Screw the barrel, you want the whole motor - sweeet gearbox and the rest can be fixed.
why not just make a head and weld a water jacket on a GP100 cylinder,or use a RG400 cylinder,you may end up with the same problems ND has with his RGV100 on the fast tracks,you would need a sleeve around 5-6mm thick to stop the bridge getting to hot.the RGV150 cylinders have a hole in the alloy part of the bridge for water to pass through for better cooling
The GP and RG400 cylinders with their single exhaust port don't allow enough blowdown time area to make decent power. But I could sleeve an aircooled GP125 cylinder and add a T or tripple exhaust port, but thats not so easy to do with a RG400 cylinder as there is not much meat around the exhaust port area on one of those.
I am not sure what the cause of ND's problems was, or what the sleeve he used was made of, or if he fitted an iron sleeve within the original steel sleeve and had a bad thermal path. I just don't know much about how he went about things but I have heard he made a new sleeve and has pretty much got on top of the long track reliability issues now.
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My plan is to use a large diameter, thick walled, plated alloy sleeve and bore the cylinder out as much as possible to maximize the heat transfer area between sleeve and alloy cylinder jacket. And of course it will be put together with CPU heat transfer paste.
I like your idea of using an RG150 cylinder as that would allow a thick sleeve like you suggest and possible a water gallery through the sleeves exhaust bridge too.
Wobbly has been planning everything for me around sleeved down RGV250 cylinders, but I like the idea of a larger sweeping bend up to the transfer port.
http://www.2stroke-tuning.nl/media/pdfjes/porting.pdf
Yamaha in their SAE paper said that the number one thing that affected power delivery was the angle of the port entering the cylinder and number two was the radius of the transfer duct, then the upswept angle of the port roof.
I will get Wobblys opinion on the shape and suitability of the RG150's port ducts which look a little different to the RGV's.
Some Links I've been reading that may be useful regarding handling etc..
http://www.motorcycle.com/how-to/cha...sics-3444.html
http://www.fatbaq.com/mainpage.phtml?topic=sag
Current Model 125 Specs Straight from the maker:
http://world.honda.com/HRC/products/...e/rs125r/spec/
Heinz Varieties
Another on aerodynamics:
http://www.sportrider.com/tech/146_0106_aero/index.html
Heinz Varieties
The 1st RGV conversion I did 4 years ago odd was a 150 based cylinder with a steel liner.
That made over 28 RWHp at only 11500 even with the std reed in place.
But its so long ago I cant remember what the actual duct differences are with the 125 cylinder.
Need to have them side by side to see - but with the bigger bore the PV positioning will be different, not an issue as this setup needs to be remade for the 50 bore anyways.
Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.
http://cgi.ebay.com/ebaymotors/Kawas...item588c1c6d79
Kel mate only $250US When you buy it, have it send it to me and I will forward it to you for a 'small' charge...
Ok it might be a Honda 50 and 4-Stroke but you still have to be impressed with 320 BHP/l
Scraped from the net............ 1966 50cc twin 4 Valves a cylinder GP Racer.
But Honda was always about the engines, and they reached their pinnacle in the 1960's with the RC116
Bore = 35.5 mm
Stroke = 24.14 mm
16.5 BHP @ 21,500 RPM...Redline at 22,500 RPM
And that is 320 BHP/Liter
Yes...that's a dry clutch
Yes...those are flat-slide semi-downdraft carbs (And, yes, they are Keihins. Just 40 years older than the FCR model they sell today)
And yes...it is mostly magnesium (except, obviously, the cylinder head)
And just because the cylinders were little didn't mean Honda was going to go all cheap-ass and crude.
It is still a four valve per cylinder design...they just happen to be very small valves (13mm In / 11.5 mm Ex...3.5 mm stems)
............
This was before the Aprilia, Jan is wearing the yellow T shirt.
Interview with Jan Thiels about his work with Rumi ............
Translated version:- http://translate.google.co.nz/translate?hl=en&sl=fr&u=http://nrmoteur.skyrock.com/166.html&ei=Lm1ETdvvK8ieceu9qZIO&sa=X&oi=translate&ct=result&resnum=1&ved=0CBwQ7gEwAA&prev=/search%3Fq%3Dhttp://nrmoteur.skyrock.com/166.html%26hl%3Den%26client%3Dfirefox-a%26hs%3Ds8b%26sa%3DG%26rls%3Dorg.mozilla:en-GB:official%26channel%3Ds%26biw%3D1024%26bih%3D574 %26prmd%3Divns
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