Dynamic Valve Train Analysis

Static checks (engine off) are to be made on the engine prior to the dynamic procedure.

 CAUTION: Do not perform dynamic analysis on overhead camshaft engines because of oil splash.

Start the engine and, while running at idle, check for proper operation of all parts. Check the following:

Rocker Arm Assemblies, Individually Mounted

• Check for plugged oil feed in rocker arm or cylinder head.
• Check for proper overhead valve train lubrication.
• Check for plugged oil feed in rocker arm.

Rocker Arm Assemblies

• Check for plugged oil feeds.
• Check for proper overhead valve train lubrication.

If a condition of insufficient oiling is suspected, accelerate the engine to 1200 rpm ± 100 rpm with the transmission in NEUTRAL and the engine at normal operating temperature. Oil should spurt from the rocker arm oil holes such that valve tips and rocker arm are well oiled and/or, with the rocker arm cover off, oil splash may overshoot rocker arm. If oiling is insufficient for this condition to occur, check oil passages for blockage.

Push Rods

• Check for bent push rods and restriction in oil passage.
• Check for proper rotation of push rods (non-roller tappets).

Positive Rotator and Keys

• Check for proper operation of positive rotator.

Valves and Cylinder Head

• Check for plugged oil drain back holes.
• Check for missing or damaged valve stem oil seals or guide mounted oil seals.

If a condition of insufficient oiling is suspected, check oil passages for blockage, then accelerate the engine to 1200 rpm with the transmission in NEUTRAL and the engine at normal operating temperature. Oil should spurt from the rocker arm oil holes such that valve tips and rocker arms are well oiled. With the rocker arm cover off, some oil splash may overshoot rocker arm.