Cam Motion cams.....
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Joined: Jun 2011
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I disagree. The ls7 has a .590 lift cam. Call it .600 if you will. Those engines go 100k+ on stock springs. Only about 10% have valve drop issues. I could easily see Mikes car going 75k miles on these springs. Really doesn’t matter if they turn out to be weak springs after Tony tests them…Mike drives this car SUPER easy. we all drive around on used, weak, valve springs. Heck…my wife has put over 300K on her last 4 Alimas. No problems with valvesprings on any of them… Know what I mean?
As the for the valve springs measuring low not being an issue because of conservative driving; if the valve springs are weak it won't take high rpm to damage the cam at that point. Just rpms from normal acceleration will be enough to start damage which will propagate. It's absolutely relevant if the spings are weak regardless how he drives.
^^Right there. Said it better than I could, factory Cam is much more easier on the Valve Springs that are installed in OEM stuff. Aftermarket Cam with agressive Lobes will reduce Spring life, we've covered that already.
Excellent post and exactly what happened here.
I'll break down what it really is. This is a psychological problem some people have. It's a control issue. We all brough in VALID and RELEVANT facts to the situation here, this person doesn't like hearing something they may not know or was wrong, and they can't take the criticizm. Multiple parts to an Engine and we identified several possible problems, you know that whole coming together as a forum and helpful community thing that was brought up as to why it doesn't happen anymore. Well, when it happened it "wasn't about the Cam", "this is about Cam Motion Cams ONLY".
Yup, that's what's going on. So what's the point of making a thread when you can't handle the comments?
Question at this point is if someone can have some humility and come in with an open mind and embrace what we all are saying with some really good posts, but given what has happened already in this thread with the "it's my way or no way" attitude, nope that won't happen. That's the problem in all reality, some people's attitudes. I don't care what you've done in life and how long you've lived it, you don't have a good attitude then take it somewhere else.
I've said what I've said to the truthfullness of it enough. Now lets see if ALL the technical results of EVERYTHING comes in..
So, him not disclosing that his heads previously had valve guide issues and that he was running 95 thousandths lifter preload with johnson lifters were nonfactors and those of us asking about those details are bad people? LOL. Just trying to understand why asking details about the build and previous issues with the combination to help understand possible root causes makes us bad members here?
Odd that I was insulted for asking these questions like what was the lifter preload and how did you measure it? Those seem like legit questions to ask when there is a valve train failure no? When I ask those things I'm compared to a 5 year old because he doesn't want to be asked about details because it might be discovered that he had previous valve guide failure through no fault of his, but it did happen and might be discovered he was running lifter preload 50 thousandths beyond the upper spec limit of the lifters.
Instead of dismissing anyone who asked questions specific to the engine build and valve train setup and comparing them to 5 year olds he could have simply stated I did have a previous valve guide failure on my ls7 heads, but I don't believe that impacted the cam. Right or wrong that would be a better answer than attacking anyone who questioned him. When asked if lifter preload was checked and what preload was he running he could of simply stated how he checked and that when he switched from ls7 lifters to johnson lifters he had the lifters measured on precision equipment to make sure the same pushrod length would result in the same lifter preload for both lifters. This is probably satisfactory if you ignore the fact that ls7 lifters and johnson lifters require different preload. Instead he attacked anyone that questioned him.
The facts are he started multiple threads on the same topic which is a red flag in my opinion. Then would not answer questions about the build and attacked those that would question him. Some things were eventually answered and then showed some incorrect specs were used. The valve guide issue was never disclosed by the op and was only known because another member remembered that thread. Most of us know nothing about the op's engine combo so these types of questions seemed very reasonable to me, but we were attacked and compared to children for asking these types of questions. No one really said the op was at fault just asked questions about specifics of the build. After some of those facts did come out then that is when a few members started getting sarcastic. They got sarcastic because their questions were dismissed and they were compared to children how dare anyone ask the op any questions and when they did the OP immediately started making claims that his credentials were better than anyone else here how dare you question me...LOL.
