bowtie350_428

I’m running a 70’s 350 with roller retrofit hydraulic cam and lifters. I know the procedure to adjust the rockers with engine off.

The problem I face is that right after I find zero lash on the pushrod, I start to tighten that extra 1/4 to 1/2 turn and the darn valve spring starts to compress. I can’t get the preload on the pushrod into the lifter without opening the valve.

Some pass posts I’ve read here say that it is almost impossible to compress the lifter plunger when it is fully primed with oil. But isn’t priming the lifter with oil supposed to be the proper procedure?

If so, how can I prime lifters already installed in the engine without removing the intake? Loosen all rockers then Crank engine over a few times to fill lifters with oil???

BTW, does anyone know if the steel fully roller rockers from CompCams tend to be a little noisy?

Thanks

ede

if you find zero lash and go another 1/2 turn the valve won't open there is .1 of travel inside the lifter so it'd take a bit more than 1/2 turn to open the valve.

bowtie350_428

When I first assembled the engine, I adjusted the rockers in exactly the same manor. I know I am at zero lash and no more past that point.

It seems since the engine has been running for a while, the lifters are fully primed with oil or "pumped up" (as other call it) and as a result, any preload past zero lash compresses the valve.

I am just wondering if I should just continue adjusting all in the same manor or should I somehow bleed out the oil inside the lifter to set the correct preload or what?

F-BIRD'88

Some people like to soak the hyd lifters in oil overnight
in oil to fill them with oil.

This not nessessary, advised and is actualy the cause of your problems.
They are hydrolocked. But adjusting the rockers to 0 lash
+1/2 turn and then spinning over the motor a few times and waiting for the lifters to bleed down should allow you to go back and readjust the preload without the valve opening. (or it should close by it self in time once the lifter bleeds down.
Are you sure you are not over compressing the plunger
in the lifter?
Be sure to lossen off the rocker nut and allow the lifter plunger to rise and then readjust them. (takes a little time)
"0 lash" is just when the push rod starts to just drag when rolled in your fingers while adjusting the rocker nut.
(pushrod locked is too far)
You can spin the motor over and check compression to see if you over tightened any valves. (The old thumb over the spark plug hole is good enough.)

As a note: it s best to just coat the new lifters in oil
and install them in oiled lifter bores.
Once you prelube the oiling system and start the motor they will fill with oil just fine.

One you let the motor sit for a while the lifters will bleed down a bit and the rockers will rattle a bit between your fingers, But, they should make no noise when the motor is running.
Since there is no lash.

A fast bleed down racing lifter or restricted lifter oil galleries would be an exception.

bowtie350_428

Thanks F-bird.

Can anyone tell me about CompCam Steel Full Roller Rocker being noisy? Not a ticking sound but kinda like a light disiel engine sound...