Cylinder Head Installation

1. Remove gasket material:






a. Using a plastic or wood gasket scraper, remove all the gasket material from the cylinder block surface.
b. Clean the cylinder block bolt holes of any residual sealer, oil, or foreign material. Remove any oil with solvent.
c. Clean the cylinder head bolt threads with a wire brush.
d. Coat the bolt threads with engine oil.
e. Inspect cylinder block orifice for any debris.

CAUTION: Be careful not to scratch the cylinder block aluminum surface when installing cylinder head.






2. Inspect top of cylinder block for flatness. Using a precision straight edge SA 9177NE (or equivalent) and feeler gauge SA 91101NE (or equivalent), measure the surfaces contacting the cylinder head gasket for warpage.

Maximum Warpage:
Transverse:
Standard is 0.03 mm (0.0012 inch)
Service limit is 0.05 mm (0.002 inch) max.
Longitudinal:
Standard is 0.07 mm (0.0028 inch)
Service limit is 0.10 mm (0.004 inch) max.






3. Inspect liner height at four locations around the cylinder bore using a sled gauge SA 9179NE (or equivalent).

Liner height
Standard is Flush
Service limit is ± 0.013 mm (0.0005 inch) max.






4. Inspect cylinder bore and tops of pistons for debris, deep scratches, excessive carbon built up, etc.

CAUTION: The crankshaft must be correctly positioned to prevent valve and piston damage. Dowel pins in each camshaft must be located at the 12 o'clock position.

5. Position number one cylinder (clockwise as viewed from the accessory drive end) 90 degrees past TDC (top dead center). The crankshaft is correctly positioned when the crankshaft keyway and sprocket timing mark is aligned with the cylinder block main bearing cap split line.






6. Install a new cylinder head gasket.

NOTE: Whenever a cylinder block or head bolts are replaced, install the cylinder head and torque the bolts to 65 Nm (48 ft. lbs.). Next, remove the bolts, coat the threads with engine oil and follow the torque angle procedure steps. Torquing the bolts one time prior to following the torque angle steps insures proper clamp load is achieved.

7. Install the cylinder head, aligning it on the dowels.
a. Carefully guide the head into place.
b. Thread the bolts (threads coated with engine oil) in by hand until finger tight.

CAUTION: The following steps must be completed in sequence. This will make sure of uniform bolt tension.

NOTICE: The torque specifications in this article have been updated from the GM service information website.

8. Cylinder head bolt tightening procedure:

Head Bolt Torque Sequence:

a. In sequence, torque the cylinder head bolts to 30 Nm (22 ft. lbs.).
b. In sequence, torque all bolts to 45 Nm (33 ft. lbs.).






c. Install torque angle gauge SA9140E (Snap-on Tool 360 or equivalent.).
d. Calibrate gauge to zero.
e. In sequence, turn each bolt an additional 90 degrees.