ESE's works engine tuner

[husaberg]

A 125 cylinder with 310cc of " case " volume at tdc would have a primary com of 310/310-125 = 1.67.
That ratio would indicate huge pumping losses.
But the engine with 310 at tdc and 238 at BDC is only 1.3 - perfectly normal for a race 125.
So what am I missing in the Ryger " concept " of using big primary com to force transfer the charge into the cylinder, instead of an efficient pipe
pulling it thru around BDC.

I think it comes down to the higher speed at which the smaller "crankcase" volume attains its peak efficiency.
With the conventional style engines reducing the primary comp to anywhere near the same level had required the crankcase airflow and transfer flow to become so hugely stifled it became irrelevant, I believe it was because it created huge boundary friction in the areas around the crank wheels. plus other flow airflow restrictions.Thus I muse separating the crankcase might be the difference.
Also it would seem the ryger benefits from modern transfer control and durations. As devloped over the last 40 years.

There is an engine speed at which maximum air delivery to the cylinder occurs, and that this engine speed is inversely proportional to crankcase volume, but that the maximum value changes only slightly with changes in crankcase volume. To put it another way, the crankcase-pump's volumetric efficiency is nearly constant, but the engine speed at which it attains maximum efficiency rises as crankcase clearance volume is reduced. pumping losses (horsepower absorbed in doing this work) rise as to the third power of compression ratio. Researcher Fujio Nagao, of Kyoto University

or it might just be overhyped horse poo.

[breezy]

A 125 cylinder with 310cc of " case " volume at tdc would have a primary com of 310/310-125 = 1.67.
That ratio would indicate huge pumping losses.
But the engine with 310 at tdc and 238 at BDC is only 1.3 - perfectly normal for a race 125.
So what am I missing in the Ryger " concept " of using big primary com to force transfer the charge into the cylinder, instead of an efficient pipe
pulling it thru around BDC.

are you able to factor in a cooler intake charge and reduced crankcase turbulance, as the fuel air is no longer being churned around and heated up prior to entering the transfer ports. if the high primary comp forces a fast movement of charge into the cylinder, wouldnt that pressure drop cause the reeds to open allowing a secondary wave of intake flow? like a pumping action.

[Grumph]

are you able to factor in a cooler intake charge and reduced crankcase turbulance, as the fuel air is no longer being churned around and heated up prior to entering the transfer ports. if the high primary comp forces a fast movement of charge into the cylinder, wouldnt that pressure drop cause the reeds to open allowing a secondary wave of intake flow? like a pumping action.

How much masking effect does the dirty great post down the center have ?
Still got to get the mixture in and distribute it to the transfers....

[peewee]

are you able to factor in a cooler intake charge and reduced crankcase turbulance, as the fuel air is no longer being churned around and heated up prior to entering the transfer ports. if the high primary comp forces a fast movement of charge into the cylinder, wouldnt that pressure drop cause the reeds to open allowing a secondary wave of intake flow? like a pumping action.

couple questions from a dummy trying to figure it out. true it wouldn't be churned up but wouldn't it be compressed more, between the piston and plate ? this would add heat also, in the same way high comp ratios in the cylinder , between piston and head , or am I thinking wrong ? how much combustion heat would travel into the big plate ? and if the primary ratio is through the roof , 1.67 or what ever, wouldn't that meen a much lower average pressure delivered to the cylinder ?

[Vannik]

Ryger Question:

The displacement in the chamber below the piston is roughly half the cylinder displacement - thus the pumped volume is about 70cc in a 125cc engine. So relying on pumping only at theoretical best we can only get a delivery ratio of 50% (Aprillia RSA125 ~ 140%) so where does the rest of the charge come from?

You would need some super pipe to create this sort of suction to make up the difference and that is just to match the RSA125, but the Ryger is supposed to be relatively insensitive to pipe design so not this?

The inertia of the gas flowing through the ports can help a small amount but nowhere near this difference.

[husaberg]

Ryger Question:

The displacement in the chamber below the piston is roughly half the cylinder displacement - thus the pumped volume is about 70cc in a 125cc engine. So relying on pumping only at theoretical best we can only get a delivery ratio of 50% (Aprillia RSA125 ~ 140%) so where does the rest of the charge come from?

You would need some super pipe to create this sort of suction to make up the difference and that is just to match the RSA125, but the Ryger is supposed to be relatively insensitive to pipe design so not this?

The inertia of the gas flowing through the ports can help a small amount but nowhere near this difference.

My initial guess is directly through the very short piston skirt on the inlet, ie it does not shut until well after the transfers opens.
but i have never tried to map it out, but i am picking you may have though

[Flettner]

Ryger Question:

The displacement in the chamber below the piston is roughly half the cylinder displacement - thus the pumped volume is about 70cc in a 125cc engine. So relying on pumping only at theoretical best we can only get a delivery ratio of 50% (Aprillia RSA125 ~ 140%) so where does the rest of the charge come from?

You would need some super pipe to create this sort of suction to make up the difference and that is just to match the RSA125, but the Ryger is supposed to be relatively insensitive to pipe design so not this?

The inertia of the gas flowing through the ports can help a small amount but nowhere near this difference.

Fairy dust.

[jamathi]

Ryger Question:

The displacement in the chamber below the piston is roughly half the cylinder displacement - thus the pumped volume is about 70cc in a 125cc engine. So relying on pumping only at theoretical best we can only get a delivery ratio of 50% (Aprillia RSA125 ~ 140%) so where does the rest of the charge come from?

You would need some super pipe to create this sort of suction to make up the difference and that is just to match the RSA125, but the Ryger is supposed to be relatively insensitive to pipe design so not this?

The inertia of the gas flowing through the ports can help a small amount but nowhere near this difference.

So there is NO reason why it should give more than about 30HP I can think of.....
It MIGHT be overhyped horse poo....

[Vannik]

So there is NO reason why it should give more than about 30HP I can think of.....

I updated my software to simulate stepped pistons, both ways, the traditional bigger bottom step and the Ryger smaller step, and I have tried many ways without ever exceeding 30hp on the Ryger. Maybe I am missing something....

[katinas]

ok.. thanks for that info.. i thought you would be able to give me that information because i can see you have gone into this engine set up in a good technical way...lets hope for good weather for you to test under load... thanks

now, I think its not weather, just time needed to assemble the bike....

Jack Findlay n1 in photo

[TZ350]

Maybe I am missing something....

Maybe we all are, or Maybe not.

I am looking forward to hearing Katinas impressions when he gets to ride his bike.

[cotswold]

Farmer Ken had his new engine on track today, a few nice home made goodies in this baby, NSR250 pot on TF bottom end, stroked crank, power valve, quick shifter, it's fully loaded

Getting a bit pissed off with my correct way up photo's getting rotated by this forum

[mr bucketracer]

Farmer Ken had his new engine on track today, a few nice home made goodies in this baby, NSR250 pot on TF bottom end, stroked crank, power valve, quick shifter, it's fully loaded

Getting a bit pissed off with my correct way up photo's getting rotated by this forum

thanks for the pictures , was told when driving home he had made this engine up , was guted i had not seen it .

[cotswold]

thanks for the pictures , was told when driving home he had made this engine up , was guted i had not seen it .

I mentioned to Reagan that his green meany may be a weapon water cooled and stroked to 110cc

[TZ350]

Great to see the first race ready 110cc H2O special out on the track, big up's to FarmerKen .....