Burned plugs

[Fastford]

Who has ever burned plugs in there 03's Yesterday I burned a plug for no apperent reason. I have done a compresson test and leak down test with ok results. 155 psi compression and 10% leak down. I am not sure what to do as far as pull the motor and replace the pistons with better ones.

I am not sure why the engine burned a plug it happend at 5000 rpm and has been running perfect with 17psi and made 570hp. 530 ft. lbs. I run a very conservitive tune on my motor with 19-20 degs. advance and 11.7-12.0 A/F.

What plugs do most people run with KB's with stock cats?? Were do you draw the line with the cats?? I think that my engine is holding to much heat in with the cats and doesnt flow enough air causing back pressure in the manifolds wich in turn is not allowing the combustion chamber to cool???? What do you think.

Thanks,

Jason

 

[AMB]

Fastford

What plugs are you using ?? You should be using AGSF-12s or IT-24s.

AMB

 

[Fastford]

I was using IT 22 TOOO hot. I might try some TR7 NGKs

 

[AMB]

Fastford

The IT-22s = TR-7s = AGSF-12s. YOU need the IT-24s at the stock gap of .032".

AMB

 

[Fastford]

Is that much colder plug then the 22's??? Have you ever burned a plug in your mustang.

 

[03DOHC]

Maybe you got some detonation? Which cylinder had the bad plug?

 

[Fastford]

I know that I had Detonation, but at 17 degs I should not had detonated. There was too much heat in the cyl thats why I burned a plug. I think I had too hot of a plug for my application.

 

[AMB]

Fastford

I have run 23 PSI boost with VP 103 unleaded and IT-24 plugs and have had NO problems. It is about one heat range colder than the IT-22s.

AMB