Timing Question(s)
 

The Tech Spec book for my '73 911 T says the timing should be set at 5°ATDC. However, when I timed it recently, I noticed that it ran better as I moved the timing closer to TDC. This set me to wondering----- This car was originally a MFI 2.4 car, but the PO made it a 2.7 car with Webers; still with T-Cams. Is the 5°ATDC timing spec still valid in the current configuration?

If the vacuum retard line is connected, then the spec is 5 degrees ATDC. If the line is disconnected it should be around TDC. What you really should do is check the timing at 5000 RPM. It should be between 30 and 35 degrees there. You have marks at 30-35 on your pulley. Whatever idle timing gives you the 30-35 at 5k is what you want.

-Andy

Do the 5k test with the vacuum line disconnected.

-Andy