ESE's works engine tuner

[Grumph]

I don't have much faith in the drawings that have been provided.

Something of an understatement I feel...

Given too that a standard kart ignition is fitted - and apparently working - I feel that you can rule out any HCCI at least in this version.
By the admittedly convoluted reasoning of the kart rules, if ignition didn't take place in the legal fashion, it wouldn't have been homologated.

[tjbw]

Something of an understatement I feel...

Given too that a standard kart ignition is fitted - and apparently working - I feel that you can rule out any HCCI at least in this version.
By the admittedly convoluted reasoning of the kart rules, if ignition didn't take place in the legal fashion, it wouldn't have been homologated.

This is what the CIK regulations say:

"For the KZ1 and KZ2 categories, the ignition system used must be of analogue type and any variable ignition system (system of progressive advance and delay) is forbidden"

If an engine has a homologated ignition, yet achieves HCCI without hardware to vary the timing, then I don't see how that would be against the rules.

[Flettner]

Could a pipe be tuned so that it pushes the mixture back in together with exhaust gas? A pipe tuned for HCCI? Then it would not be cooled of that much as if it would return below the piston.

Remember the exhaust is standard, so if you are making more power, more heat, more gas flow. The tail pipe stays the same size, more gas pressure has to excit this pipe so the pressure MUST be higher than a standard system. Certainly the heat retained in the cylinder (pressure / temp) must be higher at elevated rpm. This MUST be what sets the HCCI off. If there is a spark and it starts the burn at certain time, as the engine gets to real high rpm I would say the HCCI condition will have over taken the normal slow (by comparision) burn, even if the burn has already started. Spark ignition is for when the gas pressure in the pipe is under normal pressures, say up to 13,000 RPM ish. Normal engine goes flat at these rev's due to lost blow down time / area and lack of real crank case pumping pressure but in this Ryger system the crank case (under piston) will still force fuel air into the cylinder no mater how much residual pressure is left behind (within reason). So the Ryger engine can enter conditions previously unknown. These previously unknown conditions I think is what sets off the HCCI as I said. But boy it must be hard to control without being able to change the cylinder head volume, on the fly, (Ken).
And as the exhaust pressure increases, the pulse wave will travel faster.

[DoldGuy]

Does anyone know the crankcase volume of the VM motor? I would think it to be in the 250cc-275cc range. The design of the Ryger intake with 6 ports seems to have plenty of area to accommodate this volume & remember reading a post (by Frits if memory serves) you want the charge as accessible to the transfers as possible, and the Ryger does just that, as all of the charge is right there at the transfers tunnels.

[TZ350]

And as I have said a dozen times on here, its only in lawnmowers that the dropping piston has anything to do with promoting flow
from the conventional case - thru the transfers,as there is more pressure above than there is below the piston at TPO.
The Ryger is using a very small trapped volume, that is compressed substantially by the larger diameter piston portion.
Thus it simply doesnt need a ton of blowdown to reduce the combustion pressure above the transfers, and as well it doesnt need the big negative pressure
ratio created by the diffuser to pull mixture into the cylinder when the piston is at BDC.
So a single Ex port seems entirely reasonable and expected.
The top end workings I believe we have pretty much guessed the trickery, as for the 30,000 rpm capable bottom end - darkness and guessing are really confusing
and we are not even close to reality yet.

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.

[wobbly]

The problem with cutting the spring to achieve a set " pop off " is that although you have reduced static pressure on the needle
and seat , you have also reduced the number of turns of spring.
Thus you then have increased the rate of the spring as the diaphragm opens the valve, and this then leans off the fuel flow curve the further
off the seat the spring allows the needle to move.
In most cases this is exactly what isnt needed.
Thus selecting a lower/higher spring rate is far more an reliable method of changing the transition tuning via reducing or increasing the static pop off pressure.
Small changes can be made by simply squashing/or stretching the set spring length, but cutting introduces another sometimes unwanted variable - be aware.

[SwePatrick]

I have tuned it a bit now, runs smoother on idle, but as there is no venturi in this carb i figure it will work better on a engine with bigger displacement.
An engine that pulls more air before getting into the pipe so to speak.
I still have this HUGE gap in power when giving it full throttle, it just dies, no fuel is drawn into airstream, until i hit ~11000rpm(when the pipe is pulling hard)

I feel it´s the drawback on this model of carb, it´s a 'slide' model.

Rgds.

[SwePatrick]

About HCCI and that stuff on Ryger engine.
The transferport underneeth the exhaust that connects to the other ports.
Here´s my thought that might trigger HCCI without getting dirty gasses back into cylinder:

As the spigot prodtrudes into the area of the lower ports the freshgasses are forced to be drawn equal in every port down below.
In that way gasses that are exposed to heat underneeth exhaustport is heated up as the heat in the pipe rises.(there no water between lower transfer and exhaustport in my thought)
This on high rpm is building avalanche effect and the heat rises almost to self ignite temp.
And when piston compresses in cmobustionroom it will self ignite.

I had to think that everything drawn on homologisationreport must be correct and in that way find a 'harmony' in the engine.

