ESE's works engine tuner

[lohring]

Could this be the model used by VD Jimenez at the University of Valencia To produce this CFD movie of the Aprilia cylinder?

Lohring Miller

[koenich]

Does anyone have or can find the full thesis? Tried to google it but no luck...

[jamathi]

Does anyone have or can find the full thesis? Tried to google it but no luck...

The actual cylinders were made without any such studies.
So it is only backward engineering......
A whole LOT easier!!!
And not very useful when making a cylinder.
Fairly useless, but that is how you get a Doctor's title….

[Frits Overmars]

Could this be the model used by VD Jimenez at the University of Valencia To produce this CFD movie of the Aprilia cylinder?

Does anyone have or can find the full thesis? Tried to google it but no luck...

Yep, but it's too big to upload here. Try googling for Tesis Doctoral VDJiménezInPress_Version3.pdf

[jbiplane]

Not sure if anyone has had a good look at this as an option or not. https://www.nanoefi.com

This guy in apha stage for years and years...
The open project https://rusefi.com/forum/
much better and based on ARM processor. Many Speeduino contributors moving to RusEFI

Could this be the model used by VD Jimenez at the University of Valencia To produce this CFD movie of the Aprilia cylinder?

Ansys Fluent have tutorial how setup CFD for scavenging. Very detailed. But it is very time consuming.

[lohring]

That article is the only study I have found that gives a clue about flow in a tuned pipe engine. It's helpful for visualization, but there's nothing like an inertial dyno for studying scavenging's effects. Power is a very sensitive measure of scavenging efficiency. Blair used 3D printed cylinders in a single revolution test engine to study scavenging. Is this still more useful than CFD? It just takes a lot of time to study small cylinder changes in real, running engines. I'm interested in any ideas.

Lohring Miller

PS I can't find the paper by googling Tesis Doctoral VDJiménezInPress_Version3.pdf or various variations.

[Frits Overmars]

I can't find the paper by googling Tesis Doctoral VDJiménezInPress_Version3.pdf or various variations.

This is the best I can do at the moment Lohring.

[Michael Moore]

try this

https://riunet.upv.es/bitstream/hand...s_Version3.pdf

[TZ350]

This guy in apha stage for years and years...
The open project https://rusefi.com/forum/
much better and based on ARM processor. Many Speeduino contributors moving to RusEFI

Thanks. I will check it out....

[jbiplane]

Hi guys. I asked here a lot and always got good ideas. At the moment I looking for my projects lightweight 85...180cc liquid cooled cylinders kits (cylinder, piston, pin rings) which are nicasil or coated, nonexpensive and easy to buy in quantity. Without power valve, and better without intake on cylinder. It should not be too powerfull.

I want to have from this cylinder 20 hp+ at about 9500 rpm with rather small exhaust. At moment found only Yamaha Yz85 and Gilera Runner 180. BTW YZ85 cylinder weiight more than 180cc pf Runner! Both possible buy in China for below 100 USD. Nicasil is not a must, weight should be minimal. May be exists intermediate variants? If no good variant I'll produce by myself if will got good reference.

[katinas]

Hi guys. I asked here a lot and always got good ideas. At the moment I looking for my projects lightweight 85...180cc liquid cooled cylinders kits (cylinder, piston, pin rings) which are nicasil or coated, nonexpensive and easy to buy in quantity. Without power valve, and better without intake on cylinder. It should not be too powerfull.

I want to have from this cylinder 20 hp+ at about 9500 rpm with rather small exhaust. At moment found only Yamaha Yz85 and Gilera Runner 180. BTW YZ85 cylinder weiight more than 180cc pf Runner! Both possible buy in China for below 100 USD. Nicasil is not a must, weight should be minimal. May be exists intermediate variants? If no good variant I'll produce by myself if will got good reference.

Hi,
Rotax max junior 125 cc cylinder with intake on cylinder, but with friendly to piston small center intake window and two big passages directly to B trans. One exhaust window without power valve. For testing you can find many cheap used cylinders in good conditions.

https://www.ebay.co.uk/itm/Rotax-max....c100010.m2109

https://www.rotax-kart.com/upload/files/5370.pdf

[andreas]

try this

https://riunet.upv.es/bitstream/hand...s_Version3.pdf

Sagrado cabrón

[SwePatrick]

I just had to test the 3d printer at work =)

[flyincat]

By looking at the piston.

Hi Jan, I apologize for digging up an old post, but the picture of the piston you posted had me wondering. Your reply, and picture, were in regards to how you can tell if flow is attaching to transfer walls. My question is on the piston pattern. The piston you posted doesn't have a clean band around the outer diameter. The clean outer band seems to be common with super tight squish. Does the pattern you posted come from a tight squish motor? Similar to reading a spark plug, how much can we ACTUALLY tell about an engine by looking at the piston burn pattern? Example: BLACK = HOT. Can we tell much more than that if we start factoring all the variables (Jetting, fuel type, port radial, port axial, piston shape, head shape, etc....) and interactions?

Here are a couple of google searched piston wash charts. Clearly these scales are 'characteristic' of different engine configurations. Is there anything we can tell about these engines?

[Frits Overmars]

BLACK = HOT

Or not. I've seen pistons that developed a clean spot in the center of the dome, where apparently the soot had been burned off.
The more power the engine produced, the bigger the diameter of that clean center spot.