ESE's works engine tuner

[DoldGuy]

Wobbly,

Have you seen similar results with the cylinder reed intakes or just case reeds?

[Nath88]

Regarding flow bias, there is around 2 Hp in 48 in a KZ10 kart 125 engine by utilizing a reed cage that is angled up toward the piston.
All of the manufacturers use reed petals that are softer on the top, to get this bias to point the incoming flow directly at the transfer entry area.
I have tested this and got an ICC engine over 50 Hp for the first time - with the same petals/backups top and bottom.
Not allowed to use it in the current homologation engine, but that reed block is going with me to the TM factory.
If an RS125 tuner is looking, the first thing you should be into is differing petals and rev plates/backups top and bottom - free Hp in a few minutes, or should I say days,
to get it right.

For MX bikes with the bent inlet, could you use a divider plate through the bend to keep flow to all petals constant, or bias it if required?
Could the reed cage just have the tip angled like the trailing edge of a wing to guide the air to the transfers?

[richban]

This seems to result in an awfully big carb.



How big is awfully big? My 50 runs a 28mm ok. The 300 runs 2 x 40mm's and My 90 is looking like it will be around 32 / 34mm. Road racing engines that is. Stock YZ250's run 38's


What did you get form the calculations?

[oldjohnno]

How big is awfully big? My 50 runs a 28mm ok. The 300 runs 2 x 40mm's and My 90 is looking like it will be around 32 / 34mm. Road racing engines that is. Stock YZ250's run 38's


What did you get form the calculations?

Seems I may have overstated it. For a mild, 75hp 350 it gives a diameter of 55.3mm, but if you use a constant of 33 (which is in line with the averaged factory sizing) the result is 49.7mm. In other words making the throat diameter the same as the exhaust port area results in a carb with about 23% more throat area than "average". Having said that there are KTMs with a carb size constant of 40, and this gives a size for the same 350 of 54.8mm - virtually the same as exh. port area. I was wrong in saying "awfully big" - what I should have said was that it gave a size that's at the upper end of factory usage.

Out of curiosity I looked at some more stock engines and it seems they all fall into that range from 30 to 40, regardless of whether they are a docile trials engine or a more highly tuned racer. I don't know about disc valved engines but suspect they would be at the upper end of that range or perhaps a little higher.

[husaberg]

Re carb and reed size for a race engine.

Here is a note I had Neels add to the help file of EngMod


" For high performance, high BMEP, applications a quick check through the areas generated by the software will give a good indication of the engines overall efficiency, and thus a in pointer as to where to devote time with changes to an input.

In these cases the carburettor inlet area, the reed effective area, and the total exhaust and transfer areas will converge to equality, as each of these elements is optimized. Using this technique a "too small a reed" for example will quickly become evident – and a change to improve this, will immediately give a power increase when the simulation is re run. "

The reed block port dimensions are more important than the petal curtain area, as small petals will self compensate somewhat by staying open longer.

what is the rule of thumb where did i pluck .8 from?
Side note I have a AC RD350 that i are playing with at the moment.
I was going to use late model YZ85 reed valves rather than RZ350 reed valves but can't really find anything straight to match the NSR250 carbs i was going to recycle. any ideas anyone?
The only thing that seemed to suit was hacking up a RGV intake or a KR1S. Or snowmobile.
Only aiming for 50HP.

[F5 Dave]

what is the rule of thumb where did i pluck .8 from?
Side note I have a AC RD350 that i are playing with at the moment.
I was going to use late model YZ85 reed valves rather than RZ350 reed valves but can't really find anything straight to match the NSR250 carbs i was going to recycle. any ideas anyone?
The only thing that seemed to suit was hacking up a RGV intake or a KR1S. Or snowmobile.
Only aiming for 50HP.
TZR blocks fit in YPVSs, but RDs are probably a size smaller.

[adegnes]

what is the rule of thumb where did i pluck .8 from?
Side note I have a AC RD350 that i are playing with at the moment.
I was going to use late model YZ85 reed valves rather than RZ350 reed valves but can't really find anything straight to match the NSR250 carbs i was going to recycle. any ideas anyone?
The only thing that seemed to suit was hacking up a RGV intake or a KR1S. Or snowmobile.
Only aiming for 50HP.

Maybe you could cast something from suitable rubber compound?

[husaberg]

TZR blocks fit in YPVSs, but RDs are probably a size smaller.

All the TZR blocks i have seen were pretty massive, they looked bigger than the TZ750 which i think are the same as Dt250 or early It175.
I think the reed casing on the rd350 is bigger than the rd400 though.
But its pretty easy to poke a hole fitting the RZ350 reeds. which are the same petal size as a tz750 reed but physically smaller cadge.
edit found this
329208

Maybe you could cast something from suitable rubber compound?

i have seen a couple of threads where people have done that.
One for the KR1s for the 35mm SP version
http://www.kr-1s.co.uk/forum/viewtopic.php?t=5197
one for the RD's but only Angled factory spec ones for the RD's
http://www.precisiontradingsystems.com/inlet_rubbers.htm
http://www.precisiontradingsystems.com/inlet_videos.htm
I think it would be easier to make something like this
329209329210

[sispeed]

To prevent pucking a hole in the Cylinder when altering reedcase I do the following things.
Clean the Cylinder on the outside from color and dirt. Plaster the outside with JB-Weld.
If you shave to much from the case inside you see only JB and no light. That is a good thing.
Not so fine may be that you loose some cooling
Regards Siggi

[casal-fan]

The NF4 was really a motocross engine; the slant manifold served to move the carburettor out of the way of the central rear shock absorber. The effect was twofold:
The flow was reluctant to follow the bend; it concentrated on the outside, so the reeds on that side were overloaded and perished, while the reeds on the opposite side could have been much thinner because they hardly saw any flow at all.
The same was true for the crankshaft main bearings: the left-side bearing hardly received any premix lubrication. And boy, were those Honda main bearings expensive.
The short straight manifold worked a lot better, as Wobbly wrote.
So why substitute it with the long straight manifold? My guess is: to better isolate the carburettor from engine vibrations.

I came to think of this post when I found out what a left side roller crankshaft bearing for a GasGas engine costs... those are wayyyy expensive in comparisson with the ball bearing used on the right side.
The intake situation on the std. engine is the same as the one Frits describes above, but as I´m modifying it for road racing, it will get a straight manifold as well as simetrical design left and right Vforce reedcages from an Honda ATV. (usually reedcages for twisted intakes have an asimetric design).

Asking for youguys opinion if this change in setup would open for the possibility of using a ball bearing instead of roller bearing.
The extra cost of the roller covers the expenses of an extra bearing change with some change leftover for a pint... and I like pints...
Just asking for your opinion.
In advance thanks.

[adegnes]

I came to think of this post when I found out what a left side roller crankshaft bearing for a GasGas engine costs... those are wayyyy expensive in comparisson with the ball bearing used on the right side.
The intake situation on the std. engine is the same as the one Frits describes above, but as I´m modifying it for road racing, it will get a straight manifold as well as simetrical design left and right Vforce reedcages from an Honda ATV. (usually reedcages for twisted intakes have an asimetric design).

Asking for youguys opinion if this change in setup would open for the possibility of using a ball bearing instead of roller bearing.
The extra cost of the roller covers the expenses of an extra bearing change with some change leftover for a pint... and I like pints...
Just asking for your opinion.
In advance thanks.

I would keep the roller, If you ditch it you lose the floating crankshaft action and probably some power. That pint sounds tempting tho, and could be worth the power loss:D

[Frits Overmars]

according to a website, you need 33.31 cfm to make 48hp...now I know there are multiple variables that you need to take into account before assuming such a number, but doesn't 33 cfm seem rather low? I mean a 38mm carb can flow a shit tone more air then that (obviously the test pressure would need to figured). So what am I missing??? Why don't we run smaller carbs and smaller intake ports and ramp up velocity?
Because the intake doesn't flow all the time, and some of the time is does flow, it does it in the wrong direction. Sorry, no time for a real answer (and someone will probably soon chime in with a better explanation than I can provide anyway...)Perfect answer Alex.

Shnaggs, why would you want to ramp up the velocity? If that were a good thing, you could reduce all cross flow areas to 1 mm² or even smaller. But somehow I doubt that it would help performance. I prefer to ramp up mass flow.
Anyway, increasing flow velocity by means of reducing the cross flow area is largely a fairy tale. Velocity comes from a pressure differential over a duct.
Lower the downstream pressure far enough and the flow velocity will reach Mach 1. Crank up the upstream pressure far enough and the flow velocity will also reach Mach 1 with the added benefit of a higher density in the flowing medium, i.e. more mass flow for the same Mach 1 flow velocity.

The fairy tale stems from the fact that with a large cross flow area there will be so much mass flow that the upstream pressure drops markedly even before the gas column in the duct is accelerated to the velocity corresponding to the initial pressure differential. So the velocity will never reach the value that it would reach with a smaller cross flow area. But who cares; we've got more mass flow.


Using figures from eight engines from Yamaha, Honda and KTM gave an average carb size constant of 33, ie. Throat diameter = √(hpx33). The individual numbers varied from 29.5 to 40, but even after eliminating these two the average remained at around 33, so I think this would be a safe starting point.Johnno, this method will indeed give a safe starting point but you should keep in mind that averaging data from various engines will usually result in an outcome that deviates from the best engine's data.
Eliminating the extremes can also be useful, but I'd rather eliminate the engine with the lowest BMEP. And if you keep doing that, you'll end up with just one engine: the best one.


Asking for youguys opinion if this change in setup would open for the possibility of using a ball bearing instead of roller bearing.
I would keep the roller, If you ditch it you lose the floating crankshaft action and probably some power.Keep them answers coming Alex :niceone:.

[oldjohnno]

Johnno, this method will indeed give a safe starting point but you should keep in mind that averaging data from various engines will usually result in an outcome that deviates from the best engine's data.



I like that answer. A less diplomatic person would have said that using data averaged from various engines will usually result in a perfectly average engine.

[wobbly]

Anywhere you have asymmetric flow thru a reed entry you loose power - case or cylinder mounted.
Boyesen did some really nice blocks that had guide blades to turn the flow, but sadly this idea was offset by the crap two stage petals so hard to tell how good the flow idea was.

You would guess that having carbs angled down ( as most are ) would bias flow to the upper reeds as we are trying to do with soft petals on the top.
But no - put on a straight manifold and carbs that will work downdraft, and power goes up.
The reverse used to be true on ICC kart engines,they had the reed angled up under the cylinder, but with a bent manifold making the carb horizontal.
The first time I reversed the manifold and made the carb " updraft " ie normal to the intake flow direction it made a couple of Hp everywhere - a legal mod at the time,now everyone does it.

On an early version of the CPI Banshee cylinders the only way I could figure out in CAD how to fit in CR250 reed blocks onto the back of the cylinder without moving the studs
was to offset the blocks 8mm outward.
This gave severely asymmetric flow into the case and and when Calvin did an early retest with smaller reeds back on bore center, it gave +5 Hp.

[casal-fan]

Keep them answers coming Alex :niceone:.


I would keep the roller, If you ditch it you lose the floating crankshaft action and probably some power. That pint sounds tempting tho, and could be worth the power loss:D

Roller it is then, no pints next week... damm
Thanks for the help, much apreciated!

[oldjohnno]

Anywhere you have asymmetric flow thru a reed entry you loose power - case or cylinder mounted...

Let's say you have a reed cage with an opening area that's around twice as wide as it is high, and enough frame clearance to align the carb properly. Would it be an advantage to use two smaller carbs side-by-side rather than trying to blend a single, bigger throat into the wide window?

[F5 Dave]

What about a 'third' carb at an oblique angle just to cover all your bases?

[peewee]

Roller it is then, no pints next week... damm
Thanks for the help, much apreciated!

theres a few places on ebay that have skf explorer rollers for a decent price. that's usually where I get mine http://www.ebay.com/usr/247industries?_trksid=p2060353.m2749.l2754

[husaberg]

I would keep the roller, If you ditch it you lose the floating crankshaft action and probably some power. That pint sounds tempting tho, and could be worth the power loss:D

Congrads on the new minion.

[oldjohnno]

What about a 'third' carb at an oblique angle just to cover all your bases?

No, it has to be four. For symmetry.

Seriously though I think two would have advantages, especially with methanol. Each needle/seat would have to handle only half the volume of fuel and it'd be delivered through two main and needle jets. With alky it'd be easier to manage than a single carb I think.

[TZ350]

... especially with methanol ...

I just love 2t's and methanol. You can run them so rich raw methanol dribbles out the pipe's and the suckers still run.

[F5 Dave]

No, it has to be four. For symmetry.

Seriously though I think two would have advantages, especially with methanol. Each needle/seat would have to handle only half the volume of fuel and it'd be delivered through two main and needle jets. With alky it'd be easier to manage than a single carb I think.
My symmetry has three planes. :yes:

[adegnes]

Congrads on the new minion.

Thanks! He'll prove useful when time comes to overthrow the government!

[TZ350]

Ecotrons has sent me an updated 2T configuration file with both the VE and Alpha-N tables active. Ecotrons have also popped a new pressure regulator, some spare injectors and 2 bar MAP sensors in the mail, should be here in a week or so. Just enough time to get my EFI engine back together and in the bike.


Measuring the blowdown pressure pulse rather than the negative (since they should be proportional) gives you a head start on getting the fuel in. I have the pressure sample window set to 140-170° ATDC. The peak moves with RPM, because of the delay along the hose to the MAP sensor, so best to keep it as short and close to the port opening as possible. I have the injection start 10° after the sample window, so the latest pressure value is used to calculate the injector pulsewidth.

I am unable to choose where in the crank rotation I take the pressure sample. But Ecotrons allows me to choose several TPS/RPM break points for defining where the VE table swaps to the Alpha-N table. It does not have to be a straight line. It could be steps or even a rudimentary curve. so I will be able to target the problem areas in my series of dyno graphs.

329229

The dyno graphs, all Alpha-N map, start at 20% TPS (green line) and go up in 10% steps 20 - 30 - 40 etc. Not much difference in power curves between 80 - 90 - 100% TPS.

All the EFI issues seem to be below 20 - 25% maybe that is where the pipe wave collapses.

329230

I can use EngMod's predicted series of delivery ratios as a guide for the VE table.

329228

This is my exhaust pressure takeoff for the MAP sensor. It is a one way valve with a small ceramic ball with only 0.010" movement, hopefully it wont break up being hammer'd around at 200Hz. The blue hose will have positive pressure in it and a small bleed hole melted into it with a hot pin for a pressure bleed down. Hopefully this will give the 2 bar MAP sensor something worthwhile to work with, that is hopefully a smooth positive pressure that reliably reflects changes in the mass air flow through the motor.

Nath88, thanks for the ideas, hopefully I can make them work for me.

[emess]

In the pic of the KZ10B intake the tuned length isnt quite as i drew the line from reed tip to bell end.
The length as should be used for sim accuracy is a point 2/3 of the distance down the block toward the tips ( the effective length of the reed port
opening varies as the petals are closed or fully open ) and the carb bell needs end correction for the actual reflection point off atmosphere.
In a PhD thesis paper i supervised we instrumented a YZ125 fully on a dyno at Uni for using fibre optics in the combustion chamber to control
fuel injection via the colour spectrum of the flame.
One thing discovered was the actual effective length of the intake, and it varied with reed tip opening, plus it showed that the end correction was
accurate when set at approx the intake curtain area length past the full bell diameter.
Without a bell, the end correction reflection point was the classically accepted 1/2 D of the intake pipe.



Wobbly - interesting, but it leaves me asking for more - how do you define or measure "curtain area length" ?

thanks

[DoldGuy]

Wobbly - interesting, but it leaves me asking for more - how do you define or measure "curtain area length" ?

thanks

Emess,

This might help...

https://www.kiwibiker.co.nz/forums/showthread.php/143620-EngMod2T-Q-amp-A

Just adds more to what I Don't know :facepalm:

[Frits Overmars]

Wobbly - interesting, but it leaves me asking for more - how do you define or measure "curtain area length" ? Here you go Emess. D is the diameter with which the bellmouth would touch a flat sheet pushed against it.

[emess]

Emess,

This might help...

https://www.kiwibiker.co.nz/forums/showthread.php/143620-EngMod2T-Q-amp-A

Just adds more to what I Don't know :facepalm:

Thanks for that - theres a whole load of useful stuff on that page

Mick

[emess]

Here you go Emess. D is the diameter with which the bellmouth would touch a flat sheet pushed against it.

Thanks Frits, even I can understand it presented like that
Mick

[husaberg]

Thanks! He'll prove useful when time comes to overthrow the government!
Started training already.
https://4.bp.blogspot.com/-gmVakqsexio/VGTHHFsVXvI/AAAAAAAAGac/-7CtJvn0IK8/s400/10172683_383448905130197_7088721221738366906_n.jpg

[Bert]

329228

This is my exhaust pressure takeoff for the MAP sensor. It is a one way valve with a small ceramic ball with only 0.010" movement, hopefully it wont break up being hammer'd around at 200Hz. The blue hose will have positive pressure in it and a small bleed hole melted into it with a hot pin for a pressure bleed down. Hopefully this will give the 2 bar MAP sensor something worthwhile to work with, that is hopefully a smooth positive pressure that reliably reflects changes in the mass air flow through the motor.

Nath88, thanks for the ideas, hopefully I can make them work for me.

This is a really neat idea, looking forward to seeing the results of this.
<1/8" copper gas tube might survive a little longer and a little pressure release valve.

[TZ350]

329235


<1/8" copper gas tube might survive a little longer and a little pressure release valve.

Yes, I am none to sure about the suitability of the blue silicon hose myself. I do have some 8mm Teflon hose ($60/meter) that might be worth a try too.

[TZ350]

Page 1680 ......:Police:

Building a F4 water cooled two stroke Bucket racing engine.

Some more detail pictures.

Suzuki GP100 crank parts and cases are the same as the 125 and totally interchangeable, same for the TS100/125 and TF100/125.

The original Suzuki GP100 50.5mm stroke crank with its 19mm B/E pin was de-stroked to 48mm by using a RD400 rod with its 22mm B/E pin and offsetting the B/E hole 1.25mm.

329243 Suzuki GP100 crank wheels earmarked for modification so the GP100 can use a reclaimed NSR cylinder.

A:- NSR and KE to have 22mm big end pins and will be using the RD400 2T2 rod. The overall outside crank width will be the standard 50mm.
B:- KE and NSR B/E pin is to move in 1.25mm for a 48mm stroke.
C:- KE thrust face -0.6mm, and NSR crank thrust face -0.25mm and the pocket around the thrust face opened up to accommodate the RD rod and thrust washers. This is important.
D:- Alloy plug all balance holes.
E:- KE, NSR -2mm for rod beam side clearance.
F:- The cranks for the NSR cylinders to have Mallory slugs fitted opposite the big end pin and as close to the rim as practicable, the KE already has lead slugs, these could be changed for Mallory.

