I'm rebuilding my engine with new rods due to an oil problem.

But this is what i discovered. I've 2 PFR6B11B that are completly "eat"

They are around 5000 miles :(

ive never heard of detting causing a cathode on a spark plug to snap?

 

im sure someone will give you a better explanation of what may have caused this

Chamber temp to high. What do the pistions tops look like? Are any rings broken or pistons miss shaped or pitted if so you have been knocking.

i have nothing on the pistons, the just look fine.

 

But this plugs (i have 2 like this) are the one that correspond to my 2 dead rods.

So maybe high temperature du to my oil problem?

Could be the result of several contributing factors depending on how your engine has been modified. Which two cylinders are they and what engine modifications were you running?

Have the pistons been hitting the heads due to lack of big end bearing material? ;) Happened on mine....

Here's a handy one

 

http://www.spark-plugs.co.uk/pages/technical/diagnosis.htm

 

Have the pistons been hitting the heads due to lack of big end bearing material? Happened on mine....

Ouch, that would have been an expensive set of plugs!!