Engine Plans.7z 〈Fast - REVIEW〉

: Technical records used for the precision rebuilding of an engine to meet exact manufacturer specifications, such as piston deck height and valve-to-piston clearance measurements.

The .7z extension signifies a file created with 7-Zip, a free, open-source tool.

: High-quality computer-generated drawings (CAD) for internal combustion or model engines. These often include 11 or more sheets of detailed assembly notes and material specifications.