The original stroke of the Kawasaki KE and Suzuki GP/TS/TF is 50.5mm and needs to be changed to a 48mm stroke for the 54mm NSR (or Aprilia 125) cylinder.

329244

Finished Suzuki GP100 110cc crank.

329239

To marry the NSR cylinder to the GP cases the original stud holes in the GP cases were plugged with threaded aluminium rod glued and screwed into the original stud holes. And the stud holes relocated to suit the NSR cylinder. The forth GP stud hole is used to hold the spacer plate down while the fourth stud for the NSR cylinder is located in the spacer plate itself.

329236

The cylinder needs to be positioned by the spacer at a height that has the exhaust port opening at 80 deg ATDC (power valve fully up), transfers will then be 115 ATDC, our spacer plate was 15mm thick and we cut our rotary valve to open 145 BTDC and close 85 ATDC.

329237

I have used a VHM head but a standard head could be easily modified to spigot in too.

The top of the cylinder was turned down 2mm and the head was spigot'd 2mm into the cylinder, for a total adjustment of 4mm. When you turn the top of a plated cylinder it pays to grind a chamfer around the top of the bore so the turning tool does not pick up and chip the plating.

329238

There are two areas in the Suzuki GP crankcase just below the cylinder that need to be relieved for rod clearance.

A 110cc Suzuki GP100 fitted with a standard NSR cylinder, Honda RS125 pipe and 24mm carb makes about 26-27hp on our Dynojet.

[Nath88]

I am unable to choose where in the crank rotation I take the pressure sample. But Ecotrons allows me to choose several TPS/RPM break points for defining where the VE table swaps to the Alpha-N table. It does not have to be a straight line. It could be steps or even a rudimentary curve. so I will be able to target the problem areas in my series of dyno graphs.

The dyno graphs, all Alpha-N map, start at 20% TPS (green line) and go up in 10% steps 20 - 30 - 40 etc. Not much difference in power curves between 80 - 90 - 100% TPS.

All the EFI issues seem to be below 20 - 25% maybe that is where the pipe wave collapses.

I can use EngMod's predicted series of delivery ratios as a guide for the VE table.

This is my exhaust pressure takeoff for the MAP sensor. It is a one way valve with a small ceramic ball with only 0.010" movement, hopefully it wont break up being hammer'd around at 200Hz. The blue hose will have positive pressure in it and a small bleed hole melted into it with a hot pin for a pressure bleed down. Hopefully this will give the 2 bar MAP sensor something worthwhile to work with, that is hopefully a smooth positive pressure that reliably reflects changes in the mass air flow through the motor.


I found the same with mine, when tuned right, 20% throttle was about as little as the engine would take to maintain the pipe wave, keeping it firing every cycle. Less than that it would start to four stroke. It was interesting when tuning that area of the table, the engine would run clean at 20% throttle 7500rpm, would never do that with the carb.

Do you know when the Ecotrons samples the sensors? If it's tied to the injection timing or the crank trigger you might be able to tweak those to get it where it needs to be.
The mechanical bleed should work, would just need to bleed off within a few cycles to be effective. Enough for a proof of concept anyway.

Can you multiply the speed density table by the alpha-n table?
Can you switch tables based on an input? You could make an external circuit that switches when the exhaust pressure goes above some threshold value, like a fast pressure switch. Then have a table for off the pipe, and a table for on the pipe.

I don't think switching from speed density to alpha-n will be very helpful, will need to be a combination of them both.

[TZ350]

Can you multiply the speed density table by the alpha-n table? Can you switch tables based on an input?

It looks like Ecotrons uses the VE and Alpha-N tables completely independently.

329288 Ecotrons tuning guide.

329290 VE 12 RPM rows vis 16 MAP column's.

329291 Alpha-N 16 TPS rows vis 12 RPM column's.

329289 8 RPM cells with 8 corresponding TPS cells.

This map is setup as an eight step curve for choosing between VE or Alpha-N. At any RPM below a chosen TPS it is VE, above its Alpha-N.

It's pretty exciting, hopefully I will have the bike back together for a bit of a trial run by the week end. I don't expect too much straight away but it will be very interesting to see what the recorded MAP data from the exhaust port looks like.

[lucf]

The Ryger in action 12th of March at Eefde.
A few laps from Danny Aumiller with his standard Ryger..poor chassis setup but very nice laptimes !

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

[oktrg500]

At http://rygerengine.com they posted a dyno chart February 22nd 2017. Apparently, the engine will come in two flavors. Standard and Special. Strange - max hp is nowhere near the 17.000rpm's mentioned before. I wonder what the service intervals is for the engine parts. Wouldn't mind putting one of these into my 125 Aprilia streetbike :headbang:

329294

[FastFred]

At way over 30 hp at 10,000 rpm they can claim Free Blowies for Life from Wobbly .... :laugh:

[wobbly]

Be happy to oblige if it met the original bucket rules the offer applied to.

[TZ350]

Be happy to oblige if it met the original bucket rules the offer applied to.

:laugh: ..... Now that he brought it up, looks like FastFred will have to do it then.

[seymour14]

Be happy to oblige if it met the original bucket rules the offer applied to.

But I'm still waiting though?:lol:

[koenich]

The Ryger in action 12th of March at Eefde.
A few laps from Danny Aumiller with his standard Ryger..poor chassis setup but very nice laptimes !

https://www.youtube.com/watch?v=RJbxxdzhESA
and you are faster than all the lawnmowers on the track, another splendid proof :facepalm:

[ief]

If memory serves that was on a AC, no WC :)

[Nath88]

It looks like Ecotrons uses the VE and Alpha-N tables completely independently.

This map is setup as an eight step curve for choosing between VE or Alpha-N. At any RPM below a chosen TPS it is VE, above its Alpha-N.

It's pretty exciting, hopefully I will have the bike back together for a bit of a trial run by the week end. I don't expect too much straight away but it will be very interesting to see what the recorded MAP data from the exhaust port looks like.

Keen to see the data!
This might work well enough, first up set the area over say 5000rpm, and less than 50% TPS to be Speed Density. You'll want to set the TPS a fair bit higher than required to initiate the pipe wave, so when you whack the throttle on fast, the motor has a chance to fire (and pick the airflow up) before it crosses into the alpha-n table and goes to full fuel. If it doesn't fire in between, it will flood with all fuel and no airflow. Set the RPM bins like 4000, 4999, 5000, 6000 so you get a sharp cutover as you go over 5000rpm, and the system doesn't try to interpolate between the two zones (Megasquirt does this, not sure about the ecotrons). I'd probably do the same with the throttle position to be safe.

I'm not sure how the load prediction weighting works, if it's a form of blending between the alpha-N and speed density map, you might be able to have the fuelling incorporate TPS input when in the speed density mode, this will give some resolution to the fuelling between 0-50% TPS. Set it to maybe 0.5 to use half and half? Otherwise it will just be a set fuel value (with the exhaust around atmospheric pressure), until the airflow and fuel line up, motor fires and the pressure jumps up. If the load prediction does work like that, you might be able to use speed density/alpha-n half and half right up to full throttle, and should work similar to my system, alpha-n with 'speed density' correction.

On the speed density table you should make the pressure bins a sharp cutover at some threshold, so you get a 1.8x or so jump in fuelling when the motor fires. You could also have the higher pressure areas of the map give a little more fuel as the exhaust pressure wave develops with successive firings, like this:

100kPa - 55%
105kPa - 55%
105.1kPa - 100%
150kPa - 100%
200kPa - 110%

Also, you don't want any smoothing or averaging on the MAP input.

If you can use the exhaust pressure relative to barometric pressure for the speed density table it would be nicer, that way the exhaust firing threshold will adjust with altitude, luckily megasquirt gives this as an option called '%baro'. Or use a 1bar differential pressure sensor between exhaust and atmosphere as the speed density input.

You could have ecotrons give you a true multiplied table option, surely wouldn't be that hard to code.

Good luck!

[Frits Overmars]

If you can use the exhaust pressure relative to barometric pressure for the speed density table it would be nicer, that way the exhaust firing threshold will adjust with altitude, luckily megasquirt gives this as an option called '%baro'. Or use a 1bar differential pressure sensor between exhaust and atmosphere as the speed density input.If I remember correctly, the average pipe pressure in the power band at WOT is about 0,3 bar above atmospheric.

[sonic_v]

TZ

Just wondering if you have tried using a vacuum signal from the 24 mm venturi. This signal would be very sensitive to whether the engine is on pipe or indeed firing. If the delivery ratio is doubled then the vacuum signal would increase by 4 times. Flow is proportional to the square root of the signal.

This signal could maybe be intensified by running a second choke - with the exit centred in the 24 mm venturi - like an old weber carb. You would then take your signal from the second choke.

[jasonu]

The Ryger in action 12th of March at Eefde.
A few laps from Danny Aumiller with his standard Ryger..poor chassis setup but very nice laptimes !

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

Did it have 70hp?

[wobbly]

You might find a couple of people in the World who believe you.

[jonny quest]

TZ350, KTMs will now come standard with efi on certain models of their 2 stroke enduro models for 2018

[jasonu]

TZ350, KTMs will now come standard with efi on certain models of their 2 stroke enduro models for 2018

and will arrive in NZ in 2021...

[lucf]

Shit Luc, you really are your own worst enemy.
Not only have we had an endless stream of bullshit power numbers with " dyno " graphs a 10 year old could draw on an iPad, now we have " nice lap times ".
Whats the KZ2 lap record at the track, and its as simple as hitting Max Recall on the dash and use your phone camera to show a REAL result, just for once - give it a try.
You might find a couple of people in the World who believe you.


Only negative screaming, no real thinking and ask himself "where does all that power really come from?"
And those people calls themselfs a true expert in 2stroke, don't make me laugh!

[philou]

Normal to doubt

We do not know whether this power and.

No one has seen it

[Sketchy_Racer]

The Ryger in action 12th of March at Eefde.
A few laps from Danny Aumiller with his standard Ryger..poor chassis setup but very nice laptimes !

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

So what are you showing us? This could be any engine, with any driver doing any lap time. The only thing I picked up from the video is that the up shifts are terribly slow.

Why don't you stop trying to baffle everyone with bullshit and share some real technical data for a change, for that is what this thread is about.

[TZ350]

TZ ... Just wondering if you have tried using a vacuum signal from the 24 mm venturi. This signal would be very sensitive to whether the engine is on pipe or indeed firing.

Another good idea, I could need it, thanks.

[koenich]

Only negative screaming, no real thinking and ask himself "where does all that power really come from?"
And those people calls themselfs a true expert in 2stroke, don't make me laugh!
:facepalm: luc seriously? which power you mean - the 70hp, the 65hp or any new values available meanwhile? you've had like 2 years to show a proper proof and all you got are fishy posts, a fishy homologation, a fishy web shop and calling people who scrutinize those (which should be in every technicians nature...) names.

I can post a vid of me lapping RS125s/650cc supermotos on a kart track with my 50cc bike. must also produce massive amounts of power :corn:

[lucf]

We realy don't care about all those negative replies, we are use to it !

All those people will very soon be very quiet!!

[TZ350]

Why don't you stop trying to baffle everyone with bullshit and share some real technical data for a change, for that is what this thread is about.

True, this thread is show and tell and at its best when it's technically honest and open.

[koenich]

oh sry - think I missed that doubt, questioning and scrutinizing claims are negative replies.

sure - soon we'll be quiet, as you already mentioned 20 times in the last 2 years :violin:

[oldjohnno]

TZ

Just wondering if you have tried using a vacuum signal from the 24 mm venturi. This signal would be very sensitive to whether the engine is on pipe or indeed firing. If the delivery ratio is doubled then the vacuum signal would increase by 4 times. Flow is proportional to the square root of the signal.

And flow of a liquid - like fuel for example - through an orifice is proportional to the square of the pressure gradient. A cynic might say "If only there was some way to harness that venturi signal to deliver fuel directly into the engine..."

But I wouldn't...

[lucf]

Shit Luc, you really are your own worst enemy.
Not only have we had an endless stream of bullshit power numbers with " dyno " graphs a 10 year old could draw on an iPad,.

May be you have to learn some more, Read here what Jan Thiel wrote about some of my graphics.

https://www.facebook.com/luc.foekema/media_set?set=a.1992436069636.77827.1805454134&type=3&hc_location=ufi

For people who don't have FB:

Quote from : Jan Thiel on October 18, 2012 , 06:17:55
Beautiful graphics Luc ! That 'red ' abilities are 100 % definitely achievable. It will , however, most of the time, and especially money, are missing...........

Quote from Jan Thiel November 19, 2015
Calculations with a specific program are certainly very useful!
I wish I had something at Aprilia, then I had definitely become further!

[guyhockley]

Why split the cylinder height reduction between head and barrel - 2mm off barrel, 2mm spigot on head? I like the spigotted head, saves dowelling/lining up sloppy head barrel fits, but how deep could one go? What clearance for the spigot?
Please?

[sonic_v]

And flow of a liquid - like fuel for example - through an orifice is proportional to the square of the pressure gradient. A cynic might say "If only there was some way to harness that venturi signal to deliver fuel directly into the engine..."

But I wouldn't...

Off course, liquid flow through an orifice is actually proportional to the "square root" of the pressure gradient which is convenient as your hypothetical fuel delivery device could be a goer.

[SwePatrick]

About Ryger..

There are certain rules set by the universe of how much airflow you can get out of an certain area.

30mm(or 34mm, can´t remember) carburetor yes?

[F5 Dave]

. . . I can post a vid of me lapping RS125s/650cc supermotos on a kart track with my 50cc bike. must also produce massive amounts of power :corn:
Actually, that would be a nice distraction.:clap:

[Haufen]

Only negative screaming, no real thinking and ask himself "where does all that power really come from?"
And those people calls themselfs a true expert in 2stroke, don't make me laugh!

I am pretty sure a KZ2 prepared by wob would have run "nice" circles around your kart on that day. But that's just my personal opinion.

But anyway, as you mention the thinking part, I would like to offer you a technical discussion about the ryger engine. I hope that we will learn something from it, but based on the past, I don't think so. I did ask myself "where all that power could be coming from", and looking at the homologation documents and the pictures on the net, I don't see a reason why there should be "all that power", or even "as much power as the others". Because basically, due to the nature of the stepped piston, the ryger is a 125cc with reduced breathing capacity. If I had a horse and I would cut off one leg, there would be no reason this horse could then run faster, right? It's kind of the same with the ryger concept for me. So tell me, where did my thinking go wrong, what did I miss?

(by the way, the ryger is in no way "a clean two-stroke engine" just because it does not burn any oil. The main source of emissions on two-stroke engines is hydrocarbon emissions caused by scavenging losses of unburnt charge).

[wobbly]

Jans comments were about the graphics you did of an RSA125 simulation,so have nothing to do with our discussion on here about the mystical Ryger horsepower.
In every other forum I have seen he completely rubbishes everything you have said, and you have said quite alot, but with NO PROOF of anything.
Showing us so called dyno graphs, that clearly have nothing to do with a dyno,then a video of some no name kart running around on a track with 4 stroke rentals
also has nothing to do with the engine being a success in reality.
On that video day it would be my opinion that DeConto would have been 2 seconds a lap faster, with a TM " only " revving to 15,000 ( proven ) with one flat tire ( joke ).

What you dont seem to understand is that everyone on here is really, really wanting this Ryger project to be a success, all you are doing is turning the whole thing to shit
by feeding us all so much unproven rubbish.
Please SHUTUP,until the new dyno Jan told me you have,produces something that is worth writing about.

[ief]

+1 I guess :)

[TZ350]

I can post a vid of me lapping RS125s/650cc supermotos on a kart track with my 50cc bike. must also produce massive amounts of power :corn:
Actually, that would be a nice distraction.:clap:

Ha, F5 Dave just because you have run rings around much bigger bikes with your 50. I loved watching it. ... :laugh:

[SwePatrick]

Jans comments were about the graphics you did of an RSA125 simulation,so have nothing to do with our discussion on here about the mystical Ryger horsepower.
In every other forum I have seen he completely rubbishes everything you have said, and you have said quite alot, but with NO PROOF of anything.
Showing us so called dyno graphs, that clearly have nothing to do with a dyno,then a video of some no name kart running around on a track with 4 stroke rentals
also has nothing to do with the engine being a success in reality.
On that video day it would be my opinion that DeConto would have been 2 seconds a lap faster, with a TM " only " revving to 15,000 ( proven ) with one flat tire ( joke ).

What you dont seem to understand is that everyone on here is really, really wanting this Ryger project to be a success, all you are doing is turning the whole thing to shit
by feeding us all so much unproven rubbish.
Please SHUTUP,until the new dyno Jan told me you have,produces something that is worth writing about.

I wouldn´t trust any numbers from that dyno either.
A third party dynotester should be doing it.

Rgds.

[katinas]

Hi,

I can imagine the main important difference ( except mechanical side ) , between "normal" and "ryger" engines, that can play different games inside the cylinder:

The main stream from carb sucked directly to transfer ports when piston moves up and together with pipe, maybe its very strong tandem.


When piston at BDC the squash between piston and small cylinder top edge generate strong stream directly to transfers ports (maybe, at high rpm piston is like ball between two different springs).

Main piston have minimal contact with main cylinder , piston ring work without side force from piston at TDC and BDC.

Smaller suction volume ( but on bigger capacity engines, difference between working and sucking volume not so big )

But maybe Frits theory play another game

About rygerised NS 250. Finished straight header pipe, brakes, suspension. Start engine again, want to hear rpm with and without pipe. So without pipe engine max. revs 10200 rpm. Can't remember rpm without pipe on std. engine. With new pipe 13400 rpm. but carb, ignition,.... This week want to install new radiator with hoses, and a lot of small things, that EAT so much time . Maybe next week will try it.

Interesting, from homologation, Ryger exhaust final section before stinger 29mm. Is it final dimension, or dimension before smaller tube.

[Flettner]

Although twostrokes are a religion, this is not a church as in we here don't just believe something because some one said so. Results are required!
Luc, you must see that this carrot that you have dangled in front of us has all but shriveled up now. I'ts been too long with nothing. The irony is if you had been open an frank about this development we all would have helped out to see it succeed but we all now fell let down and tricked by you. SOOOOOOON isn't good enough any more. I think some better ideas are emerging now anyway but they will be kept from your view.

[jfn2]

It seems that all the comments about the Ryger engine are about the performance characteristics. If I remember correctly when this engine first came onto the scene it was claimed to be a cleaner running 2-stroke and the performance was second. We all have a pretty good idea about the claimed performance aspect but what I want to know is ' Is this engine a cleaner running 2-stroke engine with acceptable performance?' And if it is, can it be improved upon from a performance standpoint? Moderators, please feel free to move this to the correct forum.

[ken seeber]

2 thoughts on the Ryger:

1. As the seeming first application was on a KZ kart engine, this is a racing application where the performance on the track is the ultimate dyno. We now have a vid of something dashing past some Chonda GX200 clones on a kart track. This being the case, then it shouldn’t be long until the thing is on the “real” dyno for the whole world to see.

