dimented24x7

iTrader: (2)

I had to pull my engine apart when one of my lifters came apart internally and completely collapsed. I was inspecting the remaining lifter heels, and they have all lost their crown. They are all slightly dished (~.0005"), and have a sort of dull appearance, like they have microscopic pitting. I inspected them after break in, and at that time, they looked great. No lobes wiped as far as I can tell, the cam looks OK (but is likely still trash), and there was no scuffing. The lifters only have 10k miles on them. I used 5-40 synth. rotella along with ZDDPlus on each oil change.

Why did they wear so fast? Crappy lifters? Something in the oil? Too much ZDDP? Ive heard that high levels can lead to faster wear rates.

dimented24x7

iTrader: (2)

I do know that isky does not make these lifters. They are repackaged units as far as I can tell. Look like the same ones that come from other companies like edelbrock and crane. Theyre pretty cheesy, and dont have much in 'em. All they have is a plunger, metering disk at the top (which broke in one), and a free floating check valve that does a **** poor job of keeping them pumped up. I guess its just bad metalurgy?

Im going to use the GMPP units with a fresh cam. Hopefully they last longer than a single oil change this time

Guest

Only thing that would make any sense to me with that low of mileage is lack of lubrication. What happens over time is a dish on the lifter, or one that lacked adequate lubrication if the rest look fine. I've seen all kinds of wear from almost a whole set worn to just one or two trashed. But 10k miles, thats not good at all. Maybe the lifters are just junk.

1989IROC-Z5.7L

iTrader: (2)

Cam bearing installed wrong?

dimented24x7

iTrader: (2)

Pretty much most of the lubrication is cast-off oil from the crank, and maybe some of whatever comes back thru the valley, no? Barring a lack of oil to the crank, which I dont think it has, could prolonged low engine speeds be to blame? I still have highway gears, and most of my cruising is done around 1400 RPMs or so.

dimented24x7

iTrader: (2)

Heres what they look like. The surface in the center has a dull appearance. Not the usual shiny surface good lifters would have. The crown is also missing. It looks like it was in the very first stage of failure.

It would be nice to know what the answer is. If I had waited a year, I probably would have a much more conclusive (and unwelcome) answer, but I cant tell a whole lot at this stage.

dimented24x7

iTrader: (2)

I decided to crank up the zoom on my camera to 200x to see what the surface looks like

Looks like its pitted and flaking. My guess would be that the metal was simply overloaded beyond what it could take (maybe poor heat treatment, or just not strong enough).

I really hope the next set works better. Im really tired of ripping this motor back apart to fix stuff...

ntomsheck

iTrader: (1)

That last picture was from a digital camera? I really have to get with the times!

Did you use liberal amounts of assembly lube on all the lifters?

Regardless of the issue, it looks like the lifters took the bulk of wear, and not the cam. Always a plus.

Edit: Just realized you said you inspected them after break in with no issues. Bad lifters have my vote.

dimented24x7

iTrader: (2)

I took it by using a cheap microscope and putting the camera (Sony w/ Carl Zeiss lenses) up to the eyepiece. Surpisingly, it actually still can focus through the optics. My father has a freestanding microscope with a digital CCD in his office, but thats too far away just for a pic.

Yeah, it looks like they couldnt take teh load. These where generics repackaged from isky. I think many other companies use them as well.

dimented24x7

iTrader: (2)

I have a retro roller kit that I never used. I think Im just going to go with that and a small roller.

I had my semi-big cam, it was fun, but I just want to run it w/o having to worry about the valvetrain chewing itself up.

JakeJr

During my years of dealing with failed flat tappet cams it boiled down to one of two things: Improper oiling during break-in and/or too much spring pressure.

Once wear beings it continues to worsen over time.

Sorry to read about your failure, but moving to a roller is a win-win.

Jake

radical82

Same problem that is effecting many engines running flat tappets, no zinc in the oil anymore (thank your government). Some say that the zinc additives "fix" the oil, others say run diesel rated oil...only sure cure I've seen is to run rollers--which makes for a better engine anyway!!!