This is on a BB with a Crane 272 cam and new timing set at install, stock lifters from Comp Cams, pushrods and stamped steel rockers. I have adjusted the lifter preload using: EO-IC method, Lars method of every 90 degrees adjust one, rotate to TDC adjust a bunch, rotate again and adjust the rest and I still have maybe 2 cylinders that end up clacking or sounding like something is loose inside. They seem to be #1 and 2 in the front. Maytbe that is a clue of lack of oiling???

I recently replaced all the lifters and checked the push rods for round. Replaced the grooved ***** and adjustment nuts and problem persists.

I need some advise on this this issue. The engine runs fine after adjustment, idles well and pulls 17" of vacuum at idle, just the darn tick or mild clack clack. All comments are welcomed.

 

This is the only method that I trust,it might not be the fastest but I am certain the valves are correct afterwards.I mark each rocker when its done.


Instructions by 427 HOTROD

First you have to roll the motor around to set each valve right? The cam has to be on the base circle. Easiest way for me is to set them as follows:

1) When the exhaust on a cylinder is just starting to OPEN...set the intake valve on that cylinder.
2) When the intake is almost CLOSED..set the exhaust on that cylinder.


So back off all the valves until they are loose and then start bumping motor over watching the valves as above.

Once you get it on correct position to set each valve...you want to reach down and pinch the pushrod between your fingertips right below the rocker arm. Lift it up and down with the nut backed off. You want to slowly tighten the adjuster nut just until that up and down slop just barely disappears. You want to just BARELY take all the slack out of the assy. Don't overtighten...you just barely want that up and down wiggle to be gone. It only takes finger tip action...you will likely still be able to spin the pushrod when you have just barely got it to *O* lash.THAT is *O* lash.....the lifter plunger is up and you have no play in the pushrod/rockerarm/valve. THEN you tighten the 1/4-1/2 turn to put the lifter plunger down in the lifter slightly.

Repeat by bumping the motor around for each valve....it will run then just fine.


Good luck! Instructions by 427 HOTROD

 

That's the EO-IC method referred to by the op.

 

You could try the engine running method. You'll need oil deflectors to do it that way. Check for wear on the rockers where they pivot also.

 

Thanks guys. Will try again on the EO-IC method on the noisy ones to see what happens. Then I think I will try the motor running with clips if there is still the clack, clack. If these do not fix the noise then there has to be something fundamentally wrong in the valve train as I have tried to too many times and they should be right. Thx again. JP

 

With hydraulic lifters, the pre-load distance is quite generous allowing up to 1 full turn as a pre-load setting. If you've set 1/2 turn of pre-load, they should still be within their ability to take up lash even if there is a bit of wear.

However, for some to start clacking indicates that the adjuster nuts are rotating, or severe wear. Most likely, the adjuster nuts don't have a good enough grip on the studs due to worn stud threads, or the rocker nuts are worn. To resolve this issue, mark each adjuster nut towards the forward end of the cylinder head and look to see if the nut has turned when the clacking reappears.