Yep the rest of us caused this and the OP couldn't have done anything different to not send his multiple threads in an ugly direction...LOL
Odd that I was insulted for asking these questions like what was the lifter preload and how did you measure it? Those seem like legit questions to ask when there is a valve train failure no? When I ask those things I'm compared to a 5 year old because he doesn't want to be asked about details because it might be discovered that he had previous valve guide failure through no fault of his, but it did happen and might be discovered he was running lifter preload 50 thousandths beyond the upper spec limit of the lifters.
Instead of dismissing anyone who asked questions specific to the engine build and valve train setup and comparing them to 5 year olds he could have simply stated I did have a previous valve guide failure on my ls7 heads, but I don't believe that impacted the cam. Right or wrong that would be a better answer than attacking anyone who questioned him. When asked if lifter preload was checked and what preload was he running he could of simply stated how he checked and that when he switched from ls7 lifters to johnson lifters he had the lifters measured on precision equipment to make sure the same pushrod length would result in the same lifter preload for both lifters. This is probably satisfactory if you ignore the fact that ls7 lifters and johnson lifters require different preload. Instead he attacked anyone that questioned him.
The facts are he started multiple threads on the same topic which is a red flag in my opinion. Then would not answer questions about the build and attacked those that would question him. Some things were eventually answered and then showed some incorrect specs were used. The valve guide issue was never disclosed by the op and was only known because another member remembered that thread. Most of us know nothing about the op's engine combo so these types of questions seemed very reasonable to me, but we were attacked and compared to children for asking these types of questions. No one really said the op was at fault just asked questions about specifics of the build. After some of those facts did come out then that is when a few members started getting sarcastic. They got sarcastic because their questions were dismissed and they were compared to children how dare anyone ask the op any questions and when they did the OP immediately started making claims that his credentials were better than anyone else here how dare you question me...LOL.
Yep the rest of us caused this and the OP couldn't have done anything different to not send his multiple threads in an ugly direction...LOL
I'll break down what it really is. This is a psychological problem some people have. It's a control issue. We all brough in VALID and RELEVANT facts to the situation here, this person doesn't like hearing something they may not know or was wrong, and they can't take the criticizm. Multiple parts to an Engine and we identified several possible problems, you know that whole coming together as a forum and helpful community thing that was brought up as to why it doesn't happen anymore. Well, when it happened it "wasn't about the Cam", "this is about Cam Motion Cams ONLY".
Yup, that's what's going on. So what's the point of making a thread when you can't handle the comments?
Question at this point is if someone can have some humility and come in with an open mind and embrace what we all are saying with some really good posts, but given what has happened already in this thread with the "it's my way or no way" attitude, nope that won't happen. That's the problem in all reality, some people's attitudes. I don't care what you've done in life and how long you've lived it, you don't have a good attitude then take it somewhere else.
I've said what I've said to the truthfullness of it enough. Now lets see if ALL the technical results of EVERYTHING comes in..
Last edited by the_merv; Aug 17, 2024 at 11:03 AM.
So, him not disclosing that his heads previously had valve guide issues and that he was running 95 thousandths lifter preload with johnson lifters were nonfactors and those of us asking about those details are bad people? LOL. Just trying to understand why asking details about the build and previous issues with the combination to help understand possible root causes makes us bad members here?
Odd that I was insulted for asking these questions like what was the lifter preload and how did you measure it? Those seem like legit questions to ask when there is a valve train failure no? When I ask those things I'm compared to a 5 year old because he doesn't want to be asked about details because it might be discovered that he had previous valve guide failure through no fault of his, but it did happen and might be discovered he was running lifter preload 50 thousandths beyond the upper spec limit of the lifters.
