There are certain things in life we just take for granted, like the sun coming up in the morning, airlines losing our luggage, and a Corvette that will start when we turn the key.
Is the ignition system in...
Is the ignition system in your Corvette up to the task of firing your engine's mixture? Chances are it's not if you're still sporting factory components. This month we'll upgrade Project C3 Triple Ex with a new MSD ignition system to energize our Stingray.
Generally, that's exactly what happens as the stock ignition transfers electrical energy to the spark plug, jumping the gap of the plug with an arc to ignite the fuel and air in the cylinders. But as our cars age, or if we install a more powerful engine, the factory hardware may not be up to the task. Since Project C3 Triple Ex's ignition consisted of antiquated components of questionable vintage, we felt it was time for an upgrade to a more modern electronic system from MSD.
When we got our project car,...
When we got our project car, it had a factory points-style distributor that had been converted to electronic with now-defunct Crane internals. Since the distributor and coil were likely as old as the car, we decided to replace them with new MSD electronic ignition.
Chances are, if your car's engine is stock, and you keep the OEM ignition system in good condition, it will work just as GM intended. In a car as old as ours, however, the stock setup didn't offer modern conveniences or safety devices such as an engine-saving rev-limiter or multiple-spark discharge. Additionally, the mass-produced components in most Corvettes, especially those as old as, or older, than our C3, are likely worn out. Coils, condensers, and especially distributors have a finite lifespan before needing to be rebuilt or replaced, and the components in our car were definitely past due.
As the foundation for our...
As the foundation for our new ignition system, we chose MSD's new 6AL-2 ignition controller. This is a high-energy ignition system capable of 535 Volts and 135 millijoules, and it's compatible with distributors or crank triggers.
Another reason we'll be upgrading our ignition, to an MSD ignition system, is to ensure we have enough spark to fire the engine in C3 Triple Ex as we perform future performance modifications. Though only a warmed-over 350 at the moment, it'll soon be tweaked for considerably more power, and a full engine swap-to a higher-compression or boosted stroker motor-may also be in the works. Since all of these options increase cylinder pressure, requiring a hotter spark, we wanted an ignition system that not only boosted ignition energy, but also offered a rev limiter in case our right foot gets carried away. Since our C3 came with a mechanically driven factory tachometer, we were happy to see that MSD offers a Pro-Billet distributor with the correct tach drive, made specifically for Corvettes.
Most engine upgrades that add a significant amount of horsepower-such as installing a performance camshaft, raising compression, adding forced induction, or injecting nitrous oxide-raise the pressure inside each cylinder during combustion. As cylinder pressure increases, it takes more ignition energy for the spark to jump the gap of the spark plug, and eventually the factory ignition system can become inadequate.
While converting to factory HEI ignition and adding individual components such as a hotter coil are options, the technology is still decades old and doesn't offer a way to safely limit revs. The MSD ignition is also a clean-burning multiple-spark discharge system below 3,000 rpm, and it offers stable, high-energy ignition all the way up to 12,500 rpm-far higher rpm than a factory system is capable of. Changes to the ignition-timing curve can also be accomplished in just a couple of minutes, using a screwdriver and the included springs and cams.
MSD has a quality product line too long to list, covering ignition systems for everything from street to all-out race vehicles. Since our Stingray will see both street and track duty, we chose the 6AL-2 ignition box with a Blaster HVC coil. The 6AL-2 provides all digital circuitry, along with a two-step rev limiter that uses rotary dials-instead of chips-to set max rpm. The Blaster HVC is designed for sustained high-rpm use, so it works well for a street or road-course car, which we envision our project ultimately becoming.
Different Corvettes may require...
Different Corvettes may require different mounting positions; just be sure you orient the unit so that you can access the rev-limiter rotary switches.
MSD offers a Pro-Billet distributor...
