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I've got a 2S camshaft to fit into my 850 (RH10Head) - so I presume the fitment would be as a Combat cam. The workshop manual states that fitted length for the Combat outer inlet valve spring is 1.321". Measuring my head I have a fitted length of 1.259" (perfect for a STD Cam!) and that's without a heat insulation washer. I've got to find some 0.060" extra clearance - how did Norton do this on the Combat - were the heads machined differently?
I assume you've ready the…
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I assume you've ready the…
No i didn't know the pisons needed pocketing. Don't really understand the drawings so expect more questions - thanks
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Commando Service Notes Errors
Uh - Oh - There's a reason why I couldn't understand the piston drawings - someone has re-drawn them incorrectley - there are multiple errors
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I assume you've ready the service bulletin on this: https://www.nortonownersclub.org/html/archive/rh/Svs_Release/114/index.html
I wouldn't worry over much about spring fitted length. It needs to be enough to preload the valve, so shorter than the prescribed length is fine. And not go coil-bound at full lift, in fact 0.020" from coil-bound would be a reasonable target.
Would normally use an RH4 head for this; I've not had any issues fitting high-lift cams with those heads.