2. I’m sure the majority who read/write to ESE do so because they love 2 strokes. Also sure they all realize the future of the 2 stroke is limited in the commercial world, despite its advantages being outweighed by its disadvantages. So the Ryger thing came along, giving us all hope that it could take, or even jump, the 2 stroke forward to stave off being taken over by 4 strokes or ultimately electric. Unfortunately, from the viewpoint of an outsider, it has been a fizzer to date.

So I reckon that Luc, with whatever connection you may have with the Ryger project, you should tell yourself and Harry/Hendrik to go away into the back room and get the thing sorted properly and then present it to the outside world such that it can be tried and assessed independently. Bringing out half-baked dyno info or vids don’t do yourself or the project any credibility.

No-one wants to be an arsehole here, we all would love to see it go as we were originally lead to believe.

[jamathi]

It seems that all the comments about the Ryger engine are about the performance characteristics. If I remember correctly when this engine first came onto the scene it was claimed to be a cleaner running 2-stroke and the performance was second. We all have a pretty good idea about the claimed performance aspect but what I want to know is ' Is this engine a cleaner running 2-stroke engine with acceptable performance?' And if it is, can it be improved upon from a performance standpoint? Moderators, please feel free to move this to the correct forum.

Running on fuel without oil doesn't make an engine 'clean' at all!
It just doesn't smoke....
All cars have to use catalyzers.
Even the biggest manufacturers have difficulties to make engines conforming the norms!
Ryger could not even afford the necessary testing equipment I think....
And of course I fully agree with Ken Seeber and Wobbly.....

[husaberg]

Running on fuel without oil doesn't make an engine 'clean' at all!
It just doesn't smoke....
All cars have to use catalyzers.
Even the biggest manufacturers have difficulties to make engines conforming the norms!
Ryger could not even afford the necessary testing equipment I think....
And of course I fully agree with Ken Seeber and Wobbly.....

BMW should be able to sort that out.:msn-wink:

We realy don't care about all those negative replies, we are use to it !
All those people will very soon be very quiet!!

Criticism may not be agreeable, but it is necessary. It fulfils the same function as pain in the human body. It calls attention to an unhealthy state of things. Winston Churchill
The best effective way to silence critics is by producing tangable results.
No one is actually above be critiqued but some people view it beneath them to consider that Criticism can be valid feedback.husaberg 2017
some fella once said Criticism is valuable... and self-congratulatory experiences are not.

[TZ350]

And flow of a liquid - like fuel for example - through an orifice is proportional to the square of the pressure gradient. A cynic might say "If only there was some way to harness that venturi signal to deliver fuel directly into the engine..."

But I wouldn't...Off course, liquid flow through an orifice is actually proportional to the "square root" of the pressure gradient which is convenient as your hypothetical fuel delivery device could be a goer.

Tried that but a lot of it fell into the bottom of the plenum wreaking havoc with control over the air fuel ratio and the heavy oily mixture left doubts about how much oil was actually getting to the motor.

First ever startup. https://youtu.be/YxiEo8cgopg

Bit of a strop up the drive. https://youtu.be/p4ef-WUO1Qs

329303 329304

During track testing the plenum showed real promise.

329305329306

So because of plenum flooding the logical thing was fuel injection.

[lucf]

Jans comments were about the graphics you did of an RSA125 simulation,so have nothing to do with our discussion on here about the mystical Ryger horsepower.
In every other forum I have seen he completely rubbishes everything you have said, and you have said quite alot, but with NO PROOF of anything.
Showing us so called dyno graphs, that clearly have nothing to do with a dyno,then a video of some no name kart running around on a track with 4 stroke rentals
also has nothing to do with the engine being a success in reality.
On that video day it would be my opinion that DeConto would have been 2 seconds a lap faster, with a TM " only " revving to 15,000 ( proven ) with one flat tire ( joke ).

What you dont seem to understand is that everyone on here is really, really wanting this Ryger project to be a success, all you are doing is turning the whole thing to shit
by feeding us all so much unproven rubbish.
Please SHUTUP,until the new dyno Jan told me you have,produces something that is worth writing about.


I did and do write always the truth. The problem is that some people like you called it rubbish, because you don't understand and so you don't believe it.
My answer to those people is "not my problem but yours !!"

We never claimed that it is an absolute clean engine, but in comparioson with a normal 2 stroke, Yes it is !!.
Only people who want to be negative, explain it in wrong way, just like in politics.

The same at the replies on the powergraphic we show end last year. "It is calculated or simulised"
Well that reply is full rubbish, because a simulation program for the Ryger principle doesn't exist at all.
You can only calculate the differences. And I am very astonished that no one could find the positive side of the Ryger principle, which realy does exist !, only the negative side of it, which is very easy.

Choosing the negative side seems to be the most favorite way when people don't understand a situation. You can see that now every day on tv in politic discussions, before the Dutch elections.
But from clever people which are serious with somewhat like twostroke sience, you should espect something else? But I'm wrong, it seems to be exactly the same.

In the video you see a standard Ryger engine running around between many 4strokes and one KZ2. Everyone can measure laptimes, everyone can find the trackrecord (sorry not the KZ2).
But no one does! May be someone does and stay quiet. But all replies are again negative without looking a little futher!
Is that the only thing what many "2stroke tuners" can do to day?

On the Dutch forum "Racehelden" the replies are so negative, that I have stop writing there at all. On "PitLane most people, beside 1 exeption, are more patient and are waiting for our next step.
And these steps will come, but only at the moment we are ready to do so. We don't let us forced to do it in your way, beacuse it is not your but our project! You are not forced to follow it.

Stronger proofs will come in the near future, so you better start thinking about the differences to understand "where the power comes from?", instead to call it rubbish! And thinking starts with "real thinking" and not to shout every minut new rubbish suggestions. And don't tell me you did, because I did not read one good suggestion in all those years.

Because with those rubbish replies I'm not prepaired to explain anything!, Your choise !!
and sorry for my bad English!

[41juergen]

Running on fuel without oil doesn't make an engine 'clean' at all!
It just doesn't smoke....
All cars have to use catalyzers.
Even the biggest manufacturers have difficulties to make engines conforming the norms!
Ryger could not even afford the necessary testing equipment I think....
And of course I fully agree with Ken Seeber and Wobbly.....

We are supplying BMW (and all the others around the world) with the catalysts. Unfortunately even they are fighting (within the Husky activities) to get a road going 2T dirt bike running and passing the current EU4 (not talking about EU5/6) regulations...:weep:

[koenich]

luc seriously? one would think you have learned from the previous critical responses, but no - you continue being an ignorant claimer and choose to basically say all others are idiots cause they are not following your (unproven) words blindly. thats like religion, fighting who has the coolest imaginary friend - currently you fight hard for the coolest imaginary engine.

as wob and many others mentioned we all want this thing to suceed but you are making a joke of it and yourself by not being able to handle a bit backlash for your empty words.

[shnaggs]

Perfect answer Alex.

Shnaggs, why would you want to ramp up the velocity? If that were a good thing, you could reduce all cross flow areas to 1 mm² or even smaller. But somehow I doubt that it would help performance. I prefer to ramp up mass flow.
Anyway, increasing flow velocity by means of reducing the cross flow area is largely a fairy tale. Velocity comes from a pressure differential over a duct.
Lower the downstream pressure far enough and the flow velocity will reach Mach 1. Crank up the upstream pressure far enough and the flow velocity will also reach Mach 1 with the added benefit of a higher density in the flowing medium, i.e. more mass flow for the same Mach 1 flow velocity.

The fairy tale stems from the fact that with a large cross flow area there will be so much mass flow that the upstream pressure drops markedly even before the gas column in the duct is accelerated to the velocity corresponding to the initial pressure differential. So the velocity will never reach the value that it would reach with a smaller cross flow area. But who cares; we've got more mass flow. :.

Ok, I suppose I should have been less general with my question. Of coarse we need mass flow, but don't we want mass flow with as high velocity as possible? In my mind (have been known to be wrong from time to time) giving the mass flow more velocity gives it more momentum...and that would be a good thing, right? If flow is 'lazy' it will not go where it needs to go.

As an experiment, I made a w-block reed cage but turned it on its side, so it looked like two almost pyramid type reed cages with tapering angles toward the piston. Calculating the flow area was not intriguing, it had the same effective port diameter as a 80cc standard block. But when run on the dyno this reed cage made the exact same HP as the stock ktm w-block cage on a 125 & 250. Now, this either proves my point, or it proves Wobbly's point. Either my sideways w-block made good velocity, with lack of flow, or it split the inlet tracked into 2 separate channels, L&R helping the air turn the corner and charging the cylinder more uniformly?

I'm sure the answer to that would be the more uniform cylinder charging.:laugh:

[jellert]

In the video you see a standard Ryger engine running around between many 4strokes and one KZ2. Everyone can measure laptimes, everyone can find the trackrecord (sorry not the KZ2).
But no one does! May be someone does and stay quiet. But all replies are again negative without looking a little futher!
Is that the only thing what many "2stroke tuners" can do to day?


I did take laptimes and from what I can see it's struggling to do a low 30... I'm sorry, but that's not good. I went back to see what times we did when I was at Eefde the last time. We were in the high 29's/low 30's, with a second hand 2009 Energy Kart we had never driven before, on years old Mojo D2 tyres and with a 125cc PRD Fireball. Nothing special about that engine, just a nice simple old karting engine with a steel insert cilinder. Even a friend who hadn't driven a kart in more than five years was in the 30's. So either your driver is really bad, that kart is absolute garbage, it was on concrete tyres or the engine.... (or a combination of these).

You'll probably argue that is was because of traffic, but I measured some laps from one of my videos with traffic and even those were in the 30's. You could also argue it's because we don't have to shift with that PRD, but no a KZ2 with a decent driver is faster at Eefde.

The replies are not negative, they are critical, because you don't provide any extra information. You only make big claims and say "wait and see!" When you make bold claims, people want to see you back up those claims. Posting a little video of a kart going around Eefde does not back up any of your claims. Don't get me wrong, like most people here I would LOVE to see the Ryger concept working as claimed, but this video proves nothing.

[adegnes]

My first encounter with methanol/nitro in a moped.
Typical outcome.

329317

Crossing fingers for minimal damage inside.


https://youtu.be/ihmxMnAZmvM

[breezy]

My first encounter with methanol/nitro in a moped.
Typical outcome.

329317

Crossing fingers for minimal damage inside.


https://youtu.be/ihmxMnAZmvM

hope theres not to much damage inside... thing is its more beneficial to see these things for yourself and test , rather than being told things... good post:niceone:

[Tim Ey]

My first encounter with methanol/nitro in a moped.

329317


Thanks for that post! I did not want to write anything below the "real thinking" alternative fact racehorse with the missing leg.

Ouch! Didn't you hear that the engine was running way to lean? Interesting that the Pilotjet hole in the PWK is so small.

[Haufen]

We are supplying BMW (and all the others around the world) with the catalysts. Unfortunately even they are fighting (within the Husky activities) to get a road going 2T dirt bike running and passing the current EU4 (not talking about EU5/6) regulations...:weep:

I agree with you regarding the difficulty. Good news is, KTM just announced their 2018 enduro models which will meet Euro4 emissions standard (http://racerxonline.com/2017/03/15/fuel-injected-ktm-two-strokes-coming-in-2018) using transfer port injection.

Personally, I don't regard transfer port injection as 'revolutionary' (revolutionary for me would have been high pressure direct injection and no more scavenging losses at all and thus a real step forward in cleanliness, but hey, as a company you always go for the most economical way to achieve your targets), but I like the fact that one will be able to buy new two-stroke bikes in the future, too.

And I think they should mention Flettner somewhere in the article. :)

[adegnes]

Thanks for that post! I did not want to write anything below the "real thinking" alternative fact racehorse with the missing leg.

Ouch! Didn't you hear that the engine was running way to lean? Interesting that the Pilotjet hole in the PWK is so small.

I did hear it, but just wanted to give it a little try, couldn't hurt...
Yeah, that pilot jet hole, weird.
Next try will be with massive jets, like 300% more fuel than with gasoline.

[TZ350]

page 1690 .... :confused:

Alot of these posts have pictures, you will have to follow the posts back to see them.


rad....... using your swede
http://www.swedetechracing.com/techtips/How-To-Create-A-Jet-Chart/63165
http://www.dtec.net.au/Air%20Density%20&%20Tuning.htm
https://srgclub.org/Jet_BL.html
http://www.tz250.com/forums/archive/index.php/t-4295.html
http://www.everything2stroke.com/forums/attachment.php?attachmentid=3020&d=1140811026.
https://wahiduddin.net/calc/calc_hp.htm


About barometric pressure.

If the pressure is 'low' and oxygenlevel is 'high'
The engine gives the 'same' power as if the pressure is 'high' but oxygenlevel is 'low'.
The thing to measure is the density of air.
To do that with simple tools you calculate with moisture and temprature.
The moisture is complicated enough relativly to temp and pressure.
Thereby there´s an formula to calculate with relativitly moisture.
You can all find this info in dynocorrection standards, they calculate from different 'origos' but they do about the same job all of them.

To set things in perspective:
If a raise in atmosphere pressure is double, but density is half.(from originally situation)
The engine will not produce any more power.
Probably it will loose power as that situation only accurs in bad boostsetups.
(heatproblems)

Rgds.


330063

Here is a jetting chart for a KZ2 engine, showing Density Altitude and RAD Vs Jet size in a 30mm Dellorto carb.
One point on the graph was best power on the dyno with egt at 660*C - so the other 2 points used to plot the line were really widely varying density days
but with the tuning done to achieve that 660 result.
All this is doing is replicating the bsfc number at best power, with widely varying air conditions - be they affected by temp, baro pressure or humidity %.

Katinas first test ride of the Ryger he built.


https://www.youtube.com/watch?v=ckOw-Cp7wH8

https://www.youtube.com/watch?v=L-0AH79mY2E



Is Viton the preferred material for O-rings used to seal liquid cooled heads?
Viton is the material of choice for the inner ring where it seals the chamber to the cylinder top.
But around the outside where it seals only water ,normal O rings are fine.


I have been made aware of the dangers of Viton when heated or burned as in fan belts on burnt cars being dangerous.

329720



Lengthening the exhaust duct and cool it very well is one of the things I regret not having tried! I had the idea in 2007, but did not try it because I was planning to retire... Almost certainly it will give e good power improvement!
The idea floated about lengthening the Ex duct and increasing the cooling in this area is exactly what i will be advocating for the new kart engine design. Along with a shape change to include the Aux duct ears right down to the header joint and water having access into the back of the bolt on spigot.

329719

Edit - here is the optimum duct geometry as I have found in EngMod.

Turbo:-


Some further reading for TZ he might need to reverse engineer it a bit for his application.
http://www.spartgsxrspecials.com/turbo%20do%20and%20dont.htm


By the way, you should know that Albert Einstein distinguished four kinds of people:
dumb + lazy: harmless
dumb + diligent: disastrous
smart + diligent: not much better than dumb + diligent
smart + lazy: the only useful kind; those are the ones who seek efficient solutions.


Detonation.

This started te be a problem when 50cc engines started giving more than 17HP, around 1975.
At the time I thought this was a limit on engine power.
Nikasil plated cylinders were very prone to detonation.
Because of the rounded off edge at the top.
At Minarelli/Garelli I solved this problem by sticking the cylinder head insert 3mm into the cylinder.
A good solution, used for many years.
But at Aprilia we found an even better solution: plate the first 5 mm around the bore at
the top of the cylinder.
Later this was machined to a very sharp corner, and this eliminated completely the unnecessary
'dead room' at the top of the cylinder, it also gave 0,3HP more.....
A little bit of still remaining detonation was eliminated by modifying the inner wall of the
transfer ducts, cooling the piston.
But part-throttle detonation remained a problem.....
Which we never had on the dyno!
On the photo you see a piston after a 54HP run...
As long as you keep the throttle wide open a 2 stroke doesn't brake down!


The Aprilia RSW was a ROTAX design.
Later Aprilia made their own engines, but closely followed the original ROTAX design.
Except some small details.
Now they could say everything was 'made in Italy'
Which had financial 'advantages' for certain people!
Who could now take a bribe from the suppliers......as is usual in Italy.
So I am certainly not the 'father' of the Aprilia engines!

I was responsible for cylinder development, starting with 46,5HP and ending with 54HP.
Later, when working at DERBI, I had the idea of making the RSA engine, and made the first sketches.
The actual design was, of course, done on a computer by a professional designer.
Although it won several world championships I don't consider it a big success...

Aprilia always used AGIP fuels and oils for dyno testing
102 octane.
We were given face masks and special gloves, which we never needed for the 130 octane fuel.....


When modifying a cylinder measuring duct sizes is not easy, especially in the curves!
You can see our solution to this problem on the photo....
Round 'sensors' fitted to a piece of welding rod!
We had them from 7-7,25- 7,5 and so on until 28mm.
Behind the cylinder, in the wooden block.


Pistons:


We had cast and forged pistons.
Cast pistons gave slightly more HP, but sometimes cracked.
0,8mm piston rings gave more HP than 1mm rings.
As the auxiliaries and transfers overlapped each other a certain power los was caused by this.
So closing the pin hole in the piston was tried.
There were many solutions that were tested, but they all caused some trouble.
In the end the best, and most reliable, solution was welding then closed.
This was very well done by PANKL in Austria, and never caused any trouble!




Do you mind me asking why do you think cast pistons made more hp than forged? Because forged pistons had a tendency to 'bend' their top inwards.


Transfer ducts.

Many transfer ducts with small differences were tried.
We found more power by enlarging the A-port in the direction of the exhaust.
Only the lower half, but it was important to give the A-duct an inclination away from the exhaust!
The ducts were very conical, the smallest point being the port.
In and outside walls of the ducts had a constant radius from top to bottom.
The flow remained attached to the inside radius and so cooled the piston and eliminated detonation.
Flow bench testing and the Jante type testing proved useless for power improvement.
Giving the rear side of the B-duct an inclination versus the middle of the cylinder gave a big improvemet

[TZ350]

Why split the cylinder height reduction between head and barrel - 2mm off barrel, 2mm spigot on head?

329318 Honda NSR250 MC21 cylinder.

I could only take 2mm off the barrel and still have some water jacket sealing area left.

329319

Needed minus 4mm so 2mm off barrel and 2mm off head. The head spigot is a very neat fit into the barrel, maybe 0.005".

[WilDun]

I agree with you regarding the difficulty. Good news is,......... KTM just announced their 2018 enduro models which will meet Euro4 emissions standard using transfer port injection.

........... but I like the fact that one will be able to buy new two-stroke bikes in the future, too.

