ESE's works engine tuner

[Flettner]

Personaly I'll go back to the bucket foundry, probably where I should be I guess, there is a lot of pattern and foundry stuff comming up anyway.
Pity about the weather.

[WilDun]

Yes Folke,
I agree with Frits and can't see why you are in the bad books?? - I don't think there were any laws - it was just me talking about the other threads which were petering out and I have been trying to keep them going for a while now - nothing more than that - no laws or even any restrictions involved! - Kiwi biker is sort of self moderated with only the occasional input by moderators! - I'm not a moderator or anything else but just like to keep things going!
We have been enjoying your contributions so don't go away! This thread has done everything 'two stroke' for yonks, it has survived many ups and downs and will no doubt do so again! - At the moment this is THE two stroke thread so we're all here - the other two threads have ground to a halt - but who knows what will happen after the "virus" has settled down - just keep going! - don't need to be sensitive - look at me, I have managed to talk all sorts of crap, for years - (Frits, Flettner and Ken etc. think so) yet I still have the gall to stay here! ..... and you were doing so well - I thought!

[WilDun]

Personaly I'll go back to the bucket foundry, probably where I should be I guess, there is a lot of pattern and foundry stuff comming up anyway.
Pity about the weather.

Who would have thought it! ..... but the future of the two stroke may be huddling under that tarp - can't wait for the unveiling!

[TZ350]

.
It is all Ok by me. I only get to play with 2T Bucket stuff because that is what we have.

But others are playing with other 2T stuff because that is what they have.

In the end its the playing with 2T stuff and showing it to all of us that I think is interesting ..... .

And between us, by some miracle we may even resurrect 2T's.

[WilDun]

Yep, good to hear that - Oldies need to survive the virus to resurrect the Two Stroke! - otherwise it will be totally forgotten! (not that I think you're old Rob!).

[TZ350]

.
Well, with all this talk about turbo 2T's the other day, I got over exited and brought a small RHB31 turbo.

Then I discovered on Wikipedia talk about compound turbo engines where the exhaust turbine is directly connected to the crankshaft instead of a compressor impeller.

"" (From Wiki) A turbo-compound engine is a reciprocating engine that employs a turbine to recover energy from the exhaust gases. Instead of using that energy to drive a turbocharger as found in many high-power aircraft engines, the energy is instead sent to the output shaft to increase the total power delivered by the engine. The turbine is usually mechanically connected to the crankshaft, ""

Now that has got me thinking. I have a spare turbo turbine. And with a one way clutch and reduction I could attach it to a 2T engine. It could be geared onto the clutches big primary gear. I wonder what our F4 race rules say about it. Not much by the looks.
Hmmmmm a grey area I might be able to exploit .......

[TZ350]

.
All this has re ignited my interest in a turbo charged Crecy two stroke sleeve valve engine for Bucket racing.

https://ww2aircraft.net/forum/thread...e-crecy.50534/

[Flettner]

here is one, open ended sleeve like Crecy
https://youtu.be/bwsu5td6nko
https://youtu.be/6keqpL3rmwk
https://youtu.be/TmXFkbD3s5g

[TZ350]

.
Some more work in progress photos of Flettners Crecy sleeve valve engine.



I am not sure if these two casting pictures are Crecey but they show Flettners foundry handywork.

[ceci]

Hi Folke
Your experiment is of great interest to me, since you published the photos I have not stopped analyzing them and trying to understand the mechanism (for now with more mistake than success).
The last conjecture on how it works and tried to capture it in these drawings:
In drawing 1 we have a cone that corresponds to the back pressure pulse focused towards the exhaust port.
In drawing 2 we have the cone and the exhaust nozzle.
In drawing 3 in this we see the part of the back pressure cone that is added to the exhaust outlet nozzle.

[ken seeber]

UHV 1

For some time I have had the idea that one could feed the cylinder in a supplementary or totally different manner than using the side transfer ports. So, without going thru the piston (Frits April 1st) the only other way is via the head.

No camshafts or any of that 4 stroke stuff. Gotta be passive. However, the old 100 year old sprung loaded poppet valves don’t seem appropriate. So, it is a reed valve. Where to put it or them? Seeing reeds wouldn’t like non flat surfaces, the only logical position would be is the in a flat squish area. Something like this:



More to come

[yatasaki]

Ken, this would be backwards-uniflow scavenging?

[wobbly]

Anyone seen or plotted the ignition curve for a late model KTM125.

[ceci]

UHV 1

For some time I have had the idea that one could feed the cylinder in a supplementary or totally different manner than using the side transfer ports. So, without going thru the piston (Frits April 1st) the only other way is via the head.

No camshafts or any of that 4 stroke stuff. Gotta be passive. However, the old 100 year old sprung loaded poppet valves don’t seem appropriate. So, it is a reed valve. Where to put it or them? Seeing reeds wouldn’t like non flat surfaces, the only logical position would be is the in a flat squish area. Something like this:



More to come

Hi Ken
Let me remind you that there are always two limitations in any project: 1º those of the prototype's architecture or geometry. 2º the appropriate materials.
In the project you are showing I believe that the limitations are of the 2nd, because what material supports temperatures and also maintains elasticity (I tried to look for it since, as you can see, I also thought this solution).
His approach is excellent

[Flettner]

I guess pulse jets bathe their reeds directly against the fire.