ESE's works engine tuner

**tdc211** · 28th July 2013, 14:05

This raised ex floor engine is totally different in port timings and head design than the bigger engine.
Has more blowdown timing by 1 degree and different transfer timings and 3% less on the squish area.
I figured might as well change it, sense it is a smaller engine and see what happens with the raised floor.

**TZ350** · 28th July 2013, 15:47

After your tests it would be interesting to know if you think there is a worthwhile improvement and where like mid range or just coming onto the pipe, top end etc. Graphs would be good. I am making a new cylinder and it would be encouraging to know how the raised port floor is working out for you.

**richban** · 29th July 2013, 11:22

Well I have my SP heads. Thank you very much Scott. As I will be machining them for compression and squish and o ring. I was wondering if trying to put a toroid shape in there will be a good idea. I am not sure there is enough meet in the dome to get much on a curve up to the plug.

Also the tape measure showed more of the RGVs short comings. It is very long. 1380. 40mm longer than my NSR. I looks like Mr Suzuki only messed with the chassis when they released the VJ23.

**kel** · 29th July 2013, 11:43

Originally Posted by richban

looks like Mr Suzuki only messed with the chassis when they released the VJ23.

No, no, no

The VJ23's motor is different in almost every respect, different angle V config, different bore and stroke, different porting etc etc.

For discussion on after market heads try this link. http://www.apriliaforum.com/forums/s...veronesiracing

Back in the day some people skimmed the heads for production racing, top of the barrell too. But then the chrome flacks so I wouldn't recommend that.

**richban** · 29th July 2013, 12:26

Originally Posted by kel

No, no, no

The VJ23's motor is different in almost every respect, different angle V config, different bore and stroke, different porting etc etc.

I was talking about the chassis not the engine. I am well aware of the differences in the complete bike. Also I was not talking about skimming the barrel. I was talking about the head. Maybe I should re-read what I wrote but it seamed straight forward when typing it.

**kel** · 29th July 2013, 14:07

Originally Posted by richban

I am well aware of the differences ... I was not talking about skimming the barrel ... it seamed straight forward

It was general banter.

**wobbly** · 29th July 2013, 15:45

To do a toroid properly you need to drop the plug tip to approx 6mm from the piston crown.
Means welding the chamber and counterboring the plug seat face.
Very difficult to do repeatable and accurately unless done on CNC.
I model the piston dome and the head shape in SolidWorks to generate a solid then I have an accurate curve the toolpath follows and a calculated volume.

**F5 Dave** · 29th July 2013, 16:36

The SP heads (from the 2secs I held them yesterday) are very shallow large radius chambers like a new moon slither. Never seen heads quite that shape, certainly unlike std (though memory of std RGV head much more foggy, but sure it was taller & on-the-piss plug position).

Would be interesting to throw a plug in & see how low it goes to a flat surface.

I've made templates out of Kneedit (pushed in a chamber & sectioned) I want to replicate, but to do two the same for a twin would be too hard for my lathe skills.

**richban** · 29th July 2013, 16:51

Originally Posted by wobbly

To do a toroid properly you need to drop the plug tip to approx 6mm from the piston crown.
Means welding the chamber and counterboring the plug seat face.
Very difficult to do repeatable and accurately unless done on CNC.
I model the piston dome and the head shape in SolidWorks to generate a solid then I have an accurate curve the toolpath follows and a calculated volume.

I will apply the K.I.S.S rule to this one. Sp head will stay normal shape.

I might try it with the old heads. From what I can see they are the same casting, just plug location is different.

Wobbly did you mess with the RS chassis much on the 400 project? From what I have read so far they seem a little lazy in the front like the RGV. I have not riden one yet so can't comment from personal experience.

**richban** · 29th July 2013, 16:56

Originally Posted by F5 Dave

I want to replicate, but to do two the same for a twin would be too hard for my lathe skills.

I have done a little solid modelling before so might try that and employ Sketchy's skills and his great little CNC setup. I will post a pic of the heads later.

**wobbly** · 29th July 2013, 20:09

I fitted shorter dogbones, that helped make room for the fat pipes, and the big Marchesinis and slicks lifted the rear a heap.
Plus Andys one has CNC tripples holding the RS250 2006 forks with less offset that dropped the trail as well.
The slow steering isnt surprising as the whole bike is so close to a sexed up RGV its ridiculous.

**Flettner** · 29th July 2013, 20:16

richban, we can CNC from a solid model too. We have done quite a few for Wobbly.
Autoflight Ltd
07 824 1978

**Frits Overmars** · 29th July 2013, 20:42

Originally Posted by wobbly

.. tripples holding the RS250 2006 forks with less offset that dropped the trail

Huh ?

The slow steering isnt surprising

Indeed it isn't; not when you reduce the offset, which will increase the trail.

**wobbly** · 30th July 2013, 07:40

Shit I cant peek sideways at a lesbian without you looking over my shoulder Frits, dead right about the offset number - of course.
Glad someone is awake.