And I think they should mention Flettner somewhere in the article. :-)

My hope is that the words "two stroke" have not been sullied by the powers that be. The legislation was all supposedly about reducing pollution but they mentioned the two stroke as the main culprit.
We now see (and hopefully the legislators do too) that the two stroke is capable of holding it's own in the cleanliness department, however when "two stroke" is mentioned it makes people recoil in horror (like sugar in food :shit: )! ............ maybe time for some good strong advertising ...... or even a name change? ....... well, maybe not :laugh:

And yes Flettner did prove conclusively that EFI does work.:niceone:

[Frits Overmars]

Next try will be with massive jets, like 300% more fuel than with gasoline.Now that could really destroy your engine Alex, because it will make a lot more power but it may still be too lean.
300% more fuel than with gasoline would be fine with methanol; in fact you would 'only' need 130% more.
But playing with nitromethane is a different ball game. If you use 100% nitromethane, all your fuel passages need to be 9 times as big as with gasoline.
If you start mixing the various juices, it will of course depend on their percentages. You can do the math yourself, based on their stoichiometric values:
gasoline: 14,7
ethanol: 9,0 - 63 % more fuel required for the same amount of air.
methanol: 6,4 - 130 % more fuel required for the same amount of air
nitromethane: 1,67 - 800 % more fuel required for the same amount of air

Here is some more light reading on the subject.
http://www.highpowermedia.com/blog/3064/nitromethane-rocket-fuel-or-what
http://www.darkside.ca/node/77

[adegnes]

Now that may really destroy your engine Alex, because it will make a lot more power but it may still be too lean.
300% more fuel than with gasoline would be fine with methanol; in fact you would 'only' need 130% more.
But if you start playing with nitromethane, things change. If you use 100% nitromethane, all your fuel passages need to be 9 times as big as with gasoline.
If you start mixing the various juices, it will of course depend on the percentages. You can do the math yourself base on their stoiciometric values:
gasoline: 14,7
ethanol: 9
methanol: 6,4
nitromethane: 1,67

Here is some more light reading on the subject.
http://www.highpowermedia.com/blog/3064/nitromethane-rocket-fuel-or-what
http://www.darkside.ca/node/77

Ok, thanks! 400% then :laugh:

How about the 15% of oil in my mix? Judging by the mess behind my bike, alot of it just passe through, should I just consider it "dead weight"?

[wobbly]

So in reality we have seen absolutely nothing - does this make him an incompetent idiot, maybe not.

[jonny quest]

KTM has fuel injection figured out on 2 strokes

[mr bucketracer]

We have a similar situation with Suter in the field of two stroke fuel injection, as we have with Luc and his Ryger.
NO person or company, apart from Flettner , have built and then shown on the net a two stroke that runs perfectly well in its intended application.
We know Honda tried, practiced with it but it , but never raced it.
Cagiva tried it, and Foggy walked away from riding it at all it was so bad.
Aprilia tried it, and got marvelous dyno results, but the track test said it was rubbish.

Now we have Suter, a zillion dollar project, with all the big fanfare of expectation in the press of blowing everyone away at the TT.
We all hoped, but no, a complete flop on the track.
This would have been OK,but the big headed people in charge at Suter were so self absorbed in their own genius, they just assumed the thing would be a rocket
with no real track testing proof before entering the most prestigious racing event on the planet.
All it really achieved was to make them all look like incompetent idiots.

Luc has been telling us for years that the Ryger is better than sliced bread, starting with its 70Hp and 30,000 rpm,then slowly downgrading the expectations
derived from his very outdated ( MOTA ) simulation code.
They even built 50 of the things to get CIK homologation - yet no sign of a single one of them being tested.
So in reality we have seen absolutely nothing - does this make him an incompetent idiot, maybe not.
For sure most of us are sick and tired of the hype - so as I said before SHUTUP, till an independent real dyno gives us some proof.
Then we will all bow down to the new King of 2T - a title that Mr Thiel is easily hanging onto at this time.get a life you angry little man

[wobbly]

From KTM " The KTM 250 EXC TPI and KTM 300 EXC TPI models will be introduced to the global market as part of the model year 2018 lineup, while the
250 XC-W TPI model will be introduced to the U.S. and Canadian markets."
So we havnt seen the result yet,and due to the technology it wont have a chance of getting close to the emission standards that the ETEC direct injection system
slaughters easily.
Thats the real problem, the only viable way forward at the moment for a 2T to challenge the Honda incited 4T curse at present, is locked up in patent law.

[Norman]

First of all, I have followed this fantastic source of knowledge presented here regarding two strokes and tuning. I am not an engine expert at all, (I wish I would have become a Jan, Frits or a Wobbly, et.al.) and I would rank myself at the most as a very average mechanical engineer. I am working in the supply chain for close to engine parts to automotive OEMs. Back in 1983 I did, however, finally manage to tune my GP125 to severably beat my friends RD125LCs. Yes! No driving alone anymore! What could I not have done with all the information here at the time..!?

I have followed the information coming out about Ryger for some time. I must say that I have not yet lost patience. I cannot believe that somebody would be so stupid to put so much energy and money into a project like that with the goal to, by intent, try and fool a number of engine buyers/financers. I believe it is an honest project, but that they do have run into some sort of problems (as we all do in development projects) along the way. And yes, unforseen problems can take time to fix. With relatively limited resources it takes even longer. For example, a part supplier fault made in the first pre series delivery, after the initial well functioning prototypes, can be a disaster for a time plan. Complete new durability tests and performance tests might have to be conducted (and most likely much much more work). This just as an example. I do not either expect that we will be given all the details about the function of the engine, and details how we can build our own Ryger engine. If I were Ryger I would also be very reluctant to give out any very detailed findings how everythings works together. I am grateful for all the FREE information given from you with the knowhow here, but I also respect the need for the Ryger company to protect their business case.

We can only wait and see what happens and hopefully we soon can get the information that gives us a better understanding of the Ryger concept, and a final conclusion/results if it really works.

Luc is enthusiastic, but could you really blame him?

[2T Institute]

I did and do write always the truth. The problem is that some people like you called it rubbish, because you don't understand and so you don't believe it.
My answer to those people is "not my problem but yours !!"

We never claimed that it is an absolute clean engine, but in comparioson with a normal 2 stroke, Yes it is !!.
Only people who want to be negative, explain it in wrong way, just like in politics.

The same at the replies on the powergraphic we show end last year. "It is calculated or simulised"
Well that reply is full rubbish, because a simulation program for the Ryger principle doesn't exist at all.
You can only calculate the differences. And I am very astonished that no one could find the positive side of the Ryger principle, which realy does exist !, only the negative side of it, which is very easy.

Choosing the negative side seems to be the most favorite way when people don't understand a situation. You can see that now every day on tv in politic discussions, before the Dutch elections.
But from clever people which are serious with somewhat like twostroke sience, you should espect something else? But I'm wrong, it seems to be exactly the same.

In the video you see a standard Ryger engine running around between many 4strokes and one KZ2. Everyone can measure laptimes, everyone can find the trackrecord (sorry not the KZ2).
But no one does! May be someone does and stay quiet. But all replies are again negative without looking a little futher!
Is that the only thing what many "2stroke tuners" can do to day?

On the Dutch forum "Racehelden" the replies are so negative, that I have stop writing there at all. On "PitLane most people, beside 1 exeption, are more patient and are waiting for our next step.
And these steps will come, but only at the moment we are ready to do so. We don't let us forced to do it in your way, beacuse it is not your but our project! You are not forced to follow it.

Stronger proofs will come in the near future, so you better start thinking about the differences to understand "where the power comes from?", instead to call it rubbish! And thinking starts with "real thinking" and not to shout every minut new rubbish suggestions. And don't tell me you did, because I did not read one good suggestion in all those years.

Because with those rubbish replies I'm not prepaired to explain anything!, Your choise !!
and sorry for my bad English!

IF tht kart made anywhere near 60hp it would nearly undrivable, would lift the inside rear and smoke the rears at the drop of a hat. Kart doesn't even look fast in a straight line.

[FastFred]

KTM has fuel injection figured out on 2 strokes

125 ... 250 or bigger, RPM? number of injectors, MAP? pictures?

I am sure TeeZee would love to know more. .... ;)

[DoldGuy]

TZ, information on F-I...

http://smcomp.com/~smurph/RZ-EFI/index.html



http://www.rzrd500.com/phpBB3/viewtopic.php?f=5&t=1899

Bike has been on the street for years, hope there is some helpful information.

[tjbw]

Hi,

I can imagine the main important difference ( except mechanical side ) , between "normal" and "ryger" engines, that can play different games inside the cylinder:

The main stream from carb sucked directly to transfer ports when piston moves up and together with pipe, maybe its very strong tandem.


When piston at BDC the squash between piston and small cylinder top edge generate strong stream directly to transfers ports (maybe, at high rpm piston is like ball between two different springs).

Main piston have minimal contact with main cylinder , piston ring work without side force from piston at TDC and BDC.

Smaller suction volume ( but on bigger capacity engines, difference between working and sucking volume not so big )

But maybe Frits theory play another game

About rygerised NS 250. Finished straight header pipe, brakes, suspension. Start engine again, want to hear rpm with and without pipe. So without pipe engine max. revs 10200 rpm. Can't remember rpm without pipe on std. engine. With new pipe 13400 rpm. but carb, ignition,.... This week want to install new radiator with hoses, and a lot of small things, that EAT so much time . Maybe next week will try it.

Interesting, from homologation, Ryger exhaust final section before stinger 29mm. Is it final dimension, or dimension before smaller tube.

Katinas, thanks for sharing your thoughts on Ryger. Do you expect your engine to achieve HCCI?

Regarding the stinger, it appears that it's not homologated, but must match the homologated Ryger exhaust @ 29mm diameter, and one of the homologated silencers. Perhaps LucF could confirm the dimensions.

[husaberg]

We have a similar situation with Suter in the field of two stroke fuel injection, as we have with Luc and his Ryger.
NO person or company, apart from Flettner , have built and then shown on the net a two stroke that runs perfectly well in its intended application.
We know Honda tried, practiced with it but it , but never raced it.
Cagiva tried it, and Foggy walked away from riding it at all it was so bad.
Aprilia tried it, and got marvelous dyno results, but the track test said it was rubbish.
.
As far as i am aware Itoh did a full season on an injected NSR500 which s why he only had a decent result when he filled in on Doohans bike for one race 95 (i think)
I am pretty sure Honda was pretty coy about it or was it maybe they were just letting the journalists think thats what they were doing?
Honda had some success with the EXP2 which was injected.
The thing is, carbs work very well. Actually in a lot of situations feel is more important than outright power. The IOM TT is one.
There has been a few injected trials bikes but i have never tried one.

[katinas]

As far as i am aware Itoh did a full season on an injected NSR500 which s why he only had a decent result when he filled in on Doohans bike for one race 95 (i think)
I am pretty sure Honda was pretty coy about it or was it maybe they were just letting the journalists think thats what they were doing?
Honda had some success with the EXP2 which was injected.
The thing is, carbs work very well. Actually in a lot of situations feel is more important than outright power. The IOM TT is one.
There has been a few injected trials bikes but i have never tried one.

This is from "Honda GP Racers" :
93' Itho speed record at Hockenheim 320kph, 10kg/cm2 at injectors.

But during 94' Hattori recalls; throttle linearity proved to be worse than with carb, so we moved the programme back to fundamental research level, to look at fuel atomization, and flows into the crankcase and around the reed-valve. Understanding these factors is essential to obtaining good throttle control.

[husaberg]

This is from "Honda GP Racers" :
93' Itho speed record at Hockenheim 320kph, 10kg/cm2 at injectors.

But during 94' Hattori recalls; throttle linearity proved to be worse than with carb, so we moved the programme back to fundamental research level, to look at fuel atomization, and flows into the crankcase and around the reed-valve. Understanding these factors is essential to obtaining good throttle control.

Yeah, but the speed record is a bit misleading, as Itoh was a little fellow and Doohan couldn't tuck in as well due to injuries.
Not sure when the last year was on the "jungle juice" fuel but it was arround then as well.
I think Honda was attempting to conserve fuel and achieve lower emissions, more than added power.
Also on a twin crank V4 like a Yamaha the combatness of the engine is compromised by the space needed for the carbs inside the V. Not so much an issue on the NSR500 though.

[Ocean1]

There has been a few injected trials bikes but i have never tried one.

The Ossa is bloody good immediately off idle right through the range. Runs clean again straight after a throttle chop.

I know they had trouble with the early ones but that was more related to starting current for the ecu, (no battery).

[husaberg]

The Ossa is bloody good immediately off idle right through the range. Runs clean again straight after a throttle chop.

I know they had trouble with the early ones but that was more related to starting current for the ecu, (no battery).

Direct injection?

[TZ350]

300% more fuel than with gasoline would be fine with methanol; in fact you would 'only' need 130% more. But playing with nitromethane is a different ball game. If you use 100% nitromethane, all your fuel passages need to be 9 times as big as with gasoline.

There may be another approach. Nitro has slightly more fuel than oxygenate and only slightly more fuel is why you need so much "Nitro" to consume all the oxygen in the inducted air and not run lean.

My approach would be to get the engine running properly on methanol then add Nitro. Bigger jet required in proportion to the extra Nitro so that you still get the same amount of methanol as before for the inducted air. The Nitro consumes its own fuel and the extra hydrocarbons just richens things up a bit.

I would have the methanol flowing through the main jet and use a separate switchable power jet arrangement for the Nitro. That way, when the Nitro was on you would get more power and noise and heat and a slightly richer mixture.

[Flettner]

See if you can see the Euro4 DTPI Kawasaki, out doing secret testing in NZ the other weekend:laugh:
https://youtu.be/ZqzOgOJuJ1E

[adegnes]

There may be another approach. Nitro has slightly more fuel than oxygenate and only slightly more fuel is why you need so much "Nitro" to consume all the oxygen in the inducted air and not run lean.

My approach would be to get the engine running properly on methanol then add Nitro. Bigger jet required in proportion to the extra Nitro so that you still get the same amount of methanol as before for the inducted air. The Nitro consumes its own fuel and the extra hydrocarbons just richens things up a bit.

I would have the methanol flowing through the main jet and use a separate switchable power jet arrangement for the Nitro. That way, when the Nitro was on you would get more power and noise and heat and a slightly richer mixture.

That's a great idea! Only problem is I can't get hold of any pure nitro, they fear we will be making bombs...

To stay on the safe side while creeping up on this fuel I could use your approach and move the nitro % over to the air side of the equation. What are your thoughts on the oil and afr?
Maybe move it to the air side too.

[husaberg]

That's a great idea! Only problem is I can't get hold of any pure nitro, they fear we will be making bombs...

To stay on the safe side while creeping up on this fuel I could use your approach and move the nitro % over to the air side of the equation. What are your thoughts on the oil and afr?
Maybe move it to the air side too.

Try a chemist or a dry cleaner.
Or those guys that fly the pylon mini planes.
The Drag guys get it from somewhere.

[adegnes]

So...

Methanol afr 5:1
Gasoline afr 12:1
12/5 = 2.4 = 140% increase in jet area

35% of the fuel moved to the air side
140+35 = 175% increase in jet area

I think I'll start on 400% and carefully work my way down to that number. Spoke to a guy yesterday who had melted 40 plugs dialing in his scooter on methanol/nitro.

[katinas]

Katinas, thanks for sharing your thoughts on Ryger. Do you expect your engine to achieve HCCI?

Regarding the stinger, it appears that it's not homologated, but must match the homologated Ryger exhaust @ 29mm diameter, and one of the homologated silencers. Perhaps LucF could confirm the dimensions.

Honda NS cylinder is not the best options for rygerised engine. Restrictive Boyesen ports, small transfers windows, small reed cage. But I have this two NS 250 and NS 400 for experimentation. Original plan, before Ryger story, was made 3- cylinder NS400, with yamaha TZ 250 DP4 barrels (studs location on NS and DP4 cylinders almost identical - 96mm. from side to side and 1mm. difference from back to front NS-79mm, DP4-78mm.) Just needed made, aprox 20 mm. spacers with reed, between crankcase and DP4 cylinders. Maybe return some day to this.
About HCCI, I do not expect. Now, I would do little different (piston, cylinder, small cylinder). But, who knows. I would like to do first ride next week (but not the obligation).

Just remember story from Frank Zappa book about his childhood and his dad "knowing".
"The labs at Edgewood did provide young Frank with some fun toys, though. His dad would “bring equipment home from the lab for me to play with: beakers, Florence flasks, little petri dishes full of mercury—blobs of mercury. I used to play with it all the time. The entire floor of my bedroom had this ‘muck’ on it, made out of mercury mixed with dust balls. One of the things I used to like to do was pour the mercury on the floor and hit it with a hammer, so it squirted all over the place. I lived in mercury.”

[TZ350]

I think I'll start on 400% and carefully work my way down ...

It is possible to run Methanol so rich that the motor runs to cold to evaporate all the Methanol so it in effect runs lean and richening it up more only results in a leaner A/F ratio.

The trick is to add Acetone (about 180 octane) to the Methanol so the motor runs warmer, warm enough to evaporate all the fuel. Modern unleaded now has so much nasty stuff in it that it probably will mix Ok with Methanol too.

Back in the day I ran my air cooled RD on a 50/50 mixture of Acetone and Methanol, the temperature was about right. But the mix required would be different for different motors. The point is to get/keep the motor at an appropriate operating temperature.

[lucf]

First of all, I have followed this fantastic source of knowledge presented here regarding two strokes and tuning. I am not an engine expert at all, (I wish I would have become a Jan, Frits or a Wobbly, et.al.) and I would rank myself at the most as a very average mechanical engineer. I am working in the supply chain for close to engine parts to automotive OEMs. Back in 1983 I did, however, finally manage to tune my GP125 to severably beat my friends RD125LCs. Yes! No driving alone anymore! What could I not have done with all the information here at the time..!?

I have followed the information coming out about Ryger for some time. I must say that I have not yet lost patience. I cannot believe that somebody would be so stupid to put so much energy and money into a project like that with the goal to, by intent, try and fool a number of engine buyers/financers. I believe it is an honest project, but that they do have run into some sort of problems (as we all do in development projects) along the way. And yes, unforseen problems can take time to fix. With relatively limited resources it takes even longer. For example, a part supplier fault made in the first pre series delivery, after the initial well functioning prototypes, can be a disaster for a time plan. Complete new durability tests and performance tests might have to be conducted (and most likely much much more work). This just as an example. I do not either expect that we will be given all the details about the function of the engine, and details how we can build our own Ryger engine. If I were Ryger I would also be very reluctant to give out any very detailed findings how everythings works together. I am grateful for all the FREE information given from you with the knowhow here, but I also respect the need for the Ryger company to protect their business case.

We can only wait and see what happens and hopefully we soon can get the information that gives us a better understanding of the Ryger concept, and a final conclusion/results if it really works.

Luc is enthusiastic, but could you really blame him?


Thanks Norman, he he .... at least one person who uses his brains !

And with those rude words Wobbly did, I'll never come back again, even though I have a hard proof !!

