ESE's works engine tuner

[TZ350]

Ha ... time for page 1450 links list ....

Pumper carbs are a lot more complex than you would think.

The 3 main tuning variables are pop off pressure, diaphragm lever height, and needle positions. What are these variables at the moment - if you dont know, and or cant change all these,then you can't tune one.

If you can tune the top end OK with the H needle, but need the L out too far to get response off idle then you need to drop the pop off a couple of psi.

This will then allow much less L needle but still be rich enough to accelerate off idle.
But then the H needle will need to go in some to lean off the top end.

Thanks a bunch Wobbly. Your reply guided me into tuning popoff pressure, I have ordered a lot of different springs, i´m waiting for those.

A pair of old nail clippers is great for snipping a bit of the spring.

Attachment 319149

I got my hands on 1985 or 86 KX250 cylinder and main ehx (bridged) port floor is raised 4mm (stroke is 65mm and floor is on 61) transfers starts on 65, but it looks like they dropped that idea later. Wobbly I have bought servo from R1 but I don't have original connector could You tell me what is the pinout?

Attachment 319176

Yep, the top 3 are the servo position pins.
Lh = sensor earth, mid = sevo position out, Rh= +5V

Lower pair are the servo motor power from ecu.
Run a 3 pin and a 2 pin plug for each, back to the ecu so you can program it easily.

[wobbly]

Can anyone explain how we get mixture transfer from the high compression volume under the piston, into the lower duct entrances
when the seal spigot shown completely blocks them off.

[tjbw]

Can anyone explain how we get mixture transfer from the high compression volume under the piston, into the lower duct entrances
when the seal spigot shown completely blocks them off.

The section and development drawings are not to scale!

[Flettner]

Can anyone explain how we get mixture transfer from the high compression volume under the piston, into the lower duct entrances
when the seal spigot shown completely blocks them off.

Yes Wobbly, I think we all agree these are piss poor drawings, centainly NOT accurate. So I think we still just have to make it up ourselves, design somthing around Kermits description and you will have a rocket (pules jet anyway) I think.
I have a cylinder pattern sitting on the bench along these lines but FOS style, I've been unsure whether to go ahead with it or not, now I'm keen to finish it. It uses a high pressure under piston pump and augmentation.
Ken S has made and run an FOS cylinder 40 years ago, it worked then, on a standard crank case.

[Norman]

Yes Wobbly, I think we all agree these are piss poor drawings, centainly NOT accurate. So I think we still just have to make it up ourselves, design somthing around Kermits description and you will have a rocket (pules jet anyway) I think.
I have a cylinder pattern sitting on the bench along these lines but FOS style, I've been unsure whether to go ahead with it or not, now I'm keen to finish it. It uses a high pressure under piston pump and augmentation.
Ken S has made and run an FOS cylinder 40 years ago, it worked then, on a standard crank case.

It is just a guess, but I think that this drawing is not cut through the center of the cylinder and that makes things look even worse...The other dimensioned drawings suggests a 3 mm gap around the circumference, maybe this is enough considering that the piston increases the pressure on its way down?

[lodgernz]

It is just a guess, but I think that this drawing is not cut through the center of the cylinder and that makes things look even worse...The other dimensioned drawings suggests a 3 mm gap around the circumference, maybe this is enough considering that the piston increases the pressure on its way down?

Yes, other drawings show an annular gap at that point, as there has to be to accommodate the exhaust cover part of the upper piston.

[WilDun]

Flettner,
Revisiting the 'Crecy' style engine, did you come to any conclusions on the ringless sealing at the top of the recriprocating cylinder liner?

[Flettner]

Flettner,
Revisiting the 'Crecy' style engine, did you come to any conclusions on the ringless sealing at the top of the recriprocating cylinder liner?

It hasn't been tested under real load but the engine is in bits getting the cases machined to accept the YZ gearbox. On inspection the sleeve looks nice, no hot spots and just a little shinny around the top of the sleeve that says it's expanded out to the alloy cylinder to dump it's heat. Need some time to make up an exhaust system, probably have a go at hydraulicly making it? I was thinking about a system (linkage) where by the sleeve travel could be shortened at low speed, to throttle the transfers like Ken and I are doing with the FOS cylinders.

