ESE's works engine tuner

[nasone32]

Crankcase pressure is in that range, true, but i'd stick to looking at what happens at maximum torque and after that point.
I think such a design would imply a different power curve shape. if you have, say, 4000 rpm useful over the max torque, who cares what happens at mid revs.

Also, speculation, suppose we get only a compression wave from exhaust. worst case.
after EPC i'm not sure we have just exhaust gases in the exhaust duct. maybe the air purity is high, due to escaped fresh gases.
and surely the increased pressure in the crankcase compensates for decreased air purity.

this could also be a trick to HCCI
and recirculating some escaped fresh gases back to the crankcase supports the "clean engine" claim further.

[Tunisti]

...after EPC i'm not sure we have just exhaust gases in the exhaust duct. maybe the air purity is high, due to escaped fresh gases.
and surely the increased pressure in the crankcase compensates for decreased air purity.

this could also be a trick to HCCI
and recirculating some escaped fresh gases back to the crankcase supports the "clean engine" claim further.

Wrote about that HCCI and internal EGR thing before. I think that under and over the power band there's much fresh mixture inside the exhaust duct, when exhaust port closes. The pipe is capable of sucking fresh mixture into the exhaust duct, even though the engine is running under or over the power band. The proplem under the power band is that the pulse arrives too soon and the mixture leaks out before exhaust port closes. And when we are over the power band, the pipe's pulse arrives too late, and the exhaust port is already closed when the pulse tries to push the mixture in exhaust duct back into the cylinder.

So, when we are on the power band, there shouldn't be fresh mixture in the exhaust duct when the exhaust port closes. Also in this situation the pressure in the exhaust duct should drop somewhat dramatically (about 50 deg BTDC) according to the graph. If the assumed port opens somewhat 60-40 deg BTDC, there should be flow from the cranckcase to the exhaust duct. Assuming that the timing is symmetrical, the port would close at 60-40 ged ATDC, leading to about 1.4 bar pressure when closing. Outside the powerband there would be flow from the exhaust duct to the cranckcase when the "Ryger port" opens, but in this situation there would be fresh mixture in the exhaust duct. And when we want a green motor, it'd be better to take that mixture from the exhaust duct and recycle it. Even though that would mean lower flow via the inlet duct.

Bad sides of that? Yes, the mixture inside the exhaust duct would be warmer, hence not so tense as the mixture coming from the inlet duct. But on the other hand, would the pumping losses be smaller when the mixture is recycled, there sure is less distance for the flow in this method? And then there's the problem of exhaust gases slipping into the cranckcase, either by mixing with the fresh mix in exhaust duct, or just by pulse actions in larger concentrations. Here comes the HCCI aspect and green values of this motor.

If we assume that this method allows the exhaust gases to get into the "crankcase" at some or all rpms, there is this "high velocity homogenisation"-theory I wrote earlier. And it includes the "gap". Assuming that the high velocity in that gap makes the A/F mixture well homogenisated, then it should be able to homogenisate the exhaust gases somewhat well into the 70cc's of A/F mixture. Therefore the exhaust gases wouldn't cause pockets of unburnt/slowly burning mixture when the ignition occurs, those would otherwise occur if there would be big lumps of exhaust gas in the mixture when ignited.

And to quote myself, here's the internal-EGR thoughts and "high velocity homogenisation"-theory again:

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?
....The pulse theory, would offer somewhat much preheating for the mixture, and also some internal EGR-characteristics. Just to help the HCCI to stay in good state. The internal EGR-fuction would naturally be stronger when the engine is running below the sweet spot - therefore it´d help help the HCCI to get started more easily.

[wobbly]

Here is the case pressure ratio at 14,000 for the KTM85

[MotleyCrue]

Crankcase pressure is in that range, true, but i'd stick to looking at what happens at maximum torque and after that point.
I think such a design would imply a different power curve shape. if you have, say, 4000 rpm useful over the max torque, who cares what happens at mid revs.