[adegnes]

It is possible to run Methanol so rich that the motor runs to cold to evaporate all the Methanol so it in effect runs lean and richening it up more only results in a leaner A/F.

The trick is to add Acetone (about 180 octane) to the Methanol so the motor runs warmer, warm enough to evaporate all the fuel. Modern unleaded now has so much nasty stuff in it that it probably will mix Ok with Methanol too.

Back in the day I ran my air cooled RD on a 50/50 mixture of Acetone and Methanol, the temperature was about right. But the mix required would be different for different motors. The point is to get/keep the motor at an appropriate operating temperature.

Thanks for the tip! Sure about that octane rating?

I came out on top this time, a little sanding and it'll be fine. The bore is unmarked, just reflections.

329324

[lohring]

My first encounter with methanol/nitro in a moped.
Typical outcome.

329317

Crossing fingers for minimal damage inside.


https://youtu.be/ihmxMnAZmvM

We tried running model boat fuel in a 26 cc gasoline engine a long time ago. We used a custom carb. The fuel has 20% oil. The engine ran fine on 15% nitro but had the same problem with 40%. The plug electrode dented the piston and exhaust port on the way out.

Lohring Miller

329325

[schutten]

We realy don't care about all those negative replies, we are use to it !

All those people will very soon be very quiet!!




We are going to see the engines perform at Kerpen next weekend ?
Winning is more important than dyno numbers :niceone:

[jasonu]

As far as i am aware Itoh did a full season on an injected NSR500 which s why he only had a decent result when he filled in on Doohans bike for one race 95 (i think)
I am pretty sure Honda was pretty coy about it or was it maybe they were just letting the journalists think thats what they were doing?
Honda had some success with the EXP2 which was injected.
The thing is, carbs work very well. Actually in a lot of situations feel is more important than outright power. The IOM TT is one.
There has been a few injected trials bikes but i have never tried one.

Itohs bike was the fastest in a straight line but Doohan still wiped the floor with him.

[SwePatrick]

Thanks for the tip! Sure about that octane rating?

I came out on top this time, a little sanding and it'll be fine. The bore is unmarked, just reflections.

329324

You lucky sod.. =)

[SwePatrick]

That's a great idea! Only problem is I can't get hold of any pure nitro, they fear we will be making bombs...

To stay on the safe side while creeping up on this fuel I could use your approach and move the nitro % over to the air side of the equation. What are your thoughts on the oil and afr?
Maybe move it to the air side too.

In Sweden about 60km from me they sell pure nitro, but what is new for 2017 you need to go a course to get an license to use it.

170skr per litre.

http://shop.kb-rchobby.se/bransle-oljor/bransle-oljor-nitro?product_id=695

Pure methanol one can buy cheap from dragracers this season.
Many got last years leftover in stock.
But take note that Methanol can differ a bit from eachother.
I bought methanol with 49.96% oxygen for 10kr/litre.

[d2t]

125 ... 250 or bigger, RPM? number of injectors, MAP? pictures?

2018 KTM 2-stroke FI:
329326

This is the best picture I could find on the ol' interweb. Looks like a single injector facing down into the B-port and I assume one on the opposite side as well. It's a different approach than what we've seen in the past with snowmobiles' SDI (not to be confused with DI). I'm sure the engine will appear at some big motorcycle show later in the year so we can get more details.

Although it's pushing injection tech, there is still the issue of emissions in the form of escaping unburnt fuel mixture and oil in the fuel. Direct injection solves the escaping fresh charge issue but I seem to remember that DI can't perform well above a certain RPM due to the small amount of time the fuel has to atomize before firing. I believe it was around 9000RPM in Orbital's efforts on Aprilia's 50cc DiTech mopeds. It also adds a little complexity to the engine as it requires a pressurized fuel rail. As far as oil in the fuel, the Ryger concept seems to solve this and if HCCI or some other mystical power is at work, all the better. I agree that the rollout of this technology has not been ideal but aside from Katinas trying to make one on his own, most of us have only guessed at what the magic is. I do recall Ryger had an open invitation for track testing on their FB page in the past. Did anyone attend? I'm on the other side of the world but for some of you it would've been a short drive to the kart track. Lucf, it would be nice of you to share some more technical details since the engines are readily for sale now. Giving details "soon" is I guess a relative concept given the infinite expanse of time in the universe but some of us don't expect to live that long.

[koenich]

...even though I have a hard proof !!
of course you do :facepalm:

[lucf]

of course you do :facepalm:

Only if Wobbly change his rude words very fast, otherwise no chance !

[Carel H]

TZ: it just occorred to me, that if you use a deto sensor, adjust it to always deto, the output is then ''combustion". The inverse output is "no combustion". Maybe balloonies, this is from a electronical and theoretical point of view.

[Grumph]

Only if Wobbly change his rude words very fast, otherwise no chance !

Well, there goes your credibility.

You obviously don't know your history very well either. Every new departure from convention has been attacked from the outset. If the concept is viable, it's come through and been accepted.
On this side of the world, there are documented cases of "new developments" which have simply been money making scams. Europe has not had as many of these so you've had the benefit of the doubt so far.
I suspect that the goodwill you had from the first announcements is running out quickly.
Time to show and tell.

[F5 Dave]

Lucf, no disrespect, but are you like nine years old?

Past performance is the best indicator of future behavior. You, whoever you are as you haven't made that slightly clear, it doesnt take a savant to work out you have no intention of showing your 'hard evidence'. Wobbly on the other hand has been extremely open with sharing a wealth of experience.

[koenich]

Thats what she said - I honestly hope he doesn't. contrary to your behavior the world doesn't owe you a dime luc...

[peewee]

My approach would be to get the engine running properly on methanol then add Nitro..

this is what i would do also. start with small percentage and work your way up

[Flettner]

this is what i would do also. start with small percentage and work your way up

O no, if some is good, more must be better!

[adegnes]

this is what i would do also. start with small percentage and work your way up

The sensible thing to do, but as I already have the premixed rc fuel I'll go the stupid/dangerous route in a tip toing manner from now on.

Neels(thanks for the mail!) told me I should leave the oil out of the equation.

Gasoline 12:1

65% Methanol 5:1
20% Nitromethane 1:1
15% Oil

12 / [ (5x0.65) + (1x0.20) ] = 3.48 ~ 3.5

So I must multiply all my jet areas by 3.5

On gasoline:

Main 115 - π x 57.5^2 = 10387
Pilot 58 - π x 29^2 = 2642

On RC fuel:

Main
10387 x 3.5 = 36355
36355 / π = 11572^2
Square root of 11572 = 108
108 x 2
= 216

Pilot

Doing the same calculation
= 110

I'll drill out the main to 2.5mm, and the pilot to 1.5mm as a starting point.

I've also got the adjustable powerjet cranked up to further enriching the mixture.

I sure won't put it on the roller again before I know all throttle positions are pig rich...

Go?

[TZ350]

Thanks for the tip! Sure about that octane rating?

No not sure about the exact Octane rating, it was a long time ago. Tried to check the net, found nothing substantive, but from memory I am confident that Acetone has a rating as good as or higher than Methanol.

SeattleSmitty who posted a bit on here about his hydroplane racing experiences with 2T engines on nitro. He said they found there was a nitro limit, maybe only 10-15% from memory before sever heat issues with the expansion chambers. Again not sure about the exact numbers but his posts would be worth a read if you can find them.

[adegnes]

Wait!
If I just wrote off the oil, did my nitro to methanol ratio just go up, and I must take that into consideration?

[adegnes]

No not sure about the exact Octane rating, it was a long time ago. Tried to check the net, found nothing substantive, but from memory I am confident that Acetone has a rating as good as or higher than Methanol.

SeattleSmitty who posted a bit on here about his hydroplane racing experiences with 2T engines on nitro. He said they found there was a nitro limit, maybe only 10-15% from memory before sever heat issues with the expansion chambers. Again not sure about the exact numbers but his posts would be worth a read if you can find them.

Hmm wonder what afr works for acetone? It has about the same energy content as ethanol.
Thanks, I'll see if I can find his posts!

[Ocean1]

Direct injection?

No, more or less standard throttle body mounted directly onto case reed induction.

[wobbly]

OK, so I have deleted all the " nasty " posts except for the " good " bit where I suggested that Luc maybe wasnt an incompetent idiot.
This now means I have a life, and I ( we ) would also be really,really friendly if the " hard proof " was posted here - a World Exclusive, as the media would say.
Your turn Luc.

[malcy25]

The only simple position guide I can give is to say about 3 X Bore down the header from the port face.
You are trying to get out of the unburnt air/fuel zone that sits in the header - but not so far down as to see the gradual temp drop from wall heat radiation.
As far as depth into the header, do what ever you can to get it as close to the middle as possible.
The short,capped end 5mm probes some suppliers sell are useless for reliable use as a tuning tool.
This makes a HUGE difference , believe it or not.

In a 125 kart engine at the Nationals, I got completely lost for 2 days practice trying to get it tuned.
The egt said it was on the limit at 660*C, but the piston and plug were nowhere near,and we were 3/10 sec off the pace.
Luckily on the morning of the final I noticed from the outside that the probe seemed to be pushed in along way.
It was a long exposed tip Stinger type from EGT Industries ( the best and only guaranteed probe you can buy ) with a 90* bend just above the ferule and locknut.
And sure enough, it was 10mm too far in ,past center-line.
I pulled it back up to on center and in the warmup, what was 660*, now read as 610*.
At least an easy 2 jet sizes too rich.
We won, having been second all thru qualifying and the heat races.

As you are running a 10.4 cc head, you will be on Avgas, so in F you are looking for a minimum of 1220 and a max close to 1280.
Start rich, and go down a jet at at a time,you should see around 30 to 40* F increase in temp each change.
If you go down a jet and only see a 20*F increase ,or even worse it stays the same ,or real BAD it drops - then Mr Deto is in the house - go back one, or two in size.
Just remember that ignition timing affects the reading as well,+2* will drop the temp around 2 jet sizes in a RS125 - so then the delta temp change rule becomes even more important.

Wob. Interesting. When I get a chance I'll check my probe depth (again!) on the 350. I'm six inches roughly from the mid point of the exh port(64x 3 is c190, so possibly a bit close?), but always end up with way high temps showing (1375 F on green avgas), but relatively soft on jetting and are not showing any signs of distress on the plug. Prior experiments of advancing up have not changed much in reality and even changing to a different ignition system made no real impact!

[F5 Dave]

Stinger size?

[peewee]

SeattleSmitty who posted a bit on here about his hydroplane racing experiences with 2T engines on nitro. He said they found there was a nitro limit, maybe only 10-15% from memory before sever heat issues with the expansion chambers. .

i wondered why very high percentages can be used in 4t but ive never heard of it being sucessful in 2t. maybe has something to do with the expansion chamber ?

[TZ350]

i wondered why very high percentages can be used in 4t but ive never heard of it being sucessful in 2t. maybe has something to do with the expansion chamber ?

It might be that Nitro is slow burning and is still burning going down a 2T pipe.

There may be an answer, Hydrazine hurry's Nitro up, but now that is really getting into dangerous territory. As a very very small amount makes Nitro burn faster and not much more makes Nitro explosive.

329331329332

In the 70's Nitro with a splash of Hydrazine chaser was all the go. Eventually "Tipping the Can" was banned after spectators started being injured and even killed by flying shrapnel.

329333

[Grumph]

I'd have thought there's a good chance of a crankcase explosion too with Nitro.

Back when we could use it in roadrace engines here a local sidecar outfit used 11%...I asked why 11% ? The answer was because that's all this engine will take...I noticed the crankcase breather (sorry, it was a 4T) had it's end up by the steering head so asked why....The answer was that if the pilot saw a blue flame at the hose end, he was to switch off, take it out of gear and brake - then reach over, tap the passenger on the shoulder and they'd both roll off the bike...Then walk to the nearest marshals point for a broom to sweep up the bits from the crankcase explosion.

They went through a few motors before arriving at this happy place - it was fast though....

[peewee]

im quit sure i could configure my lectron to use nitro. maybe a needle change and a third powerjet. its already set pretty close for straight methanol so I would just have to add nitro until it melts the plug or piston then reduce the percentage a tad :laugh:. adegnes you have any idea how much extra power 10% would give ? I was always scared of a explosion hazard with nitro so I never tried it

[husaberg]

Itohs bike was the fastest in a straight line but Doohan still wiped the floor with him.
True but that wasn't the point i was offering. That said.
Wayne Raineys bikes were often slower than the pre big bang and two up honda.
Wayne kicked a lot of arse with bikes that were easier to ride and had more linear power delivery.


No, more or less standard throttle body mounted directly onto case reed induction.
Interesting i will have a look

[adegnes]

It might be that Nitro is slow burning and is still burning going down a 2T pipe.

There may be an answer, Hydrazine hurry's Nitro up, but now that is really getting into dangerous territory. As a very very small amount makes Nitro burn faster and not much more makes Nitro explosive.


And even if you don't get blown up, it's got lots of other ways to kill you.


im quit sure i could configure my lectron to use nitro. maybe a needle change and a third powerjet. its already set pretty close for straight methanol so I would just have to add nitro until it melts the plug or piston then reduce the percentage a tad :laugh:. adegnes you have any idea how much extra power 10% would give ? I was always scared of a explosion hazard with nitro so I never tried it

Theoretically you could just add it's btu on top of your methanol.

Methanol btu ~ 9.5
Nitro btu ~ 5

(1x9.5)+(0.1x5) = 10 = 5% gain

What's special is you can just keep on adding nitro without removing methanol.

50% added
9.5+(0.5x5) = 12 = 25% gain

100% added (50/50 mix)
9.5+5 = 14.5 = 50% gain

200%
9.5+(2x5) = 19.5 = 100% gain

This might all be wrong...

[peewee]

adegnes did you find out if the comp ratio can remain the same as with methanol or would it need to be lower or higher, would the percentage factor into this ? what about the spark lead ?

[adegnes]

adegnes did you find out if the comp ratio can remain the same as with methanol or would it need to be lower or higher, would the percentage factor into this ? what about the spark lead ?

Best ask someone else, my only experience with it(other than in rc cars) is what you saw in the video. I've been told that you need less comp compared to methanol alone, probably because with high nitro ratios there's so much liquid in the chamber.

[teriks]

i wondered why very high percentages can be used in 4t but ive never heard of it being sucessful in 2t. maybe has something to do with the expansion chamber ?
Different scales, but in the eighties my Dad were into RC hydroplanes. His fuel with "only" 40% nitromethane was in no way the highest nitro content, so for sure two-strokes for sure can burn such fuels. If that's applicable on all sizes, who knows..

[husaberg]

I'd have thought there's a good chance of a crankcase explosion too with Nitro.

Back when we could use it in roadrace engines here a local sidecar outfit used 11%...I asked why 11% ? The answer was because that's all this engine will take...I noticed the crankcase breather (sorry, it was a 4T) had it's end up by the steering head so asked why....The answer was that if the pilot saw a blue flame at the hose end, he was to switch off, take it out of gear and brake - then reach over, tap the passenger on the shoulder and they'd both roll off the bike...Then walk to the nearest marshals point for a broom to sweep up the bits from the crankcase explosion.

They went through a few motors before arriving at this happy place - it was fast though....

Hmm wonder what afr works for acetone? It has about the same energy content as ethanol.
Thanks, I'll see if I can find his posts!

Not only that but from what i have read if it comes into contact with unpickled Al it can also explode
Soak the homemade crankcases in diluted vinegar Adegnes.
it covers it in the bell book along with recomendations for jetting on nitro and methanol

[adegnes]

I'm looking through the book now!

Nitro just made my hobby alot more exciting!

[husaberg]

I'm looking through the book now!

Nitro just made my hobby alot more exciting!

plenty on jetting and comps for meth and nitro etc
pg120 for the nitro looks like its only the tanks that need pickling

[adegnes]

plenty on jetting and comps for meth and nitro etc
pg120 for the nitro looks like its only the tanks that need pickling

On moderate nitro levels, gasoline CR is the way to go, great news, I'm at 14.5:1 now and can just leave it as is.

329346

[husaberg]

On moderate nitro levels, gasoline CR is the way to go, great news, I'm at 14.5:1 now and can just leave it as is.

329346

Don't worry when if you overdo it the piston crown will vaporise lowering the comp ratio a few points.:laugh:

[adegnes]

Don't worry when if you overdo it the piston crown will vaporise lowering the comp ratio a few points.:laugh:

Exactly, self regulating!

[lucf]

OK, so I have deleted all the " nasty " posts except for the " good " bit where I suggested that Luc

maybe wasnt an incompetent idiot.
This now means I have a life, and I ( we ) would also be really,really friendly if the " hard proof " was posted here - a World Exclusive,

as the media would say.
Your turn Luc.


Thats what she said - I honestly hope he doesn't. contrary to your behavior the world doesn't owe you a dime luc...

And only to be continued, when people like koenich keeps his big mouth too !

[koenich]

i'm eager to listen for sth real.

[SwePatrick]

And only to be continued, when people like koenich keeps his big mouth too !

*lol*
So you are entering this forum with great secrets as a bait.
But will only tell if you are licked where the sun don´t shine?

Made me laugh.
Keep on!

Remember: Third party dyno!

[lohring]

Not only that but from what i have read if it comes into contact with unpickled Al it can also explode
Soak the homemade crankcases in diluted vinegar Adegnes.
it covers it in the bell book along with recomendations for jetting on nitro and methanol

At model boat heat races nearly everyone runs around 60% nitro. The smaller engines (3.5 cc) often run more while the larger engines (15 cc) may run 40 to 50%. Record runs often are made with 80% nitro. These engines all have aluminum crankcases, pistons, rods, and often chromed aluminum liners. The only problem with high nitro fuels is ball bearing corrosion with water. After run oils are essential to prevent bearing failure. Nitromethane/methanol fuels are much less explosive than gasoline. I've put out fires in gasoline fueled boats but never in a nitro fueled one.

Lohring Miller, NAMBA Safety Director

[TZ350]

Thanks, I'll see if I can find his posts!

Try this search:- hydroplane site:www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/ (http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/)

Then click on his name and select forum posts. His early posts talk about hydroplane racing.

[adegnes]

Try this search:- hydroplane site:www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/ (http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/)

Then click on his name and select forum posts. His early posts talk about hydroplane racing.

Thanks! I was able to find stuff with the forum searh before, but lately it's become totally useless...

I remember his posts from reading through this thread when I first found it some years back(well I've actually read through it twice), maybe it's time to go at it again. It's like a good book!

[adegnes]

Had the carb apart again to drill out anything I couldn't fit my thumb through.
I drenched everything in brunox(wd40 equivalent) after running it, but forgot to do the float chamber.
No residue or anything, but that smell! I can best describe it as week old dead rodent.

[F5 Dave]

Ahh your turn of phrase is brilliant :laugh::laugh:

[husaberg]

Had the carb apart again to drill out anything I couldn't fit my thumb through.
I drenched everything in brunox(wd40 equivalent) after running it, but forgot to do the float chamber.
No residue or anything, but that smell! I can best describe it as week old dead rodent.


