ESE's works engine tuner

[flyincat]

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

That is awesome! What material was that printed with? Did you have to use supports? If so, do you have any pictures with supports?

[SwePatrick]

That is awesome! What material was that printed with? Did you have to use supports? If so, do you have any pictures with supports?

I used something called 'tough pla' and used an Ultimaker printer with 'cura' software.
It generates the supports it self if clicked.

[katinas]

And 3D pistons

https://additivemanufacturingtoday.c...erative-design

[jbiplane]

Rotax max junior 125 cc cylinder
https://www.rotax-kart.com/upload/files/5370.pdf

Thanks for an idea extend search and estimate cart engine cylinders!

[jamathi]

Attachment 343420

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?

Attachment 343421 Attachment 343422

Squish was 0,75mm
Less gave much more power until 12500, but did not rev any further.
The 'clean' spots is were detonation usually begins....
They are a sign of turbulence I think
We succeeded to keep them to a minimum!!
There was no detonation on the dyno, never.
But severe detonation occurred at high rpm and small throttle openings, like 30%.
Due to insufficient piston cooling!

[katinas]

Thanks for an idea extend search and estimate cart engine cylinders!

Forget to write that this cylinder weight is 1349 g. maybe this is important.

[jasonu]

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

Attachment 343423

Nice Knipex!!!

[ceci]

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….

If this type of study was used to create real cylinders (at least Derbi itself)
In those years of backward engineering, it wasn't
were used to improve performance

https://upcommons.upc.edu/bitstream/...=3&isAllowed=y

[SwePatrick]

Nice Knipex!!!

Only the best

Used it to pull out the support from the 3dprint.

[ceci]

If this type of study was used to create real cylinders (at least Derbi itself)
In those years of backward engineering, it wasn't
were used to improve performance

https://upcommons.upc.edu/bitstream/...=3&isAllowed=y

This is the study I was referring to


https://upcommons.upc.edu/bitstream/...=1&isAllowed=y

[jamathi]

This is the study I was referring to


https://upcommons.upc.edu/bitstream/...=1&isAllowed=y

Nothing new.
A description with scientific words about copying a Honda cylinder.....
Nothing else was ever done!!!!!
And they NEVER improved performance
They needed the help of a university for this shit.
The reality was that some Honda-team mechanic brought the latest Honda cylinder each year.
Against payment of course.....
A model maker was then flown in from Italy to copy the cylinder as quick as possible!
And the university of Valencia made their scientific explanation after the season....
In order to make someone a 'Doctor', without having done something useful.
The reality is that the university of Valencia NEVER contributed ANYTHING to engine development.


The Honda-500-4 instruction book was made in a way that it could not be foto copied.

[teriks]

Squish was 0,75mm
Less gave much more power until 12500, but did not rev any further.
The 'clean' spots is were detonation usually begins....
They are a sign of turbulence I think
We succeeded to keep them to a minimum!!
There was no detonation on the dyno, never.
But severe detonation occurred at high rpm and small throttle openings, like 30%.
Due to insufficient piston cooling!

Now this is bloody interesting.
I have always believed that those "clean" spots is where the transfer streams provide plenty of cooling.
After reading this, its easy to understand that there for sure could be lots of turbulence around the piston edge..

So, what keeps those areas clean looking then? More heat burning the deposits, like Frits more or less described? Very light deto?

Might have been better to shut up to avoid proving my stupidity
Lucky me, have no throttle so at least don't have to worry about part throttle deto..

[Frits Overmars]

I have always believed that those "clean" spots is where the transfer streams provide plenty of cooling.... So, what keeps those areas clean looking then? More heat burning the deposits, like Frits more or less described? Very light deto?

Deto will certainly remove the deposits off a piston crown, not unlike sandblasting. It's a pity that it will also remove the aluminium....

[lohring]

You can see color variation on this piston before detonation burned a hole in it. I think the black area was the hottest and the brown area was cooler. The black area was the exhaust side. It was running a high nitro methanol based fuel with around 20% oil. I think the oil was mostly synthetic, but could have had some castor oil.

Lohring Miller

[katinas]

Maps on pistons from Honda RS 250 2002 manual.