Instead of dismissing anyone who asked questions specific to the engine build and valve train setup and comparing them to 5 year olds he could have simply stated I did have a previous valve guide failure on my ls7 heads, but I don't believe that impacted the cam. Right or wrong that would be a better answer than attacking anyone who questioned him. When asked if lifter preload was checked and what preload was he running he could of simply stated how he checked and that when he switched from ls7 lifters to johnson lifters he had the lifters measured on precision equipment to make sure the same pushrod length would result in the same lifter preload for both lifters. This is probably satisfactory if you ignore the fact that ls7 lifters and johnson lifters require different preload. Instead he attacked anyone that questioned him.
The facts are he started multiple threads on the same topic which is a red flag in my opinion. Then would not answer questions about the build and attacked those that would question him. Some things were eventually answered and then showed some incorrect specs were used. The valve guide issue was never disclosed by the op and was only known because another member remembered that thread. Most of us know nothing about the op's engine combo so these types of questions seemed very reasonable to me, but we were attacked and compared to children for asking these types of questions. No one really said the op was at fault just asked questions about specifics of the build. After some of those facts did come out then that is when a few members started getting sarcastic. They got sarcastic because their questions were dismissed and they were compared to children how dare anyone ask the op any questions and when they did the OP immediately started making claims that his credentials were better than anyone else here how dare you question me...LOL.
Yep the rest of us caused this and the OP couldn't have done anything different to not send his multiple threads in an ugly direction...LOL
Odd that I was insulted for asking these questions like what was the lifter preload and how did you measure it? Those seem like legit questions to ask when there is a valve train failure no? When I ask those things I'm compared to a 5 year old because he doesn't want to be asked about details because it might be discovered that he had previous valve guide failure through no fault of his, but it did happen and might be discovered he was running lifter preload 50 thousandths beyond the upper spec limit of the lifters.
Instead of dismissing anyone who asked questions specific to the engine build and valve train setup and comparing them to 5 year olds he could have simply stated I did have a previous valve guide failure on my ls7 heads, but I don't believe that impacted the cam. Right or wrong that would be a better answer than attacking anyone who questioned him. When asked if lifter preload was checked and what preload was he running he could of simply stated how he checked and that when he switched from ls7 lifters to johnson lifters he had the lifters measured on precision equipment to make sure the same pushrod length would result in the same lifter preload for both lifters. This is probably satisfactory if you ignore the fact that ls7 lifters and johnson lifters require different preload. Instead he attacked anyone that questioned him.
The facts are he started multiple threads on the same topic which is a red flag in my opinion. Then would not answer questions about the build and attacked those that would question him. Some things were eventually answered and then showed some incorrect specs were used. The valve guide issue was never disclosed by the op and was only known because another member remembered that thread. Most of us know nothing about the op's engine combo so these types of questions seemed very reasonable to me, but we were attacked and compared to children for asking these types of questions. No one really said the op was at fault just asked questions about specifics of the build. After some of those facts did come out then that is when a few members started getting sarcastic. They got sarcastic because their questions were dismissed and they were compared to children how dare anyone ask the op any questions and when they did the OP immediately started making claims that his credentials were better than anyone else here how dare you question me...LOL.
Yep the rest of us caused this and the OP couldn't have done anything different to not send his multiple threads in an ugly direction...LOL
Nobody is saying your bad people…lol.
I must have missed the part of you being insulted?
Mike had a previous thread regarding the bad guides. This is a different topic/thread about CamMotion cams. No relation there at all.
Mike did put the same thread on both areas of Internal Engine because this is a gen4 engine in a Gen3 car, and he wasn’t sure where to put it. That’s my fault actually. I should have deleted this thread in Gen3. Sorry about that one guys…
Thread Starter
Joined: Sep 2004
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Likes: 1,610
From: Michigan & Florida
So, him not disclosing that his heads previously had valve guide issues and that he was running 95 thousandths lifter preload with johnson lifters were nonfactors and those of us asking about those details are bad people? LOL. Just trying to understand why asking details about the build and previous issues with the combination to help understand possible root causes makes us bad members here?
