Volvo D16

[Nilao]

The camshaft has TDC marking etched into the camshaft that lines up with a mark on the front bearing cap. You may need to remove the gear to see this mark.
The Flywheel has a TDC 0 mark.
Once it is assembled there is a procedure to check timing

To ensure that the camshaft is correctly installed, complete a valve lift check on the
intake valves of cylinder No. 1.

Temporarily adjust the No. 1 inlet rocker arm, at the valve yoke, to zero lash.

Position a dial indicator at the inlet valve yoke for the No. 1 cylinder.

Preload the dial indicator and reset the dial to align with zero.

Turn the engine in the normal direction of engine rotation one full rotation to “0”
and past to the mark 6 degrees (after TDC) on the flywheel.

The dial indicator travel reading should be approximately 1.4 ±0.03 mm (0.05 ±0.01 inch). This reading indicates a correctly timed camshaft.

Readjust the cylinder No. 1 inlet valves and yoke.

The mark has to be there. The mark will be a line with 0TC stamped into the edge of the flywheel. When at TDC it's going to be at the top of the bell housing behind the head.