It can be said that the stunningly beautiful rocker arm assemblies manufactured for the Chrysler Hemi platform by Reid Machine are a clear case of a product which has been designed and developed to perform at the highest echelons of racing. It doesn’t hurt that a quick look at the machined contours of the arms shows that just as much care has gone into developing the appearance as has gone into ensuring the performance, and that’s a direct reflection of the mindset of the product designer, bill payer, and chief bottle washer at the company, Darrell Reid. But his path is not a traditional one.
“Most of my serious design work is done at home, after hours,” he says.
“But some of it is done here at the shop from 5 to 8 p.m. I’ll turn on Beethoven, Bach, or Tchaikovsky, and it starts to flow. As long as it keeps going, I’ve walked out of here at midnight. I don’t have a racecar, I don’t own a racecar. I started doing this because I have a passion for solving problems from a mechanical standpoint, and making things work. I really enjoy making stuff. When I got involved in this with Manton to begin with, I was like a kid in a candy shop. It’s challenged me from a mechanical and machining standpoint, from the perspective of making the part.”
Manufacturing rocker arms from scratch to withstand the levels of horsepower seen by cars like our very own BlownZ06 Corvette, which features a 3,000-plus-horsepower supercharged Hemi, and championship-winning engines which make far more power than ours—like NHRA Alcohol Funny Car—is no small engineering feat. We’d consider Darrell Reid an artist, evidenced by the precision machine paths seen on the surface of these rocker arms.
Recently we had the opportunity to tour his small shop where the magic happens, as it’s just down the road from our California office, and were impressed with the serious jewelry which comes out of this four-person shop.
What starts off as humble pieces of billet steel bar-stock ends up turning into rigid, lightweight, and extremely durable rocker arm assemblies. Darrell Reid took the time to explain some of the details to us regarding the process, although he didn’t share every detail, citing the all-too-familiar competitive secrets clause—and who can blame him?
As each one of these rocker asemblies is truly developed for its particular application, careful attention is paid to the minute details during the manufacturing process, from initial contact all the way through delivery of the finished product.
One way the company works with its customers to ensure they receive the correct products is to ship each one a mockup assembly prior to delivering the finished product, to ensure valvetrain geometry is correct.
However, he says the Muscle Head IV from Alan Johnson—which is, of course, the head used on our Hemi—requires a different configuration due to subtle differences in the design.
“We digitized the valve locations and we saw enough of a difference that we wanted to make a different stand; a unique assembly to that specific head,” he explains.
Reid rocker assemblies are an I-beam design, constructed from solid billet 4340 steel and are heat-treated for longevity. Each rocker offers pushrod oiling through the adjusting screw to ensure pushrod tips stay cool and lubricated. Reid’s secret to success is offering components which are optimized to provide the perfect location for the roller over the valve tip.
In years past, all of these design tasks would have been incredibly labor-intensive, with many, many hours invested in measuring, checking, testing, and measuring again, before a piece of material was ever touched. But these days, thanks to the advances made with respect to digital measuring, 3D modeling, and other computerized manufacturing techniques, the work is done in a different way. In fact, often the customer will be able to send a digital drawing of the cylinder head configuration so that Reid is able to work his magic right on the screen before ever turning on a machining center. Since many of the Hemi cylinder heads the company works with are manufactured from billet, the digital representation of the cylinder head already exists.
What I’m looking for is the most efficient path of converting radial motion into linear motion.— Darrell Reid, Reid Machine
But none of this happens without an initial concept of what the designer—Darrell Reid himself, in this case—envisions with respect to how the product needs to function and look once the design process is complete. To that end, Darrell shares that he doesn’t sleep much.
“What I’m looking for is the most efficient path of converting radial motion into linear motion; when you look at the valvetrain, the lifter is creating linear motion from the radial rotation of the cam. So then you have the linear motion of the pushrod to the rocker. That linear motion puts into play radial motion of the adjuster, which turns into radial motion of the roller at the top of the valve, then converting it back to linear motion of the valve going up and down. At the same time you’re using the arc of the adjuster and the arc of the roller in the most efficient manner so that we don’t have lost motion,” says Reid.
That lengthy explanation helps to explain Reid’s simple goal: maximizing the efficiency of the radial motion to create linear motion on the valve.
Bring In The Computers
Engine components in particular have benefited from the use of computerized modeling programs, as these programs make it far simpler to develop new products than in years past, where parts had to be machined from scratch and blueprints had to be developed in order to manufacture more than one part consistently. With components that see stress levels like rocker arms down—for thousands and possibly hundreds of thousands or more cycles over their lifetimes—Finite Element Analysis and Mastercam CAD/CAM software has been a lifesaver for manufacturers like Reid Machine, especially when it comes to understanding the stress points in the rocker body.
“As I’m building the rocker, I know that the basic construction—the rib thickness and things of that nature—that doesn’t change, unless we go into a Top Fuel rocker. Once I get the rocker built into its configuration, I’ll move into SolidWorks and do the FEA. We’ll put loads on the roller and loads on the adjuster, and look at it to see what bright spots we get, and then come back and add material or remove material as necessary,” says Reid.
They are also analyzing the rocker’s weight consistently to determine how much weight is over the nose of the rocker. With knowledge of the mass of the component, they can see where the center of gravity of the roller is at any given time with the roller and adjuster included. They also inspect the moment of inertia to visualize where the weight is on the rocker arm.
“The rocker itself may be ‘heavy,’ but it’s the proper distribution of weight that is most critical,” says Reid.
“Think of it as a big guy and a small guy. If the big guy is standing on the valve tip side, he becomes valve weight, which is going to affect the valvespring and the inertia of the valve going down. If it’s a high amount of weight, then the valve wants to loft, and the spring has to work harder—and slows the spring down—in the process of getting the rocker back up,” says Reid.
Since the manufacturing process at Reid Machine is kept under wraps, for the most part, we’re unable to show you how the tooling itself is configured. It’s cost Darrell many sleepless nights to determine the best ways to make the machinery do what he needs it to do in order to manufacture these products, so you’ll just have to take our word for it when we tell you it’s impressive.
If you’re looking for the ultimate solution to keep your Hemi valvetrain under control, then you owe it to yourself to check out these beauties. We’ve already tested them to well over 3,000 horsepower in our Radial Vs. The World Corvette, set a record, and won two of the first three races where the car has competed.