Odd that I was insulted for asking these questions like what was the lifter preload and how did you measure it? Those seem like legit questions to ask when there is a valve train failure no? When I ask those things I'm compared to a 5 year old because he doesn't want to be asked about details because it might be discovered that he had previous valve guide failure through no fault of his, but it did happen and might be discovered he was running lifter preload 50 thousandths beyond the upper spec limit of the lifters.
Instead of dismissing anyone who asked questions specific to the engine build and valve train setup and comparing them to 5 year olds he could have simply stated I did have a previous valve guide failure on my ls7 heads, but I don't believe that impacted the cam. Right or wrong that would be a better answer than attacking anyone who questioned him. When asked if lifter preload was checked and what preload was he running he could of simply stated how he checked and that when he switched from ls7 lifters to johnson lifters he had the lifters measured on precision equipment to make sure the same pushrod length would result in the same lifter preload for both lifters. This is probably satisfactory if you ignore the fact that ls7 lifters and johnson lifters require different preload. Instead he attacked anyone that questioned him.
The facts are he started multiple threads on the same topic which is a red flag in my opinion. Then would not answer questions about the build and attacked those that would question him. Some things were eventually answered and then showed some incorrect specs were used. The valve guide issue was never disclosed by the op and was only known because another member remembered that thread. Most of us know nothing about the op's engine combo so these types of questions seemed very reasonable to me, but we were attacked and compared to children for asking these types of questions. No one really said the op was at fault just asked questions about specifics of the build. After some of those facts did come out then that is when a few members started getting sarcastic. They got sarcastic because their questions were dismissed and they were compared to children how dare anyone ask the op any questions and when they did the OP immediately started making claims that his credentials were better than anyone else here how dare you question me...LOL.
Yep the rest of us caused this and the OP couldn't have done anything different to not send his multiple threads in an ugly direction...LOL
Odd that I was insulted for asking these questions like what was the lifter preload and how did you measure it? Those seem like legit questions to ask when there is a valve train failure no? When I ask those things I'm compared to a 5 year old because he doesn't want to be asked about details because it might be discovered that he had previous valve guide failure through no fault of his, but it did happen and might be discovered he was running lifter preload 50 thousandths beyond the upper spec limit of the lifters.
Instead of dismissing anyone who asked questions specific to the engine build and valve train setup and comparing them to 5 year olds he could have simply stated I did have a previous valve guide failure on my ls7 heads, but I don't believe that impacted the cam. Right or wrong that would be a better answer than attacking anyone who questioned him. When asked if lifter preload was checked and what preload was he running he could of simply stated how he checked and that when he switched from ls7 lifters to johnson lifters he had the lifters measured on precision equipment to make sure the same pushrod length would result in the same lifter preload for both lifters. This is probably satisfactory if you ignore the fact that ls7 lifters and johnson lifters require different preload. Instead he attacked anyone that questioned him.
The facts are he started multiple threads on the same topic which is a red flag in my opinion. Then would not answer questions about the build and attacked those that would question him. Some things were eventually answered and then showed some incorrect specs were used. The valve guide issue was never disclosed by the op and was only known because another member remembered that thread. Most of us know nothing about the op's engine combo so these types of questions seemed very reasonable to me, but we were attacked and compared to children for asking these types of questions. No one really said the op was at fault just asked questions about specifics of the build. After some of those facts did come out then that is when a few members started getting sarcastic. They got sarcastic because their questions were dismissed and they were compared to children how dare anyone ask the op any questions and when they did the OP immediately started making claims that his credentials were better than anyone else here how dare you question me...LOL.
