my intake cam snapped?!!?
Mar 15, 2009, 03:53 PM
#181
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Just got an email back from Kelford in regards to the cam failures.
Hello ,
Thank you for contacting me regarding this.
We are looking into this situation and although I do not have definite answers right now, Here is what we know so far.
First, only one customer has ever complained to us of a broken camshaft. But we know of three Kelford Cams that are broken. We also know of broken from BC, GSC, Cosworth and another from Europe.
We have not had any sent to us for evaluation, so it is very difficult to analyse what went on in any of those cases.
Two of the broken camshafts are from the same tuner (so I am told)
We use two different core manufacturers for our EVO9 Cams.
Across the world, most cam companies use the same two casting foundries for these cams.
The casting foundry that makes the camshaft that has broken says that the spec of the iron and the spec of the semi finish machining has been the same right from the start (which is 2006)
They also say that the machining matches the O.E.M sample that was supplied to them to make the pattern from.
This supplier also makes EVO9 cores for other cam companies and they have told me that the other companies have asked them to look into this
I am not taking their word for this, I am trying to find an early 2006/7 camshaft to compare to 2008/9 camshaft.
Also, we know that at some point, Mitsubishi themselves revised the machining on the O.E.M camshaft.
Since 2006 we have made well over 1500 sets of EVO9 camshafts from the core from this supplier.
The camshaft break is not caused by the filet radius being to tight, it is true that this area could be made better than it is and would be stronger if the radii were larger but then the cam will break at the next weakest point which is through the cross drillings in the second oil groove.
What I am trying to say is, an external influence is causing excessive load, enough load for the cam to break at its weakest point.
We know of and have photos of a EVO9 MIVEC camshaft that broke (in operation) through the oil holes and not at the groove radius, substantiating the theory above.
Also in destructive testing we have ascertained that we cannot break the camshaft with rotational force, only with side impact. Side impact in a running situation can only come from belt whip (belt harmonics), and with the weight of the MIVEC gear this can possibly result in a cam issue.
I am not going to accuse people, and me saying this will obviously **** some off, but there is a possibility that some people are getting the install wrong, and many of the level headed members in the forum have touched on this as a possibility already. Mivec map, Bolt torque, belt tension, tensioner... I don’t know because i am not an installer.
These camshafts by inherent design are obviously weak at the front section and I don’t think there is any room for error of any sort or we will see this happen again. It also happens on some Toyota and some European car engines that have heavy variable cam advance devices in the front gear.
The FP core is also our core, in fact outside of Japan we have the rights to that cam core.
That particular core (let’s call it the Japanese core) was a problem in earlier times, it was made from the wrong material and had lobe surface cracking issues, we would not use it others did and got themselves into all sorts of trouble over it.
Then it was made from the proper chill cast process and we used it only to find that the semi finish machining was very inconsistent and sometimes journals were too big, thrusts were too wide, dowel pin holes too deep, slot angle wrong..... We had to put on another person just to QC the cores before we could find the ones we wanted to use, so we chose to use the other supplier which had no issues whatsoever at that point. We do have the option to go back to this core because it is stronger in the front grooves and may protect against whatever issue is causing the occasional cam to break.
Remember, there are thousands out there that have no issue, lots of which are daily drivers and some with over 70,000km on the clock.
There are three that we know of with an issue and only one of them ever said anything to us, we replaced his cam with one from the same batch etc etc and he is running perfectly fine. So what went wrong the first time?? I don’t know.
I know that none of this is a real big help to you as far as making a decision on the install but now you know as much as we do about it.
If you have a machine shop close by, you could send them in for a crack test to make sure there is no cracks in the area, possibly caused by shipping.
We have seen the internal couriers in USA break a few of our camshafts in transit and we have upgraded our packaging to try and protect against this.
Please let me know if you have other question or if anything needs clarification.
Best regards
Kevin Ban
Kelford Cams
Hello ,
Thank you for contacting me regarding this.
We are looking into this situation and although I do not have definite answers right now, Here is what we know so far.
First, only one customer has ever complained to us of a broken camshaft. But we know of three Kelford Cams that are broken. We also know of broken from BC, GSC, Cosworth and another from Europe.
We have not had any sent to us for evaluation, so it is very difficult to analyse what went on in any of those cases.
Two of the broken camshafts are from the same tuner (so I am told)
We use two different core manufacturers for our EVO9 Cams.
Across the world, most cam companies use the same two casting foundries for these cams.
