booster9

iTrader: (3)

my opinion is i was the unlucky one who may have gotten a faulty cam due to a bad cast or something, say 1 in a 1000 goes. well, that poor one person just got royaly ****ed! for example, me.

tnt1106

Tomorrow I will be posting a new thread here to collect facts and info from all of the PM's I have about this so far. If you have this failure IN the mivec groove, you are NOT alone and mostly likely after (each cam) is tested you will have the same data that I have indicating metal failure / improper machining.

Please look for the thread and try to keep the format I request all the gathered info that is verified with dates / logs / pics will be forwarded to assist us with resolving our losses. Thank you guys! (This will apply to the Mivec specific failures on the IX only.)

Addiction24

I had one of my Kelford 272 cams fail before it even made it to my car. My tuner opened the box up only to find one one the lobes broken clean off, no impact marks or anything. If they can't even survive shipping, not sure if they will hold up in my engine. With all of this happening, I think my cams are coming out. I can not afford a new engine....

Early EVO

iTrader: (2)

I have had two Kelford 272 IX cams break. Bought about 6 months apart. So if its 1 in a 1000 that breaks. I should be betting in Vegas.

DIDYSIS

iTrader: (18)

HKS FTW Sorry had to be like everyone else for once, that too bad, hope you get something figured out. Court time?

JohnBradley

iTrader: (30)

At this point it seems Ocham's Razor seems to be our best bet.

A copy of the data from any testing and not circumstantial opinion without said testing would be imperative.

Remember shear does move in multiple planes, and this is not rotational shear its pulling apart (cup and cone). What is elastic modulus ( or modulus of elasticity if you prefer that term) of this particular billet as determined by this lab testing?

I think the fact that timing belt is rubber has nothing to do with preventing or contributing to failure, but acceleration in both directions between slack and tension of the belt can and will still generate harmonics.

An overtorqued cam bolt wont help this situation, it will be little more than a wedge waiting for more force before its job is done.

Cam failures like this are not new to the import world. I have seen some manufacturers OE cams fail in a similar fashion though initial cause may be different.

Anyone that has a failure needs to take pictures or send the cam in to have it examined. Just because a claim is made doesnt give it the right to be accepted as fact unless presented as fact.

NWM_Tech

""The crossdrilling for the Mivec Oiling is the culprit. Just not enough metal left for such a small journal to have any strength.""

that's what I think also, sharp inside corners is always a stress raiser.

Too small of a section and section dimension change right at a high load point. Design flaws.

It's a weak point. Harmonics could be adding to the cause but that alone shouldn't go past the margins.

If a Tbelt is tight enough to stress a cam it will howl like a mad-dog because it's stretched and the teeth won't line up with the gear teeth.

nikkadanny

iTrader: (31)

whoever is taking kelfords 272's out, sell them to me =)..

NWM_Tech

Both the pics on this thread the break is at the end of the threads, past or at the end of the bolt.

Besides the bolt force is on the threads, not the outer section.

Have seen a few bolts break but never a stripped cam.

xspsi4

iTrader: (67)

have a friend running kelford 272's in his shops rally car, So far so good but I am to poor to risk my motor to this type of failure, I have always stuck with hks 280's and had greal luck with them.

marksae

iTrader: (12)

While I don't disagree with your approach to determining the root cause of the problem, the reality of the situation is that people cannot afford to risk losing their engines while root causes are being determined. There are enough reported failures to warrant a very valid concern from people who own these cams.

These are the facts:
1) OEM cams have the radius
2) All reported cam failures do not have the radius
3) Aftermarket cams with the radius have no reported failures to date

If I had a IX w/ one of these suspect cams, I'd yank them out. Better safe than sorry.

EvoDom

iTrader: (7)

the cam was deffinetly defective, call kelford they will help you out and i think your signature says alot to

516hp 430tq @ 32psi
Race it, Break it, Fix it, Repeat <------------

l2r99gst

iTrader: (2)

JB,

I have a materials engineering degree from Purdue University and I worked in the failure analysis lab for a major US power company, performing analysis on boiler tubes and various parts used in the plants.

I always said that I couldn't tell just from a pic or two posted in this and the other thread, but in my opinion, this is either a material/microstructural defect, a design defect (improper fillet radius), or a combination of the two. Only proper lab testing from a failure analysis lab would be able to tell. And actually, I have no doubt in my mind that they would be able to 100% tell, especially given more than one set of failed cams. It's actually quite obvious once you start looking at the fracture surfaces and microstructures as well as the design up close.

A cup and cone fracture just suggests a ductile failure. I can't tell well enough from the pictures to see the fracture surfaces anyway.

Although, if you look back at the original thread, I made a comment where there are obvious signs of fatigure and at least one crack initiation point. That would be exactly what I would expect to see if the cam failed by fatigue due to crack initiation at the point of the improper fillet radius.

During use, the cam has a not only rotational forces, but also a perpindicular force appliced to one side (the cam belt/pulleys), and repetitive perpindicular forces down the line at each lobe when it contacts the rocker/lifters. So, the cam is being stressed perpindicularly thousands of times every time the car is being driven. If there is a weak point, due to design and/or material/microstructural defect, the cam will eventually break due to crack intiation, propagation, and fatigue. The shearing/rotational forces at that point will just help to propogate the crack along specific planes, but in general, it is the bending stresses that appear to be causing the damage here, not shearing stresses. Again I can't tell for sure without a proper analysis.


Eric

GrocMax

We (FP) DO NOT use the same core supplier as Kelford/GSC/"Cosworth", this is why we had trouble with backorders a few months back, but there is no backorder issue now, plenty stock on shelf.

This type of failure isn't going to happen with the FP core, there has been plenty of 'destructive' testing done without a single failure.

denver

iTrader: (9)

I am a Mechanical Engineer with 3 years worth of material science and material strength and failure as well as 2 years experience working in a product failure lab. I currently work as a designer of large industrial equipment, and i work heavily with selecting, testing, and comparing foreign steel to USA equivalent steels as well as manufacturing a producing parts made in house. I also worked as a machinist for 6 years while going to school.

I don't have actual lab test data, and I do not work at a lab currently, but I have contacted the lab I regularly use for testing for my job, and showing him just the pictures he made the same claims I am making. As always, testing needs to be preformed on the material to know for sure. I am not claiming that all the cams are bad, I have Kelfords in my car right now, and have no plans to change them, I love the cams, they are absolutely a well rounded cam, and preform great on the track and off! I do know that issues happen in manufacturing (been there done that) and I think there is a batch of these cam blanks that got out there with some issues.... but all of them that I have seen that use this blank, have poorly designed/machined groves for the mivic oil passages.... it doesn't take an engineering degree to know that a sharp corner has higher stresses than a radius corner....

I'm not patting my own back or anything, but you asked, so that is my background for making the claims I have made. I happen to know two of these guys personally, I did not install the cams, but they are both good guys and I want to make sure they get treated right...... I back my products, I expect the same out of the products I buy. If there is even one issue we research and prove we made it right, if not, then we replace and repair the issue and resulting damage cause by the issue, that just good product support plain and simple...