Stock electronic ignition - setting timing on a 440

[moparedtn]

I have a 440 magnum, pretty darn stock except for the Comp Cams Magnum 270 in it (which isn't a whole lot warmer than stock, either). A new Edelbrock AVS Thunder 650cfm sits on a stock 4barrel intake. Headers, 3" (yeah, car came with it, I don't care for it) duals thru knock-off Flowmaster looking mufflers.
Stock distributor (A-1 Cardone rebuilt unit, "new"), stock from the parts store replacement ECU.
(I have a new Mopar Performance dizzy and orange ECU sitting on the shelf)
New MSD Blaster II coil, new MSD spark plug wires, fresh Champion RJ12YC plugs.
The carb seems close now that I've gone through it with the tuning kit from Edelbrock (I jetted it identically to their 750cfm Thunder and used the "pink" springs, figured that'd be close), setting mixture screws for max vacuum. Idles around 800 or so.

Now going through tuning phase...
-Ok, factory manual says 5 degrees BTDC on initial timing (actually says 0TDC w/manual, but I ain't going there), vacuum line disconnected and plugged off.
I started out at about 11-12 BTDC, where the engine sounded "happiest".

-It then says to set total mechanical advance at 36 degrees BTDC @ 2000RPM.
Check, did that. Had to move the initial back a just a hair to around 10-11 degrees BTDC, which the car was fine with.
So far, so good....

-Finally, it says to plug up the vacuum advance and set total timing advance to 56 degrees BTDC @ up to 4000RPM.
Hey looky there, it's already there, no need to adjust anything.

Results:
-Starts easily and idles fine.

-With the vacuum advance disconnected and plugged, the engine happily and smoothly climbs to 5500 RPM, no drama whether a slow climb or an "all at once" flooring of the throttle. Great!

However...
-With the vacuum advance connected, it still climbs fine until you get up in the high 4000s. At that point, it will still go to 5500 but there are audible little pops heard like cylinders are being temporarily dropped and she shudders just a bit.

Am I doing this right? Do these results make sense?
I don't have a problem driving it with the vacuum advance disconnected if that's what it wants.
This is my street/weekend car, not going racing anytime soon.

 

[moparedtn]

Wow, nobody? Ferris?

 

[YY1]

I always set my timing by feel.

Get out on a country road and hammer it from a standing start.

Power braking is OK, too.

Advance it until it starts to knock/ping, and then back off until it stops.

 

[YY1]

Oops, should have read the whole post.

 

[Hemirunner]

What did you use for a vacuum source? I'm guessing that those pops are detonation from too much timing.

 

[moparedtn]

I always set my timing by feel.

Get out on a country road and hammer it from a standing start.

Power braking is OK, too.

Advance it until it starts to knock/ping, and then back off until it stops.

You know, I've never heard this thing knock or ping ever, no matter what setting on the timing. Weird. Perhaps the shuddering/stammering/popping is what it's doing instead of knocking?

 

[moparedtn]

What did you use for a vacuum source? I'm guessing that those pops are detonation from too much timing.

Could be. Ported vacuum from the carb like normal.
Engine seems fine with it disconnected. Is the 36 degrees total that I get from running the vacuum port plugged off enough for the engine?

 

[Hemirunner]

Yes. Vacuum advance is merely to improve idle quality and fuel economy. You can leave it disconnected.

 

[HALIFAXHOPS]

I just had something similar popping on my right bank drove me craxy turned out 6&8 were flooded with gas and no spark, just FYI

 

[moparedtn]

Yes. Vacuum advance is merely to improve idle quality and fuel economy. You can leave it disconnected.

Thanks, that's what I was hoping.
Heck of a difference between 36 degrees total timing and 56, even if arrived at @ different RPM for sure, but the engine sure likes the mechanical advance anyways.

 

[moparedtn]

I just had something similar popping on my right bank drove me craxy turned out 6&8 were flooded with gas and no spark, just FYI

Yep. In previous threads, I've gone thru the whole process I've been through with this car and just recently, I discovered VERY low voltage to the coil - making for a weak spark that pretty much fuel fouled the plugs.
Poppity, poppity.
It's been a long road to get to this point. Glad I'm down to just fooling with tuning now.

 

[moparedtn]

Update:
Got the MSD 0.8ohm ballast installed today.
Voltages at the coil:
@key on, not running: 5.5V
@ idle is about 9V
goosing the throttle: 11-12V, depending

I think that's about as far as I dare go. Want to keep a little safety margin there.
How about a little video of the results?
Here y'all go:

 

[SlinktRR]

nice! 9v lot better than 1. Sounds like you got it, long road but now you can do some well deserved burnouts.

 

[moparedtn]

Follow-up:
Wife and I took the car to town today.
It was like a different car.
Around town and on a decent stint on the highway, it was smooth and did really well winding out in each gear.
Relieved, to put it mildly.

This is the first time since I bought the car that it has behaved, well, like a car.
It's actually fun to drive now.

 

[TxDon]

Good thread, I'm having similar issues and will check the voltage as you did.

 

[moparedtn]

Good thread, I'm having similar issues and will check the voltage as you did.

Great, I hope something in all this will help you.
That's why I've posted all these threads (there's a handful) of my trials and tribulations of getting this thing back on the road. It's come a long way from sitting behind a barn in the elements for years.
This is the car "as discovered" in 2006:

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