The MSD Pro-Billet distributor, specifically models PN 8570 and 85703 for Chevrolet V8 engines, is a performance upgrade component. Installation requires careful attention to safety procedures, including disconnecting the battery, and may necessitate the use of compatible spark plug terminals. The distributor’s timing functions—initial timing, centrifugal advance, and total timing—are critical for optimal engine performance and require understanding for proper configuration. This article details the installation process, included parts, and timing considerations based on the provided documentation.
Parts Included
The MSD Pro-Billet distributor package includes the following components:
- One Pro-Billet Distributor
- One Rotor, PN 8467
- One Distributor Cap, available in Red PN 8431 or Black PN 84313
- One Wire Retainer
- Two 1.5" Self Tapping Screws
- Two Panhead Phillips Screws
- One Advance Kit
- One Gasket
- One Tube of Gear Lubricant
- Two O-Rings
Installation Precautions
Prior to installation, the documentation emphasizes the importance of disconnecting the battery cables to prevent electrical hazards. The negative (-) cable should be removed first and installed last. The distributor terminals require spark plug style terminals, and users may need to modify existing wiring or purchase compatible kits. MSD offers kits PN 8849 or PN 8848, which contain nine boots and terminals.
Gear Replacement Considerations
If the distributor gear requires replacement, the documentation specifies that MSD Gear (PN 8531) must be used due to the .500" diameter shaft. This ensures compatibility and proper operation of the distributor.
Understanding Timing Functions
Several timing-related terms are defined to aid in the installation and configuration process:
- Initial Timing: This refers to the base timing, also known as idle timing, of the engine before the centrifugal advance mechanism engages.
- Centrifugal Advance: This is the mechanical advance provided by weights within the distributor, which adjusts timing based on engine speed.
- Total Timing: This is the sum of the initial timing and the centrifugal advance. It is calculated by adding the two values together. When checking total timing, the vacuum canister must be disconnected and the vacuum source plugged.
Calculating Total Timing
The documentation provides an example calculation for total timing: 10° Initial + 25° centrifugal = 35° Total Timing. This illustrates how to determine the overall timing value by combining the initial and centrifugal contributions.
Advance Spring Selection
MSD Distributors are supplied with heavy (slow) advance springs installed. This is a precautionary measure to prevent detonation in certain applications. Users are advised to review additional information to determine the optimal advance curve for their specific application.
Distributor Capability and Centrifugal Timing
The documentation states that the distributor’s capabilities are determined by the centrifugal timing. It also notes that the centrifugal advance can be locked out if desired, with instructions available in a separate section of the documentation.
Product Registration
MSD encourages users to register their product online at www.msdperformance.com/registration. Registration assists with warranty claims and provides valuable feedback to the MSD Research and Development team for future product development.
Contact Information
The documentation provides contact information for MSD:
- Phone: (915) 857-5200
- Fax: (915) 857-3344
Conclusion
The MSD Pro-Billet distributor offers a performance upgrade for Chevrolet V8 engines. Successful installation requires adherence to safety precautions, understanding the included components, and careful consideration of timing functions. Proper configuration of initial timing, centrifugal advance, and total timing is essential for optimal engine performance. Users are encouraged to register their product and utilize the provided contact information for support.