ESE's works engine tuner

[Muhr]

Took some old Otto cycle numbers and put in, does not feel completely crazy

[SwePatrick]

Took some old Otto cycle numbers and put in, does not feel completely crazy

Ratio 6, that is air/fuel ratio?
You can run richer for more coolingeffect as methanol has a wider 'tunerwindow' so to speak.
You are able to run way rich without loosing much at all.
In aircooled engines this is a very good option as they need all the cooling they can get.

And E85 is known to beeing able to give you 7-8% percent more power than ordninary pumpfuel, so that´s about correct.

[wobbly]

EGT Tuning. Short answer to that question is NO.
First main point is that you never run an engine in 3rd gear at 1/4 or 1/2 or 3/4 for any distance - ever.
So what does the info you gain actually mean , nothing , as who knows what the egt " should " be at that rpm/load/throttle position - no one .

You can tune , real close , the idle circuit and the slide/needle/tube up to about 1/2 throttle very easily.
With the engine only just warm , you can immediately tell if there is any lean point in that range when opening the throttle very quickly.
If it doesnt rev faster than your hand opens the slide - its lean.
Start first with screwing in the air screw right in to 1/4 turn - if this fixes the initial bog , then the pilot is too small.
You should be able to have no bog , on transition off idle , with 1 1/2 turns and the correct pilot.
Then start at 1/4 throttle and do the same thing - if it wont pull up off this point faster than your hand then the slide is too lean , and or the tube too small.
The decision to change either the slide or the tube/needle parrallel is finally decided by what happens later in the tuning process.

All this initial "cold " tune , for the bottom end , can then continue with a hot engine , but with it loaded up by the rear brake - again any hesitation or bog at any point means its lean.
Assuming you have already got the main in the ballpark , then the final tube/needle combo is decided by what happens under full load in top gear , when you back off to 3/4 throttle.
If the egt stays the same or rises at all , then either the needle tip is too big , or the tube is too small.
This part of the tune is the most dangerous to the piston , and your health , so be carefull , as you are now at a point where it can be so lean that deto starts - and that can make the egt drop.
In a kart , this test can be done on the stand , but a bike rear brake generally wont have enough load capability.

Of course if the 3/4 test involves making the tube bigger - then this will affect the 1/4 tune , and the slide may need to be changed back to a leaner setting ( or a fatter needle parallel ) - if the thing smokes like hell off the bottom.
As someone said the other day about egt tuning - there are a heap of balls in the air with so many options that interact , but getting the 0 to 1/4 correct , then WOT back to 3/4 correct will be a good baseline.

[diesel pig]

Thanks for the reply Wobbly. My engine is running well on the main jet but as you descride in the third paragraph of your reply when I roll off the throttle to 3/4 to 1/2 it hesitates badly and will not respoled to the throttle until it is on the main jet at full throttle. I will print out your reply and have it with me when I am next tuning my engine. Cheers

[flyincat]

This one is in honor of Frits, continually beating resonance into our heads! Thanks Frits, Wob, Jan, others.. It's one of the best visualizations I've seen showing the power of vacuum and compressed air, and of course some resonance.

Start around 4:50 for resonance visualizations...
https://www.youtube.com/watch?v=nIL3HN4PQlI

[Frits Overmars]

This one is in honor of Frits, continually beating resonance into our heads! Thanks Frits, Wob, Jan, others.. It's one of the best visualizations I've seen showing the power of vacuum and compressed air, and of course some resonance.
Start around 4:50 for resonance visualizations...
https://www.youtube.com/watch?v=nIL3HN4PQlI

I love it!

[wobbly]

So here is the result of correct resonance in a 2T.
The intake length is correct ( for the selected rpm ) when the wave bouncing up and down from the reed tip , to the bellmouth end goes above atmospheric at the same time as the
case goes below. This puts + pressure ratio on one side of the petals , and - on the other side , thus opening them as fast as possible.

The Exhaust length is in resonance with the Ex Port timing , when you get Superposition - that is the return wave has the port sitting well above atmospheric ( zero pressure ratio ) when the piston cracks open.
Thus the new high pressure ratio wave is added to the remnant wave , giving a much higher ampltude to the subsequent wave travelling down the diffuser.

Sonic Supercharging.

[andreas]

So here is the result of correct resonance in a 2T.
The intake length is correct ( for the selected rpm ) when the wave bouncing up and down from the reed tip , to the bellmouth end goes above atmospheric at the same time as the
case goes below. This puts + pressure ratio on one side of the petals , and - on the other side , thus opening them as fast as possible.

The Exhaust length is in resonance with the Ex Port timing , when you get Superposition - that is the return wave has the port sitting well above atmospheric ( zero pressure ratio ) when the piston cracks open.
Thus the new high pressure ratio wave is added to the remnant wave , giving a much higher ampltude to the subsequent wave travelling down the diffuser.

