Norton 500cc with 650cc intake valves

Hi All,

I have a friend who is running stock Dommi Model 7 iron head with stock exhaust valves with 650ss intakes. Do you know what the installed height of the valve springs is, or valve stem protrusion. Can not seem to find this info on the web, or in my books.

Thanks,
Skip

P.S. also , thanks you all for the offers on a crankshaft, looks like one is on its way !!!!!!!!!!!!!

Nobody seems to know.There is currently some discussion on this sort of thing in the Norton forum at Britbike.com .It may be worth reading.http://www.britbike.com/forums/ubbthrea ... Post489375
So could this :http://www.accessnorton.com/rocker-contact-concepts-practice-t15759.html

2 things to consider are the valve/rocker geometry and the valve spring seated load (including possibilty of coil-bind).

As nobody seems to know, the really important bit is to prevent the valve springs getting coil bound on full valve lift by the camshaft.
For a normal street engine I would aim for a minimum of 100 thou before coil bound. If it is more than this don’t worry. On a race engine you might be less but then you really need to be checking a lot more things as well.
HTH