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Arrington Introduces Its New Line of Performance Camshafts

HEMI Performance Camshafts

Arrington Performance Camshaft Introduction

Arrington has just revamped its line of high performance camshafts. These new camshafts have been engineered with the latest technology to give your HEMI engine the maximum horsepower and torque. ShopHEMI offers the ST-3A and SR-2B to complement your Dodge, Chrysler, or Jeep motor.

Dyno Proven Results

Update- In order to provide our customers with more information about our new camshafts, we installed a set of SR-2B cams on both a stock 5.7 and 6.1 engine. These motors were then put to the test, on Arrington's in house chassis dyno, thereby proving their horsepower and torque gains across the power band. As you can see, the 5.7L engine yielded a peak power output of 334.4 RWHP and 343.9 RWTQs. Expectedly, the larger displacement 6.1L produced even more- bumping the engine's performance to 419.9 RWHP and 412.3 RWTQs.

Dyno Graphs:

6.1 HEMI Camshaft Dyno Graph
5.7 HEMI Camshaft Dyno Graph












HEMI Engine Ready – NASCAR Inspired

Technology enabled Arrington to compete with the top NASCAR teams in the Cup series. That technology is now used to develop our line of cams for your street HEMI. Top racing teams spend millions of dollars testing and developing valvetrain systems and cams that maximize power and torque while retaining the longevity. This process keeps racecars stable at high rpms for extended periods of time which is crucial to finish races. Virtual Prototyping was utilized to provide a cost effective alternative to physical testing. Hundreds of cam profiles were tested and evaluate before a single camshaft was manufactured. The first cam designed under this process helped our NASCAR customers to qualify for many races in 2009.

Virtual Prototyping Speeds HEMI Cams To Market

These HEMI camshafts began virtual design and development three weeks before valvetrain components were available to build and test! Arrington then tested the completed cam on the Spintron, or laser-based valvetrain testing rig, and then measured results. The results were identical to the results predicted by virtual camshaft testing earlier by our Mopar Engineers.

Our HEMI Camshaft Design Process VS The Competition

The background of our HEMI camshaft design team has been to use Engine Simulation and Valvetrain Simulation to design cams for professional race teams for nearly a decade. Now this process is being applied to our Mopar street and race engines. We use state of the art technologies previously only available to top-tier professional race teams for all of our HEMI cams. Our Challenger and LX Camshaft design process starts with a clearly defined goal, usually a desired improvement above the existing power/torque curves of a particular engine. Once the performance goals are defined and understood, we build a baseline engine using virtual engine simulation. Simultaneously, a baseline virtual valvetrain simulation model is built and validated. A crucial component of an accurate Engine Simulation model is an accurate representation of the dynamic valve motion found in the physical HEMI engine. Valvetrain Simulation provides a solid representation of the dynamic valve events experienced while racing or driving your Dodge, Chrysler, or Jeep vehicle. The baseline model in Engine Simulation helps us determine what changes we need to make to the HEMI valves in a given set of circumstances (dictated by the cam) in order to achieve the high performance goals. The baseline model is then used to perform a Design-of-Experiment (DoE) study to determine the optimum valve events in your HEMI heads required to obtain the desired horsepower and torque. Hundreds or even thousands of motors are virtually built, tested and analyzed throughout the DoE to find the optimum combination of valve events. Once the best combination has been identified, a Valvetrain Simulation model is built that matches the design criteria identified by Engine Simulation. From there, the lobes are designed and tested in an iterative fashion until all design criteria is met and the undesirable dynamic content is minimized. When the lobe designs are complete, they are sent to be manufactured in our state of the art manufacturing facility. 

After the prototype cam is manufactured, it's sent to the dyno for the real testing to begin. Just as a note to the usefulness of this process our new SR2 HEMI Camshaft made ~52+ hp and ~20+ ft-lbs over stock with only a cam swap and minimal ECU changes.

Arrington Performance HEMI Cams Made From The Best Materials

All of our HEMI cams are machined from billet steel and manufactured on state of the art precision CNC equipment. We choose to use CNC equipment exclusively so that we can quickly make changes to any design without the need for making patterns or "masters". Every lobe design is created from the valve - as opposed to our competitor’s process which designs based on the lobe. This "top down" design methodology considers the entire HEMI valvetrain system instead of simply the camshaft lobe. Additionally, the valve motion will be designed, tested and evaluated at the valve which is what the engine actually utilizes to produce efficiency, performance and power - valve motion, not cam motion. Not a single lobe was designed without full knowledge of the entire valvetrain including each and every component. That is the only way we have ultimate control over the quality of the results. We deliver your HEMI valvetrain in a reliable package that delivers unmatched performance. 

HEMI Virtual Valvetrain

Take a peek at Arrington's Virtual Valvetrain

This is a mesh of the HEMI intake rocker. A structured-light 3D scanner was used to obtain a 3D image of the rocker that could then be reverse-engineered. Since the mesh cannot be precisely measured for mass properties, inertia, etc. or used in valve-train simulation it is then drawn from scratch in CAD using this mesh as a guide. 

Arrington  HEMI Camshaft Arrington  HEMI Camshaft

This is a shot of the mesh overlaid with the CAD model of the intake rocker. The mesh used was one of the first ones created. Since this specific mesh was created, much higher quality scans have been completed. Using this process an accuracy of .01mm or .0004"is able to be achieved.

Arrington  HEMI Camshaft

This is the result of FEA (Finite Element Analysis). Our engineers needed to determine how stiff the stock HEMI rockers were in order to properly model them into a complete virtual valvetrain simulation. The pushrod cup is fixed, the fulcrum is treated as a hinge locked along the axis of the rocker shaft and a force has been applied to the pad. The radius where the black line is has been removed to allow accurate meshing of the model for FEA. The force used is 3x the maximum force experienced on the ST3 intake lobe. The same FEA data has also been used on the Arrington Steel roller rockers.

Arrington  HEMI Camshaft Arrington  HEMI Camshaft

Finally before production a solid model of the SR2 cam is completed for beauty shots and promotions.

Arrington  HEMI Camshaft