L03 IGNITION INFORMATION

General Info

The LO3 ignition system is pretty basic.  It is an HEI setup (High Energy Ignition).  Since the engine is computer controlled, the ignition itself, including spark advance, etc., is all under the control of the ECM.  These are the parts of the ignition system:

  • Distributor - located at the back of the engine, the distributor tells each spark plug when to fire.

  • Coil - provides the high level of voltage required to create a spark at the plug.

  • Plug Wires - the plug wires carry the spark signal and voltage to the plugs.

  • Spark Plugs - the plugs use the high voltage from the coil to create an arc (spark) across two terminals which ignites the air/fuel mixture within the cylinders. 

The ignition system in the LO3 is not bad for the main purpose of the engine...low RPM operation.  But, once you get much above 4500 RPM, the strength of the ignition to do it's job correctly decreases.  It was just simply not meant to be a high RPM ignition.  That is when you have to start to upgrade to ignition system.

 

Modifications/Upgrades

Distibutor

Cost:  About $250-300

The stock distributor works pretty well for most applications.  I actually have the stock distributor in my car...it is one of the LAST stock pieces left.  I may be wrong, but I see it as a part that only has to be replaced when either it breaks, or you are running a really high performance engine that will require the precision that an aftermarket distributor offers.

Cap and Rotor

Cost:  About $25 for both

The stock cap and rotor aren't bad, but eventually they wear out.  That is when I would recommend getting a cap and rotor from a more performance oriented company such as Accell or MSD.  Personally I like MSD, its what I have on my car.

A high performance cap and rotor gives better top end spark because of the fact that they are made to higher tolerances that a factory/stock replacement.  The contacts are usually a better quality metal also.  These two things add up to a better performing distributor, with more accurate spark and less misfiring.

MSD Distributor Cap

 

Coil

Cost:  About $50

The stock coil again, is OK for normal use, but for a high performance engine, a high energy coil is best.  the stock coil stops supplying good spark energy at around 4500 RPM so I have heard.  Not sure if it's true, but it would not surprise me.  A coil 

 

Plug Wires

Cost:  From $30 - $70

The factory plug wires could definitely use a better replacement.  They are very thin (like 6mm maybe?) and not geared towards performance usage at all.  Your best bet is to get an aftermarket set of thicker plug wires.  The standard thickness for high performance use is 8mm.  Accell has their Superstock wires that work pretty good, but I have had them and I burned a couple up pretty easily.  Now I run MSD SuperConductor 8.5mm wires.  They seem to be a lot better quality than the Accell wires, but they cost a lot more also.

 

Plugs

Cost:  From $1-$4 each

A lot of people say "plugs are plugs", which I agree with to an extent.  I don't think that the high tech plugs like the ones with 4 electrodes, are worth the extra cost.  In engines as simple as ours, I think that a regular old plug will do the job.  I only use AC Delco plugs, and I have always had good luck with them.

AC Delco has their regular old plugs for about a buck or two a piece, and the have the Rapid Fires that are about 4 bucks a piece.