ESE's works engine tuner

[porttiming124]

very good idea
I will do it in 7 port today and I will get back to you with the STA

[philou]

Any idea which resin to use for mould intake rubber?

[porttiming124]

here is the result with 7 port with the true height !the blowndown is now insufficient

[philou]

porttiming124 use "print screen" and past to Paint

[Frits Overmars]

Good morning all !
this forum is fantastic! thank you for sharing your expertise in 2-stroke engines!
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sorry I did not copy the correct link!
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Hello !
here is a snowmobile cylinder!
look at the big radius in a corner of: B: port!
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it is a 2 ring piston with ring gap between the b and c port!
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I also removed the radius!
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Regarding the A port with two steps(2.8mm) in engmod I averaged the 2 heights to have the right area in my opinion!
on the other hand by doing this I am aware that I do not have the right blowdown!
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here is the result with 7 port with the true height !

Portiming124, are you aware that you used 12 exclamation marks in 6 days on this forum alone?
You are in danger of exceeding your allocated amount of exclamation marks before the end of the month.
But do not fear, there is solution: in this forum it is permissible to end a sentence with a plain and simple period.
Sorry, I couldn't help myself . During my stay in Germany I seem to have developed an allergy to exclamation marks and prohibition signs

[porttiming124]

Sorry frits I will be careful.

[porttiming124]

porttiming124 use "print screen" and past to Paint

thank you philou

[andreas]

Haha, Porttiming your lack of b-d area is very common. It seems there is room to widen the auxillaries quite a bit, maybe even raise them a little relative to the main but there is a thin line before ex pulse get compromised. Remaining after that is only to raise all of them, this has a y- pipe? I think they work well with long ex-durations btw, but the Engmod can probably tell you all this.

[wobbly]

Achtung - not only are these Dutchmen bloody clever 2T tuners, they have a better grasp of propa English than many of us natives.
But re the 7 port ski engine , now that is a seriously wierd scavenging regime.
More especially as the B port is lower than the C , that are now C and D.

But , I have a feeling the axials are going to be wierd as well - post the transfer layout page .
I use Gadwin Printscreen , free and way more user friedly at copy/pasting any part , or all the screen to any file or printer.

I would lift the C ports about 1/2 way between the A and D , this will give more transfer STA again.
Then mod the Aux to get the Blowdown STA back in line , looks like the front top corner could go closer to the main Ex as well.
And get rid of those horrible port chamfers , completely unecessary.

[dutchpower]

In plain english How the hell you get those numbers in real live engine

[wobbly]

God save us - the axials are a nightmare 8-17-9-50.
How people ( I wouldnt be kind and call them engineers ) actually got paid to produce this complete rubbish is beyond me.
No other two stroke in the world has ever had such a complete mess , looks to me like its not even possible to "fix " by dropping the cylinder and regrinding everything.
Maybe if the Aux floor is lifted , you could start again - as the Aux roof is 6.2mm lower than the main - wtf , gets weirder every time I look.

[porttiming124]

look at the port layout (I put the cylinder upside down so that you can see the roof of the 'a' port) and also I removed the radius in the upper corner of the 'B' port as wobbly to recommend thank.

[porttiming124]

Achtung - not only are these Dutchmen bloody clever 2T tuners, they have a better grasp of propa English than many of us natives.
But re the 7 port ski engine , now that is a seriously wierd scavenging regime.
More especially as the B port is lower than the C , that are now C and D.

But , I have a feeling the axials are going to be wierd as well - post the transfer layout page .
I use Gadwin Printscreen , free and way more user friedly at copy/pasting any part , or all the screen to any file or printer.

I would lift the C ports about 1/2 way between the A and D , this will give more transfer STA again.
Then mod the Aux to get the Blowdown STA back in line , looks like the front top corner could go closer to the main Ex as well.
And get rid of those horrible port chamfers , completely unecessary.

wobbly I checked with the piston to widen the auxiliary port exaust towards the center of the cylinder as you have drawn in red and I am at 1-2 mm from the pin of the piston
so yes I can go there a little on this side but not much, I will also go there on the side of the main port,
if I put the auxiliary ports 6 degrees lower than the main port, is that correct?
thank you

[F5 Dave]

That's odd. Looks like a very nice casting though. Transfer the aux further out to the ex union. Transfers look pretty shallow from a sweeping inner point of view.

[wobbly]

The Aux are at 181* Duration now , Vs the 201* of the main port - I would go up to 191* but the transfer axial angles are the biggest issue.
How you fix them to be something normal like 25* 15* 55* I really dont know.