Question on "cut plugs"
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
There is a pic on my site and a description of my method.
Basically I use a cut-off wheel on a Dremel to cut off the ground electrode very nearly even with the inner edge of the center electrode. Then I use a fine file (finger nail file works) to dress any burs or sharp edges.
If you have a stock HEI set them to stock gap; if you have a high output coil (like HyperTech) you can go with a .045" gap.
Basically I use a cut-off wheel on a Dremel to cut off the ground electrode very nearly even with the inner edge of the center electrode. Then I use a fine file (finger nail file works) to dress any burs or sharp edges.
If you have a stock HEI set them to stock gap; if you have a high output coil (like HyperTech) you can go with a .045" gap.
Thread Starter
Le Mans Master
Joined: May 2003
Posts: 5,203
Likes: 0
From: Las Vegas Nevada
I switched out my MSD blaster back to the stock coil. Seemed like even with gaps of 50-60 this was scortching the plugs. Would cut plugs allow me to reinstall the blaster without the scortching problem?
I am running Rapid Fires #1
I am running Rapid Fires #1
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Since the Rapid Fire plugs have such a small center electrode I don't think the cut-back mod would do much there. I've cut back both the Split fire and stock AC Delco with success.
What the cut-back mod does is provide less shroucing so you get better flame front propegation, so I don't know if that would help with a scroching problem. That might require a colder plug.
If you switch to a stock style plug you might be able to run the MSD blaster again. I assume it puts out much higher voltage (like the HyperTech) than the stock HEI, in which case I'd try the wider gap.
I'm thinking that if you go to too wide a gap with a high CR, maybe it's possible that you get dieseling before the spark??
What the cut-back mod does is provide less shroucing so you get better flame front propegation, so I don't know if that would help with a scroching problem. That might require a colder plug.
If you switch to a stock style plug you might be able to run the MSD blaster again. I assume it puts out much higher voltage (like the HyperTech) than the stock HEI, in which case I'd try the wider gap.
I'm thinking that if you go to too wide a gap with a high CR, maybe it's possible that you get dieseling before the spark??
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
I would certainly just try a wider plug gap with your hot coil. I run a complete MSD ignition setup and gap my plugs at .060 without any problems. I've always heard that you should runs a large a gap as you can reliably fire. Of course stock gap on my car .050 so it's not that much of an increase.
I'm going to try a set of cut back plugs some day. I just can't bring myself to change a set of perfectly working plugs until I have some other reason to do so.
I'm going to try a set of cut back plugs some day. I just can't bring myself to change a set of perfectly working plugs until I have some other reason to do so.
