ESE's works engine tuner

[Frits Overmars]

The idea of the double pumping was more to allow continuous induction it would alternately breath through the upper and lower in turns .

You're not getting off this easily, Husa. Let's assume your lower chamber breathes from atmosphere. Then the upper chamber won't, because it gets all it can swallow from the lower chamber; no continuous induction from the atmosphere.

In practice the under and over pumping would be pumping no more that the actual capacity of the cylinder wouldn't it? so technically legalish.

With double-pumping each stroke would theoretically inhale one cylinder capacity; that's twice the cylinder capacity per crankshaft revolution; illegal as hell.

If the mixture was compressed, wouldn't it be able to flow faster buying valuable time.

Flowing through the transfer ports, yes. But flowing from one chamber to the other? What good would that do?

Bugger the rules they are made by four stroke people anyway.

These days they own the playing field, so we'll have to get through the gate in order to beat them.

[RAW]

Hmm, I thought I had missed the 30k rpm bit also. Cheers Husa, plenty of those rotors have issues when being reved quite high, 30k is well in excess of quite high, good luck, I'm more than happy to learn.

[husaberg]

You're not getting off this easily, Husa. Let's assume your lower chamber breathes from atmosphere. Then the upper chamber won't, because it gets all it can swallow from the lower chamber; no continuous induction from the atmosphere.

With double-pumping each stroke would theoretically inhale one cylinder capacity; that's twice the cylinder capacity per crankshaft revolution; illegal as hell.

Flowing through the transfer ports, yes. But flowing from one chamber to the other? What good would that do?

Yeah, at the moment they own the playing field, so we'll have to get through the gate in order to beat them.

I might have to badly draw a picture.
The muddled thought I have is it breaths into the lower chamber and the upper one in turn through a bifurcated reed.one half the v to the top one to the bottom
the upper and lower chamber communicate with a flat plated Suzuki like reed allowing flow in the upwards direction only.
when the Richard Maas drawing is at bdc the pumping chamber underneath is fully open. when the piston is at TDC the lower chamber is fully closed. but the upper one is fully onpen the rush of the air into the top pumping chamber should also allow additional air to be drawn into the upper pumping chamber.

But yes it might be very supercharged (a little) but it needs to fill all those transfers as well. my gut says that by the time the volume of a ring of transfers were added up it would be not much above atmospheric pressure.

But yes it also fails KISS. I guess with the Richard Maas drawing, it still allows near continuous flow into the transfer and the Ryger look like it does breath near direct into the transfers.

[Lightbulb]

This is all very interesting what people are coming up with ideas wise.
Lots of stuff to get your head around for sure.
Neil

[JdG]

Something like this Husa?

Shitty drawing (in dutch) I know, but I think you're thinking what I was thinking that you were thinking

[JdG]

I also didn't take the time to rotate the picture 90 deg. clockwise.

Sorry...

[Frits Overmars]

Something like this Husa? Shitty drawing (in dutch) I know, but I think you're thinking what I was thinking that you were thinking

This is double-pumping, this is illegal , and this really works .

[136kg136ps]

That ruins my idea then as well.I had thought there might be a flexible boot or membrane that separated the cylinder from the crankcase and being attached to the connecting rod provided a boosted mixture.Also very common in some types of pumps to use reeds to control flow.But if that is illegal obviously we go back to the drawing/guessing board.

Good luck in the patent process BTW!

[Lef16]

I remember that wob said once about the Aprilia's big tranfer duct divider.He said that flat sharp divider is old school and doesen't fit to modern racing engines.
But apart from the divider,I also have a question about the boost-C port,which is very small in the entry area,and if I remeber correctly it has 1.1:1 entry-exit ratio,A has 1.3 and B has 1.2,am I right?
Why karts use this style of porting instead of Aprilia-style?

[Flettner]

The riddle of the ryger, a free piston engine will oscilate at (30,000?) with no rod or crank. How does the piston not end up in a big heap at one end? Gas compression absorbs the inertia each cycle. In the ryger, if the pumping chamber ( formally called the crank case ) pumped down to a "squish" this would do two things. 1, unload the normal piston deceleration load on the conrod and 2, create the high pumping pressures required to charge a not fully blowen down cylinder but the amount of gas transfered would be limited, perhaps why fuel air does not get out the exhaust. With lots of small transfer ports control over gas positioning in the cylinder would be more accurate.
To make 70hp with a 30mm carb, it would have to be passing air all the time not gulp filling like a normal engine, soooo if we had say four smaller transfer ports either side of the cylinder feeding from the high pressure under piston pump (eight transfers) and we had three more at the rear of the cylinder that are piston ported to fill the high pressure under piston pump (at TDC) but also the same ports when the piston was at BDC feed straight into the cylinder, helping to make up for the lack of volume delivered by the high pressure under piston pump. Air fuel would be drawn in when the piston was on the way up and also when the piston is nearly down. With gas inertia and some funny looking "thing" inside what we thought was the intake reed, that helps retard back flow (not a reed), flow through the carb would be fairly constant I imagine.
I think the exhaust expansion chamber would not have a very steep reverse cone but internal system pressure would have to be fairly well controlled?
Imagine that

[adegnes]

