ESE's works engine tuner

[Jannem]

No - due to the strong superposition effect the power band is way wider than normal with a port down at 190*.

If you have properly designed time areas for 13krpm, the blowdown will be "too much" at 10krpm, but the properly designed system still has the widest powerband, meaning relatively little loss of fresh charge. Is this because the T-ports designed for 13k are somewhat lazy below, so the excess BD wont hurt that much?

[dutchpower]

Your graph Dutchpower is from the actual Exhaust port face.
It is much more enlightening to place the transducer at the duct exit, before the transition to the header.
If this hits 0.8 Mach then you know the exit area is correct.
The STA number for the port takes into account the effects of choked flow as the piston open area enlarges.
While you are at it look at the Mach at the stinger entry, again 0.8 Mach is a good place to be starting with that.

Thank you Wobble

[Jannem]

Is that sharp peak on top of the curves an indication of slightly small nozzle area? Or high blowdown area at the top of the ex. port at cylinder surface?

[TZ350]

Did you try a low pass filter? It can be as simple as a resistor in series with a capacitor in parallel.

https://www.allaboutcircuits.com/tex...-pass-filters/

Thanks for the suggestions, the ideas will come in handy.

I have had a bit of success tonight. Used a $12.90 kitset amp from Jaycar as a front end before the bridge rectifier. It worked a treat and gave a very consistent signal.



I used the 0.5W champ amp to amplify the signal from the Piezo disk then passed the output through the bridge rectifier. Very crisp, sharp and consistent signal up to 12,000 rpm.

The Champ amp is based on the LM386 Op amp. With no real load on the output, the output signal was quite high. I need a 5 Volt digital signal for the Arduino input so over the next few nights I will see if I can trade some height for signal width that the Arduino can easily see.

Anyway, very pleased, it feels like progress......

[Jannem]

So, a power valve system that brings in and out the auxiliary ports would/could/should be better than one that adjusts the port height and ex. duration.

cheers, Daryl.

I suppose it depends if your triple port becomes bd limited at some point or not.

[Frits Overmars]

Van mijn vader had ik gehoord dat hij dit systeem in 1969 uitgedacht had,
hij kon alleen geen goede gieterij vinden die een cilinder kon gieten zonder gietgallen.
Cilinders lekten constant water.
Hij is vanwege tijdsgebrek er weer mee gestopt en heeft het idee uitgelegd aan Frits Overmars.
Die zou er daarna, met modelbouwmotortjes succes mee gehad hebben.

William van Dongen

From my father I had heard that he had invented this system in 1969,
he just could not find a good foundry that could pour a cylinder without casting holes.
Cylinders were constantly leaking water.
He stopped because of lack of time and explained the idea to Frits Overmars.
He would then have had success with model construction engines.

Jasonu, your translation is 100% correct. But the original Dutch text is not. Here is what happened:
Around 1995 I discussed my FOS scavenging system with Cees van Dongen (great character, saddly missed). Cees used to cast his own cylinders, based on the Mahle-Kreidler racing cylinders. Cees then showed me an experimental cylinder in which he had added a small transfer port under the exhaust. This was the only difference. Contrary to Lucs suggestions there were no circumferential exhausts, no symmetric transfer ports, no central scavenging column, in short: no resemblance to my system.
The casting of this prototype was too porous to be properly tested, as William van Dongen confirms, and Cees let me have the cylinder as a souvenir.
The picture below with the yellow transfer port shows an impression. When I get back to Holland, I can take a picture of the original cylinder and post it.

@ William van Dongen: if this cylinder has a sentimental value to you, just let me know and I'll let you have it.

@TZ350: sorry to clutter up your thread. I didn't start this conversation and there is no other place for me to rectify what was being said here.
Now I wonder if Luc has the balls to rectify what he wrote about the Van Dongen-cylinder in this forum and in the other places where he posted the same text.
By the way, that's the way the whole thing started. At the end of 2007 and the beginning of 2008 I presented my scavenging idea in a racing newsletter and in a Dutch motorcycle magazine, accompanied by drawings and a picture of a cylinder that had clearly been running.
Luc, whom I had never heard of before, promptly launched a me-too reaction all over the internet. He even claimed to have been the first with a running engine, because he posted a video while I had better things to do.

