How to tell if cam tunnel o ring is genuine....
Posted: Fri Nov 11, 2016 2:27 pm
As part of a deal i pcked up a number of gaskets and o rings,we all know the importance of using genuine stem seals and in paticular the cam tunnel oring(slug).Having 5 of these and needing one for my a4 build but unwilling to part with £45 for one at Cradly.I was told that the gen ones are heavier ,got hold of a set of accurate "chemical"scales and weighed a genuine one i had access to at the mo,it weighed 0.332 oz four of the ones i had weighed on average 0.22 oz but one was 0.315 oz,the four that weigh less i reckon are the copies and measure .2.80 inch thick, the gens are .2.85 inch.It seems the gens are made from a denser material hence heavier.(must have too much time on my hands) 
