and should be clear anodized to protect them. He also says that 2024 is much better than 7075 for fatigue resistance, and 7075 T6 can have a problem with fast fracture failure.

6061-T6 is similar in properties to 356-T6 casting alloy that might be used to make a cast head, perhaps it is good enough? It is certainly readily available, at least in the USA.

cheers,
Michael


I have seen several 7075 inserts crack , it seems to work harden under cyclic thermal of stress loads.


https://www.makeitfrom.com/compare/2024-AlCu4Mg1-3.1355-2L97-A92024-Aluminum/7075-AlZn5.5MgCu-3.4365-2L95-A97075-Aluminum


2024 alloy is technically the go ( good temp strength ) but as long as the insert is carefully designed ( thick enough ) and has the dome retained by the cover
then 6061 works perfectly.


Would be better Al-Cu alloys - 2618, 2024, 2014. 2618- less thermal expansion and better thermal conductivity.


Great thank you guys for the input! I have some 6061 sitting in the shop so maybe I could have some trial and error on that, and then look into some 2024 down the road.

[jonny quest]

Can anyone provide a link to a video I'm looking for?

I believe it's an Italian racer that builds his own 125 GP bike from scratch. It shows him casting his own engines, all his transmission parts.... I can't seem to find it and don't remember the name

[Haufen]

Do a search on youtube for GNANI, sounds like him.

[Frits Overmars]

Here you go Jonny:

Gabriele Gnani making a cylinder.


part 1:
http://www.youtube.com/watch?v=I-2rJtnkYq4


part 2:
http://www.youtube.com/watch?v=Lj4h9666d9s&feature=related


part 3:
http://www.youtube.com/watch?v=A50p3cg90s4&feature=related

[jonny quest]

That's it!

[TZ350]

The closure of Mt Welli has been on the cards since the mid 90's when we showed up to a parking lot full of containers.
Good on you for trying but good luck trying to convince the council to change their mind.

https://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=12135782


Sadly, probably true, anyway it made the paper. Thanks for posting the link.

[dutchpower]

https://www.youtube.com/watch?v=YbjyTDe9cw8

https://www.youtube.com/watch?v=9PTKV1N3aOQ

https://www.youtube.com/watch?v=iQ1Dq48KHu0&t=17s

[peewee]

this is cool head insert. dont even think of stealing their design :laugh:

[F5 Dave]

Crack that Whip!:Punk:

[speedpro]

There won't be many that get that joke.

[jbiplane]

Matweb seems to disagree on 2024 v
Even if CTE is a wash 6061 seems to be better at conducting heat.
l

VAL14 and Val18 russian casting alloys which work fine and remain strong at 350°С Al–Cu–Mn

One can easily recreate Val 14 or buy for superior engine castings
Mn 0,5...0,9%
Si and Fe less than 0.1%
Cu 4,5...5%
Aluminum remain
Better protect surfaces contacting flame or water by anodizing

Deformating alloys 1215 have σ≥460Mpa at normal and at 150° σ=300
В-1213 σ≥490 МПа, at 150° =340Mpa

2024 and 6061 much weaker

Exist very special allous with add silver and stroncium and alloys made from powders

[Flettner]

There won't be many that get that joke.

Devo,

Not many if any.

[husaberg]

https://media1.tenor.com/images/461453ff454a6718321c1ab2f9bd824a/tenor.gif?itemid=5849028 (https://www.google.co.nz/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwi2zN69yendAhUHd94KHRIgBMAQjRx6BAgBEAU&url=https%3A%2F%2Ftenor.com%2Fview%2Fdevo-whipit-whip-gif-5849028&psig=AOvVaw1jqtPDvzKUENlzwod844sI&ust=1538632105453326)

[DoldGuy]

Devo,

Not many if any.



Whip it good...

[F5 Dave]

OK one more

[Muhr]

Anyone who has a wire diagram for a Tm MX 125 2018. Especially powervalv and ignition side?

[husaberg]

OK one more
it see why Every man and his dog has one of those now https://www.amazon.com/dp/B075W5NKL7
https://i.chzbgr.com/full/4677774848/h62305458/

[peewee]

i think it was katinas wanted a cylinder in 65cc. i guess there is now ktm copies

https://www.ebay.com/itm/65SX-KTM-Cylinder-From-Cylinder-Works-50005/202121143684?_trkparms=aid%3D222007%26algo%3DSIM.M BE%26ao%3D1%26asc%3D20180306143914%26meid%3Dc88778 ca4c814e7d9c9322927c03734a%26pid%3D100935%26rk%3D4 %26rkt%3D12%26sd%3D222772346756%26itm%3D2021211436 84&_trksid=p2056116.c100935.m2460

[husaberg]

.
2015 ... BRC EFI 250 twin supercart dyno demo https://youtu.be/dNat9ZwWbq8

BRC used two injectors and alternated between them in a manner similar to KTM's Patent application.

