ESE's works engine tuner

[Niels Abildgaard]

I wonder why is that 54 without friction and thermic losses !!!!!!!

Nobody claims that a 125 can give 54 without friction and thermic losses.
Try if You can to plot a max shaft power curve for known good cylinders versus cubic capacity of one cylinder.
We have at least three state of art points

125 aprilia 54 hp
2.5 ccm aeromodel 2.5 hp
6.5 ccm aeromodel 5 hp

all made after many failures and dead ends

The problem Wobbly and You have with 35 and 25 ccm cylinders is ,I think, internal air/fuel charge resistance in the crank chamber.
Try and compare a weed hacker engine with the 2.5 aeromodel.
https://www.kiwibiker.co.nz/forums/a...8&d=1606384149

How much was the ultimate 50ccm Kreidler cylinder able to give

[TZ350]

[dutchpower]

Nobody claims that a 125 can give 54 without friction and thermic losses.
Try if You can to plot a max shaft power curve for known good cylinders versus cubic capacity of one cylinder.
We have at least three state of art points

125 aprilia 54 hp
2.5 ccm aeromodel 2.5 hp
6.5 ccm aeromodel 5 hp

all made after many failures and dead ends

The problem Wobbly and You have with 35 and 25 ccm cylinders is ,I think, internal air/fuel charge resistance in the crank chamber.
Try and compare a weed hacker engine with the 2.5 aeromodel.
https://www.kiwibiker.co.nz/forums/a...8&d=1606384149

How much was the ultimate 50ccm Kreidler cylinder able to give

Nico and I start this project years ago
I wanted to make it at the same level as Jans baby the RSW/RSA
Nico copie scale the RSW/RSA
Nico had big friend Jan de Vries always there
Last sommer we had contact to start his project
From 10 hp we went to 12 hp Oh said Jan de Vr. there I start whit in the early days and ended 19 hp
Thats what I have now Jan !!!


That was a big stap yes ( internal air/fuel charge resistance in the crank chamber )

[Frits Overmars]

Try if you can to plot a max shaft power curve for known good cylinders versus cubic capacity of one cylinder.
We have at least three state of art points
125 aprilia 54 hp
2.5 ccm aeromodel 2.5 hp
6.5 ccm aeromodel 5 hp

Apples and oranges, Niels.
The Aprilia power is measured at the gearbox exit; it would be about 57 hp at the crankshaft. It burns unleaded petrol with 5% oil and has spark plug ignition.
Both aeromodel engines have their power measured at the crankshaft. The 6,5cc engine burns methanol with 20% oil. The 2,5 cc engine fuel probably carries a noticeable percentage of nitro. Both have glow plug ignition.
The fuel will make an obvious difference. But the ignition system may make an even bigger difference.
For maximum power, a glow plug engine needs to have the same ignition timing as a spark-ignited engine. But practice has shown time and again that this is too critical for a glow plug: one missed combustion will kill the engine completely. For a glow plug to function reliably its ignition timing must be about 30° earlier than the max.power timing. And that will cost an estimated 30% of power.

In addition, I agree with Wobbly that the development of smaller engines is seriously lagging behind the development of Jan Thiel's 125cc RSA: we do not have three state of the art points.

[koenich]

this just comes down to $$$...how much dev money and manpower went into the RSW/RSA? and who's pouring money nowadays into 50cc or below? At some point obviously no ROI. the enthusiast/single tuner can come pretty far and reach impressive results (cheers Wob and Dutch) but at some point the required effort will rise exponentially for small gains...

[Niels Abildgaard]

Honda ended up with a fourcylinder 500ccm and a twocylinder 500 ccm.
Are there some thrustworthy horsepower figures for these?
If we guesstimate 52hp for the 125ccm cylinders we can try to estimate the 250 cylinder power.

52*(250/125)** 0.66666= 83 hp

In the ballpark?

[Frits Overmars]

this just comes down to $$$...how much dev money and manpower went into the RSW/RSA? and who's pouring money nowadays into 50cc or below? At some point obviously no ROI. the enthusiast/single tuner can come pretty far and reach impressive results (cheers Wob and Dutch) but at some point the required effort will rise exponentially for small gains...

That sounds sensible, Koenich, except.... The pictures below show Dutchman Paul Lodewijkx chasing and beating Hans-Georg Anscheidt at the 1986 Dutch TT. 50cc world champion Anscheidt was riding the twin-cylinder 14-speed Suzuki works machine, Lodewijkx rode a home-built single-cylinder bike, designed and built by the man with the glasses: Jan Thiel. His budget: what he earned as a moped repair mechnanic, i.e. close to zero. His gains: just enough to buy petrol and make it to the next GP.
It was not Aprilia-money that made the Aprilia engines the strongest; Honda spent a whole lot more but did not succeed. I consider myself fortunate that I got to know Jan Thiel with his unbridled commitment as a friend. And whenever a task seems impossible, I say to myself: Jan could do it....

