Question

On a pushrod engine, all of the following are true except: a. Valve lash increases as pushrods and rocker arms wear. b. Valve lash increases as the valve and seat wear. c. A decrease in lash can cause improper valve cooling and can lead to burned valves. d. All of the above

Answer 1

b. Valve lash increases as the valve and seat wear

Explanation:If the lash setting is too loose or excessive, the valvetrain takes a severe beating. The rocker arm acts like a sledgehammer by building up momentum with the extra distance and pounds the valve tip. Much of that force is reflected back through the rocker and pushrod to the lifter. Broken lifters and burnt pushrod tips are often consequences of too much valve lash. If the lash is too tight, the intake valve may hang open.

"You can also burn a valve if it’s not fully seated,” said Godbold

Therefore, when valve lash increases as the valve and seat wear.