The casting foundry that makes the camshaft that has broken says that the spec of the iron and the spec of the semi finish machining has been the same right from the start (which is 2006)
They also say that the machining matches the O.E.M sample that was supplied to them to make the pattern from.
This supplier also makes EVO9 cores for other cam companies and they have told me that the other companies have asked them to look into this
I am not taking their word for this, I am trying to find an early 2006/7 camshaft to compare to 2008/9 camshaft.
Also, we know that at some point, Mitsubishi themselves revised the machining on the O.E.M camshaft.
Since 2006 we have made well over 1500 sets of EVO9 camshafts from the core from this supplier.
The camshaft break is not caused by the filet radius being to tight, it is true that this area could be made better than it is and would be stronger if the radii were larger but then the cam will break at the next weakest point which is through the cross drillings in the second oil groove.
What I am trying to say is, an external influence is causing excessive load, enough load for the cam to break at its weakest point.
We know of and have photos of a EVO9 MIVEC camshaft that broke (in operation) through the oil holes and not at the groove radius, substantiating the theory above.
Also in destructive testing we have ascertained that we cannot break the camshaft with rotational force, only with side impact. Side impact in a running situation can only come from belt whip (belt harmonics), and with the weight of the MIVEC gear this can possibly result in a cam issue.
I am not going to accuse people, and me saying this will obviously **** some off, but there is a possibility that some people are getting the install wrong, and many of the level headed members in the forum have touched on this as a possibility already. Mivec map, Bolt torque, belt tension, tensioner... I don’t know because i am not an installer.
These camshafts by inherent design are obviously weak at the front section and I don’t think there is any room for error of any sort or we will see this happen again. It also happens on some Toyota and some European car engines that have heavy variable cam advance devices in the front gear.
The FP core is also our core, in fact outside of Japan we have the rights to that cam core.
That particular core (let’s call it the Japanese core) was a problem in earlier times, it was made from the wrong material and had lobe surface cracking issues, we would not use it others did and got themselves into all sorts of trouble over it.
Then it was made from the proper chill cast process and we used it only to find that the semi finish machining was very inconsistent and sometimes journals were too big, thrusts were too wide, dowel pin holes too deep, slot angle wrong..... We had to put on another person just to QC the cores before we could find the ones we wanted to use, so we chose to use the other supplier which had no issues whatsoever at that point. We do have the option to go back to this core because it is stronger in the front grooves and may protect against whatever issue is causing the occasional cam to break.
Remember, there are thousands out there that have no issue, lots of which are daily drivers and some with over 70,000km on the clock.
There are three that we know of with an issue and only one of them ever said anything to us, we replaced his cam with one from the same batch etc etc and he is running perfectly fine. So what went wrong the first time?? I don’t know.
I know that none of this is a real big help to you as far as making a decision on the install but now you know as much as we do about it.
If you have a machine shop close by, you could send them in for a crack test to make sure there is no cracks in the area, possibly caused by shipping.
We have seen the internal couriers in USA break a few of our camshafts in transit and we have upgraded our packaging to try and protect against this.
Please let me know if you have other question or if anything needs clarification.
Best regards
Kevin Ban
Kelford Cams
Mar 15, 2009, 04:00 PM
#182
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Very good information about the cores, he didn't go into that level of detailed when he replied to my emails.
Sounds like they are on the case, they are just not active in the forum, so we have done in contacting them and referencing this thread on the emails.
Sounds like they are on the case, they are just not active in the forum, so we have done in contacting them and referencing this thread on the emails.
Mar 15, 2009, 05:48 PM
#187
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These camshafts by inherent design are obviously weak at the front section and I don’t think there is any room for error of any sort or we will see this happen again. It also happens on some Toyota and some European car engines that have heavy variable cam advance devices in the front gear.
The factory hung double the sprocket weight out on the end and added oil grooves without changing diameter.
If you look at the X's they are increased diameter at the front journal and the oil grooves are in the journals, not the cams.
It's an auto tensioner on these so unless you bottom it out on install you can't over-tighten the belt unless the tensioner itself is somehow over tensioning.
Still want to see a comparison of the stock cams to the ones breaking. Measuring diameter at bottom of groove, radius inside groove, and look at galling in groove.
Mar 15, 2009, 08:06 PM
#189
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There's the money statement of the entire email
The factory hung double the sprocket weight out on the end and added oil grooves without changing diameter.
If you look at the X's they are increased diameter at the front journal and the oil grooves are in the journals, not the cams.
It's an auto tensioner on these so unless you bottom it out on install you can't over-tighten the belt unless the tensioner itself is somehow over tensioning.
