Sig Erson Racing Cams was established in 1964 and as its second half century begins the company is not taking its foot off the gas. Erson Cams which has been under the PBM Performance Group umbrella since 2006, is unveiling fresh bumpsticks for 4.6- and 5.4-liter Modular Fords, late-model Chrysler Hemis, as well as new designs and profiles for the Chevy LS platform.
“The Modular Ford cams are very limited on what you can do in regard to lift because of valve spring constraints of that engine, says PBM Performance founder and accomplished engine block designer Dick Boyer. “We’re working with builders that specialize in those engines to develop profiles that will work with the valve lift you have to run and still generate the power they desire.”
Boyer is quick to point out that the LS platform offers more design freedom. “The LS is open season, with the 55 mm cam core we can do almost anything we want,” says Boyer. “The cylinder heads have a little bit of restraint on the valvetrain because of the small diameter, but people are making valve springs now that fit in the stock location and are good for .800 inch to .820 inch lift. So on the new LS we’re working really hard on the new hydraulic .365 inch to .385 inch lobe-lift roller stuff. We’re developing some new .475 inch and .500 inch lobe-lift for the race applications as well. A .500 lobe in a LS will get you up around 800 horsepower.”
According to Boyer, the Chrysler late-model Hemi also has problems with valve spring restraints so Erson is again working with lobes that work efficiently with low lift. “We actually just did a cam for a guy with a stock eliminator Chrysler Hemi engine and we picked him up about 65 horsepower over the cam he took out of the engine,” quips Boyer. “Without giving away any secrets we are looking at valve action, trying to get that valve moving as fast as we can, but that engine has hydraulic roller lifters in it so we are working with some new profile designs to keep that valve action fast without blowing down the lifter.”
Erson also had an interesting tidbit on the materials front. “One of the coolest new technologies in the cam business is tool steel cam cores,” says Boyer. “Take an induction hardened cam core, say an 8620, the heat treatment on this is about 75,000 to 100,000 stic. On a tool steel core the heat treatment rating is more in the realm of 250,000 to 300,000 stic. This makes a much stronger product so you can run lighter lobes, or narrow the lobes and not have as much contact area. Also a tool steel cam can be reground more times, and it can run a smaller, lighter barrel with the same amount of strength. The tool steel cam core is becoming pretty popular. Sprint cars guys like them because they’re light and will accelerate better … and these guys are serious about ‘light,’ putting titanium shafts in their distributors for crying out loud.
The tool steel core also works well in high spring pressure applications because the lobe is so dense all the way through it provides a solid foundation. Think about it like walking on ice. If underneath the ice is soft, it collapses but if the underneath side is solid, it won’t collapse. This tool steel is hard all the way to the core so it won’t flatten or give under big spring pressure.”
There’s some nice gear here, stay tuned for more on availability.