ESE's works engine tuner

[TZ350]

page 1760 .....

[chrisc]

Thanks or the flowers Chris. You are right, the duct was machined and the sleeve was pressed in. The cylinder isn't mine, it belongs to my friend Jan Schäffer (the German giant who wins 50 cc races). He is quite open about his engines and chassis, but he publishes most of his work on a closed forum, so I do not feel at liberty to show much of it here. But you may find some info on his company website https://langtuning.de/Shop2/Startseite-1 and on http://www.simson-rennteam.de

Thanks Frits, appreciate it. I remember his cool racer you showed us! He might be able to help me source a decent crank for this SX50 so I'll send him an email anyway, because I can only find the million dollar VHM option

[philou]

the clearance between the piston and the cylinder must be decreased with the avgas compared to the unleaded

Can you explain ?

[Frits Overmars]

... decided to lower compression from 13.8 to 12.5 and results feels immediately, is like 10 hp added.

Thanks again Katinas. When are you going to lower the compression ratio to 8 or 9 ? (I'm only partly joking ).

[peewee]

The B transfer inner duct radius is very square and unlike the teacup shape which has been recommended. The A transfer duct inner radius is comparatively much better although has a flat in the middle of the 2 radius.

the flat your talking about seems common with ktm. the 250 and 300 is the same way on both A and B. you can make your own teacup with epoxy but then youll need to grind the outer wall to match and that may require some welding on the exterior depending how large the inner wall radius is

[peewee]

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.

have you got this engine running good yet ?

[adegnes]

have you got this engine running good yet ?

It's been sitting untouched since modifying the carb, but I started working on it again a few days ago.
Confirmed that jetting was far too rich, It would start, but die within seconds, or by touching the throttle. I've returned to a stock needle jet but haven't had an opportunity to test it again yet. Let's hope the 1.5mm pilot is enough to quench its thirst at low throttle openings.
There's a video coming soon on my channel, stay tuned!

[peewee]

It's been sitting untouched since modifying the carb, but I started working on it again a few days ago.
Confirmed that jetting was far too rich, It would start, but die within seconds, or by touching the throttle. I've returned to a stock needle jet but haven't had an opportunity to test it again yet. Let's hope the 1.5mm pilot is enough to quench its thirst at low throttle openings.
There's a video coming soon on my channel, stay tuned!

I saw the other video which appeared the carb wasn't providing enough fuel. wasn't sure if you had it sorted out yet. it looked like you were using a gravity flow from the tank. will the flow through the float valve be enough for full throttle ? the main thing im wondering is if com ratio needs to be lowered as im at 16:1 for straight methanol and don't know if this is already to high for even small percent nitro. I think it was bells book that said even methanol may work better with lower com ratio which is opposite of what a lot of people say so it isn't making sense to me.

have you seen any corrosion damage to rod or main bearings ? have the crank seals melted away or their fine ? I didn't see your engine exploded so the pickled cases must be a wives tale ?

[Norman]

Hi,

Sorry for so long time without info, but just want to test as more as I can before say something.

Now just current results without details :

Done about 500 km.

Testing three different types of cylinders ( two from Honda NS, and last from Honda Cr 125 86") and three different types of pistons.

Very interesting, so different type, but result was the same. The power feels like 20-25 Hp, no more. Power band 8600-11500 rpm. ( harmonizes with pipe dimensions). It revs, but feels that engine want to overcome something.

First piston heavily seized in second gear at 100 km/h, but luckily left hand remember old habit ( absolutely my fault, cold engine, so small clearance ( 0.3 mm- top piston ) for 2618 aluminum, oil fuel ratio 1 to 200) So with Ns cylinder all ended just starting the tests.

Made new piston 58 mm.- 1 mm bigger than NS ( 133 cc) and rygerised Honda Cr 125 1986 cylinder ( very different from NS - Good thing is bigger reed cage with six petals, wrong things two exhaust windows and iron sleeve) Again the power no more than 20-25 Hp

Then made plate to close central intake window, just left side intakes to transfers. Power up to around 30 hp but no more and very clean carburation at top.

Then exhaust stinger increased from 23 to 29 mm. and again power little bit up, but with more retarded ignition. Take of intake window plate, power drops insignificantly.

Then decided to lower compression from 13.8 to 12.5 and results feels immediately, is like 10 hp added. Added 23 mm sleeve to 29 mm stinger but no big difference just feels more tension . Of course this is only my sensations, but in comparison with other motorcycles now I think power is 35-40 Hp. I feel sorry that not lowering compression on the first NS cylinder (compression was 14) before seize, and just left only consideration.

From mechanical side no issues (most surprises for me after seize ), steel tube and small aluminum cylinder good pair ( just small scratches from some sand particles or something) and the PTFE seal amazingly in good shape.

There is so much other things left to try its very complex and so much different combination exists. Now I think that Ryger type engine with clever people can achieve 60-65 Hp


I'll post pictures later and more detail info.

