General Information on Valve Timing Work
GENERAL INFORMATION ON VALVE TIMING WORKIf work had been carried out on the cylinder head, for which the camshaft was removed, there must be compliance with the following.
Hydraulic valve tappets expand without load from the camshaft and require a certain amount of time to be compressed again after installation. Consequently, in case of fast installation, even the "closed" valves could be opened and touch the pistons.
The following wait times are necessary between installing of the camshaft and mounting the cylinder head:
Room Temp (20°C) 4 minutes
10 to 20°C 11 minutes
0 to 10°C 30 minutes
After installation of the camshaft and timing chain, the engine may first be cranked after the following wait times:
Room Temp (20°C) after 10 minutes
10 to 20°C after 30 minutes
0 to 10°C after 75 minutes
Working of valve train with installed cylinder head:
Turn crankshaft in engine's direction of rotation 90° +/- 45° from TDC. In this manner none of the pistons will be in TDC. Install camshaft that peaks of cams for cylinder # 1 point to each other. Keep to the mentioned wait times.
Turn crankshaft back to TDC and install the timing chain. Crank engine for the first time 10 minutes after installation of the camshaft.