Just got a quick question about spark plugs and their weird behavior on my engine. I have TF 23degree heads on my 350 and I'm using a set of RapidFire #5 plugs which is what equals the FR3LS regular AC Delco plugs that TF recommends. I gapped them at .050 The engine runs good, but at night in complete darkness you can see the spark go through the porcelain of the plug! It looks like the porcelain glows and it happens on all the plugs. Another this my engine does quite a bit is ping with only 10 degrees of advance. Could it be that I gapped em too big ? Not the right kind of plug ? Any opinions ?

------------------
1991 Z28 6.0 TPI

360 4 bolt main block, TrickFlow 23 degree heads, CompCams CS270HR cam, Harland Sharp roller rockers, Accel base, SLP siamesed runners, 52MM SLP Throttle Body, Hooker Headers, Flowmaster catback, MSD6A ignition, Home made ramair system, 2500 stall, bullet proof 700R4, aluminum driveshaft...

 

Crucial,

I doubt that you are seeing the spark through the plug porcelain. It is far more likely that you are seeing the aura surrounding the insulator created by the high voltage. The wider gap and greater compression would increase the spark voltage requirement, so the aura would be more prevalent.

If you ever get near high voltage tranmission lines in a remote, unlit area, you can observe the same thing.

------------------
Later,
Vader
------------------
Justice and Freedom will Prevail
Adobe Acrobat Reader