ignition timing

[landon1]

k, so my new distributor is hopefully going in this weekend...what is factory spec for timing so i have somewhere to start from?

or, maybe someone with a 440, headers, afermarket electronic ignition, and a holley carb caould give me approx. what they are set at.

thanks

landon

[72Rdrnner]

k, so my new distributor is hopefully going in this weekend...what is factory spec for timing so i have somewhere to start from?

or, maybe someone with a 440, headers, afermarket electronic ignition, and a holley carb caould give me approx. what they are set at.

thanks

landon

From the 1972 FSM (pg 8-142) Ignition System Specifications. 440 4bbl A/T (non California) distributor part # 3656341

Centrifugal advance/rpm

0.5 to 4 degrees @ 650 rpm
6 to 8 degrees @ 950 rpm
10.5 to 12.5 degrees @ 2500 rpm

Vacuum advance/inches of mercury

1 to 4 degrees @ 10.5 inches
8 to 10.5 degrees @ 15.5 inches

I have a stock distributor, (completely rebuilt) Edelbrock manifold, Holley Street Avenger carb, Mopar Performance ignition box (a MSD 6a, made for MP, painted black) and a MP coil. Also have a Comp cam which is pretty much like the MP cam for the 440.

At the risk of stating the obvious, make sure you disconnect and plug the vacuum line to the distributor vacuum advance before setting/checking the centrifugal timing.

Once you get it set, up and running, you can play around with it to your hearts content.

Hope this helps.

[road chicken]

Somewhere in the 0-10 BTDC range . Once you get it fired up you can check the advance with a timing light and see how much the advance curve built into it. @ 2000 rpm. Try and run 29-32 BTDC at full mechanical advance. Little less for low compression motor. If it's hard cranking when it's hot, back it off a few degrees.

[landon1]

right now i have it set at 10 BTDC and it runs like a top...i can't really mes with the full advance to measure it (i don't think, unless there's something i don't know about...like maybe why i have several marks on my balancer to measure timing..), as my timing tab only goes from 0-10 BTDC.....but it's set and seems to be doing alright...need to change the springs in my secondaries, though slash thinking about goin thermoquad again for mileage