NGK 6061-10 spark plug trouble

I had over 10 spark plugs fail on a run, they tend to develop a crack in the porcelein from the cable end to the 13/16 hex nut . The crack apear visible after 1 run , yes it drops that cylinder . have done it on diferent cylinders on diferent runs . We changed everything , never sieize compound, spark plug wrench , taking extra care installing then.

Its a BAE 5 head , 525 hemi screw blower on a promod deal....

Thanks for your sugestions

JP

 

have had this problem before you have oil or some sort of grease in the spark plug boot and this makes the spark travel on the outside of the plug and shatters the porsitine

 

I remember bill doucet had the same problem, and a couple others, he had it figured to a certian batch number stamped on the hex. Funny i was gapping some plugs last night and was thinking about that problem.

 

I had the same issue. I changed the lot number and it went away.

 

Thanks Guys for your input

I do not think it to be a lot number problem as i only have bought about 100 spark plugs in the last couple of months and i have used 2 diferent supliers from diferent states ..

Could it be a oil issue??

Just to be sure I will replace the spark plug wires...

Any other ideas?!

 

I have had this problem also, i had 35-40 runs on a set of leads in a TAD so i changed them out and the problem went away, i now change my leads every 20-25 laps and havnt done it again since, usually change them when i change rods out, also i was told by spike gorr to spray a little brake clean in the end of the lead everytime you install them i guess it cleans them out and slightly lubricates them when you put them on
worked for me

 

Why is the 6061 better than the R 5671?

 

Great question. It costs 4x as much. Is it 4x as good?

 

I had a reputable person tell me to use them and another reputable person say I didn't need them......??

 

from what i've been able to find out, the 6061 has a different earth strap. It is trimmed short, and doesn't have the bend on the strap, it is just straight.

 

Question

Will a weak coil act the same way, the car just doesn't seem to rpm in high gear . I will replace the wires and still undecided on replacing the coil.