How do hydraulic flat tappet lifters fail?

[TT5.9mag]

I never ever soak hydraulic lifters. Simply because I want them squishy to set the preload correctly. Then I always, ALWAYS, prelube the engine before firing it to fill them. That’s another thing that can cause lifter failure is not enough preload. Effectively giving you lash in a hydraulic setup. This happens after machine work and the wrong length pushrods or not using adjustable rockers. Also, can’t believe no one has said it yet, but poor quality lifters seems to be a problem recently although I have not had that problem myself. I killed a hydraulic roller cam a year and a half ago and thought it was a lifter or spring problem. When I pulled it out of the engine I sent it to comp cams for analysis and they determined that the hardness of the cam wasn’t to spec and replaced it for free.

 

[toolmanmike]

I never ever soak hydraulic lifters. Simply because I want them squishy to set the preload correctly. Then I always, ALWAYS, prelube the engine before firing it to fill them. That’s another thing that can cause lifter failure is not enough preload. Effectively giving you lash in a hydraulic setup. This happens after machine work and the wrong length pushrods or not using adjustable rockers. Also, can’t believe no one has said it yet, but poor quality lifters seems to be a problem recently although I have not had that problem myself. I killed a hydraulic roller cam a year and a half ago and thought it was a lifter or spring problem. When I pulled it out of the engine I sent it to comp cams for analysis and they determined that the hardness of the cam wasn’t to spec and replaced it for free.

Comp Cams, here lies the problem.

 

[Righty Tighty]

For it to have failed with that few miles on it, to the degree of wear that you’re seeing now, it basically had to start failing during break it.
It starts as a tiny spot where the lifter and cam exchange a little material before the two surfaces have created a work hardened wear pattern.
Once that little surface defect is created, it’s just a matter of time before you end up with what you have there.
This is why the very first minute or two of the break in process is so important........ to make sure that exchange of material between the cam and lifter never happens.

When you remove the cam, see if there is evidence that other lobes are starting to go away.

Did you run the Lucas oil the whole time, or just for break in?

Was that cam a fast rate .904 lifter profile?
Those less tolerant of lifter bore misalignment.

I’d check the lobe taper on the lobes that are still good to verify it’s correct (you want around .002” taper).

I’d say these days, the most common reasons for a flat tappet failure of that kind is going to be from lobe taper being incorrect, incorrect crown on the lifters, or incorrect oil being used.

A few years before the whole lifter debacle situation happened(early 2000’s), I had an opportunity to see first hand how the wrong oil could impact a flat tappet cam when stiff springs were being used.
I had built a 440-6 for a customer, Crane hyd cam, Hylift Johnson lifters, Isky dual springs, HS rockers.
Dynoed the motor, no problems with break in.
There was no “break in” oil then as cam failures weren’t very common(or at least less common that now).
Motor was run with VR-1 20w50 for a few years, no issues.
The car got driven quite a bit....... it probably had 15,000 miles on it.

The owner reads some stuff on line about oils....... decides synthetic would be better for it.
Puts mobil 1 10w30 in it.
Within a month the cam has several flat lobes.

Nothing against Mobil 1...... I use it in my DD vehicles....... but gas mileage formulated oils aren’t really a good choice for your old school muscle car with a flat tappet cam and big springs.

I’m just pointing out, that they can still fail long after they have been put into service.

Lots of good info, thanks. The cam I have is the Lunati Voodoo with .454/.475 lift, 213/220 duration @ .050, 112* separation. I'm not home and don't have my cam card with me, and I don't know what the lifter profile is. How do I check the lobe taper? I'm guessing with a precision straight edge and feelers? I misspoke earlier about the lifters, they're the matching Lunati lifters that came with the cam/lifter kit, not Comp Cam lifters.

And I've always used the same Lucas high zinc with a Wix filter, nothing else.

For some reason the lifter has mushroomed at the lobe end, maybe it got so hot after failing that the metal expanded to the point where it couldn't raise into the bore and got smashed harder and harder into the cam?

 

[Righty Tighty]

And while I've got your attention, is there a better cam/lifter combo that you guys can recommend?

 

[dano]

Lots of good info, thanks. The cam I have is the Lunati Voodoo with .454/.475 lift, 213/220 duration @ .050, 112* separation. I'm not home and don't have my cam card with me, and I don't know what the lifter profile is. How do I check the lobe taper? I'm guessing with a precision straight edge and feelers? I misspoke earlier about the lifters, they're the matching Lunati lifters that came with the cam/lifter kit, not Comp Cam lifters.

And I've always used the same Lucas high zinc with a Wix filter, nothing else.

For some reason the lifter has mushroomed at the lobe end, maybe it got so hot after failing that the metal expanded to the point where it couldn't raise into the bore and got smashed harder and harder into the cam?

So I think that's a fast rate, 0.904 cam. I have one two sizes up on my 340. I don't know if I saw it but did you pre-oil before break in? As in you removed the distributor and used a prime shaft to turn the oil pump with a drill at high speeds while turning the engine over and hopefully having a oil pressure gauge show pressure?

