[DeTomaso] WARNING: .050 may be the wrong kind of Bomb

[Dan Courtney]

Jack,

I timed it at 12 deg @ idle, 32 deg total in around 2,800 rpms.
Fuel pressure is from an electric pump internally regulated at 6.5 psi.
The plugs in the same cylinders looked OK before switiching out after 600 miles of highway and desert driving.
It's not just the ceramic part missing, also the electrode and, on #5, 1/2 the top of the tip.
It's seems strange that the other 5 plugs (except #2 / fouled) look new. 
Where would I find this scope? I really don't want to pull the head.

Thank You,
Dan
Dan F. Courtney

La Jolla, CA

(858) 551-5455 Phone
(858) 551-5456 Fax
  ----- Original Message ----- 
  From: JDeRyke at aol.com 
  To: dfcex at pacbell.net ; detomaso at realbig.com 
  Sent: Sunday, May 24, 2009 12:27 AM
  Subject: Re: [DeTomaso] WARNING: .050 may be the wrong kind of Bomb


  In a message dated 5/24/09 12:10:59 AM, dfcex at pacbell.net writes:


    What worries me more is, where are the tips of the plugs? Are they sitting in the cylinders, about to punch through my brand new pistons? Or has that already happened?
    I'm also wondering if detonation could have played a role.


  Thats a sign of detonation. Check your total ignition advance and your fuel pressures. Normally, a plug gap will either fire, or not, so thats not the cause of your detonation. The piston crowns likely look shot-blasted but unless they made really deep pits, the pistons will be OK. Any extra pieces of ceramic are long gone out the tailpipe. A fiber optic borescope can look thru the plug hole and inspect the piston tops without pulling the heads. My best guess- J Deryke


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