John Deere約翰迪爾強鹿柴油發動機缸蓋平面度、厚度、氣門導管、的檢查方法與標準參數

Check cylinder head flatness using D05012ST Precision“Bevelled Edge” Straightedge and feeler gauge. Checklengthwise, crosswise, and diagonally in several places.

Specification

Cylinder Head Flatness—Maximum Acceptable Out-of-Flat

for Entire Length or Width ......................................... 0.08 mm (0.003 in.)

Maximum Acceptable Out-of-Flat

for Every 150 mm (5.90 in.) ...................................... 0.03 mm (0.001 in.)

If out-of-flat exceeds specifications, the cylinder headmust be reconditioned or replaced. (See MEASURECYLINDER HEAD THICKNESS later in this group.)

John Deere約翰迪爾強鹿柴油發動機氣缸蓋厚度的測量與標準值對照

Measure head thickness from valve cover gasketrail-to-combustion face.If cylinder head thickness is less than minimum allowable

thickness, DO NOT attempt to resurface. Install a newcylinder head.When resurfacing cylinder head, remove ONLY what isnecessary to restore flatness.

Specification

New Cylinder Head—Thickness 104.87—105.13 mm(4.129—4.139 in.)

Minimum Acceptable Thickness............................. 104.24 mm (4.104 in.)

Combustion Face Surface Finish(Surface Grind Only) (AA) 0.7—3.2 micrometers(31—125 micro-in.)

Maximum Wave Depth .......................................... 0.012 mm (0.0005 in.)

Maximum Material Removal forResurfacing................................................................. 0.76 mm (0.030 in.)

IMPORTANT: After resurfacing cylinder head, checkfor flatness as described earlier. Alsocheck surface finish on combustionface of head.

Measure and record valve recess incylinder head. (See MEASURE VALVERECESS IN CYLINDER HEAD earlier inthis group.)

John Deere約翰迪爾強鹿柴油發動機氣門導管的測量與標準值參數

Using a telescopic gauge, measure valve guide wear.

Specification

Valve Guide Bore (New)—ID 7.912—7.938 mm(0.312—0.313 in.)

Valve Guide-to-Valve Stem(New)—Clearance 0.05—0.10 mm(0.002—0.004 in.)

Wear Limit .................................................................. 0.15 mm (0.006 in.)

NOTE: Valves are available with 0.38 mm (0.015 in.) and0.76 mm (0.030 in.) oversize stems.If valve guide-to-stem oil clearance exceeds the wear

limit, oversize valve stems are available. Have a qualifiedmachine shop ream valve guides to assure guide-to-stem

clearance is within specification.If valve guide-to-stem oil clearance exceeds the wearlimit, but is less than 0.20 mm (0.008 in.), it is acceptableto knurl guides and ream to size. However, installingoversize valve stems is preferred. (See KNURL VALVEGUIDES, later in this group.)

IMPORTANT: Production valve guides have a5/16-24NF modified internal thread theentire length of guide with majordiameter of 8.052—8.128 mm (0.3170—0.3199 in.). Have qualified machine shopthread valve guides accordingly afte