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 This is called “superseded part numbers.”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 email@example.com if you have any questions regarding these new specs.