7 Key Things to Consider When Building a Performance Short-Block

We spent a couple of days at JMS Racing Engines, in El Monte, California, talking with owner Mike Johnson and his machinists and builders to get the scoop on what makes a successful budget performance-engine build. We’re assuming that you’re starting with an engine that is in good condition and hasn’t had more than one overbore, you plan to reuse as many of the stock components as you can, upgrading to higher-performance pieces as your budget permits, and you do the disassembly and reassembly yourself. As with any complicated process like this there are plenty of myths to bust, and just as many procedures to follow. We’ll break everything down into bite-sized pieces.

Devise a Plan

We cannot stress this enough—the most important part of any engine build begins with a good plan. By good we mean one that is realistic and fits within your budget. Ask yourself: What do you have to work with, and how much can you afford to spend? Are you starting with a lightly used original bore stock block that just needs new rings, bearings, and a hone, or are you starting with a “mystery motor” of unknown origin? We’ve all heard those stories of free engines that were guaranteed to run but, upon closer inspection, needed a lot