"store bought" long block (5.8) with almost 8,000 miles started out as a miss so I started out with a basic tune up also ran compression while changing plugs all cylinders had 150-154#. Went for a test drive and things got worse even started a light popping out of intake. When I took out 1st set of plugs all looked the same no concerns. I now take out plugs and #4 is black. re-compression, all same. Checked for spark at plug and that was good. Fired up in the shop with air intake tubes off and intake back fire really got worse so off with valve cover and intake............







First time I've had a lifter wear down 3/16" no wear marks on sides so doesn't appear to have been sticking. Valve is free and cam lobe looks good. Just makes me nervous to put in new lifter and put all back together.

 

Cynical me is going to guess Chinese part with improper heat treatment.
The corresponding camshaft lobe is probably going to be damaged as well.

 

Never seen that before, either. I would suggest you have the wrong lifters for your application. A lifter wouldn't just magically shrink like that without some sort of catastrophic event.

Double check your lifter application for that particular engine.

 

After looking, measuring, and checking I've decided to go with junk lifters with bad heat treating, No visual damage to cam lobes and measurements appear to be good. Working in the truck is alittle tough and this is #4 exhaust. Going to try a better check tomorrow with a dial indicator. About half of the rest show signs of bad wear.

 

Amazing that the cam lobe is okay.
That lifter must be really soft.

 

Have you ever looked to see how many lifters there are for Ford engines ? There are basically two diameters. And a short lifter would not work to start with, the pushrod would have to be longer to have it work, especially to last 8000 miles.

 

I'm aware that there are a few different lifters for various engines, from mechanical to hydraulic. Should be able to ask a dealer what size, etc, lifters would be needed for this vehicle. I don't see the problem here.

So, what are you saying? That this lifter magically shrunk in size...or was wrong to begin with and someone used longer pushrods to compensate?

 

We're on two different planes here. I figured you thought he had a different diameter or length lifter to start with. Pushrod Fords used two diameters, .874 or .875. Obviously a roller lifter wasn't used here. Possibly a solid lifter could have been used but the racket from it would have been a dead giveaway from the start that something was amiss. The lifter was obviously too soft, thus the wear over 8K miles. Nothing magical about that. Last I read nobody makes flat tappet lifters in the USA any more, nor have they for 20 years. They're all made overseas. Thus the poor quality control. Most wipe out during break-in. I've had two do this, a single lifter in each of two engines.

 

No way I'd chance using that cam again. No matter what the lobes look like. Inspect the new lifters next time before dropping them in. The bottoms should be convex (slightly domed). Also make sure they spin freely in their bores after they go in. After starting it, watch the pushrods to make certain all are rotating, if any are not, you'll wipe another during break-in. I would seriously consider converting to rollers.

 

Ok, baddad457... Got you covered on your explanation, and agree completely. Argentina, MeHeeco are some places I know of where lifters are made. Agree on lackadaisical QCC.

On one lifter goin' south on breakin-how do you explain that? Lousy lifter to begin with? I check 'em all for holding oil pressure, but I'm not aware of a test to determine metal fatigue......

I had one lifter that gave up the ghost on a 350 Chubby that came in the shop....the others weren't that far behind. Here, on the nose spring pressure was out of spec when I checked it, hence the problem....

 

One bad lifter ? Poor QC in the manufacturing process. If the bottom face isn't machined to spec (they're slightly convex, not flat) that along will prevent the lobe from setting it into motion, rotating in it's bore. This rotation, combined with the correct lubrication is what restricts the wear between the two surfaces. As for a "soft" lifter, there's nothing I know of for you to detect this. That once again is the realm of the QC process in manufacturing. The two failures I had were both a single lifter and lobe wiping out during break-in. One possibly could have happened due to the temps outside when I fired it off (30*F) making the oil too thick to allow the lifter to rotate in it's bore. The other, I'm sure was due to a bad lifter in retrospect.

 

Again, got you covered on the mechanics and function of the lifters. The clearance between the lifters and their bore is arguably the tightest of the whole engine's clearances. Even a spec of booger between the lifter and bore could wreak havoc.....

Not to highjack this thread but I have a question for you regarding the failure(s) of those two single lifters.....Do you recall where their placement was? I mean were they just after the second cam journal -from the front looking toward the back of the engine?

This is just a baffling fact that has me at a loss as to an explanation why. Three cam/lifters (over the years) that I have seen that got pooched -two during break-in and one about 500 miles after break-in - all had one failed lifter in that position....just after the second from the front cam journal.

I have a thought as to why, but failed lifters are not the norm when I build an engine...as, I'm sure, is the same with you.....so far, so good....

 

OK I guess we are all smart enough to know that when 2 metal parts run together if one wears there is a good chance both will. Number 4 exhaust lobe is .062 short!
First lesson learnt don't try to cut corners and by a parts store rebuild. I knew better just don't have access to the engine shop I used years ago. Not much for trashing people but this motor was bought from Advance Auto it is a Spartan rebuild.
Now to decide how to go on repair. This is in a decent F250 4X4 with a C6 I use it almost daily it just doesn't go far. This engine has 8,000 miles in 5 years does lots of chores around the property. But I do need it to make a trip occasionally. I also have a bad habit of not leaving everything stock. So I know you guys have more experience with this generation of gas burner than me so give me a couple opinions.

 

I don't recall the exact position, but do recall both were exhaust lobes. After break-in both caused a backfire thru the carb when the intake valve opened

 

Both of the engines I had failures in, I pulled the intake manifolds then completely flushed the internals to get the metal out. Also flushed the oiling system with gasoline to clean that out. ( don't smoke ! )To do this I filled the oil pan with gas, then spun the starter over to operate the pump. I cranked it a minute or two, then drained the gas and changed the filter. After break-in again, I changed the oil and filter. Ran it a hundred miles then changed oil and filter again. After flushing I then replaced the cam and lifters. Both ran for a couple years afterwards before selling both with no ill effects