Spark plug gap

[rangersteve]

So I bought some platinum plugs for my truck and I was going to buy a gapping tool, but the guy at the parts store, Lordco, said you don't need to gap these plugs, they are already set to spec. It this true?

According to my Haynes manual they should be gapped to 0.044 in

Any advice is appreciated,
Thanks

 

[88_Eddie]

what kind did you get? bosch platinums dont have to be gapped, i dont know the science behind it, i just read it somewhere or saw it in a store. they have 2 (or more) grounding straps on them and i think that creates a longer spark....but like i said, not sure about the engineering behind it

 

[snoman6115]

or e3's or ngk iridiums. any with more that one prong needs no gaping to waste ur money. your better off gettin autolite platinum or double platinum. midgrade plugs and they work great. buddy got e3's and had a difference, his wallet was empty

 

[BRUTUS_T_HOG]

sure, platinums are supposed to be pre-gapped. but 75% of them are WAY off.

you are supposed to check and gap them before installing, but never afterwards because the platinum can be knocked off after being run in the engine.

any spark plug with more than one electrode will only cause problems. the objective of spark plug gap is NOT to provide the shortest, easiest spark. its the provide resistance so the ignition coil will build up high and cause a nice hot spark.

so a large spark plug gap will produce the smoothest idle, but might cut out and miss under load AND it will overheat and damage the coil. a small gap would produce misfires at idle, the same thing those expensive multi-electrode are doing.

 

[Big Jim M]

Well...maybe

sure, platinums are supposed to be pre-gapped. but 75% of them are WAY off.

you are supposed to check and gap them before installing, but never afterwards because the platinum can be knocked off after being run in the engine.

any spark plug with more than one electrode will only cause problems. the objective of spark plug gap is NOT to provide the shortest, easiest spark. its the provide resistance so the ignition coil will build up high and cause a nice hot spark.

so a large spark plug gap will produce the smoothest idle, but might cut out and miss under load AND it will overheat and damage the coil. a small gap would produce misfires at idle, the same thing those expensive multi-electrode are doing.

The purpose of the spark plug is to ignite the fire in the combustion chamber.. Carbed engines must use a richer mixture which is easier to light, so carbed engines typically have a gap of .032. When our engines went to injection the mixture typically became much leaner and harder to light. It was found that the gap had to be .044 or even wider in many cases in order to have enough fuel in the gap to start the fire.
So using the recommended gap for each engine is a good plan to follow. ONE spark is all we get! No matter how many electrodes are on that plug only ONE of them sparks. ALL the rest of the electrodes just get in the way and many times impede the fuel from getting under the electrode that does spark, causing a miss.
As the gap was widened the coils had to get stronger. The stock coil and plug will fire your engine up to and over the advised rpm limit for your engine.. NO other plug or coil will run your engine better than the stock ones until the engine is used at many more rpm than the engine was designed for.
Big JIm

 

[BRUTUS_T_HOG]

The purpose of the spark plug is to ignite the fire in the combustion chamber.. Carbed engines must use a richer mixture which is easier to light, so carbed engines typically have a gap of .032. When our engines went to injection the mixture typically became much leaner and harder to light. It was found that the gap had to be .044 or even wider in many cases in order to have enough fuel in the gap to start the fire.
So using the recommended gap for each engine is a good plan to follow. ONE spark is all we get! No matter how many electrodes are on that plug only ONE of them sparks. ALL the rest of the electrodes just get in the way and many times impede the fuel from getting under the electrode that does spark, causing a miss.
As the gap was widened the coils had to get stronger. The stock coil and plug will fire your engine up to and over the advised rpm limit for your engine.. NO other plug or coil will run your engine better than the stock ones until the engine is used at many more rpm than the engine was designed for.
Big JIm

sooo... i guess you agree? or just adding to what i said?

 

[Big Jim M]

Naaa!

sooo... i guess you agree? or just adding to what i said?

Just holding class for a while... You are close enough.
Big JIm

 

[rangersteve]

Thanks for all the advice. Looking under the hood, there was a sticker that said the correct gaping was .052-0.056. I ended up buying a gap tool and after checking all of them the gap fell within specs. All were about .055.

They were NGK G-Power plugs.
http://www.summitracing.com/parts/NGK-3403/