CNC porting is hands down the most cost-effective way to port and polish your heads. One company that we’ve been working with for some time now is Ford Performance Solutions / Avenger Cylinder heads. Owner Troy Bowen has helped us with a few engine builds, and we decided to take a little closer look at his CNC-ported heads, branded under the “Avenger” name – in return. Enjoy!

Check out the video below, and read below for even more cool facts and tidbits on CNC porting:

Top Interesting “CNC Porting” Facts

  • CNC porting involves more than just loading a bare head into a CNC machine and pushing the magical GO button: “Each port design really starts out as a hand ported design,” explains Bowen. “Things such as CFM, port volume and combustion chamber profile are just a few sources for data that are collected and analyzed during this process to ensure the port-design is top notch,” added Bowen.

  • Port Digitizing is what “Maps” your port: This digital information is a graphed into a computerized model and used to set what is called the tool path. The tool path is the exact patch the CNC cutter will follow to best recreate the original hand ported design. This program takes into account the size and length of the cutter to ensure that there are no accidental cuts, especially when reaching deep into the runners.
  • Double Checking the “Map” versus the original “Port” is important:
    Before going to mass production, Bowen takes the time to ensure the tool path results in a port job that is similar to the original hand ported design.

  • Prototype Testing is Critical: “Once this first prototype is finished being ported, it returns to the flow bench and dyno for additional testing to compare it to the original hand ported model,” says Bowen. From there changes are made when necessary to ensure the final tool path results in a high flowing CNC head.

  • Matching & Blending the port entry & exit is the tricky part: The matching and blending of where the intake and exhaust ports meet up with the valve bowl is extremely important. Getting this wrong will cause even the best designed port to flow like you know what. “Making sure that the head is indexed properly in relation to the tool during setup ,” says Bowen.

  • Don’t Get Shanked: The CNC machine actually keeps active track of the shank of the porting tool to try to keep it from colliding with the port entry while reaching deep into the port. According to Bowen, “This is critical or the tool will snap or gouge the port.”

  • Hand Blending: It Helps: Avenger hand blends any “steps” formed from the cutting tool and blends in the valve job to a smooth finish. The final step for Avenger is to assemble the heads with quality springs, valves, and other valve train hardware, before packaging them up to be shipped out.