Calculating Minimum Weight
And Identifying Engine Types
Simple physics dictates that it requires more energy to accelerate a greater mass and at the same time requires more effort to slow that mass down. That science is the basis of the Unlimited All-Stars handicap system that has been proven to equalize competition on dirt tracks from coast to coast. The basic concept behind the UAS rules is that the more power potential that an engine type has, the more the kart it powers has to weigh. Furthermore, the greater the displacement of the engine, the more the machine it powers has to weigh as well. Add to that the fact that UAS events are held on short, often slick dirt tracks and it should be easy to see why this system works so effectively to even out the competition.
Many new comers to the UAS are confused when it comes to identifying what type of engine that they have so that they can calculate their own weight. This document was created to make that task a little less confusing. It is up to each competitor to find out the exact displacement of his engine. If the competitor does not do his own engine work, any engine builder should be able to make these measurements and calculations. For more help on measuring the engine displacement refer to theCalculate Displacement page.
If a kart is equipped with a multiple cylinder engine or multiple engines then each cylinder should be measured and the total displacements added together.

The competitor’s minimum weight is to be prominently displayed next to the most forward identifying number on the kart.

A. Reed and Rotary Vavle 2-Stroke Cycle Engines

B. Flat Head Four-Stroke Cycle Engines

C. Piston Valve (Port) Two-Stroke Cycle Engines

D. Overhead Cam Four Stroke Cycle Engines

E. Over Head Valve (Push Rod) Four Stroke Cycle Engines

F & G Forced Induction and Nitrous Oxide Engines / Mixed Engine Types

H. Rotary (Wankel) Engines

PDF File that includes all of the above in one printable document