ESE's works engine tuner

[speedpro]

Given the evasive responses I wondered if he was related to Wobbly's mate.

[Muhr]

Friend tested KTM SX 65 radiused piston top edge and without any head matching modification, power rise 0,8 hp.

I have never seen a better school class room than this, Frits.

what did he do with blowdown / duration during the test?

[Tim Ey]

Friend tested KTM SX 65 radiused piston top edge and without any head matching modification, power rise 0,8 hp.

The main question on this topic is: Does your engine perform "better" due to the better discharge coefficent of your ports, or does it perform "better" because it has higher timings?
I'd love to see the compared dyno sheets of
-the original setup
-radiused edge
-original piston with the cylinder raised 0,25 / 0,5 / 0,8 mm.


Because what I have seen on the radiused piston topic is similar to the "piston shamrock"
as used by...
http://www.mofapower.ch/viewtopic.ph...366&start=1160
...basic tuners.

[katinas]

So 0.8Hp with a piston edge radius, but where ?
Did it lose 2 Hp at another point in the powerband.

Yes, it lose 1,5-2 hp at mid, add 0,8 hp on top, add 3-4 hp over peak. This tests done without any other modifications, so trans/ex duration little higher and head shape not modified for radiused piston.
All would be more clear with lowered cylinder (for same duration) and adjusted head shape/volume.
For me its very interesting too and if he do some tests again, I write something

[Frits Overmars]

Yes, it lose 1,5-2 hp at mid, add 0,8 hp on top, add 3-4 hp over peak.

That can be either good or bad. I'd like to do a power range comparison. Can you post rpm-hp or rpm-kW listings of the original and the modified engine Katinas?

[ceci]

I am rookie in the forum and I will not answer as you do. Better that the images speak, being of parts of 2T engines you understand them without words

[Flettner]

I am rookie in the forum and I will not answer as you do. Better that the images speak, being of parts of 2T engines you understand them without words

does it run? or is it still just a picture.

[ceci]

does it run? or is it still just a picture.

for now it's just a picture, does it run? God and time just know it

[Flettner]

for now it's just a picture, does it run? God and time just know it

we are all rookies, no problem, speak up.

[WilDun]

"Pictures are worth 1000 words" - (that's what they say anyway) but not here! - here pictures and words always work well together...... prove that it's not just a silly guessing game.

[husaberg]

I am rookie in the forum and I will not answer as you do. Better that the images speak, being of parts of 2T engines you understand them without words

Ceci What they are asking is if you will you post a link to your facebook page?
por favor haga un enlace a disposición de su página de facebook

[Neal]

wobbly please get in touch with me .

[Neal]

So 0.8Hp with a piston edge radius, but where ?
Did it lose 2 Hp at another point in the powerband.

Wobbly please get in touch with me

[katinas]

We have some doubt about rpm., maybe this needed some dyno calibration and more practice with this new thing , but for comparison tests its no mater.

Before tests - engine Ktm SX 65 2016, cylinder tuned, head - 4,8 cc with spark plug, gasket under cylinder 0,8 mm.

1. Black: std piston, head- 4,8 cc, squash - 0,65 mm, max ign advance, RON 98.

2. Green: rounded piston (0,8 mm X 0,8 mm), no other adjustments , so head- 4,8 cc plus volume of skimmed piston material (not measured) Ron 98.

3. Red : rounded piston, head matched to piston, head volume - 4,5 cc, max ign advance, squash - 0,65 mm, Ron 102.

4. Blue: same like 3. just ignition retarded to middle point (like std).

Black and Blue very similar at mid.

Power very sensible to engine temperature, so this graphs more or less bests from all tests. Of course, would be more informative test, if Ex/Trans duration and head volume (with matched to piston) be the same like with std piston, but maybe, later after track tests.

Add my drawing graphs for quicker comparisons.

[katinas]

[QUOTE=Tim Ey;1131090210]The main question on this topic is: Does your engine perform "better" due to the better discharge coefficent of your ports, or does it perform "better" because it has higher timings?

This is the main most interesting question, but I don't know, because he did not lowered cylinder and want to try on track with this little higher timing duration.
This is not my engine and I just can say thanks for him, about this all tests info.