As Sal mentioned, I'd put a sleeve of some sort on the post to keep your total timing below 40. You're not going to get the motor to ping in your garage, it needs a load on it. Take her for a spin and floor it, while listening for pinging.

Bearing Bob wrote:

As Sal mentioned, I'd put a sleeve of some sort on the post to keep your total timing below 40. You're not going to get the motor to ping in your garage, it needs a load on it. Take her for a spin and floor it, while listening for pinging.

I've done the pinging test and lowered speed right down to where it should be in 3rd gear and floored it. I've tried at other speeds too and it will not ping.

I'm telling you, that engine will flat out not ping.  You cold run 60 degrees of timing and it won't ping (ask me how I know).  The compression is just too low, even for 87 octane, and I believe we discussed you running mid grade, and its really E10 (10% ethanol) keep in mind that ethanol has an effective octane rating of 160.  In theory they factor that in to the research octane figures, but in practice from my observations the fuel now acts as though it has a higher octane rating than advertised.  10% of the fuel also burns considerably cooler than straight gasoline, so less heat in the chamber equals less tendency to auto ignite before the plug fires. 

You've got to get a tach, its an absolute must, even if its just a clip on deal to allow you to tune.  Otherwise there's no way to set curb idle or total advance RPM. 

I borrowed a buddy's tach/dwell meter. I set the idle at 825-850 (the lowest I could go). While I had the tach hooked up I rechecked the carb and found it was running a little lean, so I fixed that.
I then set the timing at 10 degrees @ 825rpm. Car idled fine and ran fine after that.
The tach/dwell meter only went up to 1500rpm, so I couldn't check total advance, but I'm pretty confident that it would be within Ford specs now.
Would people agree?

Last edited by Toploader (10/31/2021 1:12 AM)

Toploader wrote:

I borrowed a buddy's tach/dwell meter. I set the idle at 825-850 (the lowest I could go).

I then set the timing at 10 degrees @ 825rpm. Car idled fine and ran fine after that.
The tach/dwell meter only went up to 1500rpm, so I couldn't check total advance, but I'm pretty confident that it would be within Ford specs now.
Would people agree?

WithOUT the dwell/tach...... and just reving it up..... does it still read 44* total?!
 6s6

6sally6 wrote:

WithOUT the dwell/tach...... and just reving it up..... does it still read 44* total?!
 6s6

It will still get up to 44 degrees, but that's at some pretty high revs.

FYI…3568 doesn’t do dwell if you need that function.

The 5568 does.

Try to save frustration .

Toploader wrote:

260settherecords wrote:

Adjustable vacuum advance.
light spring engages at lower RPM.
Adjustment internal Allen screw, counterclockwise lower vacuum pulls in advance earlier.

https://www.motortrend.com/how-to/set-ignition-curves-create-optimal-performance/

That is a great article! Thanks for sharing it.
The article talks about 8 degrees initial timing being optimal. Interesting...
I might back out the vacuum advance a little. How many turns is recommended?

One must use a timing light to set the vacuum advance. If base timing is set at 10 and with vacuum advance hooked up it goes to 20 but you only want 16, crank the set screw one way or the other and recheck.

The internal screw in the can only limits the amount of vacuum advance. It does not lower vacuum nor does it start the advance earlier.

260settherecords wrote:

The adjustment to vacuum advance I noted isn't in any of the articles submitted here.
This is from another source.
He stated his starting point, or ultimate setting, was fully clockwise then seven turns counter clockwise.
Your settings may be quite different, but always good to have a reference.

For manifold vacuum the easy way to know where you be is to check the timing at idle with the vacuum advance removed and plugged. This will give you the initial timing. Then plug in the vacuum advance and see how much additional timing the VA gives you. If too much or too little, disconnect the vacuum line (don't forget to plug)  and crank the screw one way or the other. Reconnect the VA and check the timing again. Repeat as necessary.

Off idle timed (ported) vs full manifold vacuum will work exactly the same. The only difference being at idle throttle. Timed will give zero advance while decelerating while full manifold will give you max vacuum advance while decelerating.

So as you can see, ported vs manifold is identical except at closed throttle. [/url]

Last edited by RV6 (11/02/2021 3:53 PM)

If I do the Shelby drop, will I have to reset my ignition timing??

6sally6 wrote:

ONLY...........only if you have 17" tarz!!
6sally6

Do I check tire pressure on the port or manifold side??

6sally6 wrote:

ONLY...........only if you have 17" tarz!!
6sally6

With 17's you'll have to retard the timing to match the retarded wheels.

Bearing Bob wrote:

Brahahaha!...you guys are some funny mo fo's.