Spark Plug Gap
Thread Starter
Instructor
Joined: Jan 2002
Posts: 227
Likes: 0
From: CA
Spark Plug Gap
Ok, so after yesterdays spark plug misshap (used wrong plugs) I have some AC RapidFire #5 plugs that are the correct plugs. Now, my service manual says the gap needs to be .35 but the plugs say that they are pre-gapped to .45 and they say DO NOT RE-GAP. So my question is, do I need plugs that are .35? Will .45 work? Can I regap anyway to .35? What gap is better for performance? I have a 1990 with an L98. Thanx!
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Spark Plug Gap (C490Vette)
The mfg has designed that plug to work with stock HEI at .045" gap so use it.
The reason it works is that the electric field is more intense at a point than on a flat surface. So their center electrode design (with those sharp points) allows the plug to fire the charge reliably with the wider gap.
The reason it works is that the electric field is more intense at a point than on a flat surface. So their center electrode design (with those sharp points) allows the plug to fire the charge reliably with the wider gap.
