SBC - adjusting rockers with engine running

Exactly. This is way I have done it for years. I never have to go back through and adjust anything after it's running. I want to replicate the valve adjustment as closely as I can to what it's going to be when it's running.

 

Yes to doing it engine running, AND using valve covers with access slots. Cleaner that way.....

4TTRUK

 

I saw in my old Motors manual how to adjust the valves (running) using a vacuum gauge. So I tried it, turning each one down 3/4 to one full turn after clatter stopped.
I increased vacuum by 3"......motor (sbc 350) runs so much better! They had previously been set (running) at zero-1/4 turn.

 

Some 70's Chevy cams weren't real solid.

 

No need to take abath in oil. Doing it while it is running is torture and not needed.

The method where you watch for the intake to move and adjust the exhaust, then wait for the exhaust and adjust the intake is the surest method for accurate adjustment. Spin the pushrod with your fingers and when you feel drag tighten 1/4 turn. No more. It's hydraulic and it'll find its own point at that adjustment. I have burned intakes with the 1/2 turn method.

For solids follow the same adjustment method but use a feeler gauge for clearance and not the 1/4 turn. Your hydraulic lifters shouldn't make noise, that's for the SOLID lifter stuff.


All the best,

Tim

 

+1 Here. This is the GM procedure. I worked as a mechanic and alawys followed this method, it fast clean and easy. I like to draw out the valves and number them on a sheet of paper and check them off as i go. I never understood the purpose of adjusting them while running. If you're trying to identify a noisy lifter you can do it with a stethescope or the old fasion way with your ear against a long screwdriver.

 

When I was young (4 decades ago!) I adjusted lifters running, and with the little clips too. It still flicked some oil out on the fenders, headers, and me! Less than with no clips, but too messy still! Once I learned from an old timer I worked with at the Cadillac dealership how to adjust them with the engine off, I wondered why anyone would ever adjust them running again?
I also tried the vacuum method. It works, but all the lifters need to be either loose or perfectly adjusted before a tight one shows up. If several are too tight, the vacuum drops off, and you keep chasing them all trying to figure out how many are too tight.

 

OK so I installed some metallic tape along the bottom of the cylinder heads to form a dam to prevent oil from oozing onto the headers. Fired up the beast and adjusted the rockers by ear til the clatter stopped. Took about 2 minutes per side. Now she's quiet as a mouse and purrrrrrrrrs like a kitten.

No fire, no oily mess, no dolphins were injured.

Success! Thanks dudes!