what to set ignition timing too? - Third Generation F-Body Message Boards

ethan169 · 09-25-2007, 04:34 PM

ok so i have a 87 formula with a 305 M5 non FI. I have the edelbrock performer 600cfm carb and performer intake mani. the newer style one with blocked off egr. borla catback.

heres my question, I swapped the electronic control distributer out with an factory HEI, what should i set the timming to. wich mark? ive had it like this for a while and it runs well but i never know where it really should be? any ideas?

thanks for the advice
ethan

five7kid · 09-25-2007, 04:45 PM

8-12 degrees before top dead center at idle with vacuum advance disconnected is a good starting point. Each mark represents 2 degrees.

ethan169 · 09-26-2007, 01:02 AM

ok so one thing i did not know was to disconnect the vacuum advance. now about the marks i have the setup that has that hole for the electric probe. now forgive my ignorance but which way is before top dead center. and if i can remember theres only like 4 marks which is only 8 degrees?

thanks again
ethan

V8 4x4 S10 · 09-26-2007, 03:07 PM

If you were facing the front of the Engine. To your Right would be Advancing the Timing, and to your Left would be Retarding the Timing.

five7kid · 09-26-2007, 04:04 PM

Quote:

Originally Posted by V8 4x4 S10

If you were facing the front of the Engine. To your Right would be Advancing the Timing, and to your Left would be Retarding the Timing.

Other way around.

If you are standing in front of the car facing the engine, the engine will rotate clockwise. So, if the ignition sparks counterclockwise to the tab (to the left), that is advanced. If it sparks clockwise to the tab (to the right), that's retarded.

ethan169 · 09-27-2007, 10:34 AM

ok guys thanks for the info, ill give it a try and let you know.