How to find the right Automotive Performance Cam & Lifter Kits AI guide

What the AI looks for in Automotive Performance Cam & Lifter Kits

Lifter type matches block

Hydraulic or solid roller lifters need a roller-ready block with provisions for a lifter retainer; otherwise use link-bar retrofit roller lifters or a flat-tappet cam Roller lifters without anti-rotation will turn in their bores and destroy the cam.

Flat-tappet break-in

Use new lifters, assembly lube on the lobes and high-zinc break-in oil, then run at roughly 2000 to 2500 rpm for about 20 minutes without idling Most flat-tappet cam failures happen in the first minutes of running from poor break-in.

Valve spring match

Springs must handle the cam's lift with roughly 0.060 in. or more margin before coil bind, at the seat and open pressure the cam maker specifies Stock springs often coil-bind or float with a performance cam.

Piston-to-valve clearance

Check with clay or a checking spring; common minimums are about 0.080 in. intake and 0.100 in. exhaust Higher lift and longer duration can make valves contact pistons, especially with milled heads or decked blocks.

Duration vs combination

Choose duration at 0.050 in. lift to suit compression, converter stall, gearing and whether power brakes need vacuum An oversized cam in a heavy car with a stock converter and gears feels slower and idles poorly.

Cylinder deactivation engines

On engines with cylinder deactivation, either keep a compatible cam and lifters or do a full deactivation delete with a tune A partial swap leaves deactivation lifters and software mismatched with the cam.