Technical Wiping new cam problem solved?

Found these two on Youtube and found it interesting but a bit controversial. It MAY be the answer but you will have to decide for yourselves.

It sounds pretty good but I'm in the camp of where are they getting all the lifters to re-build.

IF it's true then it's pretty terrible.

One thing to take away either way is check your clearances before starting the engine.

This one talks about the second video and he describes the problem pretty well.



This one gives HIS take on the problem.

 

Interesting explanation/theory on cam/lifter problems. I agree with you, where would all the usable cores come from and IMO the oils today without Zinc is a factor. If I was in the engine rebuild industry I would only use roller hydraulic lifter cam assemblies to avoid problems, but does the aftermarket industry use re manufactured hydraulic roller lifters ? staying with OEM factory parts would solve problem ? It's a shame/ fact that most items are made in China or somewhere else overseas today. I could write a long list of problems with materials purchased in my Tool & Die/Pattern shop that came with the shift to overseas manufacturing from my experience's, started in trades 1966, started my business 1976, ran till I retired 2010. I will agree the popular statement today, "Chinese Junk", I always order american brand name parts for my cars/ hobby and usually come with a sticker on box, made in china or ? rarely if ever made in USA. " It Is What It Is " applies again.

 

Very interesting. My thought on the second video was " what about hydraulic rollers?".

 

I ran solids in my stock car engines, never ever a cam related issue. On my coming 396 build, I was going to go with a hydraulic roller cam, I have some rethinking to do.

 

I suspect there is plenty of blame to go around.

Back when most cars sold here were domestically produced and had v8 engines, a typical year’s run was something like 15 million engines, or about 28000 lifters per day, assuming 260 work days, and two shifts. There were three major producers, from memory: Eaton, Rochester Products, and Sealed Power / Johnson Products.

These were, by any definition, large producers with well defined in process controls, and even then there were major failures of the cam / tappet interface. Small block Chevies for one were notorious for tappet failures in the seventies, even though the lifters were domestically sourced, probably from from Rochester products, and the oil had plenty of zinc.

In my own career in Diesel engine development, we spent a lot of time trying to make flat tappets work. We even used silicon carbide wafers on some engines. Bottom line is that we eventually gave up trying to get a good compromise between low hertz stresses / long life, and good power / performance, and went to roller followers.

Fast forward, and the number of flat tappets sold today in a year are probably not more than a days production run back in the heyday of the flat tappet v8 engine.

Furthermore, the aftermarket cams on the market all brag about more “area under the curve”, for better breathing and power gains. which translates to faster valve acceleration, and, consequently, increased hertz stresses at the interface.

My money is on poor cam design now as much as it’s on low volume lifter production without the experience and quality systems that the “big three” lifter manufacturers had thirty years ago.

 

Interesting...my anecdotal experience has been the opposite. Several hydraulic flat tappet failures over the past few decades (and as recently as last year, Mellings made in Mexico, two in a row), zero roller failures in three engines, lots of miles. (and no OEM failures, hundreds of thousands of miles)

 

Melling lifters are made in USA

 

the boxes said Mexico.

 

So far I’ve only watched the first video and while some good points are raised I’m not a believer in the re-man theory.
I do like this guy’s style, like at 2:45 when he mentions “a cam manufacturer “ and slides over to the quarter panel and draws attention to the decal on the window.
He goes on to say that .020-.030 is ground off the face of the lifters but that seems illogical and completely unnecessary. Lifter radius is on the order of sixty inches, why wouldn’t they just regrind the face and not machine .020-.030 first. Regardless, even if the lifters were shorter and you are working on an engine with adjustable rockers you adjust your hydraulic preload as necessary. His Mopar, or 330-455 Olds for example, without adjustment has to be lashed with proper length push rods. How does the suggested theory explain the wiped lobes in those engines where experienced builders had everything correct?

 

I don't buy the "rebuilt lifters" idea...

 

I saw those videos a couple of weeks ago, and thought they were interesting, and they might be on to something. But it seems to address more of the problem with fast bleed down than cam wiping. As Fordors said, the issue of reduced length doesn't really effect engines with adjustable lifter pre-load. I still think there is an issue with the machining and/or hardness of the end that rides on the cam.

So what's stopping a cam company from commissioning their own brand of lifters from a good machine shop, machined from new materials, not re-machined old cores? I realize that cost would be a barrier, but how much does it cost to rebuild an engine a 2nd time because of a cam failure? A single batch of lifters for 1 engine would be impractical, but how about enough for a few thousand engines? You'd think that for maybe 100k lifters you could get the cost down to reasonable, right? How many flat tappet cams are sold annually anyway, anyone have a good guestimate?