[TZ350]

Cees used to cast his own cylinders, based on the Mahle-Kreidler racing cylinders. Cees then showed me an experimental cylinder in which he had added a small transfer port under the exhaust. This was the only difference.

The casting of this prototype was too porous to be properly tested, as William van Dongen confirms, and Cees let me have the cylinder as a souvenir. The picture below with the yellow transfer port shows an impression.

That was a very interesting bit of back history about the FOS concept.

When we had trouble with virtual leaks in prototype cast vacuum boxes we would vacuum impregnate them with resin. I wonder if that could be a temporary solution for a porous cylinder. It could easily be done to a raw casting before machining as the resin completely penetrates all the casting porosity's.

[Frits Overmars]

So, a power valve system that brings in and out the auxiliary ports would/could/should be better than one that adjusts the port height and ex. duration.

That would still leave you with a combination of exhaust timing and pipe dimensions, meant for a higher rpm. If you really want to broaden the power band, you can:
A: Lower the timing of all exhaust ports. This will lose you the benefit of wave superposition, but strong waves at the wrong time are undesirable anyway,
or
B: use a trombone pipe. Then you can use your suggestion of bringing the auxiliary ports in and out, in order to adapt the blowdown time.area to the rpm, and still keep the main port at its optimum timing of 190°, because with the longer pipe that will work fine at lower revs, and you'll even keep the superposition advantage.

[lucf]

Jasonu, your translation is 100% correct. But the original Dutch text is not. Here is what happened:
Around 1995 I discussed my FOS scavenging system with Cees van Dongen (great character, saddly missed). Cees used to cast his own cylinders, based on the Mahle-Kreidler racing cylinders. Cees then showed me an experimental cylinder in which he had added a small transfer port under the exhaust. This was the only difference. Contrary to Lucs suggestions there were no circumferential exhausts, no symmetric transfer ports, no central cavenging column, in short: no resemblance to my system.
The casting of this prototype was too porous to be properly tested, as William van Dongen confirms, and Cees let me have the cylinder as a souvenir.
The picture below with the yellow transfer port shows an impression. When I get back to Holland, I can take a picture of the original cylinder and post it.

@ William van Dongen: if this cylinder has a sentimental value to you, just let me know and I'll let you have it.

@TZ350: sorry to clutter up your thread. I didn't start this conversation and there is no other place for me to rectify what was being said here.
Now I wonder if Luc has the balls to rectify what he wrote about the Van Dongen-cylinder in this forum and in the other places where he posted the same text.
By the way, that's the way the whole thing started. At the end of 2007 and the beginning of 2008 I presented my scavenging idea in a racing newsletter and in a Dutch motorcycle magazine, accompanied by drawings and a picture of a cylinder that had clearly been running.
Luc, whom I had never heard of before, promptly launched a me-too reaction all over the internet. He even claimed to have been the first with a running engine, because he posted a video while I had better things to do.

Well if you are right, which should be confermed by William van Dongen, I don't have any problem to correct what's wrong.
But you write 1995 while it happend in 1969

And still one point more, you didn't published your system before I did on Jan 19th 2008, so you have to correct your description too.
In my FST publication the exact description has been published as realy happend, including the prints of your text in the those Dutch motorcycle magazine, so everyone can see what is the real sequence.

This is were you find the first publication on January 19, 2008
http://www.geocities.ws/lucfoekema/FSTsystemNL.html
and here first forum http://www.kreidler.nl/forum/viewtopic.php?f=5&t=25485

This was your first reaction on jan 21, 2008 to my publication and read wel, because more than one thing doesn't stroke with the text you write above.

In a column that appeared last year in the journal KicXstart, I described how ever the idea arose of a new flushing system for two-stroke engines, the FOS-scavening.