 

[fratzog lover]

And while I've got your attention, is there a better cam/lifter combo that you guys can recommend?

Had this in a 360, very good daily driver cam.

 

[Righty Tighty]

Would the cam card say whether or not it's a fast rate? A lot of this is new information to me.

I didn't mention it, but I did prime the engine prior to break in. Several times, in fact. This is because I'd think I'd be ready for the first start, prime it, then something would come up and I couldn't start it that day.

 

[TT5.9mag]

Comp Cams, here lies the problem.

I have heard that a lot, but my experience has been decidedly different. They are (were) a sponsor of our off road race truck and have been nothing but fantastic for us to deal with and always (except the one failure in my personal vehicle) provided a great product. I also believe they are one of, if not the largest aftermarket supplier of camshafts and do have failures but if you look at the numbers, failures vs successes, you might be surprised. I attribute a LOT of the flat cams to improper break in, wrong oil, low quality machine work, and or owner negligence. But as always that is my opinion.

 

[TT5.9mag]

One major factor on the life of a flat hydraulic is cranking time. If you don’t get the engine to fire very quickly the first time, like 3 or 4 revolutions, it’s likely going to kill the cam with today’s oils.

 

[Righty Tighty]

One major factor on the life of a flat hydraulic is cranking time. If you don’t get the engine to fire very quickly the first time, like 3 or 4 revolutions, it’s likely going to kill the cam with today’s oils.

Come to think of it, it did take a few tries to get it to start because the timing wasn't quite right. Once it did start, we took it right up in RPM. I'm starting to think it was me who caused this failure.

 

[TT5.9mag]

Come to think of it, it did take a few tries to get it to start because the timing wasn't quite right. Once it did start, we took it right up in RPM. I'm starting to think it was me who caused this failure.

While it might settle your mind to know exactly why it happened, it doesn’t really matter. Make a plan, learn from the experience, and move forward. It’s something a lot of us have done. Just adapt and overcome.

 

[toolmanmike]

I had fuel issues when I started my fresh 273. I either lubed it good or the solid lifter cam isn't effected as much.

 

[TT5.9mag]

I had fuel issues when I started my fresh 273. I either lubed it good or the solid lifter cam isn't effected as much.

Lash helps.

 

[teringer]

from the picture it looks like the lifter is side ways did you get chevy lifters ,smaller in dia or does the lifter bore need a sleeve ,and it looks like you have 2 lifters touching 1 lobe but i'm old and half blind.

 

[Righty Tighty]

from the picture it looks like the lifter is side ways did you get chevy lifters ,smaller in dia or does the lifter bore need a sleeve ,and it looks like you have 2 lifters touching 1 lobe but i'm old and half blind.

Good eye! I turned that lifter sideways to inspect it, and it’s just a weird camera angle on the other lifter. It’s not touching the other one, it is directly over the correct lobe.

 

[furrystump]

What I do is oil the lifters and install the valve train. Prelube to get oil pressure and turn the motor over by hand. Then I watch each lifter as I spin the motor by hand. If they don’t spin, I pull it apart and look at that lifter/lifter bore/cam lobe to try and determine why. A nick or burr, a bad lifter bore, etc. For me they must all spin when cranking by hand, if not, I don’t run it.

 

[Righty Tighty]

Thanks furry, I'll take your advice. This was my first build, and honestly, I didn't prime the engine until it was fully assembled. I used plenty of assembly lube, but I didn't prime for oil pressure until later. By then, obviously it was too late to see what the lifters were doing. This is all a great learning process, and hopefully with experience and practice, I'll get this down!

 

[dartfreak75]

Lots of good info, thanks. The cam I have is the Lunati Voodoo with .454/.475 lift, 213/220 duration @ .050, 112* separation. I'm not home and don't have my cam card with me, and I don't know what the lifter profile is. How do I check the lobe taper? I'm guessing with a precision straight edge and feelers? I misspoke earlier about the lifters, they're the matching Lunati lifters that came with the cam/lifter kit, not Comp Cam lifters.

And I've always used the same Lucas high zinc with a Wix filter, nothing else.

For some reason the lifter has mushroomed at the lobe end, maybe it got so hot after failing that the metal expanded to the point where it couldn't raise into the bore and got smashed harder and harder into the cam?

Oh geez your making me really nervous with this. I have the cam a step bigger than that one the 702 cam and lifters. did you measure the guide height on the heads because mine would not clear. 475 lift! If they wasnt cut shorter that may be your problem. I'm sorry this happened to you that really sucks.

 

[dartfreak75]

Would the cam card say whether or not it's a fast rate? A lot of this is new information to me.

I didn't mention it, but I did prime the engine prior to break in. Several times, in fact. This is because I'd think I'd be ready for the first start, prime it, then something would come up and I couldn't start it that day.

