Reply to "spark timing"

The plug is running clean and on the lean side. For a street car, leave it all alone. It's close enough for what you want.

No oil deposits. Engine is tight.

You really can't read them if they were not changed before you did the ignition change though.

You really need to put in a new set of plugs and do it again with them.

Original plug was a Motorcraft AF-32. I don't know where the Autolite crosses over.

It may not be the exact equivelent. The heat range could be wider, or shorter.

Motorcrafts tend to have a narrower heat range.

An AF42 will also work for you to but it is a hotter plug and I wouldn't go to it unless you were showing some signs of plug fouling in city driving conditions.

The 32 tends to clean up within about 100 yards of acceleration into high speed. Sometimes sooner.

If you run the car up to speed (100mph or so) then step off of the accellerator, you might hear the engine blowing carbon off of the plugs and the valves.

It isn't just the plugs that need to be cleaned up, it's the combustion chambers and valve deposits also.

On my plugs on the ceramic insulator on the plug, you can actually see the dividing line between the intake valve side and the exhaust side.

It's like looking at the moon half full. There is light and dark.

Plugs really should be indexed where the tip of the plug electrode points at the intake valve. There is at least 7-10hp to be picked up there.

The stock iron heads have tapered seats for the plugs and I don't know anyone who makes spark plug shims for that.

The aluminum heads use a different plug. It is flat and uses a washer. Those you can shim to index the plug electrodes.



I would put in a new set of plugs drive the car then read the plugs.

To really read plugs for mixture strength there are a bunch of things you need to do as a procedure that is difficult to do on public roads without getting arrested.


My Sony Alpha on Macro sees things that you can't with the naked eye. For stuff like this it's unreal. It would see the little beads from the fuel on the electrodes.

You need a magnifying glass to see that with your eyes.