I read around the interweb that using a sparkplug gap of .045 would smooth out your idle compared to an .035 gap. What is the relation of your spark plug gap to your engine? I have looked around but I am having a hard time finding somewhere that explains spark plug gap and how it works. As in do you need to adjust your gap to your timing needs? or is the recommended setting irrelevant to timing? Such as having an advanced timing setup better to have a certain gap or is it better to stay at .035 regardless of what your timing is? any opinions are appreciated as I am switching out plugs tomorrow and havent decided whether I will stick with 035 or not.

 

spark is going to happen according to the timing. the gap effects the spark itself. intensity,ability to ignite. ive seen some real wide gaps on worn plugs and they seem to work. i know just thinking logicly it seems like a bigger gap would give a bigger spark and help to burn the fuel better but i dont think it works that way. it changes the spark itself. im sure theres a gap that is perfict but would change, with little wear, to a gap that is too wide. would work for a short time and then would have to regap. if memory serves me right the gap is purposly set a little too close to account for wear. u can change to a different heat of a plug if fouling is a problem, i figure u know that.

 

Spark plug gap on an old points style distributor setup is generally .030.
With electronic/HEI ignition, most plug gap settings changed to .045.
The wider gap does give a bigger spark, and the higher intensity of the electronic ignition can drive it.
Poo, don't you have electronic ignition?

 

i stand corrected. thanks. i wondered about that some years ago when i switched from a 65 gmc and bought a 93 chev pu. gap was way different. first tune up i took out the old plugs and thought wow these are worn. looked it up and they were close to right on. didnt look into any more.

love the look of the tunnel and duals.

 

I have a jegs hei distributor on mine. I dont think it is high performance or anything, just standard. I was curious about the spark plug gap because I know my engine prefers an advanced timing setting (we're talking like 40 degrees advanced here) and didnt know if a bigger gap would help out. I know I cant go too big since that will lead to spark plug detonation but if a bigger gap will make my car run just a little bit better then I would like to do it.

 

Widening a gap on a stock electronic ignition setup, with a relatively stock engine, will gain you nothing.
Sometimes, running too wide of a gap could make the engine perform worse because it can change the temperature of the tip of the plug from what it wants to be. Plus your ignition might not be able to give as hot a spark with a wider gap as compared to a narrower gap. Wider gap requires higher output.
By comparison, a high compression engine, or one with forced induction might perform better with a narrower gap due to those engines having a denser air/fuel mix in the combustion chamber.

 

I think I will go with the recommended gap then, thanks a lot for the help and for explaining that to me.