Links sent to me by Husaburg.

http://www.twostrokemotocross.com/fo...?topic=5482.30 (http://www.twostrokemotocross.com/forum/index.php?topic=5482.30)
he showed pics earlier of the kawasaki
http://www.twostrokemotocross.com/fo...p?topic=4884.0 (http://www.twostrokemotocross.com/forum/index.php?topic=4884.0)

https://www.kiwibiker.co.nz/forums/s...post1130571193 (https://www.kiwibiker.co.nz/forums/showthread.php/158975-Yamaha-YZ-250-EFI?p=1130571193#post1130571193)

One link shows the YZ injectors and in another a very dirty well used YZ that demonstrates the system works.

339054339055

Both the EFI Kawasaki and EFI Yamaha YZ250 were dyno tested on Team ESE's Dynojet in March 2010. Obviously the concept and bikes were well known before then, I just don't have dates and links, but others might.

To protect Flettners idea of improving 2S's and keeping the concept available as open source for better 2S development by any manufacturer wanting to explore 2S EFI.

It is important for as many people as possible to send info to places that talk about KTM's so called novel idea and to the Patent Office. Trade journalists and the Patent Office can't be expected to do all the heavy lifting on their own discovering what else was out there before KTM.



KTM's German Patent Application number:- DE 10 2017 102 792 A1 2018.08.16DE 10 2017 102 792 A1 2018.08.16

I need other peoples help with this, I need people to discover links and send them to the Patent Office. Thanks.


As far as i know flets Big Horn has been TPI since 2008.

he posted this here in 2013
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130521181#post1130521181

first pic of big horn on ese
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130526946#post1130526946

description
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130527017#post1130527017

some more
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130531409#post1130531409

plus here
https://www.rotaryforum.com/forum/kit-makers-manufacturers/rotor-flight-dynamics-dominator/43509-autoflight-700-twin


https://youtu.be/hOGZ5llowoU

here
http://www.blackwoodyamaha.co.nz/news/local/yz250-fuel-injection-project-happening-here-blackwood-yamaha


Found one earlier on ESE 2012
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130400306#post1130400306

Rob did you weld on an extension to the gearbox on one of the TF or GP gearbox mainshafts
i can't find the post?
Anyone ever made a mainshaft longer for a dry clutch or similar?

[TZ350]

Anyone ever made a mainshaft longer for a dry clutch or similar?

Yes, 1980's RD400 to 1970's RD350 conversion for a TZ dry clutch and better ratios in the TZ350.

339144

The RD has a 60mm clutch shaft and it needs to be 90mm long for the TZ dry clutch. So the RD350 nose was cut off and had an oil hole and "O" ring grove added then the RD400 shaft was spigot-ed into it.

The RD400/250 or LC350/250 or RZ ratios work well in a TZ. 1st is a help in getting off the line and the other ratios are suitable spaced. The LC has only 3 selectors so some case mods are required if you are fitting it to a earlier RD. The other box's with 4 selectors are easier to work with. The TZ cylinder base was skimmed 0.75mm to get the exhaust duration at 196 and the squish was set to 0.8, ignition 1.8mm BTDC. This got rid of the TZ power band light switch effect and made for a very fast and ride-able bike.

5 speed TS125 to GP125 conversion that shows the basic idea.


Page 1680 ...... C

Modifying an early five speed Suzuki TS gear cluster to fit the GP.

339143

Anneal both TS and GP input shafts.
Drill the center through the TS shaft for the clutch push rod.
Spigot the TS shaft with a press fit into the cut off end of the old GP shaft.
Weld the two shafts. Be careful to tack in several places to pull and hold the shafts straight.
Clean the weld and polish the shaft until the input shaft bearing slips on easily.
Case harden to a depth of 0.005" or so.

The two left hand output shaft forks need building up with bronze.
They must be built up on the inner face only, ie the center line of the original fork is offset.
Top and bottom forks are offset towards each other, ie the center lines are closer together.
And the fork ends are thicker for the wider grove in the TS output shafts sliding dogs .
The input shaft fork on the right does not need any bronze but it needs to be opened up a bit to fit the slightly larger diameter TS sliding dog.

