How To Check Piston To Valve Clearance

Camshafts are an easy swap! But failing to check piston to valve clearance can lead to disaster. Here’s how you can check.

A two-piece timing cover will allow you to do the swap without moving the oil pan which is especially convenient if your engine is still in the car. If you want to do it the traditional way, you clean one of the piston faces, put clay into the piston’s valve pockets, add oil to keep the clay from sticking, and snug down the head with the gasket on.

With every cam swap you’re going to want to check your lifters. A quick fix if you need one is set of comps OE style. Then add a pair of push rods and rocker arm set to 0 lash. After turning the engine over several times, you can remove the heads.

Cut away a small piece of clay in the area you want to check. Then use a set of dial calipers to check the depth of the valve drop. Also be sure to clear out the bolt holes to get an accurate torque reading. Put the timing cover back in place and check the new cams by zeroing in the dial indicator and move the cam and be sure you’re in the 10-20 thousandths range. Put everything back on correctly and you should be on your way.