Topic: lifter install questions

[jramey]

So I'm bout to buy a rebuild head with new valve job and decked, I plan on found a mild port just enough to clean up any imperfections,  my question is I was planning on putting new lifters in but have read alot of controversy over new lifters on an old cam. So has anyone have knowledge as to if this is ok to do and if so what would the proper break in procedure be?

[sharpxmen]

use brake-in oil and use cam assembly lube when installing the new lifters. Don't go crazy high on rpm or the other way around (don't let it idle for long time) and don't drive for extended periods at a low constant rpm (basically you need lots of oil on the cam, so avoid driving slow in a high gear). There's no problem replacing the lifters, just get good ones and not some cheapo knockoffs (Clevite is a good not expensive option).

[95 Lowbuck]

You never put new lifters on an old cam, or the other way around.
That is the quickest way to burn up your valve train.
You can't even mix up the lifter to lobe arangement.
Either leave it be, or go all new including timing chain and gears.
As for break in, their is a very specific procedure by the manufacturer to break in a cam.
Usually holding it at a certain RPM for about 20 minutes.

[sharpxmen]

You never put new lifters on an old cam, or the other way around.

really, nothing wrong with new lifters on an old cam the cam is fine. you never heard of replacing hydraulic lifters if one of them is noisy?

[95 Lowbuck]

really, nothing wrong with new lifters on an old cam the cam is fine. you never heard of replacing hydraulic lifters if one of them is noisy?
[/quote)
Maybe for a temporary fix for one bad lifter but it is still not right.
It would be a shame for him to put all that effort and money into it
only to flatten his cam with new lifters.
I learned the hard way in high school messing with sb Fords and Chevys that
you don't just throw in a cam and get results.
Once the cam is run in on a set of lifters it becomes a matched set with it's
own wear pattern.

[sharpxmen]

Maybe for a temporary fix for one bad lifter but it is still not right.
It would be a shame for him to put all that effort and money into it
only to flatten his cam with new lifters.
I learned the hard way in high school messing with sb Fords and Chevys that
you don't just throw in a cam and get results.
Once the cam is run in on a set of lifters it becomes a matched set with it's
own wear pattern.

that's valid for the tappet contact surface, they rotate, you can't put it on another lobe or reuse it on another cam, new lifters will get broken in with the cam. You need to make sure the old ones are worn even and there are no scratches or deep wear and same on the cam lobes, as long as the surface is smooth it's fine.
The other way around you're right, you can't do it.
as far as work it's really not that complicated, valve cover, 8 bolts for the rocker bridges and a magnetic pickup to pull the old lifters, and revert the process with new ones and new pushrods (and if needed new rockers and hardware). Actual work shouldn't take more than a couple of hours at a relaxed pace.

[95 Lowbuck]

That's kind of my point, a '96 XJ will have 100-150k on the clock,
the lifters will have a decent dish inward on them and the cam
will be worn to match it. ( cam surface will no longer parallel with a new lifter )
Acessive ware will happen to the cam as only a small amount of it contacts
the new lifter during break in. Once you have worn through the case hardening of the cam
ware really accelerates, flattens your cam, and takes out your new lifters.
Been there, done this.