How big should the spark plug gap be?

How big should the spark plug gap be?

SPARK PLUG GAP IS SET TO AN OPEN LIMIT OF .045 NO LARGER, DON’T CARE WHAT IGNITION SYSTEM IS USED, DON’T CARE WHAT SOMEONE ELSE SAYS, DON’T GO ANY LARGER THAN .045, PERIOD. HEAT RANGES AND TIP TYPES, STANDARD, PROJECTED OTHER ARE DETERMINED BY ENGINE COMPONENTS, NOT THE IGNITION SYSTEM.

When did GM change spark plug gap to.045?

Back in 1975 when GM started using HEI, they wanted plug gaps set at .060 till they found out it was hard on caps and rotors, as mentioned. They then changed their specs to .045. So as mentioned, .040-.045 is right on the money.

What’s the difference between Hei spark plug gaps?

Well, we simply reduced the spark plug gaps back down to the original .045 sizing, and, MAGIC, LIGHT OF LIGHTS, NIRVANA, THE WARRANTEE COIL/HEI MODULE FILURES/PROBLEMS AND FAILURES STOPPED, and failure rates went back to the levels pre-giant gap.

What kind of spark plugs do you use on a 1969 Chevy?

Engine is a 1969 350 horse 396, all stock so far. BTW, I will not use Champion plugs. Maybe their quality has improved but not willing to give them a fourth chance. Kids will be kids, but parents should be parents. Edited by 69 SS396 on 04-23-11 06:42 AM. Reason for edit: No reason given.

SPARK PLUG GAP IS SET TO AN OPEN LIMIT OF .045 NO LARGER, DON’T CARE WHAT IGNITION SYSTEM IS USED, DON’T CARE WHAT SOMEONE ELSE SAYS, DON’T GO ANY LARGER THAN .045, PERIOD. HEAT RANGES AND TIP TYPES, STANDARD, PROJECTED OTHER ARE DETERMINED BY ENGINE COMPONENTS, NOT THE IGNITION SYSTEM.

Well, we simply reduced the spark plug gaps back down to the original .045 sizing, and, MAGIC, LIGHT OF LIGHTS, NIRVANA, THE WARRANTEE COIL/HEI MODULE FILURES/PROBLEMS AND FAILURES STOPPED, and failure rates went back to the levels pre-giant gap.

Back in 1975 when GM started using HEI, they wanted plug gaps set at .060 till they found out it was hard on caps and rotors, as mentioned. They then changed their specs to .045. So as mentioned, .040-.045 is right on the money.

What’s the best spark plug gap for AMC?

If you get the Davis Unified Ignition for AMC which is basically a souped up HEI, they recommend .055-.060. If you have a coil that can fire a strong spark through the gap (they can), then it will contribute to a better, more consistent ignition of whatever is in the chamber.