ESE's works engine tuner

[trevor amos]

Birthday congratulations and best wishes Frits, one more year of learning behind you!

[WilDun]

You're probably right about that, Will. Squish will no longer be required for flame spreading, though it may still contribute to homogenizing the fuel/air mixture.

In theory that would be a yes. But it would yield an unfavourable volume/wall surface ratio, meaning big heat losses.
Anyway, the head shape also plays a role during scavenging so I'd stick with the present shape for now.

What I was trying to say is that with limited blowdown time.area not all spent charge has left the cylinder when scavenging starts, so fresh and spent charge mix, and the fresh charge gets heated. That won't impede it from washing through though.

I'd say your dead on track Will. And it may seem like I've got all the answers, but HCCI is a new and partly virgin territory for all of us
(which makes me wonder: can there be such an animal as a partly virgin?).

Just dreaming up a scheme for a layout where the homogenising of the fresh charge is taken care of just as, or just before it enters the cylinder and with no actual compact combustion area needing to be scavenged as well, this would be a bonus.
Hopefully the layout I'm thinking of using would pretty well eliminate mixing of fresh and spent charges, but as you are talking a conventional two stroke layout (quite different to mine), we could end up talking at cross purposes here!
Most probably it will remain a dream.

As for a partial Virgin ......... let's say that (in engine terms) if compression strokes occur, that might be an impossibility, but many people are led to believe that an exhaust stroke can take place without the need for a compression stroke to occur! (so a partial virgin?) - however, I have no desire to broach such a controversial subject!

Oh, and happy birthday.

[Frits Overmars]

Thank you folks

... as you are talking a conventional two stroke layout (quite different to mine), we could end up talking at cross purposes here! Most probably it will remain a dream.

I know the feeling Will. But you can do something about it: let us into your dream, and Flettner will take care of realization .

[ken seeber]

Frits, you young blokes are always having birthdays, but please enjoy another one with many more to come. And, as always, please continue your great contributions to kiwibiker and other forums.

[WilDun]

Thank you folks
I know the feeling Will. But you can do something about it: let us into your dream, and Flettner will take care of realization .

Yes, but a dream is only a dream and reality is something else and in order preserve my dignity I'll give it a go first to see if it actually works (even if it just runs in a mediocre way) then some of you guys can give it the once over and estimate it's worth!
However, if you don't hear about it again, don't hold your breath till it reappears, because either it didn't work or I've kicked the bucket!

Impressed with the efforts of Flettner, Ken and the latest one from SwePatrick.

So I'll go and at least try - sorry TZ - didn't really want to clog up your thread with bullshit!

[ief]

Another question pops up...

the 75 % resonance freq. of the membrane...

Remembered Wob saying the bigger the crankcase the thinner the reeds have to be...

So.... that 75 % ain't a rule but is in direct relation to crankcase volume (ratio)?

How would the real rule look than?

[wobbly]

In a sim the power continues to rise as the reeds are made thinner ( from being too thick ) , due to the petals resonant frequency coinciding with the forcing frequency of the intake tract.
BUT,as you drop the resonant rpm you are also effectively increasing the lift and petal open duration.
This very quickly runs into trouble at peak power and beyond,as the instant the petals hit a stop, or are not stiff enough to exhibit controlled drop back
onto the seat,they go completely spastic.
Easily seen in the sim as wildly varying tip lift ( and a big power drop ) with each sim iteration in turn.
One trace run will show a good result, the next trace the lift is all over the place.
Add a couple of 1/10 of a mm to the petal thickness and the resonant rpm will rise a few hundred, and the effect goes away in the top end.
This is exactly what the sim is for - to point you in the right direction with what to be trying on the dyno.
IMHO there are way to many variables involved to even begin to formulate a workable rule of thumb for reeds, as in reality, suck it and see is the only way.

I have just completed a huge number of sims for the KZ10 with all manner of different reed blocks, the only way to get a meaningful result was to set the petal thickness for every block
such that the 1st harmonic rpm was 10,000 with engines natural peak power at 13200 ( as in reality ).
This then shows the real effect of the reed block geometry on the power - not the differences due to the varying petal thickness - as this is easily changed during the subsequent dyno confirmation process.

[jonny quest]

Will it SIM a reed block with no reeds?

I know Frits or Jan have been talking about a reed block that basically opens up to a 360 intake as RPMS increase

[wobbly]

Frits friend Roland Holzer at Modena has tested this on a KZ2 engine with positive results, but no way would I believe it would be accepted by the CIK.
An adjustable PV mechanism isnt allowed so why would a moving spring loaded " thing " that allows the reed block faces to move apart be any different.
If you want to sim this specifically, ask Neels.

[Dutch Fisher]

Frits friend Roland Holzer at Modena has tested this on a KZ2 engine with positive results,

I must have missed the comparison dyno charts

Which page ?

[Frits Overmars]

Frits friend Roland Holzner at Modena has tested this on a KZ2 engine with positive results

I must have missed the comparison dyno charts.

No worries Dutch, you missed nothing because there was nothing here to miss. I was never at liberty to post Roland's results; I only whispered in Wobbly's ear.

[TZ350]

Dr Evil does it, a F4 class legal water cooled 110cc engine.

......

Finally, after several weeks of detailed finishing work the Frankenstein Mr Bigglesworth engine is ready.

Possibly the worlds first ever 1979 learner/commuter Suzuki GP100 engine fitted with EFI, digital ignition, a dry sump six speed gear box conversion, an oversize KE 175 rotary valve, a servo power valve and water cooling.



All that remains is to fit it into the frame. Being 12mm wider than the original five speed air cooled unit and needing a radiator, pump and associated plumbing, it is not a straight swap but hopefully I will get it all done this week.

[lodgernz]

Sterling work Rob, can't wait to see (and hear) it going. Videos please...

[mr bucketracer]

good stuff rob , other real bucket build!

[FastFred]

Yes, a very traditional old school sort of Bucket build, a Frankenstein hodgepodge of bits all sown together, great work.