bigger spark leads

[aznsiko]

hey fellas just wondering if any one knows.. if i install bigger spark plug leads.. is it compulsory that i adjust and redo my timing..

[bennjamin]

bigger ? As in , longer actual leads ? AFAIK Resistance changes over the length of a lead - but i will go out on a limb and say NO.

[Eclipsor]

If by bigger you mean thicker. The reistance will decrease. If longer the resistance will increase. The electricity won't "travel any slower" though. Not taking into account differences different cables might have in capacitance and other effects.

[**Ghost**]

so it thicker better?

[Eclipsor]

Ya. Well from an electrical sense it is. Smaller resistance the higher the current (from I=V/R) and the larger the spark I assume. Not sure of any other factors in an engine there is though.

Found the formula. R = (pL)/A

where L is length, A is cross sectional area, p is resistivity and R is resistance.

So if p or L increase R will increase and if A increases R will decrease. Resistivity depends on the material the lead is made out of.

[ah8118]

wow.. this is becomin like a maths/physics lesson....

[wynode]

I thought a good spark is dependant on a high potential differnce as opposed to a high current?

[gambate]

I thought a good spark is dependant on a high potential differnce

yes, AFAIK

[Eclipsor]

yeah you're probably right. or a combination of both. either way smaller resistance in the lead will increase current and increase the voltage across the spark plug. Because there will be a smaller drop across the lead....I think

[tinkerbell]

wanna answer the guys question perhaps?!?!?!

no - it is not compulsory UNLESS you move the distributor...

[robbo_is_mad]

So wat type of millimeter is the best?

8.5 mm 7.0 mm or 12.0 mm

someone told me the thicker the leader the more youll get out of it!!!

is this truu

[DLO01]

To answer the topic starters question: No need to as stated above.

Yes thicker is generally better.

But it not just the thinkness that your should look for

Resistance also depends on Materials used, length, Heat and also Insualtion of the leads.