ESE's works engine tuner

[marsheng]

It stopped suddenly on the track.

Ok, you have fooled me, what have you done with the piston ?

I have a small shelf for 'Offerings to the gods" but there is nothing to display in this case.

[2T Institute]

Under construction amazingly by an 18 yr old ......the yoof of today and their computers

[jonny quest]

It's my belief that the exhaust skirt of Ryger terminates in the spacer plate. The clearance slot in spacer plate does not open up into crankcase.

Are you all in agreement?

2t institute, show us more of that twin, looks exciting! Are the cases 3d printed at this point?

[F5 Dave]

Probably did it on his phone.

[jasonu]

Probably did it on his phone.

While driving...

[Bert]

Under construction amazingly by an 18 yr old ......the yoof of today and their computers

Is this the same engine shown at Milan?

http://www.visordown.com/motorcycle-...led/28510.html

Would make a very cool bucket motor..

[M.Holder]

Hi,

no, it is not the same engine.

You can follow the project here:
http://www.2t-special.it/forum/viewt...hp?f=14&t=5065

[SwePatrick]

It's my belief that the exhaust skirt of Ryger terminates in the spacer plate. The clearance slot in spacer plate does not open up into crankcase.

Are you all in agreement?

2t institute, show us more of that twin, looks exciting! Are the cases 3d printed at this point?

Yes, slot in spacerplate is just space given to accept pistonskirt, nothing else.

[SwePatrick]

You have to "get " that what is sitting in the duct just ouside of the port face ( but before the header starts ) is a slug of fresh A/F mixture.
This can only be usefully used by two effects if they exist.
The mixture can be moved inward by a depression in the " crankhouse " or by a positive pressure ratio sitting in the duct.
In this case when the extra port below the main Ex is opened by the rising piston we see a really big positive pressure ratio, so the A/F sitting in the duct
is easily moved into the expanding volume under the piston.
Just as the dropping piston has very little to do with getting mixture thru the transfers in a "normal " race engine, the Ryger uses the much stronger wave action
to shift extra A/F into the volume above the guide plate.

And yes the really big depression around BDC in that KTM pressure trace is due to a highly optimized pipe shape working with port superposition
to pull plenty of mixture thru the transfers when they are fully open, achieving a high bulk flow rate - again nothing to do with the dropping piston creating
pressure in the case.

Ok,, i almost 'get it', but still ain´t convinced.
Just to much of a gamble here.
'off' pipe it wouldn´t work good if tuned to work good 'in pipe' and vice versa.
If holding engine revs stabe at one rpm for hours it might work.
But in a shifterkart who is very dynamic in revband and different exhausttemps all the time, rpms altering all the time.
Nahh..

No wonder they seem to seize on track.

[nasone32]

Ok,, i almost 'get it', but still ain´t convinced.
Just to much of a gamble here.
'off' pipe it wouldn´t work good if tuned to work good 'in pipe' and vice versa.
If holding engine revs stabe at one rpm for hours it might work.
But in a shifterkart who is very dynamic in revband and different exhausttemps all the time, rpms altering all the time.
Nahh..

No wonder they seem to seize on track.

Not really.
Off pipe there's the same wave action going on, just with a much reduced amplitude.
at worst it would work like a normal 2 stroke when off-pipe.
my 95cc engine.
black is max torque @ 15000 rpm
red @10000 rpm

[Tunisti]

About The gap. If I understand what gap you mean, it's not connected to anything. probably it's just space clearance for the piston skirt when it goes down to bdc.

It's my belief that the exhaust skirt of Ryger terminates in the spacer plate. The clearance slot in spacer plate does not open up into crankcase.

Yes, slot in spacerplate is just space given to accept pistonskirt, nothing else.

If you're considering that the slot/gap I was talking about was the slot for exhaust side piston skirt, I was misunderstood. Look at the drawings and calculate a bit. You'll figure it out what I meant.