Start the engine on normal fuel and run it till it is completely warmed up. Then switch to the nitromethane mixture.

Beware: You can't kill your engine by stopping the ignition anymore, the nitromethane mixture is self-combustible under pressure. So make sure you can cut the fuel off at any time! or completely stop your air flow!
plus ten carrots
here is a selection of stuff i pilfered from Bells 4T book.
329347


Don't worry when if you overdo it the piston crown will vaporise lowering the comp ratio a few points.:laugh:


Exactly, self regulating!
I just watched your Video
https://www.youtube.com/watch?v=ihmxMnAZmvM

[malcy25]

Stinger size?
Same pipes and set up on identical bike, no issues.

[ief]

This ryger buisness...

Red a lot of Luc's work, he's been around for some time. Makes exhaust/ head calc's and the one I saw was great, in simulation and real life.

Why he behaves in this manner on this topic has me baffeled. although he likes to shield his knowledge (but with reason I could see that)

It ain't that complicataded....

Nuff said allready but I just don't get it.

adagenes, love your work, specialy the latest vid, bit of editing goes a long way ;)

(saiyng that here since I don't have youtube account)

[peewee]

After run oils are essential to prevent bearing failure. Nitromethane/methanol fuels are much less explosive than gasoline.

Lohring Miller, NAMBA Safety Director

im only going by what I see on tv as I know nothing about nitro. doesn't seem uncommon for top fuel cars to pop the blower off and create a fireball, im guessing that's why they use the safety straps so engine pieces will be some what contained. that's why I was always hesitant to use it as a fuel, considering if the head explodes on a motorcycle your in serious trouble

ive always used 6% castor oil in methanol, and 6% castor in the petrol to flush the engine and never had bearing trouble . on top of the 6%, would another separate oil also be needed to flush the engine ? and my next question tied to this topic, 8oz or so of petrol is all the engine will manage to consume (which seems to only take a minute or so but ive never timed it), with the even larger fuel passages needed for nitro I wonder if the engine would even run at all with petrol ? constantly tearing it down to clean the inside components would be a huge hassle for me

[TZ350]

EFI really needs to accurately know the changes in airflow vis changes in throttle position.

So I thought it about time I checked the airflow behaviour through my ball valve throttle.

On my motor the inlet closes 10 deg after the exhaust opens. So the BigSucker can suck wind right through the motor.

329351 329350

Got old trusty BigSucker and attached it to the exhaust port and purchased a cheap Anemometer (wind speed meter) of Trademe.

329349

My EFI Maps have 16 air flow steps. So I measured the maximum and minimum air flow then used Excel to calculate 16 even airflow steps from min to max airflow.

Then I recorded the 16 TPS positions from 0% to 100% that corresponded to the 16 even airflow steps.

329352

The 16 TPS steps required to give 16 even increases in airflow through the Ball Valve throttle body.

Basically it was linear from 8 to 30% TPS and 55% gave 94% Airflow. I can use this information with the Alpha-N map.

Now all I need is the 2 bar MAP sensor that is on its way from Ecotrons so I can see what sort of pressures are present at the exhaust port and how they behave on/off the pipe. Once I know that, I can develop a VE volumetric efficiency map for when the engine drops off the pipe at high RPM.

[jasonu]

Ahh your turn of phrase is brilliant :laugh::laugh:

Damn foreigners mate!!!

[jasonu]

EFI really needs to accurately know the changes in airflow vis changes in throttle position.

So I thought it about time I checked the airflow behaviour through my ball valve throttle.

On my motor the inlet closes 10 deg after the exhaust opens. So the BigSucker can suck wind right through the motor.

329351 329350

Got old trusty BigSucker and attached it to the exhaust port and purchased a cheap Anemometer (wind speed meter) of Trademe.

329349

My EFI Maps have 16 air flow steps. So I measured the maximum and minimum air flow then used Excel to calculate 16 even airflow steps from min to max airflow.

Then I recorded the 16 TPS positions from 0% to 100% that corresponded to the 16 even airflow steps.

329352

The 16 TPS steps required to give 16 even increases in airflow through the Ball Valve throttle body.

Basically it was linear from 8 to 30% TPS and 55% gave 94% Airflow. I can use this information with the Alpha-N map.

Now all I need is the 2 bar MAP sensor that is on its way from Ecotrons so I can see what sort of pressures are present at the exhaust port and how they behave on/off the pipe. Once I know that, I can develop a VE volumetric efficiency map for when the engine drops off the pipe at high RPM.

Mate you are genius! Buckets at its best!

[Frits Overmars]

On my motor the inlet closes 10 deg after the exhaust opens. So the BigSucker can suck wind right through the motor.That's quite a late-closing inlet or early-opening exhaust. Your logic seems a bit shaky though; it doesn't matter when the inlet closes, but it should open before the transfers close.


Now all I need is the 2 bar MAP sensor that is on its way from Ecotrons so I can see what sort of pressures are present at the exhaust port.The exhaust opening pressure may be lot more than 2 bar....

[speedpro]

Talking of warming the motor then switching to nitro reminded me of a V6 dragster at Meremere years ago. He would start it on Methanol, warm it up, and it sounded pretty serious just doing that, and then switch to nitro. The change in sound was awesome. It got a real crackle going and definitely sounded like something you didn't want to mess with.

[Flettner]

I agree with you regarding the difficulty. Good news is, KTM just announced their 2018 enduro models which will meet Euro4 emissions standard (http://racerxonline.com/2017/03/15/fuel-injected-ktm-two-strokes-coming-in-2018) using transfer port injection.

Personally, I don't regard transfer port injection as 'revolutionary' (revolutionary for me would have been high pressure direct injection and no more scavenging losses at all and thus a real step forward in cleanliness, but hey, as a company you always go for the most economical way to achieve your targets), but I like the fact that one will be able to buy new two-stroke bikes in the future, too.



I think they will be using what I call DTPI, 'delayed transfer port injection' , as I have done on the YZ. This approach allows for the fuel to be delivered at such a time as to NOT escape out the exhaust. It would take a LOT of time to fully map an engine to get best results and some flash equipment but the upshot is nearly as good as DFI. This approach lends to cheap and durable hardware and allows for better fuel air mixing than DFI (I guess certainly in terms of cost)
We didn't have flash equipment for the YZ, just fuel burn results and seat of the pants (and a home made oscilloscope of sorts) but to show how easily it can be done we were getting between 14% and 21% fuel savings (compared to an identical YZ with a carb), same top end power!
So I would say DTPI is certainly not to be disregarded as a useful technology.
Now all they need is a sliding cylinder and HCCI and no oil burn at all! AND a chamber wave modifier, could be called an exhaust throttle.:rolleyes:

[TZ350]

That's quite a late-closing inlet or early-opening exhaust. Your logic seems a bit shaky though; through-sucking requires inlet/exhaust/transfer overlap. Just saying :whistle:

Ex opens 80 ATDC Inlet closes 90 ATDC Transfers open 115 ATDC

Yes you are right, if the inlet is still open after the transfers open I have a real problem. But the inlet should open 30 deg before the transfers close so maybe I don't have a problem.

Inlet opens 145 BTDC Transfers close 115 BTDC ex closes 80 BTDC so on the induction side they could all be open together.

I better re-check the rotary valve disk timing. ... :scratch:



The exhaust opening pressure may be lot more than 2 bar....

Thanks for the heads up.

[TZ350]

Its all good, I had the inlet on the induction opening side..... :sweatdrop

[adegnes]

Talking of warming the motor then switching to nitro reminded me of a V6 dragster at Meremere years ago. He would start it on Methanol, warm it up, and it sounded pretty serious just doing that, and then switch to nitro. The change in sound was awesome. It got a real crackle going and definitely sounded like something you didn't want to mess with.

Fascinating to watch that transition!
Wish I could find a video of someone running a bit of hydrazine, with the infamous green flames and all.

About exploding engines, I think that's often caused by the ignition cutting out, not the explosive nature of nitro.
When you pump more fuel than air(ok, by weight so not as extreme as it sounds) into the combustion chamber and it fails to fire it hydrolocks.

[peewee]

Talking of warming the motor then switching to nitro reminded me of a V6 dragster at Meremere years ago. He would start it on Methanol, warm it up, and it sounded pretty serious just doing that, and then switch to nitro. The change in sound was awesome. It got a real crackle going and definitely sounded like something you didn't want to mess with.

any chance you saw how they flushed the engine afterwards and what fuel they used ?

[husaberg]

I think they will be using what I call DTPI, 'delayed transfer port injection' , as I have done on the YZ. This approach allows for the fuel to be delivered at such a time as to NOT escape out the exhaust. It would take a LOT of time to fully map an engine to get best results and some flash equipment but the upshot is nearly as good as DFI. This approach lends to cheap and durable hardware and allows for better fuel air mixing than DFI (I guess certainly in terms of cost)
We didn't have flash equipment for the YZ, just fuel burn results and seat of the pants (and a home made oscilloscope of sorts) but to show how easily it can be done we were getting between 14% and 21% fuel savings (compared to an identical YZ with a carb), same top end power!
So I would say DTPI is certainly not to be disregarded as a useful technology.
Now all they need is a sliding cylinder and HCCI and no oil burn at all! AND a chamber wave modifier, could be called an exhaust throttle.:rolleyes:

Hybrid indirect and direct injection system artic cat
http://www.google.com/patents/US7168401

[oldjohnno]

Talking of warming the motor then switching to nitro reminded me of a V6 dragster at Meremere years ago. He would start it on Methanol, warm it up, and it sounded pretty serious just doing that, and then switch to nitro. The change in sound was awesome. It got a real crackle going and definitely sounded like something you didn't want to mess with.

They generally start the engine on petrol from a squirt bottle; it runs and sounds quite smooth on this. Often they'll stay on a lean setting until they're staging and the changeover to the rich race setting is very plain to hear. You can see and hear it here:

https://www.youtube.com/watch?v=tAPe8-Bu0G0

Usually if they're just doing a warm-up in the pits they'll shut the fuel off and let it run for a few seconds on petrol from the sauce bottle, and again it sounds very mild and smooth. The fuel isn't particularly explosive - they do cough the blower off occasionally but that's to be expected if an intake valve hangs open and remember there's quite a few litres of compressed air/fuel mixture in the manifold at maybe 4 bars of pressure. You can hear it here (and see the "nitro-rain"):

https://www.youtube.com/watch?v=e3WFdq4yZvI

The fuel flow required to make upwards of 1000hp per cylinder is astounding; you can see it here (the first few seconds is at idle) :

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

I think two-strokes are always going to be severely limited in the use of these fuels by piston temperature. Four-strokes have the benefit of more "cold" strokes plus they don't wash the piston crown in hot exhaust gas as it exits the cylinder, but even so they often smoke the pistons towards the end of a run. I imagine the practical limit of nitro percentage in a two stroke would be quite low.

[ken seeber]

Touch of confusion in my mind about injector placement terminology. What they refer to as Indirect FI is simply manifold FI. What they refer to as direct FI is more transfer port injection (as Fletto points out above). However I will concede that it is pointed to the inside of the cylinder, so it can rightfully be classed as in-cylinder FI. Also into this classification would be where the injector is aiming directly into the cylinder from the bore, say even above exh port closure level
Therefore, I would consider direct FI as one in which the injector discharges via the cylinder head and the injector is exposed to combustion conditions.
Being overly pedantic ?? :confused:

Here's a bit more blurb on the KTM 2 stroke:

http://newatlas.com/ktm-two-stroke-direct-injection-enduro/48457/

[husaberg]

Touch of confusion in my mind about injector placement terminology. What they refer to as Indirect FI is simply manifold FI. What they refer to as direct FI is more transfer port injection (as Fletto points out above). However I will concede that it is pointed to the inside of the cylinder, so it can rightfully be classed as in-cylinder FI. Also into this classification would be where the injector is aiming directly into the cylinder from the bore, say even above exh port closure level
Therefore, I would consider direct FI as one in which the injector discharges via the cylinder head and the injector is exposed to combustion conditions.
Being overly pedantic ?? :confused:

Here's a bit more blurb on the KTM 2 stroke:

http://newatlas.com/ktm-two-stroke-direct-injection-enduro/48457/

Intersting point there Ken. one that makes the Bimota vdue a indirect set up, as it shot the injectors from the side of the cylinder toward the piston crown.
orbital which you were involved with used compressed air to mix the charge didn't it, rather than a hot piston crown.
I have a pic somewhere of the bimota set up i can't find a decent one on the net.

[Frits Overmars]

Intersting point there Ken. one that makes the Bimota vdue a indirect set up, as it shot the injectors from the side of the cylinder toward the piston crown... I have a pic somewhere of the bimota set up i can't find a decent one on the net.The Bimota Vdue shot the fuel straight into the cylinder. If that isn't direct injection, I don't know what is.
I posted a couple of Bimota pictures some time ago but I don't know how to post a link to that post. Anyone?
Anyway, here are those pics once again. The M10 bolt in the second picture indicates the injector direction.
329353 329354

[sonic_v]

True two-stroke stroke direct injection should not only inject the fuel directly into the cylinder but it should be feasible to do all the injection after the exhaust port close, hence preventing short circuiting of the fuel out of the exhaust port.

The Bimota does not achieve the second criteria as the "injector ports" opens and closes at about the same time as the exhaust port and thus all injection takes place whilst the exhaust port is open.

True direct injection engines such as the e-tec Evinrude outboards can inject all their fuel after the exhaust port closes and can even inject very late on the upstroke resulting in a stratified mixture - rich in the vicinity of the spark plug but lean everywhere else.

[Frits Overmars]

Injecting all the fuel after exhaust closure would be nice, but it's not a requirement for qualifying as direct injection. If it were, not even the E-TEC engines would qualify. Injecting all their fuel after exhaust port closure is only feasible at light loads. At WOT, injection has to start much earlier in order to create a good mixture.
The latest version, the E-TEC 850, even falls back on a couple of additional indirect injectors in order to counter this problem.
329362

[sonic_v]

Injecting all the fuel after exhaust closure would be nice, but it's not a requirement for qualifying as direct injection. If it were, not even the E-TEC engines would qualify. Injecting all their fuel after exhaust port closure is only feasible at light loads. At WOT, injection has to start much earlier in order to create a good mixture.
The latest version, the E-TEC 850, even falls back on a couple of additional indirect injectors in order to counter this problem.
329362

Frits, I have been discussing the Evinrude Outboard engines which are very much true direct injection engines.

For some reason you choose to discuss a snowmobile engine that has no relevance to the Evinrude outboard engine bar they share similar injection technology.

I will repeat, the Bimota is not a true direct injection engine as it is not feasible to inject all the fuel at any load/speed point after exhaust port closure.

The emission tests for outboard engines is infinitely more stringent compared to the rather tame emission requirements for snowmobile engines!

I personally am interested in seeing two-stroke engines make a comeback in automotive applications but only true direct injection has a chance of achieving this. Any form of injection that does not allow all the fuel to be injected after exhaust port closure over at the very least the lower speed/lower load points will be a non starter.

[Frits Overmars]

For some reason you choose to discuss a snowmobile engine that has no relevance to the Evinrude outboard engine bar they share similar injection technology.I picked the most recent member of the E-TEC family because I think the addition of inlet tract injection after years of direct-only injection is revealing. They wouldn't have done that without a darn good reason. Maybe the more stringent emission rules prevent this modification for outboard engines, or maybe throttle response is less important in watercraft; I don't know.


I will repeat, the Bimota is not a true direct injection engine as it is not feasible to inject all the fuel at any load/speed point after exhaust port closure.Then I must repeat that injecting all the fuel after exhaust closure, although desirable, is not essential to the definition of direct injection.
I am not in any way trying to defend the way Bimota messed up this system; I'd just like to clarify the definition.

Question: could you tell us at what crank angle injection starts in your Evinrude outboard engine at maximum power?

[guyhockley]

Can't remember where I got this from, but might be of some interest.

[husaberg]

The Bimota Vdue shot the fuel straight into the cylinder. If that isn't direct injection, I don't know what is.
I posted a couple of Bimota pictures some time ago but I don't know how to post a link to that post. Anyone?
Anyway, here are those pics once again. The M10 bolt in the second picture indicates the injector direction.
329353 329354
Thanks for the pics.
I was only following the Austrailian, Gallipoli all over again.

Touch of confusion in my mind about injector placement terminology. What they refer to as Indirect FI is simply manifold FI. What they refer to as direct FI is more transfer port injection (as Fletto points out above). However I will concede that it is pointed to the inside of the cylinder, so it can rightfully be classed as in-cylinder FI. Also into this classification would be where the injector is aiming directly into the cylinder from the bore, say even above exh port closure level
Therefore, I would consider direct FI as one in which the injector discharges via the cylinder head and the injector is exposed to combustion conditions.
Being overly pedantic ?? :confused:

Here is the pic i was looking for less colourful that yours though.
329367329381329380


Can't remember where I got this from, but might be of some interest.

Nice document but even with all those minior tweaks mentioned the crankcase seals were alledgedly not the job and in a lot of cases the crankcases were highly porous. the origional cases also didn't have enough material to allow for a decent size seal to be fitted.
The injectors used on the production bike were also different much spec than the preproduction and prototypes used.

Despite order books that suggested Bimota would be turning out 500 units per year – a huge number for the tiny firm, particularly given the high price of the bike – in fact only 185 of the original, fuel-injected V-Dues were produced
in 1999 built 26 carburetted, 91kW ‘Trofeo’ versions of the V-Due for a one-make race series.
In a bankruptcy sale in 2003 a new group of investors bought the Bimota company, but the V-Due project – including the intellectual property, all the remaining stocks of unsold bikes and the ones that Bimota had bought back – was sold separately to former Bimota engineer Piero Caronni. He created the 2003 ‘Evoluzione’ version of the bike, with carbs, and later the ‘Evoluzione 04’ in 2004, with an extra 7.5kW. In total, 141 Evoluzione and Evoluzione 04 models were made, and Caronni also offered a service to convert original injected bikes to Evoluzione spec.
As a last hurrah, Caronni’s company, V-Due SRL, created the 2005 Edizione Finale. This was a track-only version making as much as 97kW with a fully sorted carb-fed version of the engine.
http://amcn.com.au/editorial/13291/
Personally they are in my opinion one of the most beautiful bikes ever made. It was a gusty decision to make the bike for Bimota, shame it killed them off.

[guyhockley]

329318 Honda NSR250 MC21 cylinder.

I could only take 2mm off the barrel and still have some water jacket sealing area left.

329319

Needed minus 4mm so 2mm off barrel and 2mm off head. The head spigot is a very neat fit into the barrel, maybe 0.005".

Thanks for that, food for thought...

[wobbly]

The ETEC has one function that exacerbates the problem of short circuiting of the mixture into the exhaust whilst its still open.
It can easily create a stratified charge, wherein the mixture is lean below the port opening point and gets progressively richer as the piston approaches the firing point.
This is clever as all buggery, but I did not realize that the latest version has auxiliary injectors,so even this super clever system has its problems with fully DI operation.

