Upon installation of your WEB-CAM camshaft, check the following. These operations are very important to engine life, please follow instructions! If your cam is described as a bolt-in in the WEB-CAM catalog, you may skip 1-5 below.
Check piston to valve clearance. Provide the necessary clearance by removing material from the piston Minimum .050" intake, .080" exhaust.
Check valve to valve clearance. It may be necessary to remove material from the valves or sink valve seat height in head.
Check the valve spring retainer to valve guide clearance at maximum lift. Remove material from the top,of valve guides to provide a minimum of .030" clearance.
Check for valve spring coil bind at maximum valve lift. Clearance at every coil should be at least .015"
Be certain that cam and/or rocker arms rotate freely in head or block. Remove material from head,block, or rocker arms where necessary.
Engine and cam life depend on proper installation. New or reground followers should be used when installing WEB-CAM profiles. Apply the provided assembly lube to cam lobe and follower surfaces.
For proper break-in, after installation of a new camshaft, do not allow your engine to idle below 2000 RPM for the first 15 minutes of use.
Datsun Z Series (71-80) SOHC 12v
Part #:
20-010 ; 20-012
Grind:
155
Intake
Exhaust
Valve Lash (Inch):
.008
.010
Valve Lift (Inch):
0.488
0.488
Valve Lift (mm):
12.4
12.4
Advertised Duration:
252°
252°
Duration @ 0.050":
230°
230°
Lobe Center:
108°
111°
= 109.5° Overall
Intake Opens
7°
Before TDC
Exhaust Opens
46°
Before BDC
Intake Closes
43°
After BDC
Exhaust Closes
4°
After TDC
Valve Timing Is Checked With Zero Valve Lash @ 0.050 Inches Of Valve Lift.