The riddle of the ryger, a free piston engine will occilate at (30,000?) with no rod or crank. How does the piston not end up in a big heap at one end? Gas compression absorbs the inertia each cycle. In the ryger, if the pumping chamber ( formally called the crank case ) pumped down to a "squish" this would do two things. 1, unload the normal piston deceleration load on the conrod and 2, create the high pumping pressures required to charge a not fully blowen down cylinder but the amount of gas transfered would be limited, perhaps why fuel air does not get out the exhaust. With lots of small transfer ports control over gas positioning in the cylinder would be more accurate.
To make 70hp with a 30mm carb, it would have to be passing air all the time not gulp filling like a normal engine, soooo if we had say four smaller transfer ports either side of the cylinder feeding from the high pressure under piston pump (eight transfers) and we had three more at the rear of the cylinder that are piston ported to fill the high pressure under piston pump (at TDC) but also the same ports when the piston was at BDC feed straight into the cylinder, helping to make up for the lack of volume delivered by the high pressure under piston pump. Air fuel would be drawn in when the piston was on the way up and when the piston is nearly down. With gas inertia and some funny looking "thing" inside what we thought was the intake reed, that helps retard back flow (not a reed), flow through the carb would be fairly constant I imagine.
I think the exhaust expansion chamber would not have a very steep reverse cone but internal system pressure would have to be fairly well controled?

Clever indeed.

[wobbly]

There are a few clever enough people ( like Holzer at Modena ) working on kart engine design that I am sure enough R&D has been done to establish
if the basic ideas behind Jans Aprilia scavenging works "better" than the current monkey see monkey do Hondarish arrangement.
Problem is that we are dealing with a very different apple to the GP Aprilia.
It has a power valve and a mile of clever electronics - a KZ2 has neither.
I have replicated the actual port timing layout ( lower but with B,C opening first ) and this makes considerably better power
from peak onwards,but what it gains in overev it looses way more down at 9000.
This is the rpm when exiting the slowest hairpins ( usually only once per lap ) but it is just way too slow at this point that lap times suffer excessively.
I also have replicated the Aux ports ground around to bore centre, and this also makes a HUGE gain in overev power and useable rpm.
But in this case it looses some 1.5 Hp at 9000, and this can be got back with plugs in the small end pin.
This loss is easily offset by the fact we can add another tooth on the back and rev it alot harder ( 15,000 ) - lap times drop,so that is a worthwhile gain.
The extra rpm available also allows deleting several between corner gearchanges, again making faster lap times.

The other problem is that it is a big mistake to assume that simply replicating one small element of Jans concept will be a positive step for any old port arrangement.
I know others have tried to add material to the B duct front face, making the wide septum entry, but this then completely changes that front walls entry angle into
the cylinder - and this for sure is doomed if the whole reverse stagger,axial angles scenario etc etc isnt used as well..

[husaberg]

Something like this Husa?

Shitty drawing (in dutch) I know, but I think you're thinking what I was thinking that you were thinking

This is double-pumping, this is illegal , and this really works .

I couldn't find the crayons

The riddle of the ryger, a free piston engine will occilate at (30,000?) with no rod or crank. How does the piston not end up in a big heap at one end? Gas compression absorbs the inertia each cycle. In the ryger, if the pumping chamber ( formally called the crank case ) pumped down to a "squish" this would do two things. 1, unload the normal piston deceleration load on the conrod and 2, create the high pumping pressures required to charge a not fully blowen down cylinder but the amount of gas transfered would be limited, perhaps why fuel air does not get out the exhaust. With lots of small transfer ports control over gas positioning in the cylinder would be more accurate.
To make 70hp with a 30mm carb, it would have to be passing air all the time not gulp filling like a normal engine, soooo if we had say four smaller transfer ports either side of the cylinder feeding from the high pressure under piston pump (eight transfers) and we had three more at the rear of the cylinder that are piston ported to fill the high pressure under piston pump (at TDC) but also the same ports when the piston was at BDC feed straight into the cylinder, helping to make up for the lack of volume delivered by the high pressure under piston pump. Air fuel would be drawn in when the piston was on the way up and also when the piston is nearly down. With gas inertia and some funny looking "thing" inside what we thought was the intake reed, that helps retard back flow (not a reed), flow through the carb would be fairly constant I imagine.
I think the exhaust expansion chamber would not have a very steep reverse cone but internal system pressure would have to be fairly well controlled?
Imagine that

I think that is pretty much it.
No sim that covers rpm potential will work as the sim likely does not take the cushion into effect of its accepted parameters.

https://www.highpowermedia.com/blog/...t-applications

[peewee]

frits maybe you can offer some help. i followed your theoretical exh shape with top radius at 75% and corner radius at 8.1% and got whats show in the pic but when i try to draw it on paper i end up with less than 13.7% vertical half axis. around 12% is what i get. do you think im making a error somehow when i draw it ?

actually now i think about it, my exh width might of only been 65% of bore and thats where the error is. since your theoretical exh is based on a 70% wide window, do you have a guess what the roof and top corner radius should be for a 65% wide window and vertical half axis ?

[wobbly]

OK, with a bunch of serious patent searching ,I think we have a handle on the stepped piston multi transfers with close coupled reeds
in the plate scenario.
But no one has even come close to the safe at 30,000 bottom end.
Tear your hair out you fuckers, till we get this sorted we really are tossing into the wind.