Flat Tappet Cam Failure Investigation offer...

[Cyclone Joe]

It looks like the flat tappet cam failure bug is re-appearing after being dormant for the past few years.  It also appears that nobody is getting a satisfactory answer from the cam representatives as to why this occurring.  We thought for some time  it was the oil's fault, but based on Barry's recent experience this may no longer be true.

I would like to take another approach to this issue.  I am willing to section, polish and evaluate cams to try to evaluate what is different from the 'factory' of old:

• Visually measuring the hardness depth based on the sectioned cam lobes
• Measuring the hardness level with an indention Rockwell C method, and non-contact.  This would be done on the OD of a cam lobe, and at various locations on a sectioned lobe from OD to center
• Visually measuring the grain structure
• Verifying the cam material properties.  What are the constituents, and is there more or less of one alloying element than another when compared to the factory cams?

If anyone has a factory cam print (John Vermeersch or Dave Shoe maybe, I dont think I have a factory print in my copies) that we can compare back to, it may have hardness or basic material requirements listed.  I know the hardness requirements were listed on the SOHC rocker arms.

Would anyone be willing to participate?  All I would need from you besides a failed cam (and the lifter on the failed cam) would be:
 

• Miles until failure
• Spring pressure
• Cam manufacturer
• Day, month, year of when cam was manufactured (that may be listed in a code on the cam)

I estimate that I'll need a total of 6 failed cams.  I will section the failed lobe and two 'un-failed' lobes per cam to see if there is variation from lobe to lobe on a single cam, plus variations between cams overall.  I will also section two factory cams out of junkers at the local Pick N Pull.

If people are interested it will take me 4-5 months of weekends of sectioning and polishing to get the specimens ready and tested and report findings 

Cheers,
Joe

[cammerfe]

You may want to test iron with a Brinell tester instead of Rockwell 'C'

KS

[Cyclone Joe]

What would be the advantage/disadvantage?  What is being lost by doing one test over another?

The Rockwell test would need the diamond cone indenter given the surface hardness and localized hardness should be 50 Rc or higher, permitting measurements on a small surface.    Also, I was going to try a superfical Rockwell measurement in addition to a non-contact measurement to see if there is any difference.  The brinell tester I've used has a 10 millimeter tungsten carbide ball, and due to the large ball size it limits the usage of it, as in this case, which is why I proposed the Rockwell test.

Thank you!
Joe

[jayb]

Hey Joe, thanks for the generous offer.  For those of you who don't know, Joe is an engineer with a materials background and he is the guy who did the analysis on the rocker arm failures that I experienced on my SOHC during Drag Week in 2008.  He does a very thorough job, and finds the right answer.  He is a great resource, so if you lose a flat tappet cam I'd recommend you take Joe up on his offer!

[Cyclone Joe]

Thank you for the kind words Jay.  Maybe I should have added originally "The only cost you will incur is the cost of shipping the cam & lifter(s) to me".  The work to cut, mount, polish, dye, test and measure would be all free.  If you want the unused pieces back I'd be happy to ship them back at the completion of the study at my cost.

Joe

[machoneman]

One other factor methinks bears review: the lack of lifter rotation due to gummed-up lifter bores. I tend to think that tight bore to lifter body clearances, especially in older blocks, are also a factor when only one or two cam lobes get flattened, a point many assemblers miss. JMO.

[Kerry j]

Joe,

I had to check and make sure I still have the failed Comp XE 256H cam and lifters from my 302. I have the cam and all the lifters; the lobe that failed and it's lifter are easy to spot; LOL! Anyway, I would be happy to send them to you for the testing you're proposing. Please email or post your shipping address and I'll get them shipped to you next week.

Kerry

[Bullitt]

It does bear mentioning that it is very interesting the location of the failures.  That point was brought out on the "other" forum.

If Cylinder #5 intake and exhaust wipes out, but the other 14 are fine, why is that?

I, personally, have never felt oil was the blame for the rash of failures of times past, but moreso, a lack of effort by manufacturers to produce a quality product.

Every business is looking for a way to save even half a cent.  If the hardness treating can by completed in less time, even if it means a slightly lower quality product, I am sure many OE grinders would do that.

Same with lifters, etc.

