The blown off heater hose during 1st attempt at an MOT plus blown out section of the rad during 2nd attempt have clearly pointed to build up of pressure when the engine got hot.Joey and myself found a really knowledgeable mechanic who rapidly diagnosed this. We worked on Joey's car first.His car had exactly the same problem. The head was skimmed just under 0.4mm. We replaced the head using a standard M44 gasket and used the pukka BMW cam clamp plus flywheel locating pin. On start up the engine sounded rough so we got the mechanic to come over and re-set the cam timing after which the engine ran sweet as a nut. We've now got my head skimmed with approx 0.45mm removed. and repeated the replacement process also using a standard head gasket. On start up the engine also sounded rough. We used the same cam clamp plus pin as before. Unfortunately the mechanic has gone on holiday so we are trying to sort out how to adjust the cam timing ourselves. Does anyone know how to re-set the timing after removing 0.45mm? (It worked really well with Joey's engine so we know it can be done) Facing the cam sprockets do we:- Rotate the sprockets clock or anti-clock and by what amount? Can we re-set the timing by using the cam shafts clamped or by advancing or retarding should we no longer expect the clamp to fit over the square ends of the camshafts? As stated earlier the engine will start but runs rough. Any help regarding the above would be much appreciated.