NMRA Tech Committee Statement On Updates To 2020 Factory Stock Preliminary Rules

The NMRA Tech Department has updated the 2020 Richmond Gear Factory Stock preliminary rules to better define the Gen 1 and Gen 2 Coyote combinations using specifications instead of Ford issued part numbers.

A few years ago, Ford stopped production of Gen 1 engine parts—such as cylinder heads—when it switched over to the Gen 2 platform. The official part numbers for Gen 1 cylinder heads remains the same, but the actual parts that Ford sends are Gen 2.  This is called “superseded part numbers.” For example, if you go into a Ford dealer with your 2011-2014 Mustang GT and get a new engine under warranty, it will be a Gen 2 style engine, despite the part numbers being identical to the Gen 1 combination.

To eliminate confusion and a gray area in the rules, NMRA tech officials are moving towards specifications for the cylinder heads and the camshafts to distinguish between Gen 1 and Gen 2 Coyote engines. Using the measured specs, rather than nomenclature, is a more accurate way for NMRA Tech to verify the components used in a combination. The Gen 2 cylinder heads feature larger intake and exhaust valves with a slight port variation and the camshafts carry 1mm greater lift on both intake and exhaust lobes. Any use of Gen 2 heads and/or cams carry the full 75-pound weight adder. This is not an adder for each component, as use of either or both carries a max of 75-pound weight adder, which is the same as the 2019 rules.

Please contact NMRA Tech at nmrarules@promediapub.com if you have any questions regarding these new specs.

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