Spark Plug Wires

Joe/Ct

Joe/Ct

Senior Member
I have a '39 coupe that has been street rodded to the '50s style. It has a 59AB engine with a Mallory electronic distributor (no power box), wire looms and plug wires labeled "Autolite Powerseal Electronic Supression w/ 7.5 mm Insulast Jacket". It has been running a little rough lately, so I checked each cylinder by removing each plug wire individually while the engine was running. I noticed no change when I removed 3 of the plug wires, which seems inconsistent with the degree of roughness that I was experiencing. I then checked the resistance of each of the wires and found that only one was open (on one of the no change cylinders); the other read in the 15k to 30k range. Also when I checked under the hood at night (engine running), I saw no arcing.

What is going on? Since these wires are not made anymore, what should I use to replace (these have a carbon-based center)? What is the feeling about looms...I do like the look (I can't even move the wires in the ones that I have)?
 
carbon burnd't out of the wire, out side insulation will arc only if broke.Roy Nacewicz (734-654-9450) can supply with the correct wire.don't like the steel looms.good luck and report back. wayne
 
Wire looms can contribute to up to 5 milliamps of current loss, even if everything is new and clean. It is the capacity that does it.
If you do not need the radio suppression, change the wires to Packard 440. Most large auto parts stores have it. It is a solid core wire.
 
And if you need the suppression, go with spiral wound rather than carbon...much stronger. Looms are not a great idea, whether original or bent chrome tube, but will not cause any major problems with good quality insulation and a good ignition able to cover the capacitance loss...
A common source for spiral core resistance wire is Accel...if you read the fine print in the catalog, you will find the code for ordering anything they make in black rather than bright yellow. I think you just add a "B" to part number. 440 is still readily available and about as traditional as you can get! Look for Brillman, a company supplying electrical stuff for old tractors, as one source.
 
I have the same system on my 39 and whenever I experience roughness, I change the distributor cap. Can't always see a problem, but the new cap cures it every time. What plug gap are you running? Keep it around .025.
 
Bruce Lancaster said:
And if you need the suppression, go with spiral wound rather than carbon...much stronger. Looms are not a great idea, whether original or bent chrome tube, but will not cause any major problems with good quality insulation and a good ignition able to cover the capacitance loss...
A common source for spiral core resistance wire is Accel...if you read the fine print in the catalog, you will find the code for ordering anything they make in black rather than bright yellow. I think you just add a "B" to part number. 440 is still readily available and about as traditional as you can get! Look for Brillman, a company supplying electrical stuff for old tractors, as one source.
Click to expand...

I am not sure solid wire is compatable with electronic distributors. You may want to check before you go with the Packard 440 wire.

Just a thought

Chris
 
Hi Joe, Where did you buy your electronic ignition for your 59ab engine,I would like to put one on my car but couldn't find one? Thanks Coolcoupe
 
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