What is an engine friction test and why would you want to perform one?

When building a short block, a friction test will help you determine the amount of drag your rotating assembly is producing so you can minimize it — and it’s effect on performance.

Additionally, a friction test can help you test your rotating assembly and locate tight spots within the setup.

In this Engine Building 101 video, we’ll show you how to perform a friction test on an engine stand and determine rotating or piston drag. The lower the number, the faster the acceleration and power.