 

https://johnsonlifters.com/
the last set I bought came from these guys
has the corrct contour on the bottom
and were the correct length for my application, you might be suprised about lenght decrepancies from soome maunfactures
very important for non adjustable stuff

 

When you build an engine with what you believe are high quality parts and use proven methods and you still experience cam or lifter failure, I would like to check the rockwell hardness of said cam and lifters and compare with a known good cam and lifters. Or just buy a good roller cam and lifters and forget it like Squirrel said.

 

OK, I watched the second video and I think this guy is pretty much out to lunch, he has no concept of correct clearances or machining. He mentioned lifter faces with as much as .022 ground off them, lifter plungers with anywhere from .010 to .018 clearance and suggests that holes are “drilled” in lifter faces to allow bleed down.
I do agree that if a plunger has too much clearance it can bleed down easier, but if a lifter ID was honed to refinish it why wouldn’t the remanufacturer use correctly sized plungers?
His comment that lifters have the hole in the face for bleed down doesn’t hold water. (pun intended) Those holes are EDM’d and from what I remember that started with NASCAR engine builders to help their rules mandated flat tappet cams live for 500 miles in extreme conditions. Yes, it filtered down to some garden variety aftermarket stuff but are drilled lifters necessary for a street engine? And more importantly would they cure the wiped lobe syndrome so common now?
Bottom line? I’m not believing this guy’s arguments.

 

I'm somewhat conflicted on this, but I will say it is causing me to think about it. There are some things that make sense but not necessarily applicable to every lifter. Assuming that with flat tappet lifters, cores are plentiful and regrinding possible.
That really would not apply to hydraulic roller lifters. Each manufacturer seems to have their own design to link the lifters together and I doubt there are enough cores to rebuild them. That does not necessarily apply to roller lifters that came OEM in later model engines and use a dog bone type alignment bar.

As far as machining goes, I have to wonder that the outside diameter of the lifters would also require machining which would increase clearance to the lifter bores in the block.

If the inside of the lifter is ground larger and new parts are installed, why would they not make the new plungers larger? If they are installing original size plungers, then it makes sense why they would bleed off easily. The thing is, these parts are machined to extremely precise tolerances and a few tenths (.0002/.0003) could make a big difference.....especially if both parts got reconditioned.

There does seem to be a number of engines suffering catastropic events when restarting. Recently I saw a Cadillac 500 with shaft mount roller rockers that coughed some pushrods on restart after it had been running fine. Lifters that had bled down would seem a logical cause. Completely trashed some pushrods and the rocker arm shaft mount.

I haven't decided how much of this information I believe, but I certainly haven't discounted it either. Maybe someone who has saved some old lifters could compare their length to some new ones as well as maybe pushing on them to see how they compare resistance wise.

 

I don't think the hydraulic function makes a difference as far as wiping a cam lobe is concerned.

 

I'm trying to picture a group of guys hitting all the U-pull-it yards with buckets in their hands pulling the manifolds, valve covers and rockers off of every SBC and harvesting the lifters. Then there's the disassembly, cleaning, machining and reassembly of the usable ones. Doesn't add up economically for me.

 

^^^^^. I was just thinking the same thing.
My feeling is what’s being measured and seen is poor manufacturing.

 

If they were rebuilding used lifters there would be a variance in overall lifter length depending on how much is ground off the bottom as well as outside diameter. otherwise it would be obvious the lifters were used. Maybe in some third-world country they are remanufacturing used lifters but not on any Grand scale here in the US

 

Thanks for posting - interesting......very interesting.

 

We tried the holes drilled in the flat tappet lifter face to improve lubrication and increase life trick...it doesn’t work.

A little analysis shows that the local oil film pressure at the cam and tappet is literally magnitudes higher than the pressure in the hydraulic tappet mechanism. The hole actually causes some oil to flow backwards, into the body from the interface, effectively decreasing the oil film thickness where you need it the most.

As to the other post on the low hour failure on a 500 Cadillac, that sounds like debris in the hydraulic mechanism, causing the plunger to stick. If the plunger sticks at the bottom of the travel, you get lash and valvetrain separation.