The GP box has a big gap between 2nd and 3rd, the TS is much better.

[Vannik]

336531336532336533336534336535

Comparison of transfer port angles between a Honda RS125 NF4 and NSR250 MC21 cylinder.

TZ350,

Could you please either measure or post a section through the export above the transfers so we can get the angle of the expassage similar to this one that is next to the transfer ports?

339151

[adegnes]

Hey, where's Adegnes our favourite Norwegian shed drinking scooter fiend these days?

Thanks, and thanks for asking!
I just finished catching up, almost two years.

Been busy, mostly due to kids, and the youtube thing has surpassed anything I would have imagined. I'm having a hard time keeping up with all emails, comments, messages etc.(With hard time I mean I'm not keeping up...)

Recent events made me realize I had to get up to date on what's going on.

It all started with the idea of running the Spx with the cylinder rotated 90° and closing off the exhaust side of the wristpin, thereby being able to run full width aux ex ports without short circuiting.
Posted a video about it and Mark Atkinson(video a few pages back) left a comment saying he could make me a piston after race season.
Neels sent me a link to Marks vid just a few hours later(Thanks Neels), funny coincidence!

You saw the piston, no need for rotating the cylinder anymore.

Then I had the idea of restraining the ring with pins, allowing it to move just enough to seal well, but not enough to catch in a 100% of bore single exhaust port. Posted another video.
Wobbly watched it(thanks for watching!) and sent Mark this link http://iffitech.com/project/gp-piston/ which he forwarded to me.
http://iffitech.com/wp-content/uploads/2016/04/WP_20160426_17_24_16_Richs.jpg

Much better than my pin idea!
Mark is thinking about incorporating it in his design.

Do anyone know anything about this stepped ring design? Have it been run with a really, really wide port successfully? Does it seal well?


https://youtu.be/JlMg_O4fTNY

https://youtu.be/k2kkmWnenCI

https://youtu.be/JGK-Sa89Pmk

Clickbait titles, I know...
Feels great to be back! Now to the other two threads...
Btw, Hollaendaren, are you on here?

[breezy]

Thanks, and thanks for asking!
I just finished catching up, almost two years.

Been busy, mostly due to kids, and the youtube thing has surpassed anything I would have imagined. I'm having a hard time keeping up with all emails, comments, messages etc.(With hard time I mean I'm not keeping up...)

Recent events made me realize I had to get up to date on what's going on.

It all started with the idea of running the Spx with the cylinder rotated 90° and closing off the exhaust side of the wristpin, thereby being able to run full width aux ex ports without short circuiting.
Posted a video about it and Mark Atkinson(video a few pages back) left a comment saying he could make me a piston after race season.
Neels sent me a link to Marks vid just a few hours later(Thanks Neels), funny coincidence!

You saw the piston, no need for rotating the cylinder anymore.

Then I had the idea of restraining the ring with pins, allowing it to move just enough to seal well, but not enough to catch in a 100% of bore single exhaust port. Posted another video.
Wobbly watched it(thanks for watching!) and sent Mark this link http://iffitech.com/project/gp-piston/ which he forwarded to me.
http://iffitech.com/wp-content/uploads/2016/04/WP_20160426_17_24_16_Richs.jpg

Much better than my pin idea!
Mark is thinking about incorporating it in his design.

Do anyone know anything about this stepped ring design? Have it been run with a really, really wide port successfully? Does it seal well?


https://youtu.be/JlMg_O4fTNY

https://youtu.be/k2kkmWnenCI

https://youtu.be/JGK-Sa89Pmk

Clickbait titles, I know...
Feels great to be back! Now to the other two threads...
Btw, Hollaendaren, are you on here?

so the stepped ring piston looks like a two part piston. top of piston screws into the body and keeps the edge of the ring housed in a recess. or am i seeing wrongly?

[adegnes]

so the stepped ring piston looks like a two part piston. top of piston screws into the body and keeps the edge of the ring housed in a recess. or am i seeing wrongly?

Yep, exactly what you said.

[Haufen]

I like it. In which direction is the step facing on these pistons? To the head or to the case? Did they encounter resonance effects at some ring dimensions / weight / rpm combination? And how do you avoid that both these piston parts become loose?

[adegnes]

I like it. In which direction is the step facing on these pistons? To the head or to the case? Did they encounter resonance effects at some ring dimensions / weight / rpm combination? And how do you avoid that both these piston parts become loose?

