ESE's works engine tuner

**wobbly** · 2nd June 2022, 10:02

Nearly every Tubo pipe was 800 from the piston , and the duct roof was at 196* duration, the port radius started at 202* but using a 0.7mm x 5mm wide dead stopper blade bent at 45* = 1mm actual
height difference , it measured 198.
This is why when you do a STA analysis on the RSA it appears to have insufficient Blowdown , but the clever port radius increased the duct Cd so well that in reality the Blowdown flow
matched the Transfer power capability perfectly. Makes it hard for a single dimensional sim to replicate this correctly unless the radius effect on flow is factored into the code.

**F5 Dave** · 2nd June 2022, 12:34

Surely most engines have chamfers that vary from Conservative to pretty aggressive?

**wobbly** · 2nd June 2022, 15:34

F5 - Just like completely unnecessary chamfers on transfer ports , they reduce power.
Jans idea of putting a proper flow enhancing radius on the Exhaust ports timing edge was a piece of unadulterated genius.

**Tim Ey** · 2nd June 2022, 17:01

I have made a 54/107mm crank for the RGV250 / Aprilia RS250

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The first one from the pictures was made by myself, with a primatist conrod. The next charge will be totally made by primatist. When we tested that on track, we will order some more. PM me if you are interested.

**monkeyfumi** · 2nd June 2022, 17:40

2 centre bearings, no centre seal?

**koenich** · 2nd June 2022, 18:29

While on the subject of EngMod files - does anyone have an input file for the Bidalot RF50WR cyl?

**Tim Ey** · 3rd June 2022, 04:38

Originally Posted by monkeyfumi

2 centre bearings, no centre seal?

2 SKF bearings with seal covers & special grease filling. They are used in snowmobiles in the same application.
The seal covers work like a charm regarding sealing. Probably as airtight as a labyrinth seal...

**Frits Overmars** · 3rd June 2022, 07:42

It's friday june 3 in Thailand

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**Peter1962** · 4th June 2022, 02:49

Proficiat met je verjaardag, Jan.

Happy birthday !

**Javi** · 4th June 2022, 06:19

Feliz cumpleaños MR Thiel.Muchos recordamos su gran trabajo con Ricardo Tormo,Bultaco y Derbi.Le deseo mucha salud.

**Muhr** · 8th June 2022, 22:04

Originally Posted by wobbly

Nearly every Tubo pipe was 800 from the piston , and the duct roof was at 196* duration, the port radius started at 202* but using a 0.7mm x 5mm wide dead stopper blade bent at 45* = 1mm actual
height difference , it measured 198.
This is why when you do a STA analysis on the RSA it appears to have insufficient Blowdown , but the clever port radius increased the duct Cd so well that in reality the Blowdown flow
matched the Transfer power capability perfectly. Makes it hard for a single dimensional sim to replicate this correctly unless the radius effect on flow is factored into the code.

Thanks Wob
Just doing some tests now with r1 cylinder and programmable ignition. we'll see what length we end up with.

**TZ350** · 9th June 2022, 08:53

.
2Stroke Stuffing. 2 x rotary valves in carbon fiber. https://youtu.be/eA62z-ib4VM

DIY Industrial grade CNC machine. https://youtu.be/cqYJS27aC4w

**pete376403** · 9th June 2022, 11:39

Originally Posted by TZ350

.
2Stroke Stuffing. 2 x rotary valves in carbon fiber. https://youtu.be/eA62z-ib4VM

DIY Industrial grade CNC machine. https://youtu.be/cqYJS27aC4w

that CNC machine - just WOW!

**ceci** · 13th June 2022, 23:05

I always thought that Alex's project was the most appropriate for it to be twin-cylinder, since from the first video I saw how he wasted twice as much fuel.

I am not the only one, the creator of the Bimota V2 500 engine, he has just been granted a patent in this regard "2022-04-20"