Welcome to Short Block Charlies

As one of the premier Harley-Davidson machine shops in the U.S.A., Short Block Charlie’s specializes in performance head modifications and engine building. We are located in Tempe, Arizona, and have a summer facility in Montana. We are a Haas/Sunnen/Newen machine shop with the latest and most state-of-the-art equipment available.

There have been design and procedure changes in our cylinder head program recently. From port finishes to our new CNC valve seat machine and computer software, these changes have put us one step ahead of our competitors in the industry!

Project M8

Learn all about our new project! We will very soon be developing new products and services for the all-new 2017 Harley-Davidson M8 107ci Street Glide. Continuous updates and segment videos will be released throughout the entire process so you can remain in the loop.


Intake Port Finish

Recently, we have changed the surface finish on our intake port runners. Rather than employing the standard sanding roll finish we now use a DIAMOND tool cutter to secure a finish which dynamically enhances the air-flow and air velocity through the intake port.

Computer Software

We are using sophisticated software which assists in the optimum design of ports. We can now simulate the air-flow through any given port. With this program we can change port shape, valve seat angles, and obtain an accurate reading of what these theoretical changes will yield in both physical air-flow and port velocity. This software can duplicate both swirl and air-tumble situations. An added benefit is that we have a 3-D snap shot of ports and combustion chambers rather than a linear reading.

CNC Profile Editor

CNC-Machined Valve Seats

Our NEWEN BB Contour valve seat machine employs both the machine and the Port-Flow software, which allows us to transfer air-flow simulation into reality in order to design and cut any type of optimum valve seat profile imaginable. With this machine, one designs the seat angle interface via a CAD, then presents this data to the machine and a CNC-machined valve seat is cut with a single point CBN cutter blade. The finish and angles are within .0001" accuracy to blue print.


The combination of CNC technology for valve seat profiles, porting changes, and flow-bench information applied to the cylinder head puts us in a unique position among our competitors. We have raised the bar in cylinder head porting performance! Our drastic changes in air-flow numbers and port velocity have resulted in substantial increases in both horsepower and torque on our dyno runs.

Charlie's NEWEN Machine Expertise

Charlie’s exposure to new technology and information are facilitated by his relationship with the NEWEN CNC machine company. Charlie trains clients from NASCAR, NHRA, and other leaders in the automotive and motorcycle industry who have purchased a NEWEN CNC machine. Charlie helps the client develop programs for their specific machining needs. Due to this, Charlie has become an expert on the NEWEN CNC machine, and he is able to put his knowledge to good use when performing his top-notch services he is known for on your cylinder head.

New Services

  • Vapor blasting service
  • Paint stripping service
  • Electric compression release machining and installation
  • SBC Scotsman head service
  • Scotsman Pro-Series head service
  • SBC R&D projects
  • Cylinder head baseline procedures