Differences · Item 3 Valve discs, valve springs

911 Carrera (996) Engine Differences Item 3 Valve discs, valve springs The following parts distinguishthe higher-performance enginefrom the standard engine in the area of the cylinder head: 1. Valve keys (standard part) 2. Valve disc at top 3. Valve spring on outside 4. Valve spring on inside 5. Valve seal (standard part) 6. Valve disc at bottom 7. Valveguides 8. Cylinderhead 9. Valve seats The valve seats are additionallyprovided with a seat surface of 60°, 21_99 further to Item 3 Valve guides The valve guides were shortened in the area of the inlet and outlet ducts. 2O_99 further to Item 3 Cylinder head The cylinder heads already have a reduced height. Subsequentmachining of the sealing surface is therefore not permissible. 19_99 1 3.4 I engine performance kit / X51 1-13 Printed in Germany -21, 1999 9961_7