Hei question

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Apr 22, 2013 | 11:02 AM

BARRY L-48

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Racer

Joined: Jan 2005

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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 ?

Apr 22, 2013 | 11:23 AM

Easy Mike

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From: Southbound

Cruise-In II Veteran

Quote:

Originally Posted by BARRY L-48

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...

What is the current gap? Car running okay? You may not have to change the gap.

Quote:

...is the # 1 position on the distributor cap have to changed...

Shouldn't make a difference since the firing order did not change from points to HEI.

Last edited by Easy Mike; Apr 22, 2013 at 01:19 PM.

Apr 22, 2013 | 12:00 PM

BARRY L-48

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Racer

Joined: Jan 2005

Posts: 307

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From: McCordsville Indiana

runs ok but does use alot of fuel

Apr 22, 2013 | 12:25 PM

F22

Le Mans Master

Joined: Oct 2006

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From: Palmdale CA

Quote:

Originally Posted by BARRY L-48

runs ok but does use alot of fuel

That's not ignition related. Most likely, how your carb is set up and what carb you have will affect the mileage. After that, it's the outside factors, tire pressure, alignment, driving style, etc.

Apr 22, 2013 | 03:06 PM

JimT

Burning Brakes

Joined: Nov 2006

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From: Orange Park Florida

The HEI runs a hotter spark - I set my plugs at a 50 gap, initial timing at 14 degrees, all in at 36 degrees. Runs great

Apr 22, 2013 | 03:13 PM

7T1vette

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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.

Apr 22, 2013 | 08:11 PM

Ironcross

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Joined: Nov 2002

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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..