valvetrain · FF-0395

Why is push rod length so important on an ARDUN engine?

The push rods come up through the block where the valves used to be, and the holes have to be clearanced so the push rod can move through the whole valve event, because its angle changes as the rocker arm pivots. At the rocker there is an adjusting ball that sits in a cup on the push rod. A shorter push rod leaves plenty of adjustment, but running the ball down moves the point where the push rod leans over, and there is very little room between the push rod and the hole in the head.

Expert

Steve Coppock

Evidence

expert attributed

Component

push rod length and clearance

Applicable scope

Ford Flathead V8 with Don Ferguson reproduction ARDUN heads