Packard Forum Index » V-8 (1955-56)

My car had some tappet issues that an overfill did not completely solve, so last fall I replaced the oil pump with the olds conversion from Jack. (Sorry Jack, I know I still owe you the old pump!)

I still have what seems to be a couple of recalcitrant lifters/tappets, probably leftovers from the Daley administration that hate working full time.......

Several questions:

How difficult is it to replace lifters/tappets?

Do you replace individually, or by set?

And somewhat irrelevantly, what are "hardened valve seats"? Do they attach to the valve or are they welded into the head or what?

Wishing to learn!

You can replace lifters individually, but honestly if several have "given up the ghost", why take a chance on leaving others of the same vintage in place.

Though I'm sure many have had good experiences, it's generaly not a good practice to put new lifters onto a camshaft that may be worn. Best practice is to have the cam removed and polished or profiled before putting new lifters in.

Hardened valve seats (exhaust only) are hardened steel rings complete with the valve seating face. A special cutter is installed in the guide (after a new guide has been installed, preferrably) and the block cut to sufficient relief to allow the new hardened seat to be installed. Usually a shrink fit - chill the guide first and when it expands to room temperature it is a permanent fit. Others will comment on the requirement for installing these seats but it would be recommended for an engine that going to see hard, continuous high speed service and not required to engines that see a more liesurely life. The tetraethyl lead that was once in gasoline acted to lubricate and protect the exhaust valve seat, thus the requirement for hardened seats or induction-hardened conventional seats is an advent of the no-lead era.

Easy to install lifters but I'll let others who have done it more recently that I comment.

Dear Pat:

I assume from your note that the problem has improved and that is good. If the lifters were starving for oil then it is possible that the clackers got damaged. I believe you can get a Dodge V-8 lifter via the auto parts store that will work.

However, the motor could also have dirt and sludge it in, so pulling the oil pan when you do the lifters is a must.

Finally, worn valve guides can also make noise so you should remove the valve covers, unload the lifters and check for valves that move alot when you push on them.

Hope this helps

I believe that Federal Mogul's HT-879 is the Mopar lifter than interchanges.

I have been using some incorrect terms. As I understand it, several tappets come and go with some noise, The tappet is the thing that touches the cam and sits under the pushrod, right? As far as I know, the lifters are fine. Apologies for the confusion.

I don't want to replace a few tappets if it is really more sensible to go all or nothing. Problem for me (as with others) is revving up for say a valve job is difficult economically.

Of course if you have to pull and refiddle the cam, then we would seem to be talking a project. What is the thinking on why the cam needs to be worked on at that time?

Hi, Pat,

Replacing lifters (yes, lifters and tappets are somewhat interchangeable terms) one at a time can work. If the cam lobe surfaces are good, new lifters on an old cam is fine.

Because Packard V8s use soft valve springs, cam lobe wear is not common, but not unheard of. If the cam lobe is worn, usually when the lifter is removed, there will be corresponding wear on the lifter face.

If you need them, I've got NOS lifters at $10 each.

jack vines