Here's the plug.
Eric, from the videos I've watched, a black band about .100 wide is what we want, but this is tan. Oh, and looking closely, you can see it's probably wider than the 1/8" I described.
Rich
Reading spark plugs
I'm using Autolite 3924 plugs in my aluminum headed 454, Holley 780 carb, appx 10:1 compression. Yesterday, I put 2 new plugs in #1&2 cylinders, wound it out to about 60 mph for awhile, then coasted to a stop, shutting the engine off as soon as I could. Replaced those two new plugs with the ones I took out, then headed home. Back home, I cut the threaded base off one of the new plugs and found that the insulator was mostly white with a slightly tan band about 1/8" wide at the bottom. I was expecting to see some black so I could get an idea of where to go with a change in jets, but maybe more running time was needed to see that?
The jets that are in the primaries now are 72's any ideas where to go from here?
Thanks,
Rich
The jets that are in the primaries now are 72's any ideas where to go from here?
Thanks,
Rich
1 - 4 of 8 Posts
Here's the plug.
Eric, from the videos I've watched, a black band about .100 wide is what we want, but this is tan. Oh, and looking closely, you can see it's probably wider than the 1/8" I described.
Rich
For safety sake, no. I had it up in the rpms, but not WOT.
Rich
Rich
Today, I tried it again with a larger set of primary jets, 74's. The ones that were in there were actually 71's, not 72'as I posted. The car is running stronger with the 74's, but the plug looks the same as before.
Maybe I'm not giving it enough run time? After switching to a new plug, I ran it about 50 mph, hard on the gas and shut it down about 1/4 mile later.
Rich
Maybe I'm not giving it enough run time? After switching to a new plug, I ran it about 50 mph, hard on the gas and shut it down about 1/4 mile later.
Rich
1 - 4 of 8 Posts
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