Modern distributor cap

Dean Lemoine

Dean Lemoine

Senior Member
Is there a difference in performance of the modern style distributor cap and wires versus the original cap and bronze spark plug connectors?
 
Quite a bit of difference. With the modern cap the engine won't misfire when it gets wet, modern wires won't emit huge amounts of RFI when the car is running.



Frank
 
I prefer the original distributor cap , first for the original look . The gaps can be measured between the rotor tip and the 4 contacts in the distributor cap . The 4 contacts can be filed for equal gaps at all four contacts in the original cap . I consider equal gaps as part of a tune up . I prefer a gap of .035 between the rotor tip and the contacts in the cap for equal and hotter spark at all cylinders . Measuring gaps at the rotor tip isn't possible with the modern style distributor cap .
 
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Thanks guys. I agree with the original look and honestly I hadn’t thought about the ability to check and adjust the gaps. If there is/was a significant performance increase, I was thinking about going with the modern cap and wires. Stay safe.
 
Maybe the worry about setting air gaps is not as important with modern caps? How often to you see info about people setting air gaps on later V8 or any car up to electronic ignition?
 
Just thinking,,, if electricity travels at roughly 11, 628 inches per second how long does it take for the spark to jump .025 or .035?
 
redmodelt said:
Maybe the worry about setting air gaps is not as important with modern caps? How often to you see info about people setting air gaps on later V8 or any car up to electronic ignition?
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While it is possible to measure and adjust air gaps with the original model A or B distributor caps, I don't see how measuring air gaps would be possible with a modern style distributor cap .

Air gap distance won't make a day and night difference in performance but there does need to be air gaps for the spark to jump . Ford recommended gaps of twenty five thousands at the rotor tip . More gap to a certain point will increase spark intensity . I set mine at thirty five thousands . I believe that equal size air gaps at the rotor tip will send equal spark to each cylinder for better performance .
 
I like putting a clear distributor cap on the distributor body. At night the little ones like to see the "sparklers". You can't do that with a modern distributor cap. :p:p
 
Ruth said:
I like putting a clear distributor cap on the distributor body. At night the little ones like to see the "sparklers". You can't do that with a modern distributor cap. :p:p
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Someone made up a Model A distributor body (the bakelite part) entire. A one-off I think. I'd like one of those.

Sort of like painting the engine red - proven to make the car go faster.

Joe K
 
If the original style distributor cap body and cap was made as one part , you would lose the ability to measure and adjust the air gaps . I've used and found NO advantage to a modern style distributor cap when used with the original model A distributor .
 
I have an original style cap and have driven long miles in the rain and never had an engine miss from the bronze spark plug connectors.

John
 
divcoone said:
Mikes was selling the “A” style cap that could be used with modern cables.
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I have one of those on my engine. They are made by Renner’s Corner which is where I bought mine. Works / looks great. Best of both worlds??
 
They just don't look the same.....
MAG said:
Just thinking,,, if electricity travels at roughly 11, 628 inches per second how long does it take for the spark to jump .025 or .035?
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That's the thing, The time for the coil to build up enough juice to jump the gap is measurable. I've never measured it myself, but when i was making electronic ignition, if the gap was too wide i needed 12ms of coil activation time versus 2ms for normal plugs.

And all the clear cap comments make me wonder how hard it'd be to make a mould and cast one in resin.
 
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