Yep the rest of us caused this and the OP couldn't have done anything different to not send his multiple threads in an ugly direction...LOL
It's not equivalent to use a factory LS7 cam or Altima camshafts as a comparison for spring vs. camshaft lift longevity.. OEMs design their camshafts extremely conservative because they are expected to pass durability testing the equivalent well over 100k miles. The ramps and nose are very gentle so they can run them for thousands of hours in rpm sweeps as part of their verification. And that's just 1 of 100s of tests they're expected to live through in the vehicle, as an engine assembly, or on a bench, in order to simulate exposure. To state it plainly, they abuse the heck out of those cars and engines both in function and durability testing before they're deem them fit for sale. Heck, in my early days I've pulled load dynos behind vehicles in the desert sun purposely holding a lower gear @ 60mph (keeping it 4500-5000rpm) for several laps; just to heat soak the engine as much as possible before doing a restart and driveway test. And that's just a function test, not even durability). And the same vehicles then went on to be used for tons of other testing. Rental cars lead a cushy life in comparison.
As the for the valve springs measuring low not being an issue because of conservative driving; if the valve springs are weak it won't take high rpm to damage the cam at that point. Just rpms from normal acceleration will be enough to start damage which will propagate. It's absolutely relevant if the spings are weak regardless how he drives.
As the for the valve springs measuring low not being an issue because of conservative driving; if the valve springs are weak it won't take high rpm to damage the cam at that point. Just rpms from normal acceleration will be enough to start damage which will propagate. It's absolutely relevant if the spings are weak regardless how he drives.
Thread Starter
Joined: Sep 2004
Posts: 3,207
Likes: 1,610
From: Michigan & Florida
^^Right there. Said it better than I could, factory Cam is much more easier on the Valve Springs that are installed in OEM stuff. Aftermarket Cam with agressive Lobes will reduce Spring life, we've covered that already.
Excellent post and exactly what happened here.
I'll break down what it really is. This is a psychological problem some people have. It's a control issue. We all brough in VALID and RELEVANT facts to the situation here, this person doesn't like hearing something they may not know or was wrong, and they can't take the criticizm. Multiple parts to an Engine and we identified several possible problems, you know that whole coming together as a forum and helpful community thing that was brought up as to why it doesn't happen anymore. Well, when it happened it "wasn't about the Cam", "this is about Cam Motion Cams ONLY".
Yup, that's what's going on. So what's the point of making a thread when you can't handle the comments?
Question at this point is if someone can have some humility and come in with an open mind and embrace what we all are saying with some really good posts, but given what has happened already in this thread with the "it's my way or no way" attitude, nope that won't happen. That's the problem in all reality, some people's attitudes. I don't care what you've done in life and how long you've lived it, you don't have a good attitude then take it somewhere else.
I've said what I've said to the truthfullness of it enough. Now lets see if ALL the technical results of EVERYTHING comes in..
Excellent post and exactly what happened here.
I'll break down what it really is. This is a psychological problem some people have. It's a control issue. We all brough in VALID and RELEVANT facts to the situation here, this person doesn't like hearing something they may not know or was wrong, and they can't take the criticizm. Multiple parts to an Engine and we identified several possible problems, you know that whole coming together as a forum and helpful community thing that was brought up as to why it doesn't happen anymore. Well, when it happened it "wasn't about the Cam", "this is about Cam Motion Cams ONLY".
Yup, that's what's going on. So what's the point of making a thread when you can't handle the comments?
Question at this point is if someone can have some humility and come in with an open mind and embrace what we all are saying with some really good posts, but given what has happened already in this thread with the "it's my way or no way" attitude, nope that won't happen. That's the problem in all reality, some people's attitudes. I don't care what you've done in life and how long you've lived it, you don't have a good attitude then take it somewhere else.
I've said what I've said to the truthfullness of it enough. Now lets see if ALL the technical results of EVERYTHING comes in..
Results are coming in already. We already know the cam had hardness issues. Now waiting for spring numbers.
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Completely aware of this sir. The point I was attempting to make here was that this is an extremely mild camshaft with appropriate springs, set up to go many years of driving by a very competent shop. Mike drives his stuff easy and only occasionally revs it high. I’m sure the springs in all of my wife’s cars were very worn, and I was simply using it as a comparison. We don’t even know how the springs will figure into this until Tony posts his findings. They might be toast, and that’s the problem here. It is very suspect to me that the bad lobe tested softer than the rest however. Coincidence? I doubt it. We shall soon see.
