ESE's works engine tuner

[wobbly]

We have two entirely different scenarios in any fully tuned two stroke where one is a Rotary Valve , the other a Reed Valve.
The Aprilia had a large case in the order of 1.24 , and this was due in large part to the long 120mm rod.
The R1 is a few cc over 1.3 and the R2 with thinner covers over the flywheels is a few cc under 1.3.

I have previously cut 5mm off the reed box face on an R1 and lost power , then added a 10mm spacer back in ( ie +5mm over stock ) and that lost power even more so.
In both cases I changed the reed backups to see what the effect was , and it turns out the smaller case liked slightly stiffer 1st Mode frequency.
The bigger case liked less tension , but it was obvious in that test , that the reeds fluttered at high rpm and the big case in fact achieved the opposite of what was expected , due to reed effects - not the volume change.
ie it made a little more front side power , but fell over badly up top due to the thin reeds loosing control.

So - no you cant run a big case under 1.3 with reeds due to the bigger volumes Helmholtz value requiring thin petals that then promptly bugger the power curve by going spastic at high rpm's.

[diesel pig]

We have two entirely different scenarios in any fully tuned two stroke where one is a Rotary Valve , the other a Reed Valve.
The Aprilia had a large case in the order of 1.24 , and this was due in large part to the long 120mm rod.
The R1 is a few cc over 1.3 and the R2 with thinner covers over the flywheels is a few cc under 1.3.

I have previously cut 5mm off the reed box face on an R1 and lost power , then added a 10mm spacer back in ( ie +5mm over stock ) and that lost power even more so.
In both cases I changed the reed backups to see what the effect was , and it turns out the smaller case liked slightly stiffer 1st Mode frequency.
The bigger case liked less tension , but it was obvious in that test , that the reeds fluttered at high rpm and the big case in fact achieved the opposite of what was expected , due to reed effects - not the volume change.
ie it made a little more front side power , but fell over badly up top due to the thin reeds loosing control.

So - no you cant run a big case under 1.3 with reeds due to the bigger volumes Helmholtz value requiring thin petals that then promptly bugger the power curve by going spastic at high rpm's.

Interesting, If only there was a way to get rid of reed flutter at high rev's. Maybe a physicist's could help. I hear Netherlands physicist's are quite good.

[ken seeber]

Why, in heaven's name??

Frits,
Sorry for the delay.
Why is a fair question. There might be an opportunity to demonstrate an IC engine to run on either ammonia directly as part of the “green” renewable energy world. In Western Australia, there is much discussion and interest in creating huge renewable energy “farms”, with the intention of exporting this energy. It is recognised that transporting hydrogen, say by ship, is not practical (temperature, pressure and leakage) so ammonia is the logical alternative.
Further to this, apparently there are some applications where there is a place for smaller, lower speed powerplants, running directly on ammmonia(NH3).
Sort of interesting, an engine running on fertilizer.

[husaberg]

Frits,
Sorry for the delay.
Why is a fair question. There might be an opportunity to demonstrate an IC engine to run on either ammonia directly as part of the “green” renewable energy world. In Western Australia, there is much discussion and interest in creating huge renewable energy “farms”, with the intention of exporting this energy. It is recognised that transporting hydrogen, say by ship, is not practical (temperature, pressure and leakage) so ammonia is the logical alternative.
Further to this, apparently there are some applications where there is a place for smaller, lower speed powerplants, running directly on ammmonia(NH3).
Sort of interesting, an engine running on fertilizer.

Thats funny Ken, as most urea CO(NH 2) 2. ie the worlds most common nitrogen fertiliser is generally made from hydrocarbon gas.
although its somewhat unfashionable its needed to double food production so the poor can afford to eat as well.

[Condyn]

The cases and big end pin were widened by 12mm. The inner face of the flywheels trimmed back to the b/e thrust washer faces and the rod was 25mm longer than stock. Massive crankcase volume. The engine still started easily and made more power then ever.

Very crafty TZ.
It would be interesting to find the upper limit on rv case volume before you start going backwards. With no familiarity with that engine, where did the rod/stroke ratio end up?

Wobbly, given the vastly different scenarios between developing each engine type rv/reed, which would you choose if given a clean slate to build a 2t moto GP engine? I would guess you could make either work, but just curious.

