Question for Six Engine People, TDC and Z1 mark Options

[Robarabian]

I have a 911 engine I am working on. I am practicing setting cam timing so I can feel comfortable with it prior to the tear down. My Crankshaft pulley has a Z1 mark that has 2 lines. So I have seen 911 pulleys with Z1 and 1 line.

The question de jour is which of the 2 lines at Z1 is TDC? Or are the 2 lines giving me the dwell of where TDC is and if so, where should I put them in relation to the case to set cam timing and do valve adjustments.


it looks like " Z | | 1"

It is a 2.4


Somebody knows this answer.

[ClayPerrine]

A suggestion for setting the cam timing.

Only put on the intake rocker for #1. Leave the rest off. Set the cam timing per the book. Then put the #4 intake rocker on and set the cam timing on it.

Check it about 20 times before putting the rest of the rockers on. I like to have a dial indicator on each side and repeatedly recheck to make sure the numbers match side to side.

All 911 motors are interference motors. If you don't put the rockers on, then you can't accidentally bend the valves.

I had to replace a chain box on the 4.0L engine recently. I pulled all the rockers on that side before I started just to be sure. It's cheap insurance.