by Jon Mikelonis

Introduction
Although a new car equipped with a mechanical advance distributor hasn't rolled off the assembly line in more than 20 years, the mechanism also known as the centrifugal advance, has remained a tried and true method for controlling spark timing in all varieties of Ford project cars running non-computer controlled V8's. While nearly full-proof, centrifugal advance counts on the proper functioning of several moving parts, is almost always linear with RPM, and is awkward to tune with "small part" kits that provide interchangeable color-coated springs and stop bushings to get the job done. Regardless, old habits die hard and until an early model enthusiast watches a late model enthusiast plug in a fresh advance curve through a tuner or laptop, traditionalists will never fully understand how outdated mechanical advance assemblies really are. Until recently, the point has been moot because if you're running a carburetor then you're spark timing is controlled mechanically by the distributor and if you've gone EFI then your spark timing is controlled electronically through the vehicle's computer. Simple as that, until now there were no options to mechanical advance distributors for early carbureted V8's.

	The speed and control with which you can change and tune your advance curve with an electronic advance distributor allows you to sweep away aging centrifugal advance parts.

Enter the development of the electronic advance (EA) distributor. If you have not already discovered them, Mallory, MSD, and Crane Cams have all released EA distributors for early carbureted Ford V8's over the past few years.

If you are wondering what the big deal is about another electronic ignition, let us make something clear, the "electronic" in "electronic advance" isn't referring to the spark trigger
method (ie, breaker, magnetic, or optical), it's referring to the manner in which your spark ADVANCE is controlled. This being said, EA distributors completely eliminate the need for mechanical advance assemblies inside the distributor and better yet, your vehicle DOES NOT need a computer to run one. What this means to the early Ford enthusiast or for those of you who remain "carburetor comfortable", is that you can now ditch mechanical advance kits and begin programming and experimenting with advance curves as fast and often as your EFI counterparts.

The MSD Digital E-Curve and the Crane Pro-Curve both use rotary dials that allow the user to choose from a set of predetermined advance curves.

Market Snapshot
The FordMuscle staff has been eager to get their hands on an EA type distributor since Crane Cams introduced their "Pro-Curve Billet" variety back in 2004. While that never materialized, we're glad we waited because the market has become more balanced now that MSD introduced their "Digital E-Curve" and Mallory developed the "E-Fire" and the "Max-Fire". While all four electronic advance distributors are designed to target the same enthusiast profile and early carbureted applications, there are differences among them all.

The primary point of differentiation between the current market of EA distributors is how the advance curves are determined by the user. Mallory has taken the lead in developing custom tuning software to accompany their Max-Fire and E-Fire distributors while Crane Cams and MSD have integrated rotary dials into the distributor itself and predetermined the possible advance curve settings for the user. Crane Cams uses external dials while MSD keeps them under the cap. See image above left. While the dial type advance controls of MSD and Crane Cams do not require a computer, they do not allow the user to map their own custom advance curve. This may or may not be a limitation depending on your desire to experiment and personalize. After all, the MSD Digital E-Curve provides almost 100 different advance curves and even Crane's 27 available curves will satisfy most enthusiasts. Keep in mind, both Crane and MSD arrive at their total number of curves by multiplying the number of "centrifugal" curves by the number of vacuum advance curves.

Another important area of differentiation among EA distributors is which units have a built-in ignition and which do not. Both MSD's and Mallory's versions have ignitions under the cap, eliminating the need for an external box. However, Mallory is the first to have added a capacitive discharge (CDI) which is available in the Max-Fire. The MSD Digital E-Curve and the Mallory E-Fire also do not require an external box, however their ignition's are inductive (IDI) and do not provide multiple sparks like the Mallory Max-Fire.

The table above provides a good comparison summary but we still urge you to visit each manufacturer's website for a complete review of product attributes. Please see the manufacturer links in the table.

Up Close with the Mallory Max-Fire
Broad Ford V8 coverage, a built-in CD ignition, included custom advance programming software, and a solid "non-prototype" appearance, all lead us to choose the Mallory Max-Fire in order to share our first experience with an electronic advance distributor. Let's take a preliminary look, then we'll show you how it works on the following page.

The Max-Fire is surprisingly compact considering what's underneath the cap. Remember, in addition to electronic advance, the Max-Fire's got an integrated CD ignition. The three harnesses shown accommodate the coil, 12V source, and a serial cable.		Here's what's inside the box. Note the Windows based advance curve programming software, plug wire cap retainer, and the 9 volt harness (far left). The Max-Fire can be powered up by a 9 volt battery and programmed on your desktop computer or left in the motor and programmed with a laptop.
The two-piece cap keeps the internal electronics contamination-free.		Removing the rotor and cap reveals the brain and adjustable rev limiter. Rev limiting can be performed through the software or on the distributor itself.

(Programming the Advance Curve)