Porsche Repair: 944 engine tdc marking, tdc mark, exhaust stroke

Question
1986 944 - on the flywheel there is a line and the marking 'OT' next to it. Is this the top dead center line, or is there a line on the other side of the flywheel.  I recall an issue with this last time i opened the engine. but i lost my notes. i dont want to turn the flywheel since i already have attached everything.

Answer
Frank, the OT stands for 'Over Top', which is the German reference to Top Dead Center, so you've found the mark.  I'm not quite sure what your previous issue was...but perhaps it was this:

The TDC mark needs to be identified with the number 1 piston's compression stroke, not its exhaust stroke.  Every mechanic in the world makes this mistake once.  

Here's two ways to double check your work:

1.  On the 944 there is a rubber inspection hole plug in the camshaft cover just above the distributor cap.  If you're at TDC, the mark on the camshaft sprocket will be lined up with the mark on the housing.

2.  Both valves for cylinder #1 must be closed for compression to occur and that only happens at TDC.  By looking at the positions of the valve stems at TDC, you can check your work.  If you already have the valve cover (the camshaft cover) on and everything's buttoned up, then you'll have to rely on the camshaft mark, which is telling you exactly the same thing through the cover.

I hope this helps,  please respond with a follow-up question if you'd like.

Dave