Hei question
Thread Starter
Racer
Joined: Jan 2005
Posts: 307
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From: McCordsville Indiana
Hei question
My 74 coupe had been converted from points to hei by a previous owner,2 questions, Do I have to reset the spark plug gap from .035 to 0.60 and is the # 1 position on the distributor cap have to changed,different postion is shown for points ignition and hei position ?
Team Owner
Joined: Jun 2000
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From: Southbound
Cruise-In II Veteran
...is the # 1 position on the distributor cap have to changed...
Last edited by Easy Mike; Apr 22, 2013 at 01:19 PM.
Le Mans Master
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From: Palmdale CA
Team Owner
Joined: Jan 2006
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From: Crossville TN
.035" gap for points ignition with stock coil; .045" gap for most electronic ignition systems with higher potential ignition coils (ie, GM HEI system, Pertronix, etc.). Some high $$$ electronic systems advise you to go to .060" gap, but there is no real benefit in doing so.
For proper conversion from points to electronic ignition, you need to determine the proper way to get 12v power to the coil. The C3 points system used a [ballast] resistance wire to limit current to the stock coil. Many electronic systems MUST have a direct 12v supply source without a ballast resistor in the circuit. Many folks have improperly wired-up their electronic ignition systems and/or don't have a compatible ignition coil for that system.
For proper conversion from points to electronic ignition, you need to determine the proper way to get 12v power to the coil. The C3 points system used a [ballast] resistance wire to limit current to the stock coil. Many electronic systems MUST have a direct 12v supply source without a ballast resistor in the circuit. Many folks have improperly wired-up their electronic ignition systems and/or don't have a compatible ignition coil for that system.
Race Director
Joined: Nov 2002
Posts: 12,142
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From: Taylor Michigan
.035 gap is correct for points or electronic distributors....that is also where you get the best performance...that other dancing everywhere mid 70`s plug gaps was emissions orientated for those low HP engines and really didn't work there either and that's why .035 is better..
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