What are the cylinder head bolt torque settings on an OPEL astra 1800cc 8 valve SE motor?

The cylinder head bolt torque settings for an Opel Astra 1800cc 8-valve SE motor typically require an initial torque of around 30 Nm (22 lb-ft) followed by a final torque of about 90 Nm (66 lb-ft). It is important to follow a specific tightening sequence and to use a torque angle gauge for the final tightening, usually an additional 90 degrees. Always refer to the vehicle's service manual for the precise specifications and guidelines for your specific engine variant.