Re: Noisy Lifters

Posted by JeromeSolberg On 2023/4/16 11:37:02

I have had some struggles with noisy lifters, and I haven't quite resolved them, but here is some insight I have learned from the experience of another member of this site:

There is the specified clearance for the lifters, IIRC it is 0.030-0.070, but don't quote me on that. It can be measured with the little gage that may be purchased from Max Merritt or Pacific Northwest Packards, or the lifters from Kanter have instructions on how to disassemble a lifter to turn it into a gage.

The poster reported the same issue that I have had, and others do - that the lifters were quiet when cold but one (in his case) lifter was noisy when hot. He replaced the lifter a couple of times to no avail, but finally measured the clearance and found it to be tight, and then after having the stem ground shorter to put it within range, the problem went away. He believes that the lifter needs enough clearance to be able to "pump up", and when the engine gets fully warm is when the clearance gets smallest.

My problem, I believe, is that when I measured the clearance for a number of the valves it was on the low end. It may be that, because it is not easy (for me at least) to do this measurement, that it actually was/is below. It is also true that because of valve recession the clearance can get tighter over time, which may be the crux of the issue - since it was on the low end, after running for a few hundred miles it went below the tolerance.

So the moral of the story is - it may not be your lifter (though if you take the head off to check, it may make sense to replace the lifter at that time), it may be valve recession has caused the clearance to tighten up. Most machine shops can grind the valve stems, my understanding is that it needs to be done carefully so that the valve stem end is still flat and perpendicular.