Packard Forum Index » Post-War (1946-54)

Hi Folks,

I'm trying to measure the clearance for the hydraulic lifters in a 1953 327 using the special gage from Pacific Northwest Packards (also available from MM, or by taking the lifter apart).

The clearance is supposed to be between 0.030" and 0.070".

I have 3 questions:

a) Assuming I measure these all correctly and take some/all of the valve stems to be ground down, what would be the best clearance to aim at? 0.050"

b) What's a good way to hold the valves down while I am doing this? I tried putting a bottle of brake fluid on top of the valves, but maybe there is a better way. Ideally, of course, one would have a "helper". No such luck, there.

c) The thickest feeler gauge I have found goes up to 0.035". I can "stack" them up thicker than that, but that's not a very accurate process, especially as I try to get up to 0.050". Is there some feeler gauge set I don't know about available, or is there some technique I am not aware of?

Thanks in advance!

Well, to answer two of my own question:

b) I found a nice heavy hammer that I can set on the valves which seems to go a good job.

c) Taking my feeler gauge sets apart completely makes it far easier to "stack them" to get a good reading. Never realized I could do that before.

Follow shop manual procedure exactly. Used lifters may not have full plunger travel due to gum and debris accumulation. I would proceed with extreme caution.

Not sure if it would answer your question but Ross has a video on lifters for those engines

youtu.be/aWYycF-DpAA

Yes, thank you. I have a version of Ross' tester which he offered a little while back (thank you, Ross) and a new set of lifters and my old lifters, and plan on finding out the very best set. But I was concerned that the last time I checked the lifter clearance I had not done a good enough job, which could be the root of the problem, so am going through that process very, very carefully this time.

I guess my only question is, if I do decide that some of the valve stems need to be shaved down, what clearance should I aim for? I am thinking 0.050", which is half-way between the spec 0.030" and 0.070".

I typically keep the gap to the low end and, of course, if the valve seats need grinding, that must be done first. Also, when reusing lifters, it is very important that they go back in the same position where they came from. I’m not sure what Ross and the other experts think but I’ve always had the bottom of the lifter bodies ground with a slight radius too, especially if regrinding the cam.

I'm not actually changing the "tappets", e.g. the the thing that contacts the camshaft. I'm talking about the hydraulic lifter plungers, e.g.

Part #410845, Group #5.1715

The spec is that there should be 0.030" to 0.070" clearance between the valve and the special gauge, available from Pacific Northwest Packards and Max Merrit, also can be made via instructions from Kanter from a lifter plunger.

Attach file:

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  LifterPlunger.JPG (44.16 KB)

I understand that but if you are using any originals, they should go back into the same lifter bodies from which they were removed.

Thanks for the advice!

Any advice out there on the clearance to aim for?

Thanks in advance.

I did a valve job on my 39 Cadillac replacing all the exhaust valves. I had a machine shop make me a gauge to set the clearance. I went for the middle of the plunger travel as I felt this would be the safest. I did my measurements and had a machine shop grind off the necessary amount from the stems. It all worked out well. The Cadillac V8 valve tappet and hydraulic lifter design is similar to what Packard used. For what it is worth...