I'm as blank as you are... Got a mail from someone who said he was involved in testing, asked a bunch of questions, waiting for a reply.
The step should face down I suppose for the ring to work properly, looks like that in the pics too.

[speedpro]

Missed seeing the reverse dykes ring bit. I had Moriwaki 2-ring pistons in my Z1. the motor turned over easily and made noticeably more power. Has a few other bits added as well so not totally the pistons and rings.

[wobbly]

I worked for Savice in China on a mini MX bike project, that company gained the patent for the reversed L ring concept.
The ring is a reversed Dykes,with the vertical leg facing down.
This enables the combustion pressure from above to force the ring down ( as normal ) but also outward against the restraining slot wall ).
Thus it works the same as a Dykes,the additional wall friction prevents ring flutter at any rpm, the very reason the L ring was used in 20,000 rpm kart engines.

[adegnes]

From http://iffitech.com/news-and-media/denver-lawson-the-kiwi-who-is-cleaning-up-the-two-stroke/

"Despite the setback, Lawson remained convinced that two-strokes were the way of the future, and recently performed a detailed computer analysis for Martin Aircraft that showed that a properly-designed two-stroke could result in power production that was 19 per cent denser than that of an equivalent supercharged four-stroke, while producing far less emissions than the rotary engines currently favoured for aero use.

“We started out just trying to prevent the two-stroke from smoking, and we can now make them amongst the lowest emitters of any type of combustion engine. We can equal any four-stroke on header pipe emissions and produce far less emissions than a rotary.

“With a two-stroke you can contour the combustion chambers perfectly for improved combustion. I’m reluctant to go into further details, but we use a modified form of toroidal chamber.”

Lawson says that these chambers when combined with a refined direct-injection fuel system and separate oil injection can effectively sanitise a two-stroke engine. His latest company, Integrated Forced Fuel Injection (IFFI), has been formed to complete the process of applying for patents for the fuel injection system and the accompanying piston design that have been developed"

That combustion chamber sounds familiar...

I'm talking with Kevin Nairn who worked with Denver developing and testing the ring. I'll ask if I can share some info(don't want to step on toes) or better yet if he's willing to join and share himself.
He's made a nice watercooled cylinder pressure sensor too.

Seems to have been a success!

[adegnes]

Quick question that's probably been answered before(hell I might even have asked it myself and forgotten...)

Why weren't the RSA transfers done like this? If duct volume and entrance/exit ratio were kept the same, and maybe the wall angle next to C-transfer tweaked a bit, wouldn't that be "better"?

339158

The answer is maybe that the hook introduces some needed "swirl"?
Your RC engine has more the shape I'm thinking of Frits, why?

[adegnes]

Just received a mail from Kevin, he's going to help me out with the ring but I'm not allowed to share anything that's not already public. His call, got to respect that.

Uncomplicated design though, just a matter of getting the clearance right I suppose.

[Frits Overmars]

Why weren't the RSA transfers done like this? If duct volume and entrance/exit ratio were kept the same, and maybe the wall angle next to C-transfer tweaked a bit, wouldn't that be "better"?
339158
The answer is maybe that the hook introduces some needed "swirl"? Your RC engine has more the shape I'm thinking of Frits, why?The Aprilia RSW cylinder had to fit existing crankcases; the same transfer layout was used for the RSA because it had proven itself. With the RC cylinder I had complete freedom re the stud positions.
Swirl, or indeed any form of turbulence is fine for speeding up combustion, but turbulence during the transfer phase would only mix fresh mixture with spent gases.
And I don't like hooks; I'm not an angler.

[adegnes]

The Aprilia RSW cylinder had to fit existing crankcases; the same transfer layout was used for the RSA because it had proven itself. With the RC cylinder I had complete freedom re the stud positions.
Swirl, or indeed any form of turbulence is fine for speeding up combustion, but turbulence during the transfer phase would only mix fresh mixture with spent gases.
And I don't like hooks; I'm not an angler.

Yes! I had a feeling you'd say something along those lines, hurray!
I was afraid the only thing distinguishing my (distant)future cylinder project from the other RSA clones would be slightly different transfer timing and the 100% width single exhaust port... Oh, wait. Maybe a narrower C port too and maybe with a bit less upwards angle.

Need to get some machines and a foundry up and going, might take a while...

Edit: when thinking about it that sounds very much like a copy of your small creation...