[wobbly]

We are going to see the engines perform at Kerpen next weekend ?
Winning is more important than dyno numbers :niceone:


Well that went well Schutten - Kerpen in Holland, the first big race of the year has been run,and not one Ryger on the grid.
Whats the new excuse I wonder - in a very un nasty way.

[jamathi]

*lol*
So you are entering this forum with great secrets as a bait.
But will only tell if you are licked were the sun don´t shine?

Made me laugh.
Keep on!

Remember: Third party dyno!

Today is the first important kart race at Kerpen, near Holland.
Not 1 Ryger competing......
You would expect them to show their 66HP.
But apparently nobody has bought an engine from them!
This might end badly, with someone losing a lot of money.
50 unsold engines......
Future scrap.

And indeed: a third party dyno would be the only way to convince people now.....

[ken seeber]

Wow, lots of thoughts on injector position & timing. So for my mind, based on placement, there’s 2 fairly obvious types:
1. Cylinder Bore Direct Injection (CHDI, covering the points and examples shown by Frits
2. Cylinder Head Direct Injection (CHDI)
Neither type distinguishes between the actual commencement of injection timing.

However, what we or I or anyone wants to call it, it doesn’t make any real difference to anything.

From (a fading) memory Orbital’s 2 fluid system, when on high power, commenced injection before BDC. This didn’t necessarily mean that unburnt fuel is lost out the irretrievably exhaust, both due to the injection into the scavenging air and also the gas dynamics due to the exhaust. In Orbital’s applications, the injector was placed towards the rear of the cylinder, directly facing the uprising scavenging flow path. For the lower load settings, the containment of the fuel was aided by a small bowl in the piston crown, this being on centre with the injector axis. This caused the fuel charge to reverse direction, back towards the plug and the offset combustion bowl in the head.

[Flettner]

Today is the first important kart race at Kerpen, near Holland.
Not 1 Ryger competing......
You would expect them to show their 66HP.
But apparently nobody has bought an engine from them!
This might end badly, with someone losing a lot of money.
50 unsold engines......
Future scrap.


And indeed: a third party dyno would be the only way to convince people now.....

No need to further convince people. Luc said so, isn't that enough?

[guyhockley]

i don't know. The Ryger should have had plenty of development time, given that the original idea was over 110 years ago!

[guyhockley]

http://amcn.com.au/editorial/13291/[/url]
Personally they are in my opinion one of the most beautiful bikes ever made. It was a gusty decision to make the bike for Bimota, shame it killed them off.

Agreed. Link to a 13 page article showing diagrams and engine parts that was way too big for KB - 33mb.

https://www.dropbox.com/sh/uv3encacgpez9fp/AADaI0z30lSUIjbz_4GerniDa?dl=0

[F5 Dave]

Actually Ken, I've kinda been hoping for some time you would throw down a bit of a past life history of your involvement in Orbital, but haven't asked as I understand you are still busy.

[katinas]

i don't know. The Ryger should have had plenty of development time, given that the original idea was over 110 years ago!
From this forum, DKW pump cylinder http://www.kfz-tech.de/ZweitaktmotorA.htm

[katinas]

That would be a perfect example of history repeating itself. Suzuki used this idea in 1962; they made the third transfer port of their 50 cc works racer as high as the exhaust port, with the intention of pressurizing the crankcase. But in 1963 this third transfer port was no longer any higher than the others...

Just remember Ryger letter:

Port timing ? …not important !

[tjbw]

i don't know. The Ryger should have had plenty of development time, given that the original idea was over 110 years ago!

That's one of the things that amazes me about two strokes, it seems no matter what idea you have, someone's tried it before.

[guyhockley]

From a book written in 1968, bet there's an earlier one!

[Frits Overmars]

From a book written in 1968, bet there's an earlier one!Bet you're right :D.
329404 329403329405329406

[guyhockley]

I had a bet with myself that it would be an MZ...

[Frits Overmars]

I had a bet with myself that it would be an MZ...Nah, I've never seen an MZ with more than one inlet disk per cylinder, not even in their attic (below).
MZ did however build an engine with a piggyback inlet decades before Aprilia did.
329408 329409 329407

[katinas]

Nah, I've never seen an MZ with more than one inlet disk per cylinder, not even in their attic (below).
MZ did however build an engine with a piggyback inlet decades before Aprilia did.
329408 329409 329407

Amazing. Which motorcycle was with this 3-cylinder engine

[Frits Overmars]

Amazing. Which motorcycle was with this 3-cylinder engineThis one.
329410
And here are some more pictures: 329411

[guyhockley]

Did they ever actually race the tandem twin?

[katinas]

This one.
329410
And here are some more pictures: 329411
Thank you.

Remember card on this motorcycle: not for sale, but.

[JanBros]

This one.
329410
And here are some more pictures: 329411

my german is pretty good, but this I do not understand :

Dreiplattendrehschieber steuern den Einlass aus drei Amalrennvergaser

for those who do not understand german :
drei=three
platte = probably a disc here
drehen = turning
schieber = a slide ?
steuern = controling, as in determining open/closing of the inlet
Einlass = intake
Vergaser = carb

can't see anything being fitted between carb and crankcase. if they mean the slide inside the carb's with the "schieber" why mention it specificaly ?
and what is turning ? a rotary disc ? where should it be fitted and how would they be driven ?

[guyhockley]

Three rotary discs fed by three Amal carbs?

[katinas]

https://www.youtube.com/watch?v=ckOw-Cp7wH8

https://www.youtube.com/watch?v=L-0AH79mY2E

[guyhockley]

Looking through the zip file of MZ pictures, it seemed they were experimenting with crank-case water cooling back then. Vic Willoughby describes Helmut Fath using a watering can on Phil Read's Yamaha engine running on the dyno, but, I guess, that would be later.

[Haufen]

I think they will be using what I call DTPI, 'delayed transfer port injection' , as I have done on the YZ. This approach allows for the fuel to be delivered at such a time as to NOT escape out the exhaust. It would take a LOT of time to fully map an engine to get best results and some flash equipment but the upshot is nearly as good as DFI. This approach lends to cheap and durable hardware and allows for better fuel air mixing than DFI (I guess certainly in terms of cost)
We didn't have flash equipment for the YZ, just fuel burn results and seat of the pants (and a home made oscilloscope of sorts) but to show how easily it can be done we were getting between 14% and 21% fuel savings (compared to an identical YZ with a carb), same top end power!
So I would say DTPI is certainly not to be disregarded as a useful technology.
Now all they need is a sliding cylinder and HCCI and no oil burn at all! AND a chamber wave modifier, could be called an exhaust throttle.:rolleyes:

If KTM's next big thing is anything like you just said, then we know what's going on here :laugh:

Of course, DTPI definitely is a useful technology. Do you know how much of your fuel savings came from better AFR control and how much was due to increased trapping efficiency? Are you injecting against the transfer flow direction, too? Seems kind of counter productive in regards of increasing trapping efficiency (but is ideal for mixing).


Generally, I think for two-strokes to have a comeback in anything else than a niche market, they need to be just as clean as four stroke engines regarding engine raw emissions.
Compared to four-strokes, two-strokes are typically:


lower on NOx emissions (lower peak temperatures if you fire twice as often)
much worse in HC, which is due to the scavenging losses (see below)
worse in CO2 emissions, which is basically fuel consumption, or BSFC (grams of fuel per kW per hour)
better or worse in particulate emissions (better with PFI, might become worse with high pressure direct injection, longer mixing time is better)
and CO values depend on AFR setting


(Both types of engines burn oil, but it has already been shown that this can be dealt with, regarding the two-stroke, once the other problems have ben solved.)

So, scavenging losses and BSFC need to be improved. Luckily, if you reduce scavenging losses you also reduce fuel consumption.
Okay then, so the E-TEC is exactly what we are looking for? Well, not quite. The E-TEC has a DI system capable of about 35bar pressure from what I read. This is not enough to get the required mixture in the cylinder and mix it between exhaust port closure and start of ignition (~70 ish deg CA). So at higher loads, it has to inject for much longer periods of time thus generating scavenging losses just as a carbureted two-stroke. How can this be solved? Simple, more pressure. How much? Much more. How much exactly? Well, today's latest car technology uses an injection pressure of about 250 bar in their gasoline engines. These are turbocharged around roughly 20 bar (4-stroke) BMEP, which would be equivalent to 10 bar two-stroke BMEP. And they turn about 6500 rpm. That's 3250 injections per minute, let's say 1/3 of what we would need (~10k). So we're at 750 bar now, right? As we would only need half of the mixture per injection (assuming one injection per stroke), we can halve that and arrive at 375 bar and we realise that we have only about 70 deg CA to get everything done, whereas the 4stroke has more than 180°, (but uses the time available for more than one injection most of the time).

All in all, I think as soon as gasoline DI injection technology has reached a level of 500 bar in serial application (500 bar is what F1 is currently running), and CFD computing power is available abundantly, too, one could give it a try. On the other hand, adapting today's car technology one could already get a quite clean two-stroke, only that it's "clean" area of the engine map woud be somewhat revs and power limited.

[Flettner]

If KTM's next big thing is anything like you just said, then we know what's going on here :laugh:

Of course, DTPI definitely is a useful technology. Do you know how much of your fuel savings came from better AFR control and how much was due to increased trapping efficiency? Are you injecting against the transfer flow direction, too? Seems kind of counter productive in regards of increasing trapping efficiency (but is ideal for mixing).


Generally, I think for two-strokes to have a comeback in anything else than a niche market, they need to be just as clean as four stroke engines regarding engine raw emissions.
Compared to four-strokes, two-strokes are typically:


lower on NOx emissions (lower peak temperatures if you fire twice as often)
much worse in HC, which is due to the scavenging losses (see below)
worse in CO2 emissions, which is basically fuel consumption, or BSFC (grams of fuel per kW per hour)
better or worse in particulate emissions (better with PFI, might become worse with high pressure direct injection, longer mixing time is better)
and CO values depend on AFR setting


(Both types of engines burn oil, but it has already been shown that this can be dealt with, regarding the two-stroke, once the other problems have ben solved.)

So, scavenging losses and BSFC need to be improved. Luckily, if you reduce scavenging losses you also reduce fuel consumption.
Okay then, so the E-TEC is exactly what we are looking for? Well, not quite. The E-TEC has a DI system capable of about 35bar pressure from what I read. This is not enough to get the required mixture in the cylinder and mix it between exhaust port closure and start of ignition (~70 ish deg CA). So at higher loads, it has to inject for much longer periods of time thus generating scavenging losses just as a carbureted two-stroke. How can this be solved? Simple, more pressure. How much? Much more. How much exactly? Well, today's latest car technology uses an injection pressure of about 250 bar in their gasoline engines. These are turbocharged around roughly 20 bar (4-stroke) BMEP, which would be equivalent to 10 bar two-stroke BMEP. And they turn about 6500 rpm. That's 3250 injections per minute, let's say 1/3 of what we would need (~10k). So we're at 750 bar now, right? As we would only need half of the mixture per injection (assuming one injection per stroke), we can halve that and arrive at 375 bar and we realise that we have only about 70 deg CA to get everything done, whereas the 4stroke has more than 180°, (but uses the time available for more than one injection most of the time).

All in all, I think as soon as gasoline DI injection technology has reached a level of 500 bar in serial application (500 bar is what F1 is currently running), and CFD computing power is available abundantly, too, one could give it a try. On the other hand, adapting today's car technology one could already get a quite clean two-stroke, only that it's "clean" area of the engine map woud be somewhat revs and power limited.
You know, the irony, one of my first home made engines, a uniflow, with two pistons in one cylinder controlled the hydrocarbon loss easily just by architecture. More complicated engine but simple fuel control, just with carburetor. Perhaps I should revisit this engine. The apparent down side of this kind of engine is poor transfer delivery, I think with careful transfer layout / aiming this problem can be largely mitigated. The last version of this uniflow engine had an air buffer between the fuel air and the exhaust gases. Cooling the exhaust piston was supposedly going to be my main issue (experts said) but in fact was not a problem with the eventual layout, being all the fuel was delivered through under the exhaust piston. Maximum piston cooling. I guess another one of the problems with the uniflow was combustion chamber shape but with HCCI or perhaps I should differentiate my system by calling it just CCI, Controlled Compression Ignition, this combustion chamber shape might not be such a problem?
katinas, whats happening with your Ryger test engine?

[Peter1962]

Three rotary discs fed by three Amal carbs?

100% correct !

[Grumph]

my german is pretty good, but this I do not understand :

Dreiplattendrehschieber steuern den Einlass aus drei Amalrennvergaser

for those who do not understand german :
drei=three
platte = probably a disc here
drehen = turning
schieber = a slide ?
steuern = controling, as in determining open/closing of the inlet
Einlass = intake
Vergaser = carb

can't see anything being fitted between carb and crankcase. if they mean the slide inside the carb's with the "schieber" why mention it specificaly ?
and what is turning ? a rotary disc ? where should it be fitted and how would they be driven ?

Well if we're assured it's three rotary discs, are they inside the crankcase chambers ? Looking at the angled inlets, If the discs are inside - with one crankweb cut away - and the inlet ports come into each crank chamber at an angle, that would explain the layout.
I've seen a similar internal disc in one of Irvings books - used in a cyclemotor of about 30cc.

[SwePatrick]

Today is the first important kart race at Kerpen, near Holland.
Not 1 Ryger competing......
You would expect them to show their 66HP.
But apparently nobody has bought an engine from them!
This might end badly, with someone losing a lot of money.
50 unsold engines......
Future scrap.

And indeed: a third party dyno would be the only way to convince people now.....


Less value than pure aluminiumscrap also as it is contaminated with nicasil ;)

[husaberg]

Did they ever actually race the tandem twin?

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page721
plus some more MZ
https://www.kiwibiker.co.nz/forums/showthread.php/151865-Old-multi-cylinder-bikes-of-the-50s-to-later-on-Japanese-British-Euro-etc?p=1130887057#post1130887057

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130411899#post1130411899
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130410698#post1130410698
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130150906#post1130150906

[husaberg]

This one.
329410
And here are some more pictures: 329411

https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=308992&d=1423881325

https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=308988&d=1423880708

[guyhockley]

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page721
plus some more MZ
https://www.kiwibiker.co.nz/forums/showthread.php/151865-Old-multi-cylinder-bikes-of-the-50s-to-later-on-Japanese-British-Euro-etc?p=1130887057#post1130887057

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130411899#post1130411899
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130410698#post1130410698
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130150906#post1130150906

Thanks for that. I have actually been around a few racing MZs including a 125 which had a Rotax barrel fitted...

[Frits Overmars]

Thanks for that. I have actually been around a few racing MZs including a 125 which had a Rotax barrel fitted...Then this chaos might look familiar :msn-wink:.
329433

[wobbly]

Well it appears that me who has no life, and is an angry little man + SwePatrick + jamathi ( Jan ) + koenich, have scuppered the whole Ryger reveal.
We simply have not been nice enough and licked Luc's bum sufficiently for him to tell us anything.
He has visited her twice recently and gone away saying nothing.
Maybe the big race where nothing occurred , when winning was supposed to happen, with 66Hp was too much of an embarrassment to continue the charade here any longer.
Really would have been great to have the " Exclusive World First Ryger Reveal of Hard Fact " from Luc on here - but no, we are not good enough, just yet.
So lets all try " not mentioning the war " at all, and maybe he will come back.

[seymour14]

You might be right there.

The bung may have fallen out of his engine on this occasion...

[guyhockley]

Then this chaos might look familiar :msn-wink:.
329433

Well, the one I looked at was all in one piece! It was only because I poked my head almost inside the fairing that I noticed the Rotax barrel but it made me wonder if there was some connection between the two companies.

[guyhockley]

plus some more MZ

https://www.kiwibiker.co.nz/forums/showthread
.php/86554-ESE-s-works-engine-tuner?p=1130411899#post1130411899

The page this links to also has a picture of a 1962 Kreidler with twin rotary discs so also older than the kart engine I posted... I'll get me coat :(

[2T Institute]

Then this chaos might look familiar :msn-wink:.
329433
A bit more than a Rotax barrel there

[husaberg]

The page this links to also has a picture of a 1962 Kreidler with twin rotary discs so also older than the kart engine I posted... I'll get me coat :(

Yeah i have posted a write up on it before and Frits has posted pictures of it as well.
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130412381#post1130412381
my word that took some finding.
https://www.kiwibiker.co.nz/forums/album.php?albumid=4915


Well if we're assured it's three rotary discs, are they inside the crankcase chambers ? Looking at the angled inlets, If the discs are inside - with one crankweb cut away - and the inlet ports come into each crank chamber at an angle, that would explain the layout.
I've seen a similar internal disc in one of Irvings books - used in a cyclemotor of about 30cc.

Or an apha
329462329463329464329465329466329467
or an even odder version anzani
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130150906#post1130150906

[Grumph]

Using the OD of the crank as a rotary valve like the Alpha is straight Vespa practise.

I'm still looking for the pic of the cyclemotor with a disc valve keyed to the shaft, inside the crank chamber, with the inlet coming in from the side.

If you've got "pork chop" shaped flywheels it's one way of doing a rotary valve with little alteration to the engine.
Disc diameter is of course limited to that of the crank OD.

[husaberg]

Using the OD of the crank as a rotary valve like the Alpha is straight Vespa practise.

I'm still looking for the pic of the cyclemotor with a disc valve keyed to the shaft, inside the crank chamber, with the inlet coming in from the side.

If you've got "pork chop" shaped flywheels it's one way of doing a rotary valve with little alteration to the engine.
Disc diameter is of course limited to that of the crank OD.

I have posted it but after spending so much time looking for that last set of Kreidler pics i are not looking for it in my pics posted.
i will have a google.
https://under50cc.files.wordpress.com/2007/09/04.jpg
There is a good pic in the Draper two stroke book but i think its upstairs.
https://images-eu.ssl-images-amazon.com/images/I/51mEuVXUeiL._SL500_SX369_BO1,204,203,200_.jpg

There is of course that vairation of the through disk that the 2 stroke triumphs used (Zee german ones) pretty sure DKW used it as well for a while.

[WilDun]

Using the OD of the crank as a rotary valve like the Alpha is straight Vespa practise.

I'm still looking for the pic of the cyclemotor with a disc valve keyed to the shaft, inside the crank chamber, with the inlet coming in from the side.

If you've got "pork chop" shaped flywheels it's one way of doing a rotary valve with little alteration to the engine.
Disc diameter is of course limited to that of the crank OD.

GRUMPH -I think you are looking for the "Cyclemaster" engine which was fitted inside a bicycle rear wheel - that little engine above I think is basically the same engine in a moped frame, but the Cyclemaster was really compact and quite clever really!
Will look for the pics of it I have somewhere. - I used to own own one long long ago and was intrigued by the rotary valve (because it was like the MZ which was cutting edge technology in those days!

