How We Build the JB Racing Distributor Housing for Porsche 911

Kallin here at JB Racing walks through how we machine, finish, and QC our aftermarket distributor housings for classic Porsche 911 engines. If you are restoring, racing, or simply trying to keep a vintage 911 alive, these housings replace hard-to-find originals and add options the factory pieces never offered.

What this part does

A distributor routes spark to each cylinder. Our housing accepts a standard cap and wires, then pairs with JB Racing internals for either single-plug or twin-plug ignition. Twin-plug capability is a big upgrade for many performance builds.

Three stages you can feel

On the bench you will see three versions of the same part. Each shows a major step in the journey from raw billet to ready-to-ship.

• Turned
  We start from a raw blank and rough the profile on the lathe. Both sides are turned. This creates datum surfaces and prepares the part for tight work in the mill.
• Machined
  The part moves into a dedicated milling fixture. We engrave logos and part numbers, drill and tap all holes, add drain passages, and chamfer edges. Internal features like the grommet hole are now fully deburred in the machine.
• Tumbled
  Parts spend 1 to 2 hours in the tumbler. Edges soften. Small tool marks blend. The housing comes out with that smooth, premium feel you notice the moment you pick it up.

From there each housing is clear anodized, assembled with its matching components, test fit, and prepped for shipment as a complete kit.

What is new for 2025

The core geometry is unchanged, so your fitment remains the same. We focused on precision, finish, and serviceability.

• Clean, centered branding
  The logo is recut so every character is the same height and centered in the pad. It looks crisp and professional.
• Date code engraving
  Each housing carries a discreet date code. That gives you traceability for builds and future service.
• Full-perimeter dovetail chamfer on the back
  Earlier versions only featured this detail in a single area. The 2025 part carries the chamfer all the way around. It elevates the look and makes handling nicer.
• Smarter hole making
  We now bore the central bushing bore with a 1/8 inch end mill rather than simply drilling. That eliminates the deep internal burrs that can fight the press fit of the brass bearing bushing. Install goes smoother. Runout stays tight.

Better fixturing, better flow

We retired an old two-up fixture and built a new four-up system in house. It clamps from the underside so the housing stands proud of the plate. That gives the cutter and probe room to reach every feature, including backside chamfers, logo work, and drain holes.

• Fifth-axis access
  The fixture lives on a trunnion. We can tilt and rotate to approach each face at ideal angles. Engraving quality is sharper. Deburring is more consistent.
• Cycle time you can count on
  A four-part run takes about an hour and a quarter. The program probes critical holes, checks tools between operations, and blows off chips automatically. You get four deburred, consistent parts at the end of each cycle.
• Two body sizes, one fixture
  We support large-bore and small-bore variants for different 911 model years. A small 3D-printed insert adapts the fixture for the smaller shaft. Everything else is identical.

Finishing details that matter

• Anodize
  Clear anodizing protects the aluminum and keeps the look period-correct.
• Rotation markers
  Small dimples on the top receive color dots that call out clockwise or counterclockwise rotation. Part numbers match rotation, so ordering and setup are simple.
• Human-friendly edges
  After machining, in-machine chamfers remove burrs. Tumbling rounds the feel even more. If you wrench on cars, you know how nice it is when a part does not grab your skin.

Why choose the JB Racing housing

• Replaces original castings that are nearly impossible to source
• Supports single-plug or twin-plug ignition setups
• Machined, deburred, and finished for easy assembly and service
• Traceable with a clean date code
• Built on modern fixtures that keep tolerances tight and repeatable

When your project needs a serviceable, high-quality 911 distributor housing, this is the piece you can bolt on with confidence. If you are unsure which bore size or rotation you need, tell us your engine year and configuration. We will set you up with the right variant and the matching components to complete the kit.