Mechanical destruction of the metal surface will get rid of the hardening. Induction hardening is deeper than Nitride hardening. One would have to talk to them to see what process they use.
You get a wore out Valve Spring that gives the Lifter room to bounce, there starts your mechanical destruction. Speaking hypothetically, of course..
You get a wore out Valve Spring that gives the Lifter room to bounce, there starts your mechanical destruction. Speaking hypothetically, of course..
Thread Starter
Joined: Sep 2004
Posts: 3,207
Likes: 1,610
From: Michigan & Florida
I have stated there was virtually no wear on the base circles. In fact, they all measured the same distance from the bearing as the brand new cam I got from Tony, within .0005". As for the lobe wear, it is approximately. 005" deep. One thing I've learned in spending most of my 44 years in the shops is .005" wear looks terrible, but it doesn't take much to clean up a cylinder, etc. Also, slightly off topic, I know there are guys here that are more familiar with Johnson lifters than I am. Today I checked the difference in PR cup heights between the Johnson 2110Rs and the LS7 lifters. I called Johnson yesterday, and IIRC, they told me the Johnsons were. 056" shorter. When measuring over a 5/16 ball today, the lifters in a V-block, my indicator showed a .040" difference. Anyone want to chime in their experiences?....
Last edited by grinder11; Aug 17, 2024 at 06:06 PM.
Thread Starter
Joined: Sep 2004
Posts: 3,207
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From: Michigan & Florida
^^Right there. Said it better than I could, factory Cam is much more easier on the Valve Springs that are installed in OEM stuff. Aftermarket Cam with agressive Lobes will reduce Spring life, we've covered that already.
Excellent post and exactly what happened here.
I'll break down what it really is. This is a psychological problem some people have. It's a control issue. We all brough in VALID and RELEVANT facts to the situation here, this person doesn't like hearing something they may not know or was wrong, and they can't take the criticizm. Multiple parts to an Engine and we identified several possible problems, you know that whole coming together as a forum and helpful community thing that was brought up as to why it doesn't happen anymore. Well, when it happened it "wasn't about the Cam", "this is about Cam Motion Cams ONLY".
Yup, that's what's going on. So what's the point of making a thread when you can't handle the comments?
Question at this point is if someone can have some humility and come in with an open mind and embrace what we all are saying with some really good posts, but given what has happened already in this thread with the "it's my way or no way" attitude, nope that won't happen. That's the problem in all reality, some people's attitudes. I don't care what you've done in life and how long you've lived it, you don't have a good attitude then take it somewhere else.
I've said what I've said to the truthfullness of it enough. Now lets see if ALL the technical results of EVERYTHING comes in..
Excellent post and exactly what happened here.
I'll break down what it really is. This is a psychological problem some people have. It's a control issue. We all brough in VALID and RELEVANT facts to the situation here, this person doesn't like hearing something they may not know or was wrong, and they can't take the criticizm. Multiple parts to an Engine and we identified several possible problems, you know that whole coming together as a forum and helpful community thing that was brought up as to why it doesn't happen anymore. Well, when it happened it "wasn't about the Cam", "this is about Cam Motion Cams ONLY".
Yup, that's what's going on. So what's the point of making a thread when you can't handle the comments?
Question at this point is if someone can have some humility and come in with an open mind and embrace what we all are saying with some really good posts, but given what has happened already in this thread with the "it's my way or no way" attitude, nope that won't happen. That's the problem in all reality, some people's attitudes. I don't care what you've done in life and how long you've lived it, you don't have a good attitude then take it somewhere else.
I've said what I've said to the truthfullness of it enough. Now lets see if ALL the technical results of EVERYTHING comes in..
