MILD THUNDER

iTrader: (3)

Yes, some guys will expire an engine a half dozen times trying to play engine builder/tuner.

SB

iTrader: (1)

And blame the builder who did everything but put the induction / ignition on.

Bawana

BB, how ? By reading the ground strap & porcelain, how will that tell you what the motor "wants". I believe it will tell you where your at with heat range & timing (kinda). I am not trying to be D-bag, but please educate me on this if you will.

Bawana

BB is this what you are saying?

Heat Range = Ground Strap, the ground strap indicates the heat-range of the spark plug. If the "color" of the ground strap "changes" too close to the ground strap's end, (which is above the center electrode), then the heat-range is "too cold" , meaning that the strap is loosing heat too quickly to the base ring, and is not able to burn off deposits until near its end. If the "color" of the strap changes near where it is welded/attached to the base ring (last thread ring), then it means that the plug heat-range is "too hot", because heat is not being tranferred/cooled from the strap to the base ring quickly enough !!!! The strap might begin to act like a "glow-plug", eventually causing preignition and/or detonation later on. Proper heat-range is when the "color" is at the half-way point on the strap, neither too cold or too hot.
But some say thats the way to tell where your timing is at. So what is correct? Reading ground strap for timing or heat range of plug?

Black Baja

iTrader: (2)

The ground strap shows both timing and heat range. If the plug is to cold and you give the motor timing it really will not show up on the ground strap. If the plug is to hot the strap will start to melt away. The best way to learn how to read a plug is by doing it. Put a new set of plugs and retard the timing a little do a good blast shut it down and pull the plugs. Pay close attention to the ground strap. Take a picture if need be. Install plugs give it 3-4 degrees of timing do another blast shut it down and pull some plugs. You don't have to go and pull them all just pull a few and compare. After you move the timing around a few times you will easily see what's going on with the ground strap. What I've found is not all cylinders want the same timing and heat range plugs... It's interesting if you really start getting into it. I agree a wideband is great. But when you spend the kind of money we spend on these motors it really the responsible thing to do by pulling some plugs and trying to get a better idea of what's going on inside the cylinder.