As to excessive blead down, that was the principle of the Rhodes variable lifter concept from the seventies. The idea is that high clearances increase leakdown rates and hence change the valve lift curve at low speeds. Leak down is time dependent, and thus rpm dependent. Sort of primitive vvt .

Not very effective, though, in practice, and made for a lot of valvetrain noise at idle.

 

The lifter issue I referred to was in my 500 caddy.
The Lunatti supplied lifters (the one we measured) was .011 shorter at the cup than the CadCo supplied Johnson lifter.
I am running stock rocker arms. This caused a rocker noise issue.
the Lunatti supplied lifter was completely flat on bottom and overall body length was .009 shorter

 

Rebuilt? Those two videos do heroes make; to very few I would hope.

 

Johnson (Sealed Power), Eaton, and Rochester Products lifters all have different designs in the hydraulic mechanism.

Aftermarket cam suppliers don’t make lifters as a rule, and many are mostly marketers of parts they buy from someone else. That is, many cams offered by specialty aftermarket companies were actually ground by people like Sealed Power back in the day.

 

OK, someone school me if I'm off in left field please, but:
It seems to me that something that has been overlooked in this discussion is the effect cam lift and ramp profile has on the lifter. My simple mind tells me that a lifter that is totally flat could have an edge 'scraping' effect (for lack of a better term) that would be detrimental to lobe life. Conversely, a radiused face on the lifter would provide a smoother transition during the rotation of the cam.
Where's Ed Isky when you need him? I'll bet he could shed LOTS of light on this!!
Thanks guys.

 

The first video...the guy raised WAY more questions than what he attempted to answer. Not so much buyin it.
If any of you have been around a while..(!), what he was describing fairly accurately was...Rhoads lifters. He looked old enough to remember them. I believe they are still being made and sold. First hand parts...or remanufactured ? Don't know.
"SOAKING..." a lifter, does NOT...fill it..! You need something to "force" oil into the lifter to fill it. Will "some" oil seep in, I'm sure that a little will end up inside the lifter body, but FAR...from being filled. A lifter is NOT...a sponge..! There is also, NO suction going on, in of any kind, inside of the lifter bodies !

The second video, I just couldn't take anymore, I turned it off at 16 minutes.. SO many errors in his comments.
I don't know, but what I did watch, I'm glad the oil factor didn't come up.
I put over 93,000 street miles on my OLD Studebaker (sold about two years back, and still on the road!), solid lifter assembly, with off the shelf oil (Castrol 20-50 GTX), and NO...oil related problems.
So...all the bad...oil "experts"...explain THAT away !

I'm not saying that what the second guy is "trying" to say isn't at least somewhat true, I'm having a hard time with his comments as a whole. Many were partial truths, some comments were not even close.

Neither...of these guys, talked at all...about actually MEASURING...ANY part of the lifters talked about, new, used, OR rebuilt. I want to see hard numbers (with PROPER...measuring equipment. Not $20 dial calipers..!)) to come even close to proving any of the above comments. Lifters are made to four decimal places (.000x). To measure four decimal places, you need expensive tools. Not so much found in normal backyard garages.

Take the videos as you see fit. Sounds like mostly wives tales, and or myths to me.

Mike

 

View attachment 5152800

Right now I'm tending toward that same conclusion, but I've been known to be kinda wishy-washy on occasion.

You made some good comments, but I don't think this conclusion is necessarily correct. It would seem that multiple unrelated mechanical parts all failed at exactly the same time and in the same manner in order to substantiate this conclusion, and in my experience that almost never happens due to identical cause. Also, if there was debris in the lifters, why did some not stick when the engine was running perfectly? On the other hand, its pretty easy to see that some lifters may bleed down at the same time due to poor clearances. Couple even minor bleed down with a shorter lifter body and you have an issue. Anthony said that his Lunati lifters were .011 shorter at the cup. Add a little bleed down and a pushrod could come out.

Have to agree with Mike here, verifying these kinds of tolerances are not something that can be done at home even for most well equipped machinists.


Here is some info from a few knowledgeable guys on another site who build lots of engines.
Quote SH
"I then did a search online and found a message board post from a while back about a Buick 455 and it rang a bell for me I had forgotten that one difference is that the plunger is at a different height inside the lifter and with our stock non adjustable rocker arm this could lead to trouble ..."







Quote SH
"I also found a reference that said in 1970 they changed the outside barrel with the outside band to standardize the manufacturing of lifters in gm ... That only early bop hydraulic lifters where like my picture above ..."