Recently commented Mr Luc Foekema that he probably had the same thought as me.Thats possible. I walk for thirty years with that idea around and I'm not the only one who occasionally logical thinking.
I would not even be surprised if the same principle eighty years ago even once conceived. I know how it feels when your own ideas popping up somewhere else.
That has happened several times myself. What do you do? Nothing. It's just sad, but I never wake located. I thought most: "You see? I was right."
And everyone who comes in the same situation may think of me the same.Mr. Foekema is honest enough to mention that the idea to him about two years ago has risen.
For me that is a while ago, but that does not matter. Ideas count only when they are realized.

So I would say: "Do your best, Luc. Shows how well the system is that you and I have independently invented.
I hope my engine runs first. But if you're too quick for me, I hope that yours runs fast. Success ".

Frits Overmars

https://www.kiwibiker.co.nz/forums/s...post1131082527
https://www.facebook.com/notes/luc-f.../4080202582494

[Frits Overmars]

Don't worry TZ350, I'm not going to bite .

[F5 Dave]

Luc you really are poisonous. Have a look at your life. But take your fucked up agendas somewhere else.

[katinas]

If you want to make sure, check with the laser sintering company and with the plating company.
When I had my cylinders lasered, experience with the process was still limited, so I sent some test samples to the plater before going all the way.
We used AlSi12 powder.
Attachment 334883 Attachment 334884

Interesting, whether was a small pits after machining and what resistance to cracking?


Last year, after second Rygerised engine broke because of too small piston ring end gap ( someone call when I prepare to adjust the gap ……), decide revert to original, because short summer time and want familirised with 1cylinder std. engine. Tried to test as much as possible until the end of the year. Not to extract max hp, but to understand the engine's response to various changes.

So forest was in the 2T smell at the second half of the year. Two times stopped near the cars with the raised hood and ladies in panic for possible engine fire. After explain what a matter, they agree that smell of racing two stroke oil much nicer than cigaretts.

Limited myself only on not to change Ex and Trans bandwidth. On cylinders only intake and bottom part was drastically changed ( boyesen ports, intake to transfers and flow through bottom Ex duct directly to A Trans). This is old boyesen type cylinder with maybe 30 hp limits, but if someone still interested I'll be happy to answer.

Maybe this is very old answered question. This particular oversquare engine (57x50,6 mm. rod 109 mm) never work well after 10500 rpm with 50 percentage ( 8,35mm ) squash band. Whatever did nothing changes: gap from 0.7 to 1,2 mm., different combustion shape, different compression different timing and combination all of that . 9 different heads. Bottom and mid good.

All changed with 5 mm squash band. Revs nice from 10500 to 13000 rpm in every combination with diff. compression and shape. Of course mid weaker ( not much from 5000-7000 )

Maybe with different rod length / stroke ratio and piston dia. some correction needed to 50 percentage.

Now return to Rygerised engine again with different flow (later put skech). Just finished piston. And other good thing is that my friend buy dyno, but he lives 300km from my home so I cant test whatever I want.

Nuoširdžiai dėkojui jums Fritsai

[wobbly]

Frits wont bite because he is a gentleman.
Im not so I will bite,again.
Luc FUCK OFF - no one believes and no one cares.
This forum is here for people to help each other by adding small snippets of helpful 2T knowledge with each post.
All you have done is blatant self promotion,and self aggrandizement.
If you carry on I am absolutely sure we ( as a group ) could ask the moderator of this excellent thread to have you locked out.


Edit - Dutchpower, just be sure that when you look at the entry to the stinger that the Ex transducer position is set to the correct length.
This is not important if its just a straight tube, but if its a nozzle then you need to set the transducer to that nozzle position.
ie if the length is set at 80mm than both ExMach(1) and ExMach(2) will be at this length down each of Pipe 1 and Pipe 2 ( 2 being the stinger )

[katinas]

Luc


I did not meet with Frits personally, but I never read any bad words from this intelligent and intellectual soul.
Personally for me, Frits and Jan made miracle when reveal so much covered small GP secrets. And if from my young days I have the opportunity meet these people they would be like second fathers.

[JanBros]

Wobbly :

Luc is amazing, he makes the best engines. EVER. Yes it's true.
He is the hardest working dutchman and he want's to make Luc great again, after that horrible Ryger-president (or is it spelled precedent ?) yes it 's true. He is the best, everybody loves him.
and the Mexicans will pay for his FST