CN24

When your adjusting the valves, solid lifters, and the specs are for a hot engine, how much do you allow for a cold engine?

rmbuilder

Carm,
Iron Block Iron Heads Add .002"
Iron Block Aluminum Heads Subtract .006"
Aluminum Block Aluminum Heads Subtract .012"
Bob

WETTE VETTE

I have found on my aluminum head 598 the lash opens up .004 when up to temp. I run the water temps at 140 degrees. I checked by setting the lash cold, warming the engine and re checking hot. I think .006" is the rule of thumb many cam grinders recommend which is probably right on at 180 - 200 degree water temps commonly found on cars. I have also found with iron heads it closes about .002 when hot with cooler water temps. Getting it consistent is the key. Being off .002" either way will not make a noticable power difference. I have alsway found being a tad on the loose side makes the overall performance of the motor better.