1. Cylinder Head Machining ‘Surfacing’ the head ‘Surfacing’ the head Machining the mating surface or the head Machining the mating surface or the head Makes mating surface flat Makes mating surface flat Restores proper surface finish Restores proper surface finish Proper surface finish is essential for sealing Proper surface finish is essential for sealing A mirror finish will cause gasket to fail! A mirror finish will cause gasket to fail! Increases static compression ratio by making combustion chambers smaller Increases static compression ratio by making combustion chambers smaller Don’t take off too much or Don’t take off too much or Corrects cam bore alignment on overhead cam engines Corrects cam bore alignment on overhead cam engines Overhead cam heads must be straight before machining! Overhead cam heads must be straight before machining! Or cam bores will be out of alignment Or cam bores will be out of alignment Valve seats may be warped Valve seats may be warped Straightening process invented by Gary Lewis/Dema Elgin at DeAnza Straightening process invented by Gary Lewis/Dema Elgin at DeAnza Straightening process Straightening process

2. Cylinder Head Machining Methods Methods Sanding belt Sanding belt Sanding belt Sanding belt Poor method for a performance engine Poor method for a performance engine Should never be used for overhead cam engines Should never be used for overhead cam engines Little control over how much material is removed Little control over how much material is removed Machine is inexpensive Machine is inexpensive “Quick and dirty” “Quick and dirty” Poor surface finish Poor surface finish

3. Cylinder Head Machining Grinding Grinding Produce good surface finish Produce good surface finish Can cut hard metal such as diesel pre-combustion chambers Can cut hard metal such as diesel pre-combustion chambers Takes relatively shallow cuts Takes relatively shallow cuts Uses abrasive wheel Uses abrasive wheel Intended for Iron head Intended for Iron head Can machine aluminum but... Can machine aluminum but... Must lube wheel with soap or wheel could burst Must lube wheel with soap or wheel could burst Must “spark out” Must “spark out” Slower than sanding or milling Slower than sanding or milling

4. Cylinder Head Machining Milling Milling Milling Face mill cutter Face mill cutter Face mill cutter Face mill cutter Has multiple teeth Has multiple teeth Carbide for aluminum heads Carbide for aluminum heads Single point tool Single point tool Single point tool Single point tool 1 or 2 cutters 1 or 2 cutters CBN for iron heads CBN for iron heads Produces good surface finish Produces good surface finish As always, quality is in control of the operator! As always, quality is in control of the operator!

5. Cylinder Head Machining Repairing valve guides Repairing valve guides Knurling Knurling Sleeving Sleeving Replacing valve guides Replacing valve guides Bronze guides Bronze guides Match valve guide material with valve stem material Match valve guide material with valve stem material Titanium uses beryllium/copper Titanium uses beryllium/copper Always consult with valve manufacturer for compatible guide material, they will know what is best! Always consult with valve manufacturer for compatible guide material, they will know what is best!

6. Cylinder Head Machining Valves (draw valve parts on board) Valves (draw valve parts on board) Reface valve stem tips Reface valve stem tips Don’t grind through hard metal Don’t grind through hard metal Tips ‘friction welded’ Tips ‘friction welded’ Reface valves Reface valves Cleans up valve face Cleans up valve face Do not thin margin too much Do not thin margin too much Causes valve burning Causes valve burning Typically ground at 45 degree angle Typically ground at 45 degree angle

7. Cylinder Head Machining Valve seats Valve seats Valve seat may be replaceable Valve seat may be replaceable Do not cut into water jackets when replacing Do not cut into water jackets when replacing

8. Cylinder Head Machining Valve ‘jobs’ Valve ‘jobs’ Grinding seats, valves should be new or refaced Grinding seats, valves should be new or refaced Guides must be in good shape Guides must be in good shape Straight Straight Round Round Not ‘bell-mouthed’ Not ‘bell-mouthed’ Must be repaired before grinding/cutting valves Must be repaired before grinding/cutting valves

9. Cylinder Head Machining Grinding Grinding Uses grinding stones for 3 angles Uses grinding stones for 3 angles Accurate Accurate Good surface finish Good surface finish Cutting Cutting Carbide cutters Carbide cutters Some do each angle individually Some do each angle individually Some cutters have all three angles in one cutter Some cutters have all three angles in one cutter Consistency from seat to seat Consistency from seat to seat CNC (computer numerically controlled) cuts all 3 angles with a single point tool automatically CNC (computer numerically controlled) cuts all 3 angles with a single point tool automatically

10. Cylinder Head Machining “3 angle valve job” “3 angle valve job” No such thing as any other number of angles No such thing as any other number of angles The 3 angles creates valve seat of proper width The 3 angles creates valve seat of proper width Locates seat properly on face of valve (draw on board) Locates seat properly on face of valve (draw on board) 5 angle valve job = blending for better port flow 5 angle valve job = blending for better port flow Angle that touches valve face (45 degrees) is the one that matters Angle that touches valve face (45 degrees) is the one that matters Check manuals for recommended valve seat width Check manuals for recommended valve seat width Wider seat conducts more heat Wider seat conducts more heat Narrow seat seals better Narrow seat seals better

11. Cylinder Head Machining Valve lapping Valve lapping Valve lapping Valve lapping Never, ever lap a seat using a new valve Never, ever lap a seat using a new valve Will create groove in valve face Will create groove in valve face Will cause premature valve failure Will cause premature valve failure Valve expands faster than seat Valve expands faster than seat If valve job done properly, don’t need to lap If valve job done properly, don’t need to lap Valve lapping alone not acceptable for high performance Valve lapping alone not acceptable for high performance

12. Cylinder Head Machining Draw on board Draw on board Valve keepers Valve keepers Inspect and replace if worn Inspect and replace if worn Valve retainers Valve retainers Inspect and replace if worn Inspect and replace if worn Valve springs Valve springs Inspect for cracks or dings Inspect for cracks or dings Should be perpendicular Should be perpendicular

13. Cylinder Head Machining Camshaft machining Camshaft machining Dema Elgin will discuss in his lecture Dema Elgin will discuss in his lecture Machining videos Machining videos Serdi valve and seat Serdi valve and seat Serdi valve and seat Serdi valve and seat Resurfacing BMW head Resurfacing BMW head Resurfacing BMW head Resurfacing BMW head