How to measure IC or CI engine at TDC? Do not open any cover head,fly wheel,Timing gears cover

Turn the crank shaft pulley and see the timing mark or u can do two turn to do tdc

Open the injector or the spark plug to see the piston position inside the cylinder, To make sure we can use screw driver or stick

remove the spark plug number 1 and insert a small piece if metal to identify the engine is on TDC, and  turn the crankshaft pully using a socket wrench and ratchet..

Remove spark plug 1 insert a small screw driver and turn the engine through crank pully

Dear sir they are doing courses 

Remove the spark plug for number one, use a plastic rod and turn the pulley to observe the movement of the rod at TDC

check

flywheel mark.its easily know the piston located in tdc.

Most of engine's TDC position mentioned on crank pulley or flywheel.We can rotate the engine and find TDC position.

measuring IC or CI engine at TDC wihout open any covers of engine by workshop manual book of the recmended brand  and year of manufacturing.

i agree with MR. ALi Ramadan