Cylinder Head
CLEANINGRemove all gasket material from cylinder head. Be careful not to gouge or scratch the aluminum head sealing surface. Clean all engine oil passages.
To ensure engine gasket sealing, proper surface preparation must be performed, especially with the use of aluminum engine components and multi-layer steel cylinder head gaskets.
Never use the following to clean aluminum gasket surfaces:
- Metal scraper
- Abrasive pad or paper to clean cylinder block and head
Fig. 129
- High speed power tool with an abrasive pad or a wire brush (Fig. 129).
NOTE: Multi-Layer Steel (MLS) head gaskets require a scratch free sealing surface.
Only use the following for cleaning gasket surfaces:
- Solvent or a commercially available gasket remover
- Plastic or wood scraper
- Drill motor with 3M Roloc Bristle Disc (white or yellow)
CAUTION: Excessive pressure or high RPM can damage the sealing surfaces. The mild (white, 120 grit) bristle disc is recommended. If necessary, the medium (yellow, 80 grit) bristle disc may be used on cast iron surfaces with care.
INSPECTING CYLINDER HEAD
Fig. 130
Check cylinder head for flatness with a straight edge. Cylinder head must be flat within 0.1 mm (0.004 inch) (Fig. 130).
Inspect cylinder head camshaft bearings for wear. Check the camshaft journals for scratches and worn areas. If light scratches are present, they may be removed with 400 grit sand paper. If deep scratches are present, replace the camshaft and check the cylinder head for damage. Replace the cylinder head if worn or damaged. Check the lobes for pitting and wear. If the lobes show signs of wear, check the corresponding rocker arm roller for wear or damage. Replace rocker arm/hydraulic lash adjuster if worn or damaged. If lobes show signs of pitting on the nose, flank or base circle; replace the camshaft.