Motor Oil, on the other hand, seems to strive at making the best they can.  Sure zinc and phosporus were lowered, but other additive packs were developed to compensate.

If the oil were to blame I believe the entire cam would show signs of stress and not just a lobe or 2 or 3.  Even though I have never experienced a cam failure, from what I have observed it seems to show up on one end or the other of the camshaft.  It is rare to hear of a failure at say #1 intake and # 7 Exhaust for example.

Something else is to blame and it isn't the oil.

Josh

[65er]

Something else is to blame and it isn't the oil.

Josh

I'm taking the opposite stance Josh.  The cam wiping problem from what I've read seems to cross all brands and although it is important for companies to squeeze out the last half cent of profit, it is equally important to produce a quality product.  If any one of these companies were able to produce wipe-proof flat tapped cams they would be able to gain a huge share of the market so I don't believe any of those guys are shrugging their shoulders saying that's just the best they can do.  I could certainly be wrong about that but I feel that most are much more aggressive than that.  Also you mention the location of failures but I see that scenario working pretty much the same way no matter what the root cause of the problem is.  Once the bad wear begins on one lobe it accelerates rapidly and typically would not give the rest of the cam enough time to catch up.  I've also read of cases where multiple lobes have gone flat and that to me would indicate either phenomenal consistency of the parts involved, over stressed components such as way too heavy valve springs springs or else crap parts that truly aren't up to the job.

Now the oil on the other hand, the government regulates that stuff so I'm suspicious right away.  Also flat tappet cams are typically not going to be a major concern for the oil companies and high performance or musclecar cams even less of a concern.  No doubt they have done their required testing but it seems super unlikely that they are doing any serious work toward making old school V-8 motors with healthy flat tappet cams live an extended life.  We have some specialty oil companies that are doing good things but I feel that some of the basic formulations, rather than just the zinc or phosphor contents are more to blame than anything.  I bet if a guy was running on a stash of Pennzoil from the 70's he wouldn't be having any problems with cams going flat.

I do very much look forward to seeing Joe's findings.

[Cyclone Joe]

Kerry,

I didnt see your email address attached to your signature, so please email me at mercurycyclonegt (at) gmail (dot) com and I'll send you my mailing address.

Thank you!
Joe

[Bullitt]

Something else is to blame and it isn't the oil.

Josh

We have some specialty oil companies that are doing good things but I feel that some of the basic formulations, rather than just the zinc or phosphor contents are more to blame than anything.  I bet if a guy was running on a stash of Pennzoil from the 70's he wouldn't be having any problems with cams going flat.

There are plenty of examples of people using Brad Penn, Gibbs, Kendall etc break-in oil and still having cam failures.

Maybe I'm lucky, but the last 3 Crane cams I have installed and broken in within the last 10 years I used regular Rotella and left both inner and outer springs installed.  I'm not messing with reinstalling that crap later.

No issues.

Keep in mind most cam suppliers are using cam blanks from only a couple suppliers.  So it doesn't make sense to try and compare any of the cam companies against each other.  They are all using the same stuff.

The key also is nobody is taking into account that a ZDDP content of .14% or more is good for short term break-in, but horrible for long term durability.  .008-.10 is considered the best for long term durability.

What happens is Joe Blow thinks he needs a boatload of zinc using some Brad Penn concoction with some GM EOS pushing the total ZDDP levels well over .2%.  Guess what happens?  It literally attacks the metal.  Sure the cam breaks in perfectly fine, but over time the cam then becomes wiped out.  It might take 1000 miles, it might take 10,000 miles, but running a syrup receipe of zinc isn't the answer.

Using 70s oil isn't the answer either.  It actually has lower zinc than a comparable "90s" SG rated oil.  So does SJ. SE and SF are garbage.  SA-SD are complete junk as well.

Current CJ4 diesel oil has as much or more zinc than the old SG.  How many wiped cams using SG?  How many wiped cams using SJ? 

What else was going on in 2000/2001 with the introduction of SL?  The economy tanked, Johnson no longer made high quality lifters and companies tightened their bank accounts.

Josh

[WerbyFord]

Thanx Cyclone Joe for this fantastic offer.
I hope I am unable to take U up on it, no bad lobes yet.
This is exactly the study that is needed, a great service to the hobby.