Does the stock distributor have a mechanical advance? If so, how much does it advance? When I disconect my vac advance and rev the engine I don't get but a couple degrees advance. Thanks.

 

This should give you some info on the subject. Sounds like your mech adv isn't doing much.

FORDMUSCLE webmagazine: Timing is Everything - Distributor Curving for Maximum Power

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If someone long ago changed advance springs or modified the limits of the mechanical advance then you may only see a little centrifugal advance with increased rpms. If tthey removed springs or if a spring is missing, could be the centrifugal advance is already started or even may be largely used up at very low rpms and if you then try to set timing by the book, you are retarding it.

You need to inspect your mechanical advance mechanism to know.

In my truck's case, a long time ago I added a quck advance kit, removed factory springs and installed weaker ACCEL springs. I also installed an ACCEL adjustable vacume control back then, but after some experimentation .... I reverted back to the stock vacume control.

To set my timing, because my mechanical advance having a fast start, I first marked my harmonic balancer up through 35 degrees. It's already marked every couple degrees up to 30 so adding 32 / 34 and a 35 mark was easy to lay out. I unplug my vacume line and plug it. I loosen my distributror hold down. I hook up my timing light.

Then I start the truck and watch timing marks and speed the motor up until timing is fully advanced .... like until it moves no more with higher rpms ..... and I set it at 34 degrees and lock down .... and recheck.

Remove light and hook vacume line up. I do periodically check my vacume advance can with a mighty vac to see that it doesn't leak .... it doesn't yet leak. With vacume in a light load or coast condition you can see timing pulled up way above that 34, but when you mash the gas under load vacume drops and the advance is limited by rpm alone.

 

Great link OldStyle.

 

Depends, pull the breaker plate inside the distributor and look at the numbers stamped on the reluctor arms...

They'll be different, 13L, 15L, etc., the arm with the advance slot that engages the limiting pin is the number your distributor is using...

Multiple that number by two, e.g. 13L x 2 = 26, 26 degrees is the amount of mechanical advance you should see.

 

Checked out my dizzy today. I have no mechanical advance. Tried turning the rotor and nothing. It should turn a little under spring tension. It is stuck somehow. Bought another rebuilt unit and it functions just fine. Will replace it later today I hope.

 

Ok got the new dizzy installed. The truck runs great. Before it seemed lathargic. Now it accelerates smoothly and with athority. Now for the confusing part.

Before I took out the old dizzy, I turned the engine over until it was at TDC #1. The rotor pointed towards the #1 molded into the cap. The timing marks also lined up with #1. Problem is the sparkplug wire on #1 terminal goes to #6 cylinder. The #1 cylinder wire goes to the #6terminal on the cap. OK so it seems like it is out by 180 degrees. I put my timming light pickup on the #1 cylinder wire and it matches the timming marks. This is where I got lost.... LOL I installed the new dizzy exactly where the old one was and was able to set the timming. (off the #1 cylinder wire not the #1 distributor terminal wire) I have no idea what is going on here. Why would everything line up like it should but my timming light fires corectly off the wrong wire?

 

Sounds like somebody was screwing with it. I would start over. Take out the number one spark plug. Remember this is not a Chevy the number one is the first plug on the passenger side. Put your finger in the hole and crank the engine until it blows your finger out. This is the compression stroke. Line up the 12-degree timing mark on the damper and put the dizzy back in so that the rotor is pointing at the number one position on the cap. Reconnect all of the plug wires in their proper positions and your done. Now there will be no more confusion. I hope this helps.