Thread: Setting valve lash on running motor

Tweet

Originally Posted by techinspector1

Lay a straightedge across the top of the rocker studs to make sure it isn't a stud pulling out before you start tearing into the motor for a cam change. The studs will begin pulling out with valve spring pressures exceeding about 260 lbs open.

all BBC mark 4s have screw in studs stock . the mark5 and 6 use a tower bolt no studs the mark 5and 6 heads can be made to use a stud by using a arp 7/16 to and 3/8 bottom studs and older mark 4 rockers if steel stamp for the right ball size.or roller rocker arms.this stud works good on Olds heads to . but you have to drill them out . back to the bbc mark 5&6 heads if they are going to be used for hi spring lbs i have drilled and tap the mark 5 &6 heads for 7/16 top and bottom studs . if you using stock studs with poly locks i face the top s flat on the stock studs on the valve grinder stem facer this helps the poly locks from backing off