Hey there, quick question for all of you. I have a 355/420hp motor in my 66' malibu ss convertible, with 2700 miles on the motor. I am running NGK plugs #FR4 V-POWER. It has been harder starting lately so I was checking on the plugs and pulled one out only to find out that it was blackened on the end and sort of wet with gas. Any guesses on what could be causing this, like I said, these pluggs only have 2700 miles on them. Also if you needed to know, I am running the Performer aluminum heads, performer intake, and performer 750 carb and matching cam for the whole crated package.
thanks in advance

tdjr66
1966 malibu ss convertible (canadian)
355/420 hp
th350
3.55/posi
let me know if you think it though.

You said you only pulled one plug. Are all the plugs like that? If so, sounds like you are running rich. Drop a size or two on your primaries and see what happens.

What kind of ignition are you using? If you have converted to HEI, many times people use the original distributor "hot" wire. HEI has to have a full 12 volts to it. The original wire has a resistor in it. I know of a car that had the same problem as you. He was using the original "hot" wire with HEI. When he corrected it, his plugs went from black to brown. Obviously a hotter spark burns the mixture better.
Good luck!


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-Mark "Some of us got it and some of us ain't." -Deputy Sheriff Barney Fife
TC# 717
ACES #1641
1967 Chevelle SS396/375 (http://www.chevelles.com/showroom/1BadRat2)
1967 RailVelle (http://www.chevelles.com/showroom/1badrat3.jpg)
1964 Chevelle 283/195
1975 Corvette 396/425 (http://www.chevelles.com/showroom/1BadRat1.jpg) "Wow, that's a mighty strong 350!"
Rat Garage (http://www.chevelles.com/showroom/RatGarage.jpg)

Those plugs may be wrong for your mill! The "4" is about right for a stock small block making about 250hp. I run a UR6 v-power in my 383. NGK recomends 1 range colder per 75-100hp increase. Don't confuse hotter spark with hotter or colder plugs.

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...Dennis
The '69 (http://chevelles.com/showroom/fine69_03.jpg) & the '96 (http://chevelles.com/showroom/fine69_02.jpg)
Team Camaro (http://www.camaros.net)
Camaros Limited (http://www.camaroslimited.com)

Thanks for the info guys. Hey Mark, I think it is the original "hot" wire. How do I remedy this? Do I need to just run a new 12 volt key on wire and bypass the resistor?
thanks for the help.

tdjr66
1966 malibu ss convertible (canadian)
355/420hp
th350
3.55/Eaton posi

Yes, you've got it. You have to have a full 12 volts going to the coil. This is a common mistake on these old cars. I bet this will wake up the car a little bit!

Mark