ESE's works engine tuner

[F5 Dave]

I can't imagine the Bahamas have got anywhere decent you can fire up the dirtbike & go crazy in scenic bush without getting mowed down, let alone a decent roadrace track.

and no I can't be bothered googling it.

[Grumph]

I can't imagine the Bahamas have got anywhere decent you can fire up the dirtbike & go crazy in scenic bush without getting mowed down, let alone a decent roadrace track.

and no I can't be bothered googling it.

Probably true - though the Nassau speed week is still going i think. back in the day they ran the group 7 Lolas, Mclarens and Chapparals there - and partied hard.
At the moment I think they're concentrating on laying out Americas Cup courses...and revising the hotel charges accordingly.

[wobbly]

In fact it probably does both Frits.
As the LH piston is approaching BDC the escaping pulse is a positive pressure ratio
that changes then to negative as it moves down the diffuser.
Thus the RH cylinder sees this negative ratio as an addition to that created by the piston approaching TDC ( and uncovering the bottom of the Ex port ).
Then as the LH cylinder moves away from BDC, the positive ratio from the rear cone starts to reverse the gases escaping from both
cylinders, thus helping to overfill both.
The RH cylinders piston cuts off this compression phase much earlyer than the Ex port closes on the other cylinder,but some positive effect does seem to occur.
My logic on the effect , as good as I can explain it.

[jasonu]

I can't imagine the Bahamas have got anywhere decent you can fire up the dirtbike & go crazy in scenic bush without getting mowed down, let alone a decent roadrace track.

and no I can't be bothered googling it.

Probably true - though the Nassau speed week is still going i think. back in the day they ran the group 7 Lolas, Mclarens and Chapparals there - and partied hard.
At the moment I think they're concentrating on laying out Americas Cup courses...and revising the hotel charges accordingly.

Been there recently, it's a shit hole don't waste your money and time on that dump.

[JanBros]

You made my day, Jan; you fell for it 38 years after the fact. That magazine was MOTO 73, of which I was the technical editor (and test rider, and photographer, and translator, and I also made the coffee occasionally, but somehow we managed to become the biggest motorcycle magazine in the Netherlands and Belgium).
The TVPS (Top Valve Piston System) was our 1977 April Fool's joke!

I know Frits Had to move some stuff from my parents attic and I forgot there were boxes with old magazines from '76 - '90, and so I was going through them. I just read it (so no link with the first of april) but could only think "it'll never work", which was confirmed when I read the next mag.

just thought it was funny. Wanted to see the reaction of people here and wanted to send you a pm not to tell what it is, but aparently I'm not a "involved enough" on the forum to be able to send pm's.

[husaberg]

Go Karb Fuel Injection Carburetor
I seen this on Ebay.
1-13/16" center to center on mount holes. 3/4" across throat
http://www.ebay.com/itm/Vintage-NOS-...-/251908761617
Never seen or heard of them guessing it is a single circuit carb like a Wal Philips injector.
Anyone just out of curiosity know anything about them picking 60's Tech.

[Frits Overmars]

Frits could there be advantages in skip stroking ie skiping a fuel and or ignition cycle if it was done in a controlled manner for total cylinder filling.

I intended to read all the pages you posted before giving an answer, but I stopped reading after "Let it be assumed that the conditions of heat transfer, flow resistance and flow dynamics are not significantly influenced by skip cycling". Yeah, right. That may be true in engines that solely depend on a scavenging pump. But ours don't; they depend on exhaust resonance. And when you skip just one combustion cycle, the dynamics collapse and so does the next scavenging event. And the next. And the next, until eventually there is enough mixture in the cylinder for successful ignition again.

I've long since realised that I've got no idea so I'm happy to just blurt it out. You never know something may come of all this.

That's the way I operate too, Neil. Who wants to be rich? I'm happy each time one of my wild ideas actually works.
The Ryger situation is an exception because there is more involved than just my own ideas.

I know Frits. Had to move some stuff from my parents attic and I forgot there were boxes with old magazines from '76 - '90, and so I was going through them. I just read it (so no link with the first of april) but could only think "it'll never work", which was confirmed when I read the next mag.
just thought it was funny. Wanted to see the reaction of people here and wanted to send you a pm not to tell what it is, but aparently I'm not a "involved enough" on the forum to be able to send pm's.

Too bad I wasn't aware of your intentions Jan; I would have been happy to play ball. But don't feel bad about the bouncing PM. I blocked PMs on all public forums; forums absorb far too much of my time as it is, every day.

[F5 Dave]

Can we just say again that we appreciate the time you do contribute here.

[Flettner]

Can we just say again that we appreciate the time you do contribute here.

Without dought

[adegnes]

Without dought

+1


......................