This is a little touch of Smokey Yunick´s creation(hot vapor) that is held in mystery.
But it´s a drawback,, heating up the combustion is getting good burn, but it will increase NOX gasses insanely high.

Rgds.

[G Jones]

hey guys im making a alloy fuel tank and I want it to be about 5 to 5.5 liters or so. I been trying to find some kind of online calculator that can easily do the math so I can get it in the 5 to 5.5 range the first time but I haven't much luck. do you guys know of any fancy online gadgets that will figure liquid volume of odd shapes ? heres whats its going to look like. the numbers are just generic so you get the idea that its not symmetric from front to back

Hi - is this any use ?
http://www.custompartnet.com/quick-t...ght-calculator

[Frits Overmars]

the power comes from very high Rpm

State of the art is Jan Thiel's Aprilia RSA with 54 hp @ 13000 rpm. If that Aprilia could rev to 17000 rpm without loss of Brake Mean Effective Pressure, it would produce 70.6 hp; same as the Ryger. In other words: the Ryger doesn't just rev, it also reaches the same high level of BMEP at 17000 rpm that the Aprilia reaches at 13000 rpm.

If there is a spark and it starts the burn at certain time, as the engine gets to real high rpm I would say the HCCI condition will have over taken the normal slow (by comparision) burn.

When the engine gets to those high revs, the exhaust note changes; the engine really starts singing. It's a lovely sound.

Does anyone know the crankcase volume of the VM motor? I would think it to be in the 250cc-275cc range.

The only sensible way to express the crankcase volume of a two-stroke is with the piston at TDC and with the total volume of the transfer ducts included.
I don't know the VM's volume, but at TDC it will probably be more than 500 cc. For reference: the Aprilia RSW with side-mounted inlet disc had 650 cc; the RSA with rear-mounted disc and longer con rod had 675 cc.

[Peter1962]

State of the art is Jan Thiel's Aprilia RSA with 54 hp @ 13000 rpm. If that Aprilia could rev to 17000 rpm without loss of cylinder filling, it would produce 70.6 hp; same as the Ryger. In other words: the Ryger does not only rev, it also reaches the same high level of cylinder filling at 17000 rpm that the Aprilia reaches at 13000 rpm.

When the engine gets to those high revs, the exhaust note changes; the engine really starts singing. It's a lovely sound.

The only sensible way to express the crankcase volume of a two-stroke is with the piston at TDC and with the total volume of the transfer ducts included.
I don't know the VM's volume, but at TDC it will probably be more than 500 cc. For reference: the Aprilia RSW with side-mounted inlet disc had 650 cc; the RSA with rear-mounted disc and longer con rod had 675 cc.

Frits, are you allowed to comment on the power curve of the Ryger, say between 10.000 rpm and 13.000 rpm, compared with the same curve of the RSA ?

[Flatout]

Frits could HCCI be controlled with the electronically pulsed power jet and fuel octane? Have the power jet fed with a much higher octane fuel than the main jet with a knock sensor controlling the pulse?

[Frits Overmars]

Frits could HCCI be controlled with the electronically pulsed power jet and fuel octane? Have the power jet fed with a much higher octane fuel than the main jet with a knock sensor controlling the pulse?

How do you figure that? If you close the power jet, the mixture will be leaner but HCCI does not care. In that respect it's like a diesel: as long as there's fuel, it'll burn.
If you open the power jet, you'll introduce a fuel that is more HCCI-resistant, but that won't stop the regular fuel from igniting. And this will ignite the high-octane stuff as well, raising the EGT. But if you intend to raise the EGT, you'd better give it some more regular fuel; it's cheaper.
Keeping the HCCI under control could work if you were to administer too much fuel for the available oxygen, so part of it would not burn but just act like an internal liquid coolant. But that would kill the HCCI's fuel economy and its relatively clean exhaust.

[MotleyCrue]

State of the art is Jan Thiel's Aprilia RSA with 54 hp @ 13000 rpm. If that Aprilia could rev to 17000 rpm without loss of cylinder filling, it would produce 70.6 hp; same as the Ryger. In other words: the Ryger does not only rev, it also reaches the same high level of cylinder filling at 17000 rpm that the Aprilia reaches at 13000 rpm.

But if the HCCI makes more power then wouldnt the cylinder filling have to be less. Example: if the HCCI was 20% more effective then wouldnt cylinder filling be 20% less or something like it so that power would be the same (70 @17000). But maybe HCCI at 17000 is no more effective than regular spark ignition is at 13000 ?

[Frits Overmars]

But if the HCCI makes more power then wouldnt the cylinder filling have to be less. Example: if the HCCI was 20% more effective then wouldnt cylinder filling be 20% less or something like it so that power would be the same (70 @17000). But maybe HCCI at 17000 is no more effective than regular spark ignition is at 13000 ?

Good point Motley. HCCI is indeed more effective (less negative pressure on the piston before TDC because if everything is as it should be, the burn starts later, less heat losses thanks to the faster burn, and less hydrocarbons that escape unburned) though I couldn't say if it were 20%.
I feared that not everyone might understand the Brake Mean Effective Pressure-concept so I went for 'cylinder filling' , introducing the error that you caught.
It's corrected now.