Founder of Professional Racing's Most Precise Valve-Train Geometry Since 1973

(Click Photo)  BOSS 429

Racing engines wouldn't function as they do without roller tip rocker arms. Rocker arms are sold by more than 30 different companies, with about 20 of them actually manufacturing their own products. The remaining companies buy from somewhere else and put their name, or no name on them (commonly referred to in the trade as "private label"). Rocker arms are among the most copied components sold in a high performance engine; they are also among the most popular of all parts replaced. Copied mainly because there has never been an accurate engineering standard to their design; well...almost never. Rocker arms are the "messenger of the cam." They are a "radial" instrument that converts "linear" information from one side to the opposite, plus multiplies this motion through an increased ratio. Any deficiencies the rocker arm has in doing this minimizes the cam's information from being accurately conveyed to the valve. The result, is excessive rocker arm motion across the valve, more violent cam profiles being required to make the valve lift as quickly, with increased friction and less performance. This over-arcing geometry is the way "name brand" rockers have been made for more than 30 years.

The concept of MID-LIFT® geometry began back in 1973, and by 1974 it was finalized into the principles of precision geometry by Jim Miller for the BOSS 429 Hemi, an engine which arguably had the most complex valve train of any American made engine in history. While other companies have continued to change, modify, rethink, redesign and copy improvements for their rocker arms over and over, Jim's Patent winning concepts have never wavered. In addition to establishing the "standard" by which rocker arm geometry is defined, Jim also developed critical standards that revolve around it, such as valve tip heights for head preparation, necessary for accurate rocker arm designs, and geometry tools that "work" - unlike the fixed height "stand checkers" and "plastic pushrod checkers" sold for many years. These are useless because they don't allow for NET valve lift; only a closed valve perspective, as if the valve will never open. ^

Other innovations include such standards as the "1 turn out" adjusting screw setting; the "twin beam" ball mill relief, the "drip down oil hole," dual position oil feeds to and from needle bearings; "needle THRUST bearings" (not just washers); "I-Beam" and "Y-Beam" cross sectional rocker beams with reinforced tail support webs straight up from the rocker's bottom bearing bore and around the pushrod cup (or adjusting screw), where loads distort and stretch bearing bore. And of course, other Patent Pending features thought of and used by no other manufacturer that use the rocker arm's body as its own geometry tool, with precision machined facets that synchronize to either the mounting stand, the valve, the valve spring retainer, the rocker's stud or other fixed points which allow the engine builder to follow easy but precise methods for accurately installing the rocker arm; providing maximum transfer of cam information with the very least amount of wasted in-and-out motion by the push-rod and roller tip.

PRO-STAND™ presents a new definition of value on the ever escaping control of rising prices on what has been promoted by the more advertised "name brand" rocker manufacturers as: "professional." In 2003, Jim initiated the PRO-STAND series, machined with the same, proprietary manufacturing technology used with the PRO-SHAFT series, but for a much lower cost. Now, a fully machined billet alloy rocker arm for a cost effective STAND MOUNT (aka "shaft") rocker system, that was comparable in price to the highly advertised "sportsman" rockers, but offering strength, precision and materials better than their professional systems costing upwards of $2,000 - by the time you added on all their options - which are "standard with MEI designs!

The new and Patent Pending G-TooL™ exemplifies this innovation as well, not only setting geometry, but teaching a new standard of precision to its user for measuring and setting the ever critical rocker arm pivot points; mandatory for not wasting 3, 5 or even 10 degrees of cam duration during the lift cycle to an over-arcing rocker arm. No other cam company or rocker arm manufacturer in more than 40 years - regardless of name or fame - has ever defined, explained or implemented so many fundamental advancements to establish the standards of rocker arm geometry by which all valve train development is measured. No brag; just fact.

STUD-BRIDGE™