MSD offers a Pro-Billet distributor with a mechanical tachometer drive just for Corvette owners, allowing you to retain the factory tach in your early Vette. This distributor is a nice piece, suitable for race or street applications.
The Pro-Billet distributor...
The Pro-Billet distributor comes with all the hardware needed to attain multiple timing curves. In our experience, the MSD timing graphs outlined in the instructions are dead on.
To change the timing curves,...
To change the timing curves, simply remove the distributor cap and rotor to gain access to the bushings and springs. The idea is to achieve as much initial advance as possible without dragging the starter, and to reach full total advance by 2,500 rpm.
Installing new ignition components isn't too tough for a mechanic or enthusiast with average mechanical skills, but if you're unsure about the job, we suggest thoroughly reading MSD's detailed instructions before you get started. We've done this kind of work before and had all our MSD components installed in less than a day, but taken at a more leisurely pace, we'd consider the job an easy weekend project. Though we didn't see a huge improvement at the dragstrip, our elapsed times did improve. More noticeably, the car starts instantly, runs smoother, and revs freely, making it even more fun to drive. Most importantly, if a drivetrain component ever breaks, or in the unlikely event we ever miss a shift, the engine will be protected by the built-in rev limiter.
Before removing the old distributor,...
Before removing the old distributor, mark the number-one spark plug, then pull the cap and verify the orientation of the rotor. The new distributor should be oriented the same as the old one.
The MSD distributor slides...
The MSD distributor slides right in place of the original unit. By holding the housing and rotating the rotor, you'll feel the distributor gear mesh with the cam gear, and the distributor will drop into place.
The 6AL-2 offers digital circuitry,...
The 6AL-2 offers digital circuitry, and the two stages of rev limiting are easily adjusted through the holes in the ignition housing. A small screwdriver is included with the ignition for this purpose. The LED light on the side lets you know the unit is working properly.
In addition to the detailed...
In addition to the detailed instructions, the wiring diagram for the unit is also embossed on the back. The wiring is very simple, almost as easy as wiring one of Editor Heath's guitar amplifiers.
The ignition unit should be...
The ignition unit should be mounted away from heat, and in an area that won't be exposed to the elements. After considering our options, we chose the back of the left (driver side) inner fender. Using the unit as a template, we drilled four holes and installed the rubber isolators provided with the ignition.
Using the coil as a template,...
Using the coil as a template, we drilled four mounting holes and mounted our Blaster HVC coil on the firewall near the distributor.
Taking advantage of the Corvette's...
Taking advantage of the Corvette's mechanical tach drive, we used the tachometer output on our new ignition unit to power MSD's programmable shift light.
With the major components...
With the major components in place, we installed new MSD Super-Conductor plug wires.
MSD systems aren't compatible...
MSD systems aren't compatible with solid-core plug wires, so we recommend replacing the wires when you replace the ignition components.
Since the MSD ignition delivers...
Since the MSD ignition delivers much-higher energy, the company recommends opening the spark-plug gap. For engines under 10.5:1 compression, 0.050- to 0.060-inch of plug gap is the desired starting point.
This LED shift light mounts...
This LED shift light mounts easily on the steering column or A-pillar and ensures we won't miss a shift.
The new ignition system not...
The new ignition system not only serves important performance and safety functions, it also looks good under the hood. We can now be confident that Project C3 Triple Ex will have the high-energy, reliable ignition required for future upgrades.
We took our project car to...
We took our project car to the Lakeland Drag Strip after installing our MSD ignition and ran just over a tenth of a second quicker than our previous best of 8.94 seconds in the eighth-mile. More importantly, our Stingray now starts quicker and has better throttle response. Now the ignition system of Project C3 Triple Ex is up to the task of supporting further modifications.
Thanks to CARB (the California...
Thanks to CARB (the California Air Research Board), MSD provides these decals with its ignition components. Thanks to good engineering, engines with MSD ignition generally run cleaner, so nearly all MSD components are legal in all 50 states.