Track944s

I had put this as a follow-on to another topic, and realized that It needed its own space.
I am doing a refresh on my 1988 944s and after some head work, I have realized that we need to find out on the S models, what do the camshafts look like at TDC? The factory manual (below) seems opposite what I think is right corresponding with the pics on this BBS (below). I am good with the crank indicator, but knowing which cylinder's lobes are "up" at TCD is what I am confused by. The factory seems to indicate that #4 lobes are facing up while the BBS pics say #1 lobes are facing up....Any help would be appreciated

phlip

You are reading the procedure for setting the cam timing, its adjustable on 16 valve cars. With the #4 cam lobes up #1 is at TDC but in overlap, the pic you posted of your engine is what it should look like with #1 at TDC in compression.

michaelmount123

The pistons for #1 and #4 are both up at the same time, but one cylinder is at its firing position (manual calls it "ignition TDC"), and the other is at overlap TDC. The pic with #4 lobes facing up shows the engine at #1 TDC overlap, which is where you are measuring the intake valve opening. When #1 cylinder is at TDC firing, its lobes are up.

So, when the cam belt sprocket mark lines up, #1 is at TDC firing (ignition TDC) and its lobes are up. At #1 TDC O/L, the belt sprocket mark is still 180 degrees away from the mark on the cover and the lobes for #4 are up.

So, you set the dial indicator to '0' with #1 at "ignition TDC", and rotate to TDC O/L where the valve will be open 1.4mm if the cam timing is within spec.

michaelmount123

Oops. Phil's on the money. He posted while I was typing my response.

Track944s

Great guys.
Thanks for the help!