Advance your day's timing! If there was a cereal called "Lumpy Cams," this would be its mascot.
If you don't get it, don't sweat it... So basically "cams" (short for the lobes of a camshaft) are these rolling things inside a car's engine. As they roll, the engine lets air in and exhaust out as part of its balanced diet. Sometimes if you have a modified engine and want to make more power at high RPM, you could have a more aggressive cam. Slang for this might be that you have "a lumpy cam" now; it would also make your car have kind of an uneven "burp Burb burb" sound to it when it's idling.