Thread: Setting valve lash on running motor

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OK, I've gone thru setting the valve lash on my hydraulic lifted. stamped rocker bbc with the engine off, but I am still getting a fairly loud tick from the passenger side. I replaced the header gasket just to be sure that wasn't it. So next I plan to try re-setting lash but this time with the engine running. I figured if I have a wiped out cam lobe, it might be noticeable. Ive watched a few videos and did some searches and it seems pretty idiot proof. Unfortunately I don't have an old pair of valve covers to cut up and I don't have any tappet plugs/caps so I'll just cover the valve train with rags or paper towels so as not to make a mess. My question...if I loosen the rocker till it chatters, then tighten down until it stops, am I done? or should I then set a preload? If so how much, 1/2 turn, 3/4 of a turn?

Any other best practices? or horror stories? Should I even attempt this?

OK..instead of deleting this post, I'll answer my own question:
Century Performance Center, Inc. :: Adjusting Valve Lash
found this elsewhere in the forum...Club Hot Rod rocks!

There are clips that snap on the pushrod end of the rocker arm. They prevent oil from squirting across the shop. Check with your local tool supplier.

If your sure you got em set correctly from the git go. Then more than likely it is killing a cam lobe and that can happen very quickly. I would try readjusting and see what happens,but if it starts ticking again or still, I'd be pulling it apart for a cleaning and new bearings along with a roller cam and lifters. Also on Hyd.lifters i go 1/2 turn from zero lash.

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.

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

I have a related question:

I'm about to re-set my valves too on my bb, and I was wondering about 'priming' them? I have a book that says when you are assembling the motor you need to prime the lifters first to fill them with oil before putting them in, so that's self explanatory.
But what do you do if you are re-adjusting them after the engine has been assembled and run? I don't want to pull my intake unless I absolutely have to, so since they are not accessable now does "priming" even apply? Can I just remove all the rockers and start over from cylinder #1?
Do they stay 'primed' when they are in the motor even if it's been sitting for a few weeks now?

Did you figure out the problem?

I used cut off valve covers and splashproof clips and still made a mess. Probably not as bad as without. Did you rev the motor rpm's between 1500 and 2000 rpm's when breaking it in?

Update: so I did an oil change and the tick went away. Im guessing the zinc break in oil I had in the motor to help break in the new cam didn't play well with the new comp hyadrulic lifters. 7 quarts of fresh synth oil and all is well!