In this third part of a continuing piece, Editor Bob takes notes as all-motor guru Erick Aguilar blueprints and balances the internals of our GS-R powerplant.
 Our B18C1, fresh from a Golden Eagle sleeve job and ready to be built - or so we thought. Shortly after we deliver the engine to Erick's Racing, Aguilar schools us on the intricacies of building a near zero-tolerance engine and points out some flaws in our progress.
We're big boys. We can take a little constructive criticism, especially from a guy on the verge of a 9-second, naturally aspirated run. Aguilar begins by setting our engine up for blueprinting, a process that involves hand-finishing engine parts to their most ideal specs within production tolerances. Aguilar will also balance statically and dynamically every engine part that rotates and reciprocates. Both blueprinting and balancing seek to reduce friction, wear and vibration, and increase horsepower and reliability.
May not seem like a lot, but Aguilar likes to keep his P-to-W tolerances within 0.002 of spec. "The cylinder wall is all one sleeve," he says. "The straighter it is, the closer it is to spec and the better the engine is going to perform."
Before continuing, Aguilar sent the block to one of his contacts to get it dialed in to his specs. Note that forced induction motors tend to have looser tolerances because they generate more heat. With more heat comes greater expansion, thereby needing more play.