Lobe Lift Test

Check the lift of each lobe in consecutive order and make a note of the readings.
1. Remove valve covers.
2. Remove rocker arm seat bolts, rocker arm set and rocker arms.





3. Make sure valve tappet is seated against camshaft. Install Dial Indicator with Bracketry 100-002 (TOOL-4201-C) or equivalent so the ball socket adapter of indicator is on top of valve tappet or cup shaped adapter is on top of push rod and in same plane as valve tappet push rod movement.
4. Remove spark plugs.
5. Connect an auxiliary starter switch in starting circuit. Crank engine with ignition switch in OFF position. Bump crankshaft over until valve tappet is on base circle of camshaft lobe. At this point, valve tappet will be in its lowest position. Zero the dial indicator. If checking during engine assembly, turn crankshaft using a socket or ratchet.
6. Continue to rotate crankshaft slowly until valve tappet is in fully-raised position (highest indicator reading). Compare total lift recorded on indicator with specifications.

NOTE: If lift on any lobe is below specified service limits, camshaft and valve tappet operating on worn lobes must be replaced, as well as any valve tappet showing roller wear.

7. To check accuracy of original indicator reading, continue to rotate crankshaft until indicator reads zero.
8. Remove dial indicator, adapter and auxiliary starter switch.
9.. Install rocker arm seats, rocker arms and rocker arm seat bolts.

CAUTION: After installing rocker arms, do not rotate crankshaft until valve tappets have had sufficient time to bleed down. To do otherwise may cause serious valve damage. Manually bleeding-down valve tappets will reduce waiting time.

10. Install valve covers.
11. Install spark plugs.