Still want to see a comparison of the stock cams to the ones breaking. Measuring diameter at bottom of groove, radius inside groove, and look at galling in groove.
The factory hung double the sprocket weight out on the end and added oil grooves without changing diameter.
If you look at the X's they are increased diameter at the front journal and the oil grooves are in the journals, not the cams.
It's an auto tensioner on these so unless you bottom it out on install you can't over-tighten the belt unless the tensioner itself is somehow over tensioning.
Still want to see a comparison of the stock cams to the ones breaking. Measuring diameter at bottom of groove, radius inside groove, and look at galling in groove.
Belt Harmonics are just and easy way out... it would be hard to measure that....
If you look at the other thread about broken cams our friend Greg at GSC measured their core VS stock already......
and as we established earlier, the belt is self tensioned as long as it isn't over tensioned to bottom out the tensioner, or under tensioned and not contacting the tensioner... either way, you would know right way on the install, the cams wouldn't hold position if they were under tensioned, and you would have to work at it to go and over tension the belt. So again I ask where are the random harmonics coming from? Mivic map... thats crap too. I happen to know Booster9 was on a completely stock Mivic map, and TNT1106 was on a mild tuned mivic map that is based on a map FP likes to use with their cams (FP never had a problem or failure on their cams even with a more aggressive MIVIC map then TNT had)
To address Kelfords email on the cores... the FP (Comp Cams Core) is very different from the Kelford GSC COSI core. The FP core looks noticeably better finished, the HEX on it is much more defined, there is no grinding of the part line as seen on the kelford either. While I would expect the FP to have a larger radius than it does in the mivic grove, at least it has a noticeable radius, which is not present in the kelford GSC COSI core. It should be noted that the FP core is about .050" shallower than the other core.
Ultimately, I do no think the radius issue alone cause the failures, I'm still leaning toward a material/finish treatment issue, based purely on the look of the break. Although, Kelford needs to certainly address the radius, especially if they, as seen in their email, address it as a weak spot that should be improved. Its a simple fix, just a different carbide bit in their CNC lathe, really they dont even have to change the code, sway out sharp edge tool with radius tool....
I am going to try to find time to F.E.A. Kelford, FP, and Stock cams this week at work to see what effect the differences in the groves make.....
Last edited by denver; Mar 15, 2009 at 08:09 PM.
Mar 15, 2009, 08:40 PM
#190
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How about temps these cams are being operated in (like New York has been extremely cold as of late)? Could it be a possibility the temps these cams are being operated in probably just exacerbate the issue already at hand whether it be extreme heat or cold? I'm just throwing this ridiculous idea out there (I know cams are supposed to be made to operate under the heat of a motor which is more than environmental temp./climate). Basically what I'm asking is has anyone broken one who lives in a colds state with a lot of cold starts? Maybe the cycle from cold to hot, cold to hot or vice versa could fatigue the metal (assuming the cam wasn't made properly) after time? Just a crazy idea.
Last edited by SRT-TO-EVO; Mar 15, 2009 at 09:23 PM.
Mar 15, 2009, 09:21 PM
#191
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How about temps these cams are being operated in (like New York has been extremely cold as of late)? Could it be a possibility the temps these cams are being operated in are probably just exacerbate the issue already at hand whether it be extreme heat or cold? I'm just throwing this ridiculous idea out there (I know cams are supposed to be made to operate under the heat of a motor which is more than environmental temp./climate). Basically what I'm asking is has anyone broken one who lives in a colds state with a lot of cold starts? Maybe the cycle from cold to hot, cold to hot or vice versa could fatigue the metal (assuming the cam wasn't made properly) after time? Just a crazy idea.
Mar 15, 2009, 10:06 PM
#192
Power and Boost will have no affect on failure.
I forgot to ask if these cars all had stock crank pulleys?
Belt harmonics arent an easy way out if you stop and examine the fact that it doesnt absolve them. Its simply a possible explanation of why the failure was caused related to material. It takes a grown man swing a sledge hammer at it to get a similar shear pattern when the cam is at rest.
I forgot to ask if these cars all had stock crank pulleys?
Belt harmonics arent an easy way out if you stop and examine the fact that it doesnt absolve them. Its simply a possible explanation of why the failure was caused related to material. It takes a grown man swing a sledge hammer at it to get a similar shear pattern when the cam is at rest.