BZ quote
"So I compared them and the oil bands are in the same location on the Hydraulics. The Buick pushrod cup (seat) is .060 higher in the body than the Chevy. The OD is the same and body height is the same. The Buick lifters are Delphi, and the Chevy Lifters are Comp Cams #812. Both of these have the hardened foot on the bottom."






CW quote
" BOP/Cadillac, and Chevy lifters all have the same oil band. The Johnson universal band design doesn't cause a problem in any of them. That allows them to use the same casting for all of them, which helps keep pricing down. Yes, there are also import junk lifters with the same universal oil band design (they are good at copying features like that). There are also import junk lifters (now) with the correct cup height. Some vendors selling import junk are now selling the correct cup height lifters. But the problem is, they still haven't gotten the crown on the bottom nor the the hardness really right (either being wrong will cause increased cam failure, and zinc additives slow down this kind of failure if the lifter isn't _too_ far off). They also haven't gotten their quality control right, and have a huge rate of bleed-down or other valving related problems, due to their inability to manage the super tight tolerances required for that stuff to work right. But most people can't tell any of that just by looking at them."


As you can see, there are many different things that have gone on with lifter production over the years, and even substituting other lifters as production dropped off. I don't think we can identify one issue as the cause of our problems.

 

@wicarnut You are onto something with the roller cam. Most of the builders that I know these days will not build you a motor with a flat tappet cam.

In hindsight I am surprised that many of us (myself included) did not go that way a long time ago. Roller cams for cars have been around since the '50s that I am aware of, hell my motorcycle has a roller cam from the factory and the company in question has been building the same basic lower end and valve train since '36.

With few exceptions I have not had much problem with flat tappet cams even without seeing the U tube info but common sense says that the price difference between roller tappet cams and flat tappet cams is minimal and the performance/reliability gains are immense.

Anyway this is way off base. I still run flat tappets in my small blocks and I will have to check into this closer.

 

Here is another quote from one of the guys I quoted above. I think its worth considering.
CW quote
"It wasn't that long ago that resurfacing lifters was common. When I first got into the automotive business, we rebuilt alternators, replaced AC compressor clutches, and sent lifters to the machine shop to be resurfaced and had the cam reground. Now everything just gets replaced - it's really pretty wasteful, but more profitable AND cheaper for the customer, because the replacement parts are mostly made with slave labor.
I'd use properly resurfaced lifters over China junk lifters any day. At one point, maybe 10 or 12 years ago, I was working on an oddball 50s Olds that had ruined (not rebuildable) lifters, and all I could get new was China junk - I checked the crown, and it was wrong. Everyone on the internet said those were the only option, and cam failures were a big problem (that's the cause of most cam failures - China lifters usually don't have enough crown). So I sent the new lifters to Knighton's and had them resurfaced to the correct crown, and the reground cam never failed. I didn't even put fancy oil in it...
If you are left with no option but China lifters, you can check them yourself. Hold 2 lifters bottom to bottom, and you can see the gap around the edge. Compare a pair of the China lifters to a pair of the original lifters, and if the gap looks smaller (more likely than not), find a place to recrown them properly, and they'll be fine. In most cases, if Johnson's are available, they're cheaper than China lifters + resurfacing, but if you have no other option, that's _a_ solution.
Resurfacing used lifters is usually a lot less than .020", unless the cam failed. But the hard surface should be at least .030" thick, anyway.
If they're wiped and you can't get new at all, you can get then tipped. The stellite tips on race lifters may be anewish fancy race thing, but adding a new tip to save wiped lifters was not uncommon back in the day. Grind it flat, braze on a .050" thick through-hardened plate, and grind the crown in that. I've never had that done, but I've found them in 50s and 60s cars on occasion. I would bet Tardell does that, or knows who does. I'd also be surprised if Isky doesn't do it. There are some engines you just can't get new lifters for."

 

Rebuilt lifters are a reality but I find it hard to believe that they are distributed by reputable cam grinders without proper notice. Seems like it would cross some legal lines and expose them to even more liability warrantee-wise.
So I guess the lesson here is; disassemble and verify all dimensions and clearances of each lifter and perform a Rockwell test and profile verification of the bottom surface before installation. Then you can rule out the lifters. But you still have; lobe treatment, hardness and finish, mechanical interference, ineffective break-in lube/process and unsuitable oil. It’s still the same old flat tappet crap shoot.
Roller cams seem like the best chance, especially for common power plants but not all of our beloved early engines have rollers available.