2Diffsworking

The problem stems from the valve seats not being coated with that old fashioned stuff call TEL Tetra Ethyl Lead. Before we had unleaded the valves and seats became coated with a film of oxidised lead which acted as a release agent. Without lead a soft seat welds momentarily and over time the seat becomes burned. My Series 3 engine (in a Series 1) was run on leaded for a long time but once we changed to Unleaded in Cyprus the seats started to degrade. Anticipating this 10 years ago I bought recon head with hardened seat inserts, it is still in the garage wrapped up in grease paper but it is time to do the deed and fit the new head on because Nellie is popping a bit now.