ESE's works engine tuner

[flyonly]

Any one here had their cases scanned so you have all the relative points to be able to draw them up in 3D?


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[TZ350]

May be the fixed one was not set at the right time.
At max power both should have the same pre ignition !
At lower speed the power is the same, which should be different in favor of the Ignitech progr.
This suggests that the fixed ignition was too late.

You are right, they should both be the same at max power. But the fixed was then over advanced at lower speeds. A compromise had to be made.
Both ignitions were setup on the team ESE dyno.

[TZ350]

.
2Stroke Stuffing gets the 24/7 50cc engine running on the dyno, test run to hear the sound of it howling ...... https://youtu.be/oR_JCxyPdaQ

[Tim Ey]

Wob,

probably the link has sent you elsewhere - bylund offers knock / Lambda / NOx shields for the arduino. I was talking about the knock shield.
As I understand the el cheapo Czech knock device has a given frequency range. Sometimes you need to ignore a certain rpm range, because it shows you mechanical noise.
And that is why I would like to test the bylund devide.

Lambda is helpful, but I am still struggling with it. My RS250 had a lambda output like attached in its WOT run and was WAY too lean till 8000 rpm.

So next time I will focus on my gut feeling whilst juggling jets first - and afterwards note the corresponding lambda.

[TZ350]

Lambda is helpful, but I am still struggling with it. My RS250 had a lambda output like attached in its WOT run and was WAY too lean till 8000 rpm.

Because of short circuiting in a two stroke. Lambda will always look lean and only start to come right as the engine gets up on the pipe and the trapping efficiency improves.

My EFI bike's Air/Fuel would be something like 18:1 and the reading would slowly improve until it was about 12:1 at max torque but of course in reality it was probably close to 12:1 in the cylinder all the way through even though the gauge registered lean. I think you are right to go on gut feel to get things right then use your recorded data as a development guide for later.

Mine might look even leaner than yours at low RPM but the Lambda trace on your dyno graph looks pretty much what I would expect. The big lean hump where the power dip is just before coming strongly onto the pipe makes sense too.

[koenich]

Any one here had their cases scanned so you have all the relative points to be able to draw them up in 3D?

yep...it sounds tempting and an easy way forward but in reality if you are not at least an advanced CAD user it's rather useless.

Long story - I had one half of a 50cc scanned, model was 120 MB. First problem was converting it to solid: you need to heal the open surfaces to convert and while converting Catia kept crashing even on the latest workstations while Fusion only accepted smaller models. If you have the solid it won't have perfect cylindrical bearing seats nor flat surfaces where you just can place a concentric axis or planes, so some approximation is necessary. The "easier" way IMO would be to measure the necessary distances on a X-Y measuring machine, use those values to set critical dimensions and if you have a scan use that to roughly dial in the outer surfaces etc.


BTW - does anyone have a link for the Czech deto thingy? With 0-5V that could even be coupled with a datalogger (Starlane, Mychron) I suppose?

[philou]

Knock gauge Czech

http://www.knockgauge.eu/

https://www.ebay.com/itm/18441368845...YAAOSw7aBVBEom

has anyone read this book

[Tim Ey]

Mine might look even leaner than yours at low RPM but the Lambda trace on your dyno graph looks pretty much what I would expect. The big lean hump where the power dip is just before coming strongly onto the pipe makes sense too.

And exactly that was my problem. I focused too much on the numbers I have expected.


Regarding 3D scanning: What koenig said. But it is useful for complex geometries and mock ups. If your CAD system can handle it.

[lohring]

I have 3D models of Zenoah and Quickdraw cases for their 26 cc engines. It took a lot of measurements, not scans.

Lohring Miller

[Frits Overmars]

Stop thinking "Lambda says lean". You all know better than that. Lambda can only say how much unused oxygen is present in the exhaust gas. It does not say anything about the presence of unused fuel. So if you keep using the words Lambda and lean in the same sentence, you may be forcing your thoughts in the wrong direction.

[TZ350]

Lambda can only say how much unused oxygen is present in the exhaust gas. It does not say anything about the presence of unused fuel. So if you keep using the words Lambda and lean in the same sentence, you may be forcing your thoughts in the wrong direction.

Yes, good advice, that paints a better picture of the situation. Thanks.

[wobbly]

The Czech gauge shows ONLY noise from the first 4 lights , so its easy to dial up the sensitivity to the max , showing only noise , by having them light up under load.
Then the red light shows ONLY deto when its happening and is independant completely of the bore.

[OopsClunkThud]

Any one here had their cases scanned so you have all the relative points to be able to draw them up in 3D?


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if I recall, Flettner set up the cases on the manual mill and then picked up the bearing locations. With that info you can do whatever you want to in CAD.

precise measurement of the section you care about.

[flyonly]

if I recall, Flettner set up the cases on the manual mill and then picked up the bearing locations. With that info you can do whatever you want to in CAD.

precise measurement of the section you care about.

That would work. I would draw it all up in CAD. Just remove the things I don’t need first e.g. kick starter. Then it would be possible to add in some of the ideas talked about in this group. Who has a mill in NZ with a DRO that has time to help out?

[SwePatrick]

Does anyone think they have the best design

https://m.youtube.com/watch?v=G8L9_XO3iCw

This is quite irrelevant to twostrokes as i have noticed that twostrokes(highrevving) can´t have too short intake.
And thereby everything that makes it longer is a failure.