Since ignition is what you have changed, ignition is the most likely cause. You cannot assume that a rebuilt distributor is going to be curved the same as your old one. You will need to check and adjust all aspects of it. If you do not know how the old one was tuned, and it may not be possible to find out, given it's problems, you will need to start the tuning process from scratch.

Regarding the mixture screws, the initial setting is not that important, so long as you know what it is and the engine will idle well enough to begin the tuning process. The initial setting is rarely what the engine actually needs. You just need to know where you started so you know where you ended up.  I don't know what effect the air cleaner has.


Lawrenceville, GA

Mike;

Good thoughts. When I set the initial advance, I did disconnect the hose from the vacuum canister, but I didn't plug it off. I will re-check the initial timing with both the carb vacuum port and the vacuum canister plugged. I believe both distributors were similar, the old a Motorcraft and the new a rebuilt FoMoCo. Thanks for the info on the A/F mixture screws. I won't mess with them yet until I look more at the timing.


Thanks,

Rono

  Ron Lane,  Meridian, ID

Just a thought. If the vacumn advance is hooked up, either ported or manifold, is the advance in the new one about the same as the old one? I'm assuming the 12* initial is with it plugged off.

My older Edelbrock (I'm pretty sure) said to start at 1 1/2 turns out. No idea on a dual set up.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

One small problem that has developed now is an erratic idle when the motor is hot. I am running dual Edlebrock 500 cfm carbs (#1404) and have set the initial advance at 12 degrees BTDC. The motor has a Comp cam with a .389 lift and I'm not sure if I need more advance or it's an A/F mixture issue. The manual on the Edlebrock carb says you need to adjust the fuel mixture screws with the motor hot and the air cleaner in place. I have a 1 piece air cleaner that mounts over both carbs and I can't get to the adjusting screws without removing the air cleaner. The manual does not give you a starting point for these mixture screws (i.e. 2 turns out from a lightly seated position) so I have no baseline to work with. Even if I increase the idle speed screw, it will still have an erratic idle. It did not do this prior to replacing the old distributor so I question that the fuel mixture adjustment screws are the answer. I have also checked all my vacuum lines and plugs and have retightened all carb studs so I don't believe I have any leaks there. Kind of stumped.


Rono

  Ron Lane,  Meridian, ID

Good advice Charlie. I did buy a new MSD distributor for my blown stroker motor, but the distributor that went bad in my 56 was a rebuilt unit from NAPA. It did go through several dyno pulls and I did make a pass on a race track in Maine with it, but it only had 7,000+ miles on it when the bushing failed. Our Ranch Wagon needs a distributor upgrade so I think I will go with an MSD unit when the time comes.

Rono

  Ron Lane,  Meridian, ID

Those are Chinese MSD imitations.  I know people have used them.  Buyer beware, though.  Since they are Chinese, don't expect any kind of support if problems arise.  Another thing to consider is tune-up part availability - the cap and rotor, when they need replacement within a few years, as all do with normal use, will they be available or do you have to buy another entire $220 distributor?.


Lawrenceville, GA

Glass Top;

Yes I did. It was a worn distributor shaft bushing causing a slight wobble in the shaft and misfiring on #7 cylinder.. I installed a new (rebuilt) FoMoCo distributor with new Pertronix ignition and even bought one of those new style timing lights with the degree dial on the back to get everything timed correctly. The motor is running great again now.

 I did notice there is a new small cap HEI distributor for Y Blocks being sold on Ebay from CRT Performance that includes the coil and pre-cut 8mm wires for $214. Here is the item number; 351894808762

I was wondering if anyone has tried one of these?

  Ron Lane,  Meridian, ID

Just wondering if you ever found the source of your miss

Just swap at the cap and plug with the wire next to the suspect one. If the plug problem moves then its the wire.


Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Charlie;

Thanks for the tip! The dizzie went right in when I held it down and bumped the remote start. Glasstop, the plug wires are new, 8mm Taylor wires. I haven't checked resistance on #7 plug wire, but being that they are new I didn't think I needed to.

Rono

  Ron Lane,  Meridian, ID