[Niels Abildgaard]

Apples and oranges, Niels.
The Aprilia power is measured at the gearbox exit; it would be about 57 hp at the crankshaft. It burns unleaded petrol with 5% oil and has spark plug ignition.
Both aeromodel engines have their power measured at the crankshaft. The 6,5cc engine burns methanol with 20% oil. The 2,5 cc engine fuel probably carries a noticeable percentage of nitro. Both have glow plug ignition.
The fuel will make an obvious difference. But the ignition system may make an even bigger difference.
For maximum power, a glow plug engine needs to have the same ignition timing as a spark-ignited engine. But practice has shown time and again that this is too critical for a glow plug: one missed combustion will kill the engine completely. For a glow plug to function reliably its ignition timing must be about 30° earlier than the max.power timing. And that will cost an estimated 30% of power.

In addition, I agree with Wobbly that the development of smaller engines is seriously lagging behind the development of Jan Thiel's 125cc RSA: we do not have three state of the art points.

Are there some model aircraft/boat classes where both spark ignited and glow engines compete?
The 2.5 and 6.5ccm engines have a ringless pistons and that can help produce as much power as they do
Has it ever been tried to modify a weedhacker engine with glow ignition and ringless pistons?

[Niels Abildgaard]

That sounds sensible, Koenich, except.... The pictures below show Dutchman Paul Lodewijkx chasing and beating Hans-Georg Anscheidt at the 1986 Dutch TT. 50cc world champion Anscheidt was riding the twin-cylinder 14-speed Suzuki works machine, Lodewijkx rode a home-built single-cylinder bike, designed and built by the man with the glasses. His name: Jan Thiel. His budget: what he earned as a moped repair mechnanic, i.e. close to zero. His gains: just enough to buy petrol and make it to the next GP.
It was not Aprilia-money that made the Aprilia engines the strongest; Honda spent a whole lot more but did not succeed. I consider myself fortunate that I got to know Jan Thiel with his unbridled commitment as a friend. And whenever a task seems impossible, I say to myself: Jan could do it....

Are there pictures of the two cylinder Suzuki somewhere?

[Frits Overmars]

Honda ended up with a fourcylinder 500ccm and a twocylinder 500 ccm. Are there some thrustworthy horsepower figures for these?
If we guesstimate 52hp for the 125ccm cylinders we can try to estimate the 250 cylinder power.
52*(250/125)** 0.66666= 83 hp. In the ballpark?

Not even in the same time zone, Niels . The 125cc Honda works cylinders of that era made about 44 hp at the gearbox exit which, according to your calculation method, would give their NSR500V 2x70 hp, a value that is not too far from their manufacturer's specification: 136 hp.

Are there pictures of the two cylinder Suzuki somewhere?

Hundreds. Any specific wishes?

[koenich]

Almost 35 years ago Frits...don't want downtalk the great effort and results we see from several people. Nor Jans achievements in any way.

But in the end it was Aprilias $ that could pay Jan to work full time on engines, a dyno facility, I'm certain a lot of engineers/technicans in the background making parts, all the prototypes,... which is necessary to achieve such results. My point just was that to develop a 25HP plus 50cc you'd need quite some time, parts and tools (= money), not talking about small batch industrialization requiring invest up front and then hoping to make a profit so you didn't bin your retirement fund.

[Niels Abildgaard]

Not even in the same time zone, Niels . The 125cc Honda works cylinders of that era made about 44 hp at the gearbox exit which, according to your calculation method, would give their NSR500V 2x70 hp, a value that is not too far from their manufacturer's specification: 136 hp.


Hundreds. Any specific wishes?

The estimation method of sonic max limit of two strokers is maybee not fundamentally wrong.
If You have a picture of the Suzuki like the last one You showed of Thiel special homebrewed it will be lovely

[JdG]

https://youtu.be/oJcnaM-hB8Q

Zundapp crankcase, std. Derbi cilinder modified. Build in a Dutch shed by 2 brothers.

Lots of hours spend though...


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[Niels Abildgaard]

https://youtu.be/oJcnaM-hB8Q

Zundapp crankcase, std. Derbi cilinder modified. Build in a Dutch shed by 2 brothers.

Lots of hours spend though...


Verzonden vanaf mijn iPhone met Tapatalk

Very,very good.

Your 24.8 rearwheel for a 50ccm and the 52 from RA125 is a datapoint more.

52*(50/125)**.6666= 28.2 minus 12% gives Your 24.8.
We now have Two measurement based datapoints and an idea of magnitude of losses for almost fully develloped two strokes

[Frits Overmars]

The estimation method of sonic max limit of two strokers is maybe not fundamentally wrong.

I would say that your method of determining engine power for engines with equal BMEP and different cylinder capacities via their angle.areas is basically correct.

If you have a picture of the Suzuki like the last one you showed of Thiel special homebrewed it will be lovely.

Like I wrote, I have plenty pictures but I cannot post them all, so I will show a small selection of the 50-twin you asked about (but I could also show the 50-single, the 50-triple, the 125-2, the 125-4, the 250-2, the 250-4, the 500-2, the 500-4 and the 750-3).