Rocker arm tick

chevrolet

#1

I am having a problem with rocker arm tick on my chevy 350. It’s newly rebuilt with edelbrock e-street heads, new stamped steel rocker arms and nuts, new pushrods. I installed gm performance hyd. roller cam and lifters that have 15 hours on them (they are from a boat engine). I have adjusted them 5 times both with engine off and running, taking to zero lash and then 1/2 to 1 full turn tight. Can anyone help?


#2

Are they all noisy or just one or two? Is the engine in a boat now?


#3

it seems to be at least a couple of them but cant tell which ones and it’s in a truck


#4

Have you run the engine at lower speeds long enough to purge any air bubbles in the lifters?


#5

I want to say immeditaly that you did a bad thing with used lifters (yes 15 hrs is used) and a new cam, but I will restrain my self. How did you prepare the cam to lifter surfaces?

I was never a big believer that proper cam break in is required, just an urban legend I thought, till I saw the results of improper cam break-in on a FORD Cleveland engine.

Did the rebuild fire immeditaly or did you have long periods of cranking before it started?


#6

yes it has about 200 miles on it


#7

it fired immediately, actually first time i had an engine fire that quick. the cam is a hydraulic roller and put oil on the lifters and cam and lube on the cam bearings.


#8

Question. You installed a roller cam but are the lifters you used flat tappet lifters?

You CANNOT run flat tappet lifters on a roller cam and vice-versa; or at least not for very long.


#9

You did not use any special breakin lube on the cam lobes and lifter faces? Perhaps you got lucky but wasn’t this specialized lubricant included with your cam? It is usually grey in color.


#10

no, i used roller for both and they are both gm


#11

it didn’t come with any and from what my friends and things I have read, i didn’t need to use any on a roller cam and lifters


#12

Using mis-matched parts is ALWAYS a recipe for disaster…The cam and lifters should come in the same box…A “boat” cam doesn’t tell us much, but I doubt it will work well in a truck, but that’s another issue…

Here is how to set your valves (and lifters) With valve cover removed, engine warm and running, (they make little clips to prevent the oil from flying all over) loosen the rockers one at a time until it starts to snap pretty good. Have a helper, with a 3’ length of heater hose in his ear listen to the rocker you are working on. Tighten it down until the helper says it’s quiet. Tighten it 3/4 of a turn more. The engine should stagger for a few seconds until the lifter bleeds down. Move on to the next valve. Repeat for all the valves. Put the valve covers back on and clean up the mess…


#13

It’s possible that there are simply a few bad lifters in that batch of used ones and they simply won’t pump up as they should. A boat engine is likely to have been through some serious thrashing anyway.


#14

Are the annular oil supply rings on the lifter outer diameters at the same level as the oil supply ports in the lifter bores?

I have never confirmed this on any engine but assume that the annular rings and the oil supply ports should line up when the lifter is resting on the base circle of the cam to give the lifter an oil charge as needed before it rises.


#15

Good point Whawho…Perhaps THE BLOCK was never designed for the roller lifters and the lifter feeds are in a different location…


#16

would the engine run smooth at idle & through out the RPM range with a bad lifter?


#17

The block is a 91 that has the bosses for the lifter “spider” and for the cam thrust retainer plate.


#18

I have no idea. I think they are because all the rockers receive enough oil.


#19

OK, that rules out that problem…


#20

i have tried this, without a helper, and the rockers still tap…would having pushrods a tad bit shorter make that noise. I measured before i put the engine in the truck and the rockers where between the intake side of the valve tip and the center and the rockers looked fine when i turned the engine over, not getting too close to the edge of the valve stem.

From what everyone has told me, from my machinist to the techs at Summit Racing, said the used roller lifters are perfectly fine to use.