They are a fast rate cam all the voodoo cams are relatively fast

 

['63GT]

PRH is spot on, with his comments.. Oil seems to be the biggest offender.
I had a long conversation with Tim Cole of CompCams back in the late 90's - 2K for the same reason PRH mentioned it.
His answer, then, was the centerline between lobe to lifter, MUST be offset by .050 to ensure proper lifter rotation. (this mostly applies to shivis, although it's never really been an issue with mopars )
BUT, that lifter is chipped. very unusual in my book. thinking a metallurgy issue..? bad set of china lifters perhaps ???
that lobe profile has been around since the 70's (213/.454), it's not like the Brookshire lobes, renamed voodoo by Lunati. that is considered to be a .742 lobe... it's very safe on a .904 lifter. baring a good oil has been used and correct break-in.

 

[Righty Tighty]

Oh geez your making me really nervous with this. I have the cam a step bigger than that one the 702 cam and lifters. did you measure the guide height on the heads because mine would not clear. 475 lift! If they wasnt cut shorter that may be your problem. I'm sorry this happened to you that really sucks.

Thanks, yeah it does suck. But, hopefully I can learn from it and someone else reading this can learn as well. The machine shop did have to cut the guides down. By how much I don't remember.

PRH is spot on, with his comments.. Oil seems to be the biggest offender.
I had a long conversation with Tim Cole of CompCams back in the late 90's - 2K for the same reason PRH mentioned it.
His answer, then, was the centerline between lobe to lifter, MUST be offset by .050 to ensure proper lifter rotation. (this mostly applies to shivis, although it's never really been an issue with mopars )
BUT, that lifter is chipped. very unusual in my book. thinking a metallurgy issue..? bad set of china lifters perhaps ???
that lobe profile has been around since the 70's (213/.454), it's not like the Brookshire lobes, renamed voodoo by Lunati. that is considered to be a .742 lobe... it's very safe on a .904 lifter. baring a good oil has been used and correct break-in.

The offset makes sense in order to cause a spin, otherwise lobe is just pushing straight up against the center of the lifter, and maybe it'll spin, maybe it won't. The lifters are Lunati lifters that came as a kit with the cam. I've heard that the vast majority of lifters nowadays are made overseas, even big names like Comp, and in turn people have seen an uptick in failures. Is there any truth to that?

I used Lucas Hot Rod & Classic oil, 2100 ppm of zinc. However, my break-in may have been subpar. My timing wasn't set correctly at first, so it took a few tries of cranking to get the engine to start. After that, I took it up to 3000 and kept it there. I've had a couple people tell me the cranking wasn't a big deal, but it seems most here would disagree. Either way, that lifter did fail, and I'm wondering if the lifter failed because of the flattening lobe because of poor break-in, or if the lifter failed and flattened the lobe? It's been said before and I agree, that the damage is done and just move on and get it back together, but I'm still curious as to what exactly happened.

 

[PRH]

that lobe profile has been around since the 70's (213/.454), it's not like the Brookshire lobes, renamed voodoo by Lunati.

Actually......

The cam I have is the Lunati Voodoo with .454/.475 lift, 213/220 duration @ .050, 112* separation.

This is the the 701 Voodoo cam, which is a fast rate .904 design.

Depending on the barrel diameter of the cam core, and how “cupped” the lifter has become, it’s not all that uncommon to see the lifters get chipped on the edge, from where the edge has been contacting the barrel.

You can see the witness marks on this cam where the edge of the lifter was contacting the barrel of the cam:

 

[Black Girl]

Righty, I'm sorry this happened to you. Every winter I think of changing to that cam in my stock eddy headed short block 360. Then I see this post. I work on heavy equipment, the parts for everything are made like junk now for lack of a better term. I'm gonna keep my 204/216 crane. Good luck, keep us posted!

 

[Righty Tighty]

Righty, I'm sorry this happened to you. Every winter I think of changing to that cam in my stock eddy headed short block 360. Then I see this post. I work on heavy equipment, the parts for everything are made like junk now for lack of a better term. I'm gonna keep my 204/216 crane. Good luck, keep us posted!

Thanks for the sympathy! I definitely wasn’t pleased to have this happen. But before you discount the Lunati Voodoo, keep in mind that there’s a high likelihood that it failed from a botched break-in, not from poor workmanship or metallurgy (although the metallurgy part is up for debate in my opinion regarding the lifter). All that being said, this was my first rebuild, and I don’t know if you have read my previous posts in the thread, but the timing was off and it took a bit more cranking than is healthy for it to get her started. I will certainly keep y’all abreast of the progress to come.

 

[Righty Tighty]

Actually......



This is the the 701 Voodoo cam, which is a fast rate .904 design.

Depending on the barrel diameter of the cam core, and how “cupped” the lifter has become, it’s not all that uncommon to see the lifters get chipped on the edge, from where the edge has been contacting the barrel.

You can see the witness marks on this cam where the edge of the lifter was contacting the barrel of the cam:

View attachment 1715614043

I think (I hope) we’ll find some answers when I pull the cam and lifters. Drained the oil today and it was very, very clean. I’m going to cut into the filter and see what it looks like, and check the rod and main bearings (at least a few) to ensure they’re in good shape.

When I pulled the valve cover, I saw the #1 intake pushrod shifted to the side. Here you can see the divot it made in the rocker. And yes, I have a new rocker to replace it!