I've bought a 2S cam - so that's going in! along with all new rods, mains, valves, pistons and bores. I've also bought a nice glass Burette and before it gets broken it I'll measure the CC's. I would like to aim for a 9.5:1 CR but I believe it's way below that as it is.
At the moment there is no base gasket but a 0.040" copper head gasket, I've set the cam at 158" lift on the inlet pushrod at TDC and the valves are touching the pistons.
Now my concern is that in Norton's notes the valve cut outs are machined out to 1.438" diameter but the inlet valves are 1.490" in diameter and so in my mind the valves would hit the pistons!
Perhaps someone who has the ability to attach images here could do so for me from 'Norton 850 Commando Stage One Perf Mods' up in the 'Resources' tab at the top of this page or just go straight to
https://www.accessnorton.com/resources/norton-850-commando-stage-one-perf-mods.15/
Cheers