Mar 15, 2009, 11:27 PM
#193
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ktk - "Instead what seems to be happening is that there is a force that is acting on the cam gears as the tension in the timing belt pulls down on them."
is there a way to lower the force by like making the timing belt slightly looser? I installed my GSC S1's yesterday with a help of a co-worker/friend who owns a evo 8 and installed his hks cams himself. when we were working on my 9 cams we zip tied the cam gear along with the belt and tried loosening it and it would loosen somewhat, but not a lot, but on his 8 he was able to loosen it to the desired position.
topturtle - "I have a set of S1 in my garage that Kevin swapped out for the S2s. After seeing the pics Kevin posted I dug them up and looked at the grooves. The grooves look very similar to the FP cams."
whew that's a relief. hope that my gsc s1's won't give me any problems. mivec cams getting snapped / broken is more so on the GSC S2's instead of S1's if i'm not mistakened... didn't hear of any S1's breaking/snapping yet.. "knock on wood" but for those who have had their cams snapped maybe it should've been well lubed / greased since a lot of time metal to metal will wear and eventually break w/o it being well lubed/greased and babied for say like 500 - 1000 miles before pounding it since it takes some time to break in the newly installed parts and for it to "learn"?? just my .2 cents on that; but sorry to hear those who had to pay the loads of $ for repairing the damages. it's not ur guy's fault as for me i still need an e-mail flash from mellontuning sometime soon since cams are a major mod which requires an upgraded map.. after the installation i've been hearing a slight ticking / rattling noise at a very low rpm/idle and i'm thinkin that's normal since before i heard a slight ticking / rattling noise when the engine bay shakes a little as if it was about to stall out at low rpm/idle.
is there a way to lower the force by like making the timing belt slightly looser? I installed my GSC S1's yesterday with a help of a co-worker/friend who owns a evo 8 and installed his hks cams himself. when we were working on my 9 cams we zip tied the cam gear along with the belt and tried loosening it and it would loosen somewhat, but not a lot, but on his 8 he was able to loosen it to the desired position.
topturtle - "I have a set of S1 in my garage that Kevin swapped out for the S2s. After seeing the pics Kevin posted I dug them up and looked at the grooves. The grooves look very similar to the FP cams."
whew that's a relief. hope that my gsc s1's won't give me any problems. mivec cams getting snapped / broken is more so on the GSC S2's instead of S1's if i'm not mistakened... didn't hear of any S1's breaking/snapping yet.. "knock on wood" but for those who have had their cams snapped maybe it should've been well lubed / greased since a lot of time metal to metal will wear and eventually break w/o it being well lubed/greased and babied for say like 500 - 1000 miles before pounding it since it takes some time to break in the newly installed parts and for it to "learn"?? just my .2 cents on that; but sorry to hear those who had to pay the loads of $ for repairing the damages. it's not ur guy's fault
as for me i still need an e-mail flash from mellontuning sometime soon since cams are a major mod which requires an upgraded map.. after the installation i've been hearing a slight ticking / rattling noise at a very low rpm/idle and i'm thinkin that's normal since before i heard a slight ticking / rattling noise when the engine bay shakes a little as if it was about to stall out at low rpm/idle.
Mar 15, 2009, 11:33 PM
#194
If you created enough cylinder pressure prior to tdc through a pre-ignition/auto-ignition event you could send a pretty nasty harmonic through the timing belt attempting to shear off your cam gears...
*** now that I think of it... you'd jump time, loose teeth off the timing belt, wail on the belt tensioner long before you'd generate enough shear force to fail the camshaft :P ***
Aaron,
I bought a set of GSC S2's from you in October of 2008...I have not installed them yet. What identification on the camshafts will lend to the date of manufacture/batch etc? I bought my cams at the same time these people with failures did... to be honest I'm a bit spooked.
*** now that I think of it... you'd jump time, loose teeth off the timing belt, wail on the belt tensioner long before you'd generate enough shear force to fail the camshaft :P ***
Aaron,
I bought a set of GSC S2's from you in October of 2008...I have not installed them yet. What identification on the camshafts will lend to the date of manufacture/batch etc? I bought my cams at the same time these people with failures did... to be honest I'm a bit spooked.
Last edited by R/TErnie; Mar 17, 2009 at 10:04 PM.
Mar 16, 2009, 12:49 AM
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aiyaaah... that doesn't sound good.. ehhh wat's tdc stand for again? srry i'm not familiar w/some of the evo abbreviations :-/ how can u prevent that..? making sure the hash marks line up with the timing belt, making sure the belts also tight enough, torque down the mivec cam bolt, and the correct tensioner position..?? is that one reason why some evo owner's mivec cam gear are sheared? Thanks for the info.