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NoDOHC · 04-19-2011, 10:12 PM

My camera is on the blink, so I can't get any pictures, but I have been experiencing a lot of spark plug issues since I upgraded my ignition. The most recent problem is erosion of the electrode. The engine didn't start as well as I was used to after a hard drive down some curvy roads. I pulled my spark plugs and found that the electrode has retracted way back into the plug. These plugs have about 200 miles on them. The trailing plugs were fine, the leading plugs were not.

I have also been experiencing pre-ignition at very low advance numbers (32-34 degrees) this only occurs after prolonged hard acceleration up a steep hill. I am running 9.2:1 polished S4 NA Rotors. I ran 38 degrees just fine with non-polished 9.4:1 S4 NA rotors with the stock ignition system.

Add to this the failure seen on the dyno (corners of two apex seals broke exactly as Barry Bordes illustrated in This Thread), obvious failure point right after leading spark plug hole, black residue on both sides of highly polished leading plug hole. The same housing also had a crack going out from the trailing plug hole. I will get some pictures when I get a different camera.

This behavior is all very indicative of excessive spark plug temperature.

Questions for the community:

How many of you have tried the really cold NGK plugs (BR10EIX, R6725-105, R6725-115)?

Has any one tried running a BRK9EQ from the trailing position in the leading position for a high-powered NA application?

I have no trouble with fouled plugs, so I am not worried about using slightly colder plugs, I will try the colder plug even without feedback, but I will appreciate feedback on non-stock plugs.

Thanks!

04-19-2011, 10:12 PM	#1
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 17	Spark plug issues My camera is on the blink, so I can't get any pictures, but I have been experiencing a lot of spark plug issues since I upgraded my ignition. The most recent problem is erosion of the electrode. The engine didn't start as well as I was used to after a hard drive down some curvy roads. I pulled my spark plugs and found that the electrode has retracted way back into the plug. These plugs have about 200 miles on them. The trailing plugs were fine, the leading plugs were not. I have also been experiencing pre-ignition at very low advance numbers (32-34 degrees) this only occurs after prolonged hard acceleration up a steep hill. I am running 9.2:1 polished S4 NA Rotors. I ran 38 degrees just fine with non-polished 9.4:1 S4 NA rotors with the stock ignition system. Add to this the failure seen on the dyno (corners of two apex seals broke exactly as Barry Bordes illustrated in This Thread), obvious failure point right after leading spark plug hole, black residue on both sides of highly polished leading plug hole. The same housing also had a crack going out from the trailing plug hole. I will get some pictures when I get a different camera. This behavior is all very indicative of excessive spark plug temperature. Questions for the community: How many of you have tried the really cold NGK plugs (BR10EIX, R6725-105, R6725-115)? Has any one tried running a BRK9EQ from the trailing position in the leading position for a high-powered NA application? I have no trouble with fouled plugs, so I am not worried about using slightly colder plugs, I will try the colder plug even without feedback, but I will appreciate feedback on non-stock plugs. Thanks! __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)