[husaberg]

GRUMPH -I think you are looking for the "Cyclemaster" engine which was fitted inside a bicycle rear wheel - that little engine above I think is basically the same engine in a moped frame, but the Cyclemaster was really compact and quite clever really!
Will look for the pics of it I have somewhere. - I used to own own one long long ago and was intrigued by the rotary valve (because it was like the MZ which was cutting edge technology in those days!
this one mainly shows the gear box thingy (its technical name) but in the background it can nearly be seen
Its correct name is the Norman Cyclemate cyclemaster
http://www.icenicam.org.uk/articles7/art0128a.png

[Grumph]

There is a good pic in the Draper two stroke book but i think its upstairs.


GRUMPH -I think you are looking for the "Cyclemaster" engine which was fitted inside a bicycle rear wheel - that little engine above I think is basically the same engine in a moped frame, but the Cyclemaster was really compact and quite clever really!
Will look for the pics of it I have somewhere. - I used to own own one long long ago and was intrigued by the rotary valve (because it was like the MZ which was cutting edge technology in those days!

You're both correct - it's the Cyclemaster - and the pic is in Draper's book. Can you scan your copy Husa ? It's an odd setup with drawbacks but looking at the inlet port angles on that MZ, it wouldn't surprise me if that's how it's done. The layout with internal discs has the benefit of giving a crank the same length as a piston port engine. If the MZ was a peripheral valve - like the Vespa and Alpha - I'd have thought the inlets would be pretty well straight in and not angled as the MZ is.

Edit - just looked at the last pic. Gives the idea, if you want to the Draper pic is a little clearer.

[ken seeber]

All in all, I think as soon as gasoline DI injection technology has reached a level of 500 bar in serial application (500 bar is what F1 is currently running), and CFD computing power is available abundantly, too, one could give it a try. On the other hand, adapting today's car technology one could already get a quite clean two-stroke, only that it's "clean" area of the engine map woud be somewhat revs and power limited.

Haufen, I must say I do wonder if 500 MPA is feasible or the only way to go for CHDI. Undoubtedly it must offer improved atomization (presuming the nozzle spray details have been designed correctly), but it certainly comes at a price of high fuel pump costs, much finer filtration, possibly more power to overcome the extra forces and increased latency.
As to alternatives, don’t forget air assisted injection. In addition to Orbital’s system, Piaggio also did a version and was produced for a while on 50 c scooters (maybe called the FAST) under a programme run by a Marco Nuti. This used a small compressor mounted on the head, discharging via a small passive conical outlet valve. The beauty of this was that it essentially could be made to run at any speed the engine could go. Happen to have a head here:


329471329472329473

On a different topic, have the Draper book, so here is the pic of the Cyclemaster valve. Also don’t forget the cutaway crank as used on Vespas for are radial entry. I remember seeing a pic somewhere when Orbital was mucking about with Bajaj (who made Indian Vespas). This showed a complete crank assy (inc rod) all wrapped up prior to the final assy grind of the OØ of the cutaway crank half, presumably for greater running trueness to allow smaller clearances and hence, improved sealing. If the springs were light enough, the valve could also possibly act as a “reed” valve, albeit a shitty flow path.

329474329475

[WilDun]

That's the Cyclemaster pic I was looking for! but couldn't find it.
The Alpha engine pictured earlier ended up in a fire (the whole bike was burnt out). Looked a very promising machine in my day, very narrow for a twin disc engine (it was twin cylinder of course). Then Japan turned up the gas and all that stuff just disappeared, but I think that Cyclemaster possibly was a Dutch idea originally ?? - not really sure, but I think they may even have beaten MZ to the disc valve concept!

[ken seeber]

That's the Cyclemaster pic I was looking for! but couldn't find it.
but I think that Cyclemaster possibly was a Dutch idea originally ??

Will, Will, Will...

Who's going to get a big head now ???????? :facepalm:

[tjbw]

That's the Cyclemaster pic I was looking for! but couldn't find it.

...

Cyclemaster possibly was a Dutch idea originally ?? - not really sure, but I think they may even have beaten MZ to the disc valve concept!

To quote Frits "disc valves were patented in 1918 by the british Sun company who actually raced their 250 cc disc-valver in the 1921 TT on the Isle of Man"

Cyclemasters were made by EMI in London, the design was based on drawings by DKW.

Cyclemaster history here:

http://www.users.globalnet.co.uk/~pattle/nacc/arc0322.htm

[WilDun]

Oh.........Well.......there you go! and I normally know everything!:rolleyes:
At least that certain person won't be getting big headed!

[tjbw]

Oh.........Well.......there you go! and I normally know everything!

...



I know how you feel. I had thought that Daniel Zimmerman made the first disc valve engine.

https://www.500race.org/web/Marques/Zimmerman.htm

[Frits Overmars]

I think that Cyclemaster possibly was a Dutch idea originally ... I think they may even have beaten MZ to the disc valve concept!
Will, Will, Will... Who's going to get a big head now ???????? :facepalm:Who, me? In any case not because we beat MZ to the disc valve concept. There was nothing to beat there, as tjwb wrote:
To quote Frits "disc valves were patented in 1918 by the british Sun company who actually raced their 250 cc disc-valver in the 1921 TT on the Isle of Man"
Cyclemaster history here: http://www.users.globalnet.co.uk/~pattle/nacc/arc0322.htmThe cyclemaster history reveals that it was based on the Dutch-built Berini engine, one of the engines I tuned as a youngster. And tuning it was quite easy.
It surprised me that nobody commented on the red circles in Husabergs Cyclemaster picture, showing the engine's most interesting part: the governor.
It was a spring-loaded vane that gradually closed the inlet opening in the disc as the revs went up. Removing the vane gave the little engine a second wind.
329476


Back to Grumphs original question about the inlet discs in the MZ triple.
Well if we're assured it's three rotary discs, are they inside the crankcase chambers ? Looking at the angled inlets, If the discs are inside - with one crankweb cut away - and the inlet ports come into each crank chamber at an angle, that would explain the layout. I've seen a similar internal disc in one of Irvings books - used in a cyclemotor of about 30cc.MZ wouldn't let me pull the triple apart for pictures, but I see engines with similar internal discs every day in the streets of the former German Democratic Republic.
Yep, the Trabant. It has one carburetter serving two discs as shown in the pics below.
329477 329478 329479 329480 329481

[Grumph]

Thanks for the information everybody. Thanks for the trabbie pics Frits, I'd never seen the internal layout. I note that the discs are larger diameter than the crankshaft. Makes for a bit more complicated casting - but if you're going to produce them in the numbers they did, it would be worth it.

Will - you may be familiar with the Alpha journal type rotary valve which is a truly horrible device. You'd think that this type of internal disc would be preferable, they must have known about it but chose the journal type.....WHY ?

[TZ350]

page 1700 ..... :wacko:


By the way, you should know that Albert Einstein distinguished four kinds of people:
dumb + lazy: harmless
dumb + diligent: disastrous
smart + diligent: not much better than dumb + diligent
smart + lazy: the only useful kind; those are the ones who seek efficient solutions.



US Chrome, good buggers, both 7075 rods have been hard chromed at minimal cost. Because they are keen to help out with the projects (and I guess ultimately would like to do more paid chroming for me in the future).

But odd that they will not send the components back to NZ, they can only sent within the US? No problem I'm getting the parts sent to the guy that makes the Gyro rotor blades for me in Florida, so they will be sent out to NZ in due course in a box of rotors, hopefully shortly. This will have to be sorted in the future if I'm going to get more done. Anyone needing 7075 parts hard chroming?

https://www.youtube.com/watch?v=qDjG4bNCLWw
https://www.youtube.com/watch?v=TmXFkbD3s5g
https://www.youtube.com/watch?v=6keqpL3rmwk

Katinas first test ride of the Ryger he built.


https://www.youtube.com/watch?v=ckOw-Cp7wH8

https://www.youtube.com/watch?v=L-0AH79mY2E



Is Viton the preferred material for O-rings used to seal liquid cooled heads?
Viton is the material of choice for the inner ring where it seals the chamber to the cylinder top.
But around the outside where it seals only water ,normal O rings are fine.


I have been made aware of the dangers of Viton when heated or burned as in fan belts on burnt cars being dangerous.

329720



Lengthening the exhaust duct and cool it very well is one of the things I regret not having tried! I had the idea in 2007, but did not try it because I was planning to retire... Almost certainly it will give e good power improvement!
The idea floated about lengthening the Ex duct and increasing the cooling in this area is exactly what i will be advocating for the new kart engine design. Along with a shape change to include the Aux duct ears right down to the header joint and water having access into the back of the bolt on spigot.

329719

Edit - here is the optimum duct geometry as I have found in EngMod.

Turbo:-


Some further reading for TZ he might need to reverse engineer it a bit for his application.
http://www.spartgsxrspecials.com/turbo%20do%20and%20dont.htm



Vannik or anyone that knows stuff, I don't have your software so don't know this, if combustion does not happen, what happens to the air velocity in the combustion chamber at / after TDC? Does the rapid turbulence in the combustion chamber stop and reverse at some stage, as the squish starts to open up again? Or does it keep going but just slow down a bit?

The turbulence is caused by the breakdown of the main flow. Because of the viscosity (in effect the internal friction of the fluid) the main flow progressively break down into ever smaller eddies and if left long enough all the main flow and all the eddies will stop. The main flow is from the transfer port loop and a stronger better directed flow with more kinetic energy can generate a lot of turbulence before it stops. If you have weak flow by the time combustion happens you need the extra flow from the squish to generate extra turbulence to get good combustion.

On the other side if you have strong flow and thus good turbulence the extra turbulence can speed up the combustion too much and you loose power but mostly overrev. This explains why engines do not always behave the same to squish changes. Good engines use squish to minimize end gas to stop detonation while poor engines use squish to add turbulence.

So to answer the question: Turbulence cannot reverse, it is a one way street after creation. The bulk flow with the squish opening will loop slower and slower, both because of the increase in volume and because it keeps generating turbulence until it completely stops.


Detonation.

This started te be a problem when 50cc engines started giving more than 17HP, around 1975.
At the time I thought this was a limit on engine power.
Nikasil plated cylinders were very prone to detonation.
Because of the rounded off edge at the top.
At Minarelli/Garelli I solved this problem by sticking the cylinder head insert 3mm into the cylinder.
A good solution, used for many years.
But at Aprilia we found an even better solution: plate the first 5 mm around the bore at
the top of the cylinder.
Later this was machined to a very sharp corner, and this eliminated completely the unnecessary
'dead room' at the top of the cylinder, it also gave 0,3HP more.....
A little bit of still remaining detonation was eliminated by modifying the inner wall of the
transfer ducts, cooling the piston.
But part-throttle detonation remained a problem.....
Which we never had on the dyno!
On the photo you see a piston after a 54HP run...
As long as you keep the throttle wide open a 2 stroke doesn't brake down!


When modifying a cylinder measuring duct sizes is not easy, especially in the curves!
You can see our solution to this problem on the photo....
Round 'sensors' fitted to a piece of welding rod!
We had them from 7-7,25- 7,5 and so on until 28mm.
Behind the cylinder, in the wooden block.


Detonation.

This started te be a problem when 50cc engines started giving more than 17HP, around 1975.
At the time I thought this was a limit on engine power.
Nikasil plated cylinders were very prone to detonation.
Because of the rounded off edge at the top.
At Minarelli/Garelli I solved this problem by sticking the cylinder head insert 3mm into the cylinder.
A good solution, used for many years.
But at Aprilia we found an even better solution: plate the first 5 mm around the bore at
the top of the cylinder.
Later this was machined to a very sharp corner, and this eliminated completely the unnecessary
'dead room' at the top of the cylinder, it also gave 0,3HP more.....
A little bit of still remaining detonation was eliminated by modifying the inner wall of the
transfer ducts, cooling the piston.
But part-throttle detonation remained a problem.....
Which we never had on the dyno!
On the photo you see a piston after a 54HP run...
As long as you keep the throttle wide open a 2 stroke doesn't brake down!


The Aprilia RSW was a ROTAX design.
Later Aprilia made their own engines, but closely followed the original ROTAX design.
Except some small details.
Now they could say everything was 'made in Italy'
Which had financial 'advantages' for certain people!
Who could now take a bribe from the suppliers......as is usual in Italy.
So I am certainly not the 'father' of the Aprilia engines!

I was responsible for cylinder development, starting with 46,5HP and ending with 54HP.
Later, when working at DERBI, I had the idea of making the RSA engine, and made the first sketches.
The actual design was, of course, done on a computer by a professional designer.
Although it won several world championships I don't consider it a big success...

Aprilia always used AGIP fuels and oils for dyno testing
102 octane.
We were given face masks and special gloves, which we never needed for the 130 octane fuel.....


When modifying a cylinder measuring duct sizes is not easy, especially in the curves!
You can see our solution to this problem on the photo....
Round 'sensors' fitted to a piece of welding rod!
We had them from 7-7,25- 7,5 and so on until 28mm.
Behind the cylinder, in the wooden block.


Pistons:


We had cast and forged pistons.
Cast pistons gave slightly more HP, but sometimes cracked.
0,8mm piston rings gave more HP than 1mm rings.
As the auxiliaries and transfers overlapped each other a certain power los was caused by this.
So closing the pin hole in the piston was tried.
There were many solutions that were tested, but they all caused some trouble.
In the end the best, and most reliable, solution was welding then closed.
This was very well done by PANKL in Austria, and never caused any trouble!




Do you mind me asking why do you think cast pistons made more hp than forged? Because forged pistons had a tendency to 'bend' their top inwards.


Transfer ducts.

Many transfer ducts with small differences were tried.
We found more power by enlarging the A-port in the direction of the exhaust.
Only the lower half, but it was important to give the A-duct an inclination away from the exhaust!
The ducts were very conical, the smallest point being the port.
In and outside walls of the ducts had a constant radius from top to bottom.
The flow remained attached to the inside radius and so cooled the piston and eliminated detonation.
Flow bench testing and the Jante type testing proved useless for power improvement.
Giving the rear side of the B-duct an inclination versus the middle of the cylinder gave a big improvemet

[oldjohnno]

Lots of photos of the Alpha (and the disc valved Centuri twin) here: http://www.villiers.info/Alpha/

[WilDun]

I was always under the impression that the Alpha also used discs. (and I see that I was correct) but hadn't studied the earlier single.
So which came first? the MZ (Trabant) twin or the Alpha twin? - anyway it doesn't matter, it's a very tidy layout - they should have done that with the Ariel Arrow!

TZ, is your Ariel Arrow still languishing under the bench?

[Frits Overmars]

Thanks for the trabbie pics Frits, I'd never seen the internal layout. I note that the discs are larger diameter than the crankshaft. Makes for a bit more complicated casting.Nah; you can't cast decent disc recesses like that anyway; they'll always need some final processing.
I suppose the simplest approach would be to cast those cases 'full' and then dip in a cutter blade.
329483 329482

[WilDun]

Nah; you can't cast decent disc recesses like that anyway; they'll always need some final processing.
I suppose the simplest approach would be to cast those cases 'full' and then dip in a cutter blade.

Yes, that would be the best way to do it - I always found over the years that machining cast "pockets" like that was really a pain in the arse and often very difficult to get a smooth even finish - much easier to machine areas like that from solid!

Just as a matter of interest, the Trabant engine has been used successfully in some light aircraft.

[Grumph]

Nah; you can't cast decent disc recesses like that anyway; they'll always need some final processing.
I suppose the simplest approach would be to cast those cases 'full' and then dip in a cutter blade.

True. Given the stories about the Trabbie bodyshells, I was pleasantly surprised to see the quality of the castings - and the level of finish too.

[Frits Overmars]

Just as a matter of interest, the Trabant engine has been used successfully in some light aircraft.I didn't know that. And I'm interested. Got any pictures Will?


Given the stories about the Trabbie bodyshells, I was pleasantly surprised to see the quality of the castings - and the level of finish too.Not everything in the DDR was of 'Russian' quality. Trabbi castings were allright, as were Simson castings. MZ street bike castings were not great, MZ racing cylinder castings were horrible.
By the way, if the East-Germans describe something as Russian, you'd better steer away from it. It's their summary of ponderous, clumsy, rude, churlish, inane and dumb. Not much love lost there....

[WilDun]

I didn't know that. And I'm interested. Got any pictures Will?

Not everything in the DDR was of 'Russian' quality.
By the way, if the East-Germans describe something as Russian, you'd better steer away from it. . Not much love lost there....

Ha ha, used to be a joke here "when does a Skoda look good? ..... "when it's parked next to a Lada". ...... But then a while back the Americans got a nasty surprise when they found that their fighter aircraft were not as good as the Russian ones - and they very quickly had to do something about it!

Yes quite a while ago I saw a video of a light aircraft fitted with a Trabant engine but I'll have to find it. - performed well!

[tjbw]

Yes, that would be the best way to do it - I always found over the years that machining cast "pockets" like that was really a pain in the arse and often very difficult to get a smooth even finish - much easier to machine areas like that from solid!

...



Agreed, though those deep grooves would still be tricky (for me) even from solid, in fact I'd be inclined to redesign the crankcase, making the central section an insert.

[WilDun]

Agreed, though those deep grooves would still be tricky (for me) even from solid, in fact I'd be inclined to redesign the crankcase, making the central section an insert.

Yes, was just now thinking along those lines myself, however a production machine set up to do that specific job would be a much cheaper option than an insert (ie in a factory which churns them out!).

FRITS, here are a few links :-

http://www.lightsportaircraftpilot.com/sd-1-minisport_experimentalaircraft/

https://www.pilotmix.com/sd-1-minisport

http://www.youtube.com/watch?v=u2R7VznSGVw

https://en.wikipedia.org/wiki/Air-cooled_engine

[tjbw]

...

It surprised me that nobody commented on the red circles in Husabergs Cyclemaster picture, showing the engine's most interesting part: the governor.
It was a spring-loaded vane that gradually closed the inlet opening in the disc as the revs went up. Removing the vane gave the little engine a second wind.
329476

...



Might there be some merit in something similar, that adjusts the inlet timing depending on rpm?

[WilDun]

Might there be some merit in something similar, that adjusts the inlet timing depending on rpm?

I think Flettner is already working on some form of controlled variable disc timing and knowing him, he's probably got it just about sussed by now!
BTW, I don't remember there being any timing adjuster on the Cyclemaster I owned.

[tjbw]

I think Flettner is already working on some form of controlled variable disc timing and knowing him, he's probably got it just about sussed by now!
BTW, I don't remember there being any timing adjuster on the Cyclemaster I owned.

It's hard to see on the photo, but it's a vane that actually closes the inlet port as rpm increases, don't think it changes the timing. Perhaps some kind of performance limiter was required in some markets.

[wobbly]

Flettner has had a variable disc valve timing setup for ages, a moving insert that changes the closing timing with an Ignitech controlled PV servo motor.