640 Pre 03 to 03+ cylinder swap
 

I picked up an older cylinder for my 03 spare engine build and had to do a small mod to make it work, so I figured I would share it:
http://i302.photobucket.com/albums/n...s/IMG_4046.jpg
The pre 03 is on the left and takes a much larger dowel
http://i302.photobucket.com/albums/n...s/IMG_4048.jpg

http://i302.photobucket.com/albums/n...s/IMG_4053.jpg
Made up a bunch of slugs to convert the hole size
http://i302.photobucket.com/albums/n...s/IMG_4051.jpg

http://i302.photobucket.com/albums/n...s/IMG_4052.jpg
The dowel slug in place:It can be used to fit the 03 + cylinder to the older cases or the older cylinder to the 03 + cases

The pre Hi- flo engines take a thicker base gasket so I need to establish if the 01 cylinder is a fuzz shorter or if the 03 just ran a slightly higher compression ratio... I will go with the thicker pre- 03 gasket regardless when I assemble the spare engine...

Thanks Gunner,
That was a black hole.
bill

Yep , it's good to have a machinist friend to help out on the odd project...

Neat job. I like elegant solutions. :1drink

Gunner,
Now you have me thinking and wondering, is it settled that a Hi-flow head/cam will fit on a low flow cylinder and vice versa.

I have forgotten if that is settled.

Your ideas?
bill

Well guys there is a factory solution to that (as I believe):

part # 579.30.023.000 ZENTRIERSTIFT GESTUFT 4/9,8 CENTERING PIN GRADED 4/9,8

no need to grind and co. :)
One need 2 of them to make it work.

Hi Bill,

Yes, a high flo head will mount on a lo-flo cylinder, that is the combo I will be using on my spare engine build...

I have quite a mix of parts from both pre and post 03 going into this engine...

Yep, looks like the exact part needed to do the swap... When the later model LC 4 -400 went to a juice clutch they used the Hi Flo engine cases... Instead of changing the 400 cylinder because of the different sized dowels KTM did the exact thing I did to make it work... The downside is that those parts will likely get backordered to the factory...

Here in Eastern Europe we can get almost every part from the KTM factory in just 5 days - sometime even less, maybe 3 :)

Most of the 640 parts I order are usually in the dealer in 3 days from the warehouse in Ohio, if it has to come from the factory then it's 2 weeks...

I ran a part # 579.30.023.000 search through some North American KTM dealers and no results came up... Even special order part #s usually still yield results when run through a search, I wonder if that part is even still available?