Sonic Supercharging.

I gather this shows a third harmonics intake setup, it comes natural or it's the preferred one?

[jfn2]

OK Wobbly
In your opinion where would you set these resonance events?
Intake resonance at peak torque rpm and exhaust resonance at peak HP rpm ?
Or intake resonance and exhaust resonance at peak HP rpm?
Or intake resonance and exhaust resonance at peak torque rpm?
Or somewhere in-between?
Or, as an after thought, would you set the intake resonance for the dip in the power curve that is seen on most 2-strokes?

[Flettner]

Ok, we have talked about this before, RK tech heads.
With the crinkle cut combustion chamber. Kels the RK designer says the design is patented. I ask him repeatedly to explain how it works, no problem with giving away secrets as, like he says, its patented. Can not get an answer. Intetesting that customers are more than happy to shell out dosh not knowing (or careing to know) how it actually helps combustion. It is an old idea so I do wonder about the patent. Those that use it swear by it, is it just because they spent a lot of dosh on it or is it because of its pretty anodised surface?
Why are people so keen to spend money on somthing thats workings appear unexplainable? And if you have a peice of technology that works but you dont know why, where to from there? Its as good as useless.
https://youtu.be/MIWaJe2tYWo

[wobbly]

Andreas , yes that graphic shows a 3rd harmonic resonannce , and the 3rd is prefferred due to a couple of important characteristics .
I have found that the third , with several " bounces " per cycle has the best combination of amplitude Vs band width of effectivness.
This harmonic also has the most reasonable physical length for the rpms we use the most.
In a 125 race engine with peak torque around 12,000 say - the length ( using 2/3 of the reed petal + correct bellmouth end correction ) is around 125mm. Fits in easily with usual carb lengths.

This works well over about a 2000 rpm band - and if tuned to peak torque it does in fact help the 2T common power dip.
But - intake tuning ( super effective in efficiency with a 4T ) has only probably 20% of the tuning "power " to be had compared to the pipe.
This is why an intake boost bottle is nowhere as good as an Exhaust boost bottle in helping mid range power , under the pipe.

The first harmonic would not fit in a bike or kart , though would give a bigger boost in power , but over only a 500rpm range.
Knowing this makes me sad ( annoyed ) that huge numbers of "tuners " think that because the intake on a 250cc MX engine was built to fit into the same space ( reed block to shock spring )
that having the same intake exactly as a 125 ( carb and manifold ) is somehow " OK " , even though the engine peaks over 2000 rpm lower.

Pipe superposition tuning is highly effective , and can be used to dramatically change the character of a race engine.
For high speed road racing type use , then having the effect start just under peak power , then keep working well into the overev , gives the best result.
But for wider range MX use , or in cases where the gearbox ratios have bigger drops ,then having the effect start below peak torque and continue up to peak power is the most usefull.
This can be made even more efficient by using the fact that Ex timing duration around 190 * gives the greatest superposition amplitude / bandwidth.
That is only possible where it is not absolutely necessary to have huge Blowdown STA to support really big bmep numbers.

[teriks]

Ok, we have talked about this before, RK tech heads.
With the crinkle cut combustion chamber. Kels the RK designer says the design is patented. I ask him repeatedly to explain how it works, no problem with giving away secrets as, like he says, its patented. Can not get an answer. Intetesting that customers are more than happy to shell out dosh not knowing (or careing to know) how it actually helps combustion. It is an old idea so I do wonder about the patent. Those that use it swear by it, is it just because they spent a lot of dosh on it or is it because of its pretty anodised surface?
Why are people so keen to spend money on somthing thats workings appear unexplainable? And if you have a peice of technology that works but you dont know why, where to from there? Its as good as useless.
https://youtu.be/MIWaJe2tYWo

That looks very much like its been turned in a lousy setup causing a huge amout of chatter..
It had different squish and increased compression though, so would for sure run different than the original.
I can not see how the effectively terrible surface quality could help in any way though.

[Muciek]

There was a video of milling similar or same thing, it looked like it was programmed to do it as fast as possible ... https://www.youtube.com/watch?v=7Me6...ature=emb_logo

[andreas]

Very interesting Wobbly

[Flettner]

There was a video of milling similar or same thing, it looked like it was programmed to do it as fast as possible ... https://www.youtube.com/watch?v=7Me6...ature=emb_logo

Making that surface is easy enough with a CNC mill, but why would you?
My only thought is, I need to get into this market because you could produce anything, paint it red, talk some bullshit and sell heaps of them.
I just can not understand how people will buy somthing like this but not know or care how it works or is that just me, do I have the problem? ��.