my intake cam snapped?!!?
Apr 2, 2009, 10:22 PM
#331
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Apr 5, 2009, 08:12 PM
#333
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Bump, i think we have another. cosworth cam this time, installed by a shop in new mexico, not sure when it was purchased. i have yet to see the car, but judging by his description its a broken intake cam 
Apr 8, 2009, 12:05 PM
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its definately a broken intake cam. cosworth M2. installed by a shop in new mexico, the car was shipped here, drove it for a day, cam broke. i haven't seen the car in person, but he sent me pictures so i could help diagnose the problem. i tried posting the pictures but they are on my iphone. i'll try again right now.
Apr 8, 2009, 05:36 PM
#338
So far we have no other information but limited numbers of camshaft failures.
I have not read of any proof that would lead me to believe it was a bad batch other than here say.
Not naming a couple of distributers (dont feel comfortable naming), but they have sent the Kelfs for independant testing material testing. The batch they used was sent for analysis and returned fine. What batch and what kind of analysis is unknown to me.
There are quiet a few explainations for what happened to possibly include material and/or design flaw but nothing has lead me to believe that yet.
IMO, What we know is the design is common with all cams sold; yet there has been limited failure. One thing that differentiates us from one another (being we have the same cam design and material) is the manner in which it was installed.
If, for instance, a cam cap bolt began loosening from vibration because of incorrect torque applied, the cam could begin a vibration due to rotation and the loose cam cap. This in turn may cause impact forces perhaps causing the breakage at the weak point of the cam....the oil groves.
I have not read of any proof that would lead me to believe it was a bad batch other than here say.
Not naming a couple of distributers (dont feel comfortable naming), but they have sent the Kelfs for independant testing material testing. The batch they used was sent for analysis and returned fine. What batch and what kind of analysis is unknown to me.
There are quiet a few explainations for what happened to possibly include material and/or design flaw but nothing has lead me to believe that yet.
IMO, What we know is the design is common with all cams sold; yet there has been limited failure. One thing that differentiates us from one another (being we have the same cam design and material) is the manner in which it was installed.
If, for instance, a cam cap bolt began loosening from vibration because of incorrect torque applied, the cam could begin a vibration due to rotation and the loose cam cap. This in turn may cause impact forces perhaps causing the breakage at the weak point of the cam....the oil groves.
.
Apr 12, 2009, 09:52 AM
#340
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Can you explain a little further as to what exactly you were doing and what happened when the cam snapped? Were you using stock springs, what RPM and boost, was the tensioner replaced, conditions during the break, etc. ?
There has to be a logical cause to this as cams don’t snap by themselves like that, they need a lot of force to do that. It has happened before with other brands of EVO9 cams, with cores from various sources, but I am not sure what the cause of that was because I was not involved in the discussions.
Kelford has done some testing in their labs, (destructive and non destructive) and found no fault with the castings.
It is near impossible to break these cams with a rotational motion, the only way they could replicate the breakage was by side impact. The only side impact that happens in operation is from belt harmonics which can be caused by various things.
All I know is it took a lot of force for them to break that cam in testing, that amount of force is not normal in the engine.
Some possible causes may stem from;
Spring coil bind
Belt tension
Valve spring harmonics, (trying to run the stock spring at extended rpm and boost)
Not replacing the tensioner with a new unit when installing
Etc.
If you could give us more information on this particular incident we may be able to point you in the right direction.
There has to be a logical cause to this as cams don’t snap by themselves like that, they need a lot of force to do that. It has happened before with other brands of EVO9 cams, with cores from various sources, but I am not sure what the cause of that was because I was not involved in the discussions.
Kelford has done some testing in their labs, (destructive and non destructive) and found no fault with the castings.
It is near impossible to break these cams with a rotational motion, the only way they could replicate the breakage was by side impact. The only side impact that happens in operation is from belt harmonics which can be caused by various things.
All I know is it took a lot of force for them to break that cam in testing, that amount of force is not normal in the engine.
Some possible causes may stem from;
Spring coil bind
Belt tension
Valve spring harmonics, (trying to run the stock spring at extended rpm and boost)
Not replacing the tensioner with a new unit when installing
Etc.
If you could give us more information on this particular incident we may be able to point you in the right direction.
a lot of people miss align the mivec cam gear and force the dowel into the cam and with the torque spec being so low in comparison to the exhaust it would probably not push the dowel all the way in causing miss alignment and additional stress on the cam
Greg
Apr 13, 2009, 12:54 PM
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You know, thats kind of interesting. I put in an order about two weeks ago with ETS and includsed in the order was a set of Kelford 272's for my 9. After I placed the ordr I came across this thread and of course got a little nervous.
ETS Michael told me last week when I called him that he called Kelford and spoke with them directly regarding the issue. He said that they have seen very minimal failures (<1%), which I believe, but he also said Kelford told him that many of these people weren't running an upgraded valvetrain. He said that Kelford told him that the Supertech dual springs were not even providing the right pressure (or dispersing the pressure evenly) and that they recommend Beehive Springs for the application. I just find this weird because you and I were told two different things regarding the spring set up with these cams. Also I find what I was told a little weird since Kelfords website recommends the use of Supertech products.
I wonder why you and I were told two different things? Maybe ETS can shed some light on this. I guess I need to email Kelford to clarify, because I'm not putting these in my motor unless I'm sure I'm running the valvetrain they recommend.
ETS Michael told me last week when I called him that he called Kelford and spoke with them directly regarding the issue. He said that they have seen very minimal failures (<1%), which I believe, but he also said Kelford told him that many of these people weren't running an upgraded valvetrain. He said that Kelford told him that the Supertech dual springs were not even providing the right pressure (or dispersing the pressure evenly) and that they recommend Beehive Springs for the application. I just find this weird because you and I were told two different things regarding the spring set up with these cams. Also I find what I was told a little weird since Kelfords website recommends the use of Supertech products.
I wonder why you and I were told two different things? Maybe ETS can shed some light on this. I guess I need to email Kelford to clarify, because I'm not putting these in my motor unless I'm sure I'm running the valvetrain they recommend.
Apr 13, 2009, 04:49 PM
#344
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. That's what has me doubting it's been shipped yet.