Another way to look at it, if this exhaust gas backflow into the crankcase thing works, then why would it have to be a Ryger engine to work, why not on a regular single cylinder engine and if so would not someone have built one already and we'd all have one by now because of the 4000 overrev ? Knowing that it has been done on 2 into 1 pipe twins, then it seems reasonable to expect it has been tried on a single too.

A 2 into 1 pipe twin I can see possibilities, there is a pulse in the pipe every 180 degrees at every engine speed, that way the pulse setting up the TDC conditions is fixed and not a reflection of a reflection of something from somewhere like on a single at some engine speeds.

[TZ350]

Page 1460



Fun days racing at the Cemetery Circuit Wanganui, Buckets used to be able to race there but rumor has it, they stopped being invited because, being so nimble they would humble the big bikes.

[SwePatrick]

Is it actually proven to be HCCI mode, or just mumbojumbo from people that wants to hide things behind smoke and mirrors?

Cause i don´t see how it´s gonna be 'needed' for those rpms the power is within, old 100cc karts revved above 18k without problems.

[nasone32]

okay. now I'm also pretty sure that port is not connected to the exhaust.
I still wonder if with proper design is possible to use that wave pulse.

Fun days racing at the Cemetery Circuit Wanganui, Buckets used to be able to race there but rumor has it, they stopped being invited because, being so nimble they would humble the big bike.

nice video mate. what bike class is that in the video?

[MotleyCrue]

okay. now I'm also pretty sure that port is not connected to the exhaust.
I still wonder if with proper design is possible to use that wave pulse.

I think yes for a window of rpm. Outside that window of rpm the possibility of large quantities of 500C + burnt exhaust entering the crankcase might be a show stopping event. I don't think a 2 into 1 twin would have this problem though.

[adegnes]

....

Check your PM's Muciek.

[speedpro]

Page 1460



Fun days racing at the Cemetery Circuit Wanganui, Buckets used to be able to race there but rumor has it, they stopped being invited because, being so nimble they would humble the big bike.

There's been 2 fires there I think. One was a Hossack with girder style front end with a Honda 500 single. Some guy from Oz I think. The other was a GPz550 with the previous years World championship winning cylinders and head from the Moriwaki team.

They stopped accepting entries from buckets because we were too slow. I managed mid pack finishes there on mine and always had to start off the back of the grid, except when they put me in "Clubmans". Now that was some scary racing, RG50 with TS100 engine lined up on the grid next to some guy on a GSXR1100. They didn't allocate grids so I used to race round and make sure I wasn't at the back. Most of the field would drag me off going to the first turn and I'd dive past them into the corner, or passing them as they backed off for the right turn going through the cemetary. I used to change into 6th in the middle and lift the front wheel over the hump as you change direction. The bike was so light, as Rob said you could just dive past people as they started to turn. Had many a "conversation" in the pits with other Clubman riders mainly.

[nasone32]

About the video and stuff, was there some actual accident involved or they stopped accepting buckets because they feared it might have happened?

I noticed one thing on the ryger. the pipe length is quite long for an engine running in the 17k range. exhaust gases must be so hot.
someone could play in engmod, and see if tinkering a bit with the prescribed combustion model can replicate some results.

[speedpro]

No incident I'm aware of. I think I was the last one to enter and initially was denied entry, by Barbara. A friend knew her and argued my case and finally I was allowed entry. Back of the grid starts that year despite times that should have put me a row or 2 further up. Even good finishes didn't help for the next race. I spent most of tbe day angry and vowed never to enter again.

[SS90]

I noticed one thing on the ryger. the pipe length is quite long for an engine running in the 17k range. exhaust gases must be so hot.
.

I have been waiting for someone to bring this up.

[MotleyCrue]

I have been waiting for someone to bring this up.

And yet HCCI would make exhaust gases cooler not hotter.

Maybe at the very high revs plain back pressure from the stinger becomes enough that the reverse cone pulse doesnt matter, or maybe the reverse cone pulse comes back into favor at 35-40% overrev as I proposed many pages ago.

[2T Institute]

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

CNC to soon follow