ESE's works engine tuner

[Flettner]

OK, with a bunch of serious patent searching ,I think we have a handle on the stepped piston multi transfers with close coupled reeds
in the plate scenario.
But no one has even come close to the safe at 30,000 bottom end.
Tear your hair out you fuckers, till we get this sorted we really are tossing into the wind.

I got my bottom end sorted
I'll post a before and after, after being, picking all the bits up from where they spreed themselves round the yard

[Frits Overmars]

frits maybe you can offer some help. i followed your theoretical exh shape with top radius at 75% and corner radius at 8.1% and got whats show in the pic but when i try to draw it on paper i end up with less than 13.7% vertical half axis. around 12% is what i get. do you think im making a error somehow when i draw it ?
actually now i think about it, my exh width might of only been 65% of bore and thats where the error is. since your theoretical exh is based on a 70% wide window, do you have a guess what the roof and top corner radius should be for a 65% wide window and vertical half axis ?

Let's assume a port width of 65% of the bore. Then you can calculate the vertical half-axis yourself; that is why I posted my port shape concept in the first place.

The minimum safe vertical half-axis becomes
0,7 x (port width / cylinder bore)^4,57 x cylinder bore
= 0,7 x 0,65^4,57 x cylinder bore
= 0,09775 x cylinder bore

Converting this half-axis into center and corner radii can't be done with a simple formula, so I'll do it for you, once-only.
center radius = 88% of bore
corner radii = 5,2% of bore

But wait, there's more.
From your screenshot:
exhaust port height from top = 47,0 mm
exhaust port window height = 30,7 mm
You didn't stipulate the cylinder bore, the stroke and the conrod length and I don't fancy searching through the forum to see whether you gave them before, so I'm going to assume the values I need:
stroke = 77,7 mm
con rod length = 148 mm
exhaust timing = 172°
Now I'll leave it to Wobbly to tell you what to expect...

[Frits Overmars]

I got my bottom end sorted
I'll post a before and after, after being, picking all the bits up from where they spreed themselves round the yard

I do hope you were wearing your bulletproof shorts, Neil.

[husaberg]

I do hope you were wearing your bulletproof shorts, Neil.

Is the ryger made of Kevlar..............

[PFPRAIDER]

Most of it has seemingly been scrubed from the Internet. It appears to be a mop up and clean excersize. just saying............
http://forum.pyrotherm.rs/forum/inde...ge__pid__91798
Pretty sure it is not 30000 RPM though maybe the rev counter is in lira?
There seems to be a mention of it in the Search for this page but maybe only for Friends. bet lozza is a facebook friend of his though
https://www.facebook.com/luc.foekema...&type=3Special
Again? the same info
http://www.rygerengine.com/index.emissions.htm
its all German to me.......

http://www.rygerengine.com/
I had another page but I can't find it (I think I looked under cached pages)
....... have you looked on pitlane Ken?
I do know how to find obsolete and deleted information.. but not tonight.
Frits will be along soon to explain all.......... LOL


I haven't either?

Marketing
Create a buzz
Peak peoples interest
Limit information available.
What better advertising than word of mouth.

Just saying...........

Hi Guys if you look carefully you will find it must have a very long piston as the CIK Fiche shows it only has a 90mm long rod. Sorry spelt Ryger wrong in title,
just noticed you had all ready mentioned all this earlier.

[adegnes]

Was reading trough old posts and found this picture:



Now thats a bucket racer! The front number plate and rear fairing looks to be cut from the same trash can or wathever. Great idea! I think I'll borrow that patent in my pursuit of a more streamlined rear end.

[adegnes]

Is that tail-piece a side cut Bucket? Very nicely done! Top marks.

Yes a bucket for a Bucket. The front number board is the off cut from the bucket tail piece.

Old news, sorry...

[philou]

Trash goes well with minarelli am6 engine

[adegnes]

Trash goes well with minarelli am6 engine

Yep, both Derbi and Piaggio has better more well built alternatives.

[wobbly]

I will wait till peewee sends me the EngMod file to review, as even with only the Ex analysis page on here so far
I can see that the Aux are too high and all wrong in shape anyway.
The Ex by itself is pretty irrelevant till the transfer height is part of the analysis to generate the blowdown number.

[peewee]

Let's assume a port width of 65% of the bore. Then you can calculate the vertical half-axis yourself; that is why I posted my port shape concept in the first place.

The minimum safe vertical half-axis becomes
0,7 x (port width / cylinder bore)^4,57 x cylinder bore
= 0,7 x 0,65^4,57 x cylinder bore
= 0,09775 x cylinder bore

Converting this half-axis into center and corner radii can't be done with a simple formula, so I'll do it for you, once-only.
center radius = 88% of bore
corner radii = 5,2% of bore

But wait, there's more.
From your screenshot:
exhaust port height from top = 47,0 mm
exhaust port window height = 30,7 mm
You didn't stipulate the cylinder bore, the stroke and the conrod length and I don't fancy searching through the forum to see whether you gave them before, so I'm going to assume the values I need:
stroke = 77,7 mm
con rod length = 148 mm
exhaust timing = 172°
Now I'll leave it to Wobbly to tell you what to expect...

my apologies frits. i should have mentioned that a simple answer would of been fine as im sure you havent much time for these type of questions . really the question i was getting at earlier was if i would be ok with a flatter roof, since the window width will likely be less than 70%. ill try your 88% value . i found my old calculator from college and it says based on 90.5mm bore and 58.5mm flow width the vertical half axis to be 9.5% (8.6mm) so ill keep that in mind also

wobbly i can send it as its in a pack file. what you see in the pic is as the cylinder was cast for the most part. except the welding of the main port. btw where do i send it , wobbly@yahoo.com ? would you rather see it after ive finished or before i get started ?

keep in mind ill be completely restructuring the trans tunells per rsa style radiuses but i dont know how much that will affect the STA values. i hope to have some templates in a few days but its not so easy as the studs wont allow exact rsa radiuses so ill need to fudge it alittle

[wobbly]

I will have a look when its finished.
The transfer duct geometry does not affect the STA, only the scavenging model used and the duct entry conditions.

[peewee]

wob just a question on the C window or D window in my case. i got noticing on a few cylinders (rsa, ktm250, yamaha twin) that the C width is consistant at approx 36-37% of bore. this cylinder im working on has D (A,B,C are side ports) width at 38% but it has a 8mm bridge going vertical through it. if you subtract the bridge, the two D windows combined only eqaul 29% bore. theres no way in hell ill get the C all the way around to the D, which will leave some empty wall space. do you see any good reason i shouldnt make the two D windows wider ? the total width of D would be closer to 45-50% bore but the windows (minus the bridge) would only be around 35-40% bore depending how wide i made them and depending how far around back i can get C. i started working on the inlet but you can see what i meen about D

if your thinking to remove the small section of bridge between the D windows, im not sure if thats a good idea. i would be very nervous about the lower section cracking. the lower portion of bridge through the big windows is only 5mm wide and tapers to a smaller bullnose as it goes toward the reed block, if that makes sense

[wobbly]

The twin D port flow will be less than a single port due to the greater enclosing wall area, so you will need extra port anyway.
But use EngMod and see what the STA is going to be once you have widened C to where you are happy.
Its the old story that wider and lower makes it easyer to generate the blowdown without having to resort to an excessively high Ex timing
and or enormous Aux.

[Frits Overmars]

this cylinder im working on has .. a 8mm bridge going vertical through it.... do you see any good reason i shouldnt make the two D windows wider ?

Where are your piston ring gaps?