Very interesting and good work! Looking forward to your pictures.
I have missed out the Ryger patent application from 08-02-17 with the number EP3128149 (A1). You can find it on google patents and some info at "https://register.epo.org/application?number=EP15179826&lng=en&tab=doclist".

It is an application, and not yet a granted patent, but I guess it is just a matter of time.
But, as always, the concept needs to meet the technical requirements and we have not yet received the full information on this. I am looking forward to the final confirmation of, not at least, the durability aspects.

[adegnes]

I saw the other video which appeared the carb wasn't providing enough fuel. wasn't sure if you had it sorted out yet. it looked like you were using a gravity flow from the tank. will the flow through the float valve be enough for full throttle ? the main thing im wondering is if com ratio needs to be lowered as im at 16:1 for straight methanol and don't know if this is already to high for even small percent nitro. I think it was bells book that said even methanol may work better with lower com ratio which is opposite of what a lot of people say so it isn't making sense to me.

have you seen any corrosion damage to rod or main bearings ? have the crank seals melted away or their fine ? I didn't see your engine exploded so the pickled cases must be a wives tale ?

It's sorted I think, I've made every fuel passage alot larger and started slowly working my way down from there.
I can't remember the exact number, but I believe I have sufficient flow through the float valve, it's drilled out to the absolute maximum allowable by the needle.

I'm at 14.5:1 and really have no clue if that works for the fuel. It's (by common belief at least) far too low for straight methanol, but with the nitro it's maybe not that far off.
We'll find out!

I have not noticed any damage, but it hasn't had much exposure to the nasty stuff yet.

No explosions, I don't think it's as bad as people want to believe. The nitric acid exhaust is tho.

[wobbly]

Regarding the bore clearance when running different egt levels Philou.
There is a finite amount of energy in each combustion cycle, and the combination of static + dynamic compression + the ignition timing affects
the distribution of that energy.
Some goes into the water, some into the combustion process that heats the gas that then expands and pushes down the piston.

With high compression and or lots of advance - or both, a larger amount of this heat energy is transferred to the water , or is consumed very early in the combustion cycle thus when the Exhaust opens
there is less temp ( and by inference - energy ) dumped into the Ex port,then to the pipe.
With low com,or retarded ignition, there is still alot of energy available late in the combustion process as the piston cycles downward, that then can be used in the pipe.

The amount of heat energy transferred into the piston does not vary a huge amount, except when " normal " combustion is replaced by say ,detonation.
When this happens a vast amount of the available energy is used to create free radicals,that then initiate " knock " and we see the egt drop instantly when this occurs.
This energy distribution within a normal cycle is a completely different scenario to simply " running lean ".
Then of course the piston gets overheated,and it seizes in protest.
So in answer to the question, bore clearance isnt an issue even at 700*C as long as we have a "normal combustion " process occurring.

[Flettner]

So Wobbly, and all, how do we reliably and consistently promote detonation in the squish area? HCCI.
dont cool the squish area and have a taper that tightens up, leaving a volume around the annuls near the cylinder wall?
Have a squish area on the head that can be heated (controlled) to accurately set off combustion?
Feed hydrogen into this annuls to promote ignition, methane perhaps?
I'm assuming a 'magic' piston that absorbs nothing, reflects everything and won't burn.

[Jannem]

Would there be any power to be gained from improved piston cooling in the exhaust side of a well developed modern 2-stroke? Directly or indirectly. I 'd suppose longevity at least if not hp.

Edit: Does the ex.port side of the piston run hotter than cooled ex.port adding heat to the intake charge returning from ex.port when on the pipe?

[Frits Overmars]

I have missed out the Ryger patent application from 08-02-17 with the number EP3128149 (A1). You can find it on google patents and some info at "https://register.epo.org/application?number=EP15179826&lng=en&tab=doclist". It is an application, and not yet a granted patent, but I guess it is just a matter of time. But, as always, the concept needs to meet the technical requirements and we have not yet received the full information on this. I am looking forward to the final confirmation of, not at least, the durability aspects.

First, I'd like to make it clear once more that I am no longer involved in any way with the Ryger organisation, and haven't been since ultimo 2015 (but I am still bound by a non-disclosure agreement).
Here is the latest Ryger patent: It describes the engine but it does not give a clue about where the power comes from.

[katinas]

Thanks again Katinas. When are you going to lower the compression ratio to 8 or 9 ? (I'm only partly joking ).

Just remember your words about Germany 50 cc champion with 9 ratio. I will try
Sometimes its easy made wrong consideration when experimenting with high compression engines, because things that filling cylinder better ended with less power and opposite. Picture of seized first NS piston. Clearance top 0.3 mm, skirt 0.15 mm too small for 2618 alloy. Second piston made without clearance , then heated, turned, and when tool was 15mm from top, directed air stream to skirt. When piston cool down clearance on ring land 0.60 mm. skirt 0.25 mm. Its just experimenting, but very interesting to see the shape. On engine, up to now, works fine.

Thanks