[wobbly]

When the SwissAuto engine went into the Pulse I had the opportunity to measure the different Cd of the B ports you describe Adegnes.
The hooked corner design was well down on flow compared to the swoop radius style , and on the dyno its trapping efficiency was well down, needing much leaner jetting
that mad less power ( same egt. )

[adegnes]

When the SwissAuto engine went into the Pulse I had the opportunity to measure the different Cd of the B ports you describe Adegnes.
The hooked corner design was well down on flow compared to the swoop radius style , and on the dyno its trapping efficiency was well down, needing much leaner jetting
that mad less power ( same egt. )

Thanks wobbly!

[ken seeber]

[QUOTEAnd I don't like hooks; I'm not an angler.[/QUOTE]

I don’t go fishing either Frits.

The below pic is of rubberies of the ports of a TM KZ10B. The B passages do go around a tortuous path, limited by the basic engine design. Key issues being the actual stud pattern and the stud height, the latter resulting in the nut height (and resultant spanner clearance) forcing the B passage path to go around its tortuous path.

The complicated B passage can clearly be seen. Opposite the standard B passage, I crudely created (in plasticine) the shape of a B passage that wasn’t constrained by the presence of the stud position and nut height.

Whilst I am sure it’d flow better, I also recognise that if it was simply substituted instead of the standard OEM B passage, it might not perform better (after watching ESE for quite some time and understanding just how bloody finicky high performance 2 strokes are) as the flow performance and direction etc might not suit the currently developed balance of the existing A,B & C passages and ports. That aside, I would think that it would ultimately offer a higher performance level than the current arrangement.

339164339165

[SwePatrick]

Quick question that's probably been answered before(hell I might even have asked it myself and forgotten...)

Why weren't the RSA transfers done like this? If duct volume and entrance/exit ratio were kept the same, and maybe the wall angle next to C-transfer tweaked a bit, wouldn't that be "better"?

339158

The answer is maybe that the hook introduces some needed "swirl"?
Your RC engine has more the shape I'm thinking of Frits, why?

Cause they would flow a lot worse.
The flow from crankcase is secondary to flow into cylinder.
It´s the freshmixture trapped on top of the piston that produces power ;)

You would have less control of flow into cylinder in your example.
This with the hard bend that is the result of that design, in my eyes, no good.

You need to remember that flow into the cylinder isn´t a constant flow, it´s like puncturing a ballon when piston opens the transferports.
Thereby you want a lot of volume ready just next to the pistonskirt when it pops.

[adegnes]

Cause they would flow a lot worse.
The flow from crankcase is secondary to flow into cylinder.
It´s the freshmixture trapped on top of the piston that produces power ;)

You would have less control of flow into cylinder in your example.
This with the hard bend that is the result of that design, in my eyes, no good.

You need to remember that flow into the cylinder isn´t a constant flow, it´s like puncturing a ballon when piston opens the transferports.
Thereby you want a lot of volume ready just next to the pistonskirt when it pops.

Wouldn't my illustration have more mixture available just outside the port opening and a less torturous path to get there?
And as there is no hook, but a more or less straight path wouldn't that lead to better control?
I've been mislead by my own "common sense" more than once(most times when dealing with women or two strokes), but this just seems too wrong.

Edit: My sketch might be a bit misleading, I was trying to illustrate a wider duct vs the "around a corner and hook" design. I certainly don't want any sharp bends.

[jonny quest]

I think Adg is trying to illustrate a whole new transfer port with his blue line. No hook, no swoop, a port that has an exit directed like a modern shape but the tunnel has only a 2 dimensional arc. (No 3d swoops or hooks).

[adegnes]

I think Adg is trying to illustrate a whole new transfer port with his blue line. No hook, no swoop, a port that has an exit directed like a modern shape but the tunnel has only a 2 dimensional arc. (No 3d swoops or hooks).

Yep! Illustrations are not my strong side, though this was pretty bad even for me...

[jonny quest]

I just realized, Adeg drawing kind of represents how the FOS style transfers are laid out (kind of for ease a description)

[shnaggs]

I would think that a B-port designed as Adeg is suggesting would cause less trapping efficiency. I would think that the port's speed would be on the high side causing more mixture to be lost to the Exh port, but then again on the reverse pulse from the pipe, the stronger stream may mix less with the exhaust and purity might go up? As Adeg has said, my common thinking has been proven wrong multiple times on these 2 -strokes.

Wobbly, you are saying that the port 'with NO hook' had better trapping efficiency?

[adegnes]

Pretty much exactly like this:

https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=334846&d=1437231535