Just wondering whether the (controversial) relatively tight gap (3mm calculated from the drawings) between the adapter plate´s cylindrical part and the "Ryger ports" in the cylinder wall could have a specific meaning. To open the name of HCCI=Homogeunous Charge Compression Ignition, we can see that there must be something in that motor, which makes the charge homogenous enough. Okay, we have this 30mm carburator, but I´d bet that it´s not capable to mix the fuel into the air well enough. Then we have this space beneath the piston, it´s pumping volume is 70cm^3 and it has somewhat small passage. Let's say that it's somewhat 1,5cm^2. Assuming that there would be 70cm^3 of mixture to be pumped through that 1,5cm^2 passage bethween TDC and BDC we could make this coarse assumption, that the mixture would have speed of at least 265m/s@17krpm through that relatively small gap. Sounds like a good change to force the mixture into homogenous state?

'off' pipe it wouldn´t work good if tuned to work good 'in pipe' and vice versa.
If holding engine revs stabe at one rpm for hours it might work.
But in a shifterkart who is very dynamic in revband and different exhausttemps all the time, rpms altering all the time.

Btw. The operating of this system outside the "sweet spot" would be somewhat terrible. It'd be good to have some kind of governor in the "Ryger port". And that governor could shut the duct fully, when necessary.

E: Nice graphs nasone32! Could you make those calculations at 12krpm and 6krpm?

[MotleyCrue]

Not really.
Off pipe there's the same wave action going on, just with a much reduced amplitude.
at worst it would work like a normal 2 stroke when off-pipe.
my 95cc engine.
black is max torque @ 15000 rpm
red @10000 rpm

There must be some kind of vacuum in the crankcase approaching TDC maybe 0.8 to 0.9 on the scale, to me it looks like at 10000 rpm its all backflow from the exhaust to the crankcase the entire time you have circled, and at 15000 rpm there is back flow from the exhaust to the crankcase most of the time you have circled. Just sayin...

I can appreciate that a 2 into 1 twin cylinder would be a different beast than a single.

[wobbly]

Hey Motley, you must be looking at the screen thru broken Warehouse glasses.
On the LH side of the pressure sweep the ratio is above atmospheric right up to EPO, then on the RH side as we get past EPC the ratio is below
atmospheric the whole time ( apart from a small upward bump at 10,000 ) - for both the 10,000 and 15,000 traces.

[MotleyCrue]

Hey Motley, you must be looking at the screen thru broken Warehouse glasses.
On the LH side of the pressure sweep the ratio is above atmospheric right up to EPO, then on the RH side as we get past EPC the ratio is below
atmospheric the whole time ( apart from a small upward bump at 10,000 ) - for both the 10,000 and 15,000 traces.

I can see atmospheric pressure no sweat through my warehouse glasses but I don't think the pressure in the crankcase is atmospheric at that time (BTDC), I put forth that the pressure in the crankcase is probably 0.8 to 0.9 bar BTDC. If flow is from the crankcase to the exhaust then the exhaust pressure has to be below 0.8 to 0.9 bar, and I dont see that at all at 10000 rpm and only for may 25-30 % of the opening time at 15000 rpm.

Is there a crankcase pressure trace that shows otherwise?

[SwePatrick]

Not really.
Off pipe there's the same wave action going on, just with a much reduced amplitude.
at worst it would work like a normal 2 stroke when off-pipe.
my 95cc engine.
black is max torque @ 15000 rpm
red @10000 rpm

Still not convinced, As i´ve got my own dyno with logging of heat in exhaust i have tested a lot with different temprature in pipe, Isolating pipe etc etc etc.
And a red line thoughout all tests is that every pull is starting with about 200-250degree celsius(5000rpm) and ends up with 450-640 degree depending on setup.
This results in severeal hundreds of rpm difference were engine hits 'stop' in pipe.
And also a lot of difference where the peak power is.
If i got about 620 at end of pull the peak power is at ~12800rpm.
And if i delete isolating i end up in about 450degree, and the peak power is at 11700-11900rpm

This is a ~1000rpm wide area, a quite huge difference in tuned length of pipe.
Therefor i say off pipe, the pipe tunes at an another rpm than 'in pipe' due to dynamic change of heat.
That means that reflecting pulse arrives at different crankdegrees when heat is changing.

Rgds.