S. Jennings Racing, LLC is owned and operated by brothers Cliff and Kevin Jennings who continue the company’s well-established legacy in the racing industry.  As a company, S. Jennings Racing LLC has been building high-performance racing engines for over 40 years.  Placing the highest emphasis on quality and reliability, our company prides itself on customer satisfaction.  SJR, LLC strives to deliver products in a timely fashion that meet every customer’s specific racing needs.  We specialize in full engine rebuild services, research and development opportunities, and custom or off-the shelf manufactured parts.  Every engine that leaves our shop is a complete package of the highest quality available.


S. Jennings Racing, LLC has extensive experience in rebuilding engines from virtually every decade of racing.  We have produced engines for everything from an antique 1930’s MG to Porsche 993 cup cars.  Utilizing state-of-the-art research and development techniques, we pride ourselves on our continual pursuit of the best racing package available.   Upon arrival, all engines are disassembled, cleaned, and evaluated in a meticulous fashion using such processes as magnaflux, pressure testing, and precision inspection equipment.  All assembly and rebuild processes such as main line and cylinder honing, rod reconditioning, and complete cylinder head services are performed in-house.  Should the need arise for a component that is no longer in production, our full CNC machining capabilities allow us to manufacture custom parts within our facility, focusing on quality control and exact replication.  All engines are run through a break-in and tuning process on either of our two water brake dynamometers utilizing the latest Depac data acquisition software.


S. Jennings Racing, LLC is equipped with full CNC and manual machining capabilities which allow us to provide services to a wide range of customers. As the racing industry has evolved, SJR, LLC has found a niche in creating and manufacturing ready-to-install components for a number of engine applications. Four-cylinder engine parts ranging from CNC ported cylinder heads to smaller internal components such as valvetrain and camshafts are all available on a moment’s notice.  Additionally, we offer aluminum cylinder blocks and completely machined raw castings.   We also specialize in the creation and production of antique or obsolete engine parts necessary for complete engine restorations.  Utilizing only domestic materials and 100% lot traceability on all processes allows us to ensure the quality and reliability of our products.  With our wide variety of machining equipment, we also excel in taking custom projects from conception to design to working component all within compressed time frames.  Custom projects that include complex castings and sub-assemblies are inspected, packaged, and shipped from SJR to anywhere in the world.

  • Fadal 4020 FX Vertical Machining Center with 4-Axis Milling capabilities with Renishaw touch probes

  • Fadal 3016 Vertical Machining Center with 4-Axis Milling capabilities with Renishaw touch probes

  • Haas SL-20 Horizontal CNC Lathe capable of machining an 11” diameter part that is 20” long

  • Chevalier FSG 1224 Surface Grinder capable of grinding 24” long by 12” wide and 12” tall.

  • Sunnen Bore Cylinder Hone up to 6” in diameter

  • Manual Lathe

  • 2 Manual Mills

  • Horizontal & Vertical Band Saw

  • Cold Saw

  • Rockwell Hardness Tester

  • Complete GibbsCam Programming Software

  • 18″ Starrett Optical Comparator

  • Brown & Sharp Coordinate Measuring Machine 24″x24″x18″ work envelope