18 years ago
sizes refer to increase in bore diameter, or to thickness of material
removed from cylinder wall?
I had always assumed the former, but, I have just had to order a new ring
for S-T Type N (yes I know!) which wears a brass tag reading +0.010. The
bore however actually measures 1.7690" (digital verineers on unworn area).
Assuming standard bore is 1.75", that is pretty much 20thou oversize. So,
have I been wrong in my assumption or has the engine had another rebore?
Margaret Maddock (engine-parts.co.uk) advised sending an old ring to avoid
any mistake, which I have done.