[TZ350]

[wobbly]

Condyn , one would have to do the R&D first.
On one side you have the Rotary , easy and has all been done before , then add Niels gibbs , not been done on a race engine , but is being designed as we speak in the form of a 500cc parallel twin
with twin Rotary Valves across the front ,with gibbs.
Then the reed , with 24/7 , about the same fiddly mechanism needed to drive that setup as the gibbs but as I havnt seen Rolands dyno results from Modena , I would have to reserve
judgment till the results were in.

[F5 Dave]

Frits,
Sorry for the delay.
Why is a fair question. There might be an opportunity to demonstrate an IC engine to run on either ammonia directly as part of the “green” renewable energy world. In Western Australia, there is much discussion and interest in creating huge renewable energy “farms”, with the intention of exporting this energy. It is recognised that transporting hydrogen, say by ship, is not practical (temperature, pressure and leakage) so ammonia is the logical alternative.
Further to this, apparently there are some applications where there is a place for smaller, lower speed powerplants, running directly on ammmonia(NH3).
Sort of interesting, an engine running on fertilizer.

Whereas a decent ammonia leak on a ship would result in it arriving somewhere, anywhere, with no one standing up.

[ken seeber]

Whereas a decent ammonia leak on a ship would result in it arriving somewhere, anywhere, with no one standing up.

Correct Dave, but they do actually get there in one piece...

[F5 Dave]

If you open a cryogenic facility, I might give it a miss. . .

[skako]

Hi,
I apologize for my poor English. For this I must used google translator. I have been following this forum for many years and this translator works great for me.
I give all praise to this forum and many experts. Here I found a lot of good information and answers. I live in Croatia and my hobby is mopeds. I mostly use them for experimenting and studying and very little for driving. Life circumstances determined it that way.
About thirty years ago, I designed and made a seven-speed gearbox for the Tomos 15SL moped. For the last few years, with longer or shorter interruptions, I have been trying to make a Two-stroke simulator.
I based the simulator mostly on the work of Prof. Blair. The simulator is not completely finished. But it already gives me a lot. The results obtained guide me how to arrange the engine parameters for what I want. The appearance of the simulator can be seen in the picture.

[Vannik]

I based the simulator mostly on the work of Prof. Blair. The simulator is not completely finished. But it already gives me a lot. The results obtained guide me how to arrange the engine parameters for what I want. The appearance of the simulator can be seen in the picture.

That looks very good! Did you base it on Prof Blair's first or second two-stroke book?

[F5 Dave]

Isn't technology marvellous! Here (New Zealand) we were brought up speaking just one language due to our colonial past and isolation. We then feel somewhat embarrassed that we speak no other languages when we are exposed to the world wide Web. Sadly even the alternative indigenous language was suppressed when I was young and sign language would be great to learn.

Now you are here posting better English than most of us can manage through software augmentation.

Welcome.

[trevor amos]

Hi,
I apologize for my poor English. For this I must used google translator. I have been following this forum for many years and this translator works great for me.
I give all praise to this forum and many experts. Here I found a lot of good information and answers. I live in Croatia and my hobby is mopeds. I mostly use them for experimenting and studying and very little for driving. Life circumstances determined it that way.
About thirty years ago, I designed and made a seven-speed gearbox for the Tomos 15SL moped. For the last few years, with longer or shorter interruptions, I have been trying to make a Two-stroke simulator.
I based the simulator mostly on the work of Prof. Blair. The simulator is not completely finished. But it already gives me a lot. The results obtained guide me how to arrange the engine parameters for what I want. The appearance of the simulator can be seen in the picture.

Top work Shako, terrific software and, your own 7 speed gearbox, wow, makes me feel quite inadequate keep up the great work, oh and welcome to the site.

[Frits Overmars]

Hi, I apologize for my poor English. For this I must used google translator. I have been following this forum for many years and this translator works great for me.

Welcome Skako. I must say your 'poor English' is definitely better than what Google Translator can do, and I am looking forward to more contributions from you.

For the last few years, with longer or shorter interruptions, I have been trying to make a Two-stroke simulator. I based the simulator mostly on the work of Prof. Blair. The simulator is not completely finished. But it already gives me a lot. The results obtained guide me how to arrange the engine parameters for what I want.

Putting together a simulator will have forced you to fully understand every physical, mathematical and logical step in the process, and that alone will have given you a level of insight not many of us will achieve. My respect!