[Flettner]

What if, lets assume that this 30,000 rpm thing is just a ruse. At that sort of rpm friction would be so high it would be lucky to have enough combustion pressure to overcome this situation and even turn itself. So forget 30,000 rpm.
But what if the crank arrangment was such that it turned two turns per every stroke ( why you would want this I don't know? ) perhaps some sort of crank angle advantage thing. A bit like a rotary where by the time the rotor has turned once the output shaft has turned three times.
Like you say Frits I've long since realised even if I did have a good idea ( and I'm just about clean out of those, as you can see I'm scraping the bottom of the barrel now ) you are never going to make any money out of it. No one want's twostroke tec any more, accept a few bucket racers.
And the cost to patent!
And the lack of protection anyway.

[breezy]

What if, lets assume that this 30,000 rpm thing is just a ruse. At that sort of rpm friction would be so high it would be lucky to have enough combustion pressure to overcome this situation and even turn itself. So forget 30,000 rpm.
But what if the crank arrangment was such that it turned two turns per every stroke ( why you would want this I don't know? ) perhaps some sort of crank angle advantage thing. A bit like a rotary where by the time the rotor has turned once the output shaft has turned three times.
Like you say Frits I've long since realised even if I did have a good idea ( and I'm just about clean out of those, as you can see I'm scraping the bottom of the barrel now ) you are never going to make any money out of it. No one want's twostroke tec any more, accept a few bucket racers.
And the cost to patent!
And the lack of protection anyway.

if i was the big bear, struggling with my economy, id be pretty cheesed off if someone came up with an idea for an engine that no longer needed as much oil as previously..... also anyone who felt that their empire as going to be brought down by a powerful two stroke engine invention , i may feel the need to protect myself and buy out such an invention to lose it.Personally, i would also be unlikley to accept a large vodka, while in london on a day out, from a smiling stranger, unless of course i had an antidote for polonium poisoning .........

[Flettner]

I intended to read all the pages you posted before giving an answer, but I stopped reading after "Let it be assumed that the conditions of heat transfer, flow resistance and flow dynamics are not significantly influenced by skip cycling". Yeah, right. That may be true in engines that solely depend on a scavenging pump. But ours don't; they depend on exhaust resonance. And when you skip just one combustion cycle, the dynamics collapse and so does the next scavenging event. And the next. And the next, until eventually there is enough mixture in the cylinder for successful ignition again.

That's the way I operate too, Neil. Who wants to be rich? I'm happy each time one of my wild ideas actually works.
The Ryger situation is an exception because there is more involved than just my own ideas.

Skipping a cycle at low rpm ( off the pipe ) this would work, making the engine more like a fourstroke for " hookup " , off road applications.
But as you get into the resonance you would need to stop this nonsence. If fact the bottom part of throttle could be controlled by fuel only.Assuming port injection.

So from the above we can imagine that there are in fact ideas of yours in this Ryger engine? 24 / reed? No need to say, we are just imagining.

[Flettner]

if i was the big bear, struggling with my economy, id be pretty cheesed off if someone came up with an idea for an engine that no longer needed as much oil as previously..... also anyone who felt that their empire as going to be brought down by a powerful two stroke engine invention , i may feel the need to protect myself and buy out such an invention to lose it.Personally, i would also be unlikley to accept a large vodka, while in london on a day out, from a smiling stranger, unless of course i had an antidote for polonium poisoning .........

The old conspiracy theory aye

[husaberg]

if i was the big bear, struggling with my economy, id be pretty cheesed off if someone came up with an idea for an engine that no longer needed as much oil as previously..... also anyone who felt that their empire as going to be brought down by a powerful two stroke engine invention , i may feel the need to protect myself and buy out such an invention to lose it.Personally, i would also be unlikley to accept a large vodka, while in london on a day out, from a smiling stranger, unless of course i had an antidote for polonium poisoning .........

The poison to use on a two stroke genius would be Ricin as it is fittingly made from castor beans....................
Sadly a Professor actually did that here.

I intended to read all the pages you posted before giving an answer, but I stopped reading after "Let it be assumed that the conditions of heat transfer, flow resistance and flow dynamics are not significantly influenced by skip cycling". Yeah, right. That may be true in engines that solely depend on a scavenging pump. But ours don't; they depend on exhaust resonance. And when you skip just one combustion cycle, the dynamics collapse and so does the next scavenging event. And the next. And the next, until eventually there is enough mixture in the cylinder for successful ignition again. .

The experiments were run only up to 3500rpm, but I think it is worth a read on, the engine was curiously a 125 disk valve, pretty uncommon back then. 1956 a disk valve two stroke 56x50mm I can't think what it was?
As Neil said a 4 stroke button does have applications in tough going.
That next sentence after the one you quoted was. Let it be assumed that the conditions of heat transfer, flow resistance and flow dynamics are not significantly influenced by skip cycling- an assumption which appears to be justified by the experimental results reported herein. I and many others certainly appreciate your time to steer us in the right directions.
Success in life is measured in constitution collaboration and contribution rather than cash assets.

I remember there was another scavenging design Villiers used in the 1930's I am pretty sure it had a transfer between the exhausts had a flat crown.I can't find any decent drawings of how it worked Greg might know it was the one with the radial finned head.