[ken seeber]

Ken S has made and run an FOS cylinder 40 years ago, it worked then, on a standard crank case.

Crap Neil, it was only 35 years ago.
Well, let the good wife drag you away for a few days and come back.......jeez you guys have been busy. Hard to work out where to post at present, ESE or Foundry. All good stuff though. Haven't seen any definitive Ryger solutions though.
Anyways the sliding cylinder is coming along (slowly of course), bit of cleaning up required and then off for a splash of Nikasil. When back, break out the dividing head for the O ring grooves on the cylinder around the 3* exh ports and the 3*exh ports in the water jacket. In twixt times, it's making up al large adapter plate for the reed fed crankcases.

[WilDun]

Yes Ken, the two forums are a little intertwined just now but still relevant on both (so long as you can post your casting stuff on the foundry thread as well Neil). - there is a lot of head scratching going on with the Ryger at the moment, so why not!
I feel that Ken's engine and all Neil's engines could end up morphing into one very good engine - a 'bitza' - just like the two threads!

[ken seeber]

Can anyone explain how we get mixture transfer from the high compression volume under the piston, into the lower duct entrances
when the seal spigot shown completely blocks them off.

Wob, can't answer this one, but I can say when one has a close look at the pic, it is clear (by the coarse jagged lines) that the valve plate, non piston ring rings, the additional transfer ports and some areas of the read valve cavity have been done in Paint on top of the original VM cylinder homologation drawing. So, really anything can be anywhere with this level of drawing change....not much better than a hand scribble.

However, it is clear that no additional reeds are used in the valve plate, so there must be some neat gas dynamics going on..

Now we have been questioning the auxiliary exh ports and can see the actual cylinder ports have been removed, but not the re-entrant side ports in the main passage. Is it possible that these are connected to the 2 front low level transfer ports, not the 4 that feed the A and B passages? So, on exhaust opening, there is a very high exit velocity on the exh passage. So with a bit of Bernoulli, is it possible that there is a depression created in these passages and allow a huge quantity of mixture to be drawn out thru the under piston volume and also the reed (24/7) and pass out the exhaust? So rather than a little bit of mixture being drawn out from the normal 5 transfer ports when on the pipe, we are talking about shitloads of mixture. This then ultimately gets pushed back into the cylinder by the pipe, as per normal. So, possibly a much greater trapped volume purity in the cylinder giving:
1. More power
2. The cooler pipe
3. Worse fuel consumption and emissions due to the much greater potential of unburnt mixture loss.

Dreaming?

[Grumph]

Ken, the port diagram in the homologation papers shows a wide port entry below the exhaust. This would be timed by the piston skirt which extends full length in this area. It may as you suggest lead to the side entries in the ex duct. It could very possibly give a short suction pulse to the under piston volume.

[jfn2]

wobbly;
If you zoom in on the picture that shows the bottom of the cylinder, (the picture that has the cylinder , the head, a case half and the top of the cases), you'll see there are windows cut into the bottom inside of the cylinder at the normal transfer cut out area. Knowing that the cylinder has cut outs around the inside bottom, there has to be a channel around the inside bottom of the cylinder. When the piston descends it forces the mixture into these port windows and around the channel at the bottom into the transfer ports.

[Flettner]

Downloading this thesis may take hours (you can finally take that bath) but if you really want to know about hypocycloid engines, it is worth the wait!

Perhaps not the results I might have hoped for.
But hey what do they know?

[bjorn.clauw.1]

Perhaps not the results I might have hoped for.
But hey what do they know?

Sure whenever a gears is introduced there is some power loss because off the added friction. Butt they didn't adress the changed volume off their crankcase, also the exhaust pipe used is far from optimal. And because you will be sealing off the crankcase you can make a proper exhaust for your design . Think it can make a lot more power this way. The bearings between the small crank and big crank got me worried a bit. Since they are counter rotating the bearings will 'see' double rpm's.