It is not obvious but the oil drain on a Norton single is not a straight drilling...due to the fact the head and the crankcase do not align due to the fact they used the same crankcase for the 350 and 500.
I acquired a very old ES2 barrel and am now boring it out to 85 mm...removed top fin and the rope under the fin is to reduce ringing when on the lathe. The cloth under it is to catch it when it comes off the chuck -at slow revs!
Plan 'B' is to fit a Vincent barrel with a spacer on the sleeve .
...these are wonderful photos of the Perthshire Gask circuit. They give a flavour of the open countryside of Perthshire.
If you drive from on the A9 heading north toward Perth you will see a sign saying to the left 'Findo Gask' . The circuit was a WW2 airfield and is all now disappeared for housing and returned to farming.
I seem to be forced by circumstance to bore out the 350cc to be a 500cc.... the current set up is a long conrod which allows a triumph 650cc twin t120 piston . It has a compression height of about 26mm which is the same as a Honda 400 XR. Hence I am experimenting with the possibility of 85mm X 88mm giving the 500cc dimensions of BSA Gold Star . However I am very conscious that I do not have the breathing capabilities that machine has/had. However I am looking forward to the weekend of 12/13 August for the GB memorial sprint at East Kirkby. ...it has become a sprinters version of the Goodwood revival.