Monthly Archives: February 2010

Ignition wires/ Spark plugs

a very overlooked part of your engine is your ignition wires. Most people….and i have been guilty of this myself in the past…change the plugs, cap, and rotor but re-use old plug wires. if you are taking the time to change your plugs- change your wires don’t scrounge around the garage of find a dead motor in a corner of the barn to rob a plug wire, and have extra wires on hand for when you go to the track.

a hard lesson learned goes back to my buddy dave’s vega drag car. he had a set of crane ignition wires on his engine and had no problems for the first 2 years. well, after several drivetrain changes they kept running into inconsistent times at the track. they tried carbs-ignition boxes-distributors… one point they even tore down an engine i had built claiming i didn’t install the heads right……still had a problem. finally after several months someone walked over to the trailer one day at the track with a set of new wires and it was like night and day. they kept checking the wires for resistance and they checked fine….but never realized that constantly changing around the engine compartment had loosened the plug wire ends at the cap and was spark-arcing under hard accelleration along with cutting out spark. This is WAY too common around the pits at a demo derby. i see old wires that are duct taped, electrical taped, wadded together, and hell even cut wires while they are tuning a carb!!!

on a stock application a good set of wires should go 80-100,000 miles these days. for performance you need a good 8mm plug wire or bigger with sturdy ends at the plugs cause you will be pulling plugs a lot to read them. i will get into that later. i run and prefer Taylor spiro-pro 8mm wires. they are well built, easy to install, easy to use, and dress up an engine nice. the ends for the plugs are well built. MSD wires aren’t bad either. i avoid 7mm wires for performance. 9-10mm wires, as well as solid core wires, are usually overkill unless you have a magneto or something radical for an ignition system. you want a resistor core wire for an HEI style ignition. solid core wires can do funky things to the electronic ignition sometimes. not sure why.

I prefer buying the universal wire kits and make them to the lengths i want. By doing this you can route them nicely through looms to keep the wires from touching…..which is always a good idea…..and make it look nice. On a derby engine since you don’t have ends on yet you can route your wires through plastic wire loom, heater hose, or even hard tubing to protect the wires. it also makes it easier to route the wires around/under the header stacks without having the inevitable short wire that usually ends up burned off on a pipe.

Reading spark plugs is not something i am very good at but a necessary evil to see if the carb tuning is in the ballpark. Depending on the type of fuel you run it can be different from one engine to the next. Chosing the heat range of the plugs to run is also something to take into account when running alternative fuels or nitrous oxide as well. For street and derby application i start with a stock replacement spark plug and seek out a different heat range plug if i notice the electrodes are burning up and cooking the plugs….and it’s not something you have to deal with much outside of hardcore race engines. I hardly ever mess with it. If you are in the Zone of tuning, Cheap gas will have a white electrode, cam 2 will be an off purplish white color not ghost white. I always would play with timing and carb jetting/tuning before playing with heat range on the plugs. you want the plugs to run warm and clean, but not so hot they melt and crack. starting off or going to too cold of a plug can cause fouling issues and lack of performance. Also read your plugs after you have made a few runs and your engine is up to temp and ran UNDER LOAD. on a derby car, if you wanted to worry about it, you would beat on it for 10 minutes in the bean field.

I am a big fan of NGK V-Power spark plugs for just about everything. i seem to get the best compromise of longevity and performance for me personally. Platinum plug to me are usually overpriced for what you get. as a rule of thumb though i was taught that you use AC Delco for GM products, Motorcraft or Autolite for Ford stuff, and Champion plugs for a Mopar engine. This is a good rule of thumb and works. i am not a fan of Bosch plugs they suck for the most part.