ignition timing 352
 

Is there any prep work involved in timing my ignition, such as removing vacuum lines, or do I just go at it as Is? Sorry for dumb questions, im new at this.

Remove the vacuum line to the distributor and plug it. You are then ready to time your engine. Realistically, if your engine is in good shape and idling smoothly at 600-650 rpm then there will be no vacuum drawn on the distributor advance system anyway.

Are you using a timing light only?

Thank you! And yes the plan was just a timing light...

Have a vacuum gauge? I time my cars with my vacuum gauge and then use the timing light to see where I am.

Nope but I can get one, if it's not too much trouble could you explain the process to me?

Ok, stock timing is 6 BTDC. All Ford V8's could use and like a bit more initial timing. Probably safe to say that your distributor is most like set for 26 degrees mechanical advance from the factory. So you could go up to 12 BTDC for the initial.

Plug the vacuum gauge into manifold vacuum warm up the engine and have your idle speed at about 650 rpm. Now advance your distributor, which should start at 6 BTDC, and watch the vacuum gauge. As the timing advances the gauge will read higher and higher. At a certain point it will stop giving you a higher reading and then will decline when advanced too far. So find that point where it stops rising and then retard just a bit from there. Timing light will probably be around 10-12 degrees.

Check idle speed and make sure it is at 650 rpm. Now you can check the idle mixture screws. I start with the both screws 1 1/2 turns out already. I know it will be on the lean side so all I need to do is open them more. As I open the vacuum gauge will read a higher vacuum just like timing did. Once again you will hit a point where it goes no higher. Mine hits that point at 2 1/2 turns out. With that optimized I check idle speed again as a higher vacuum also means a higher idle speed so I set for 650 one last time.

Thank you so much, that is very helpful!

I have mine 8* advanced and it seems to like even more intial timing. My question is the effect it has on total timing. I'm at 37* total. If I advance 12* initial; the total goes even higher. This can't be good. It's the original FOMOCO dizzy with Pertronics.

Given the gas of today it is probably smart not to use more than 10 degrees initial advance. This combined with a typical FE distributor using the 13L slot for 26 degrees you will have a total of 36 degrees. If gas was like it was in the 70's then a good 9.0:1 engine or less could run 38-42 degrees total. Not today.

You say you have 37* total??? Running a Ford distributor you will only see mechanical advance slot labeled 10L, 13L, 15L and 18L. Using 8* initial then you have either 34*, 38* or 42* as you don't have a 10L slot distributor.

Thanks for the reply. I'm looking in the dizzy but don't know where the mechanical advance slot is? Under Pertronix unit on weight? Yes; I have 37* at full advance with 8* initial.

You have to pull off the breaker plate if you want to see the advance slots and springs.

OK...gotcha. Thanks! Was just chatting with some old time FE guy and he likes to run 16-22* initial timing with a recurved distributor. I had mine at 20* initial by accident and the truck ran so much stronger and never detonated. Has me curious.