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How Do I Know Which Distributor I Have and How Do I Hook It Up?
BluePrint Engines offers several distributor styles depending on the engine package and application. Before wiring your ignition system, it is important to identify which distributor is installed on your engine. Most BluePrint distributors are either a Ready-to-Run (RTR) Distributor, HEI Distributor, or a distributor designed to be used with an aftermarket ignition box. BluePrint Knowledge Base resources include distributor installation, timing setup, and wiring information for these ignition systems.
Ready-to-Run Distributor
A Ready-to-Run distributor will typically have:
- A small harness exiting the distributor body
- Four wires:
- Red
- Yellow/Orange/Brown
- Black
- Gray
- No large HEI-style ignition coil built into the cap
These distributors require the use of an external canister-style ignition coil.
HEI Distributor
An HEI distributor can usually be identified by:
- A large diameter distributor cap
- Internal ignition coil located inside the cap
- Power connection directly to the distributor
HEI distributors are commonly found on some Chevrolet applications and require a full 12-volt power source.
Ready-to-Run Distributor WiringFor BluePrint Ready-to-Run distributors:
| Wire Color | Connection |
|---|---|
| Red | Coil Positive (+) / Switched 12 Volt |
| Yellow, Orange, or Brown | Coil Negative (-) |
| Black | Engine Ground |
| Gray | Optional Tachometer Signal |
This wiring arrangement is referenced throughout BluePrint distributor wiring documentation and technical support resources.
Important
- Do not use a ballast resistor.
- Distributor requires full battery voltage.
- Ensure all grounds are connected to clean metal surfaces.
- Poor grounds can cause ignition issues and intermittent operation.
Wiring To An MSD Ignition Box
If using an MSD ignition box, wiring may differ from a standard coil installation.
For many MSD applications:
- Red distributor wire → Switched 12V
- Trigger wire from distributor → White wire on MSD box
- Black distributor wire → Ground
Always verify wiring using the MSD installation instructions for your specific ignition box. Technical support documentation references this configuration for common MSD installations.
Can I Use A Hyperspark Coil?No.
BluePrint Ready-to-Run distributors are designed to work with a standard canister-style ignition coil.
If using a Holley Hyperspark system, a Hyperspark distributor should be used instead. Technical support records specifically note that the Ready-to-Run distributor is not intended to be used directly with the Hyperspark coil.
Recommended Coil Specifications
For BluePrint Ready-to-Run distributors:
- 45,000 volts or greater
- Primary resistance of 0.700 ohms or less
Common examples include:
- MSD Blaster 2 (PN 8202)
- BluePrint BPP82021BK
These recommendations are referenced in BluePrint distributor support information.
Does The Gray Wire Need To Be Connected?
No.
The gray wire is only used if you are connecting a tachometer.
If a tachometer is not being used, the gray wire may remain disconnected. BluePrint distributor wiring references identify the gray lead as the tachometer output.
Frequently Asked QuestionsDo I Need a Ballast Resistor?
No. BluePrint Ready-to-Run distributors require full battery voltage and should not be used with a ballast resistor. Using a ballast resistor can cause ignition performance issues.
Can I Wire the Distributor Into My Factory Harness?
No. The distributor should be wired directly according to the recommended ignition wiring diagram and connected to a compatible ignition coil.
Is Timing Already Set?
The distributor timing was set during dyno testing. However, BluePrint Engines recommends verifying ignition timing after installation to ensure nothing shifted during shipping or installation.