Thread Starter
Joined: Sep 2004
Posts: 3,207
Likes: 1,610
From: Michigan & Florida
Update...... Tony has received, and tested my springs. ALL 16 came in within spec at my installed height of 1.760. Hats off to PAC for making a quality spring that went 50,000 miles and was still within spec. I have a NIB set of the 1905s for sale, if anyone is interested. The weakest one came in at 164lbs on the seat, and exceeded the 420lb rating at .600" lift. Still can't say with 100% certainty it was the lobe, but this is another arrow pointing in that direction........
Hey grinder - what alloy did you select from cam motion? A good heat treater can get 8620 up to about a 62HRC with oil quenching. With water quenching, you might only get 8620 into the high 40's HRC. 5150 can get to about a 55 with oil quenching, due to the lower (read "unspecified") moly and nickel contents. Since moly and nickel are not specified, nobody would add them. it's expensive. I'm wondering if you got 5150?
There is an argument for using 5150 because sometimes the case will be a bit thicker due to the higher carbon content, shifting the transition temperature down a smidge, but the higher surface hardness would be king in my opinion. But honestly, if I wanted the thicker case, i'd go to 8660 instead of 8620, and then i'd get in the 60's HRC AND a thick case. I don't know the lifter specs off the top of my head, but if you tested the lifter wheels and they are harder than the lobes, you definitely could be on to something.
Someone mentioned nitriding earlier in the thread, and I'm pretty sure the cams are not nitrided. it's generally not needed.
i will say some of the pitting does look like it got beat up. but also, the springs were weaker, not stronger. Typically when I see the lobes get pounded (not the base circles), it's from pole-vaulting, which requires strong springs and small pushrods. usually weak springs cause the valves to bounce off the seats. At least that's my limited experience. but even that said, I tend to see the pole vaulting damage always on the "trailing" side of the lobe, not the lifting side.
As to some earlier comments regarding life expectancy - cam motion hydraulic cams tend to run 53 degree ramp rates. Comp XER are 49 degree. the XER tend to be harder on the system.
All that said, I'm a big cam motion fan, but I also understand the feeling of being 'burned', and so if you have lost faith and feel better with a different company, it makes sense. I definitely feel your pain in the sense that the fluids and gaskets cost as much as the cam. if you're working with Tony, you will likely already be going down this route, but I suggest to run as massive a pushrod as you can (OD > wall thickness for overall stiffness), thus avoiding all the issues entirely and ensuring the spring gives long before the rod flexes.
Still - to your earlier point - the lifter wheels should give out before the cam
There is an argument for using 5150 because sometimes the case will be a bit thicker due to the higher carbon content, shifting the transition temperature down a smidge, but the higher surface hardness would be king in my opinion. But honestly, if I wanted the thicker case, i'd go to 8660 instead of 8620, and then i'd get in the 60's HRC AND a thick case. I don't know the lifter specs off the top of my head, but if you tested the lifter wheels and they are harder than the lobes, you definitely could be on to something.
Someone mentioned nitriding earlier in the thread, and I'm pretty sure the cams are not nitrided. it's generally not needed.
i will say some of the pitting does look like it got beat up. but also, the springs were weaker, not stronger. Typically when I see the lobes get pounded (not the base circles), it's from pole-vaulting, which requires strong springs and small pushrods. usually weak springs cause the valves to bounce off the seats. At least that's my limited experience. but even that said, I tend to see the pole vaulting damage always on the "trailing" side of the lobe, not the lifting side.
As to some earlier comments regarding life expectancy - cam motion hydraulic cams tend to run 53 degree ramp rates. Comp XER are 49 degree. the XER tend to be harder on the system.
All that said, I'm a big cam motion fan, but I also understand the feeling of being 'burned', and so if you have lost faith and feel better with a different company, it makes sense. I definitely feel your pain in the sense that the fluids and gaskets cost as much as the cam. if you're working with Tony, you will likely already be going down this route, but I suggest to run as massive a pushrod as you can (OD > wall thickness for overall stiffness), thus avoiding all the issues entirely and ensuring the spring gives long before the rod flexes.
Still - to your earlier point - the lifter wheels should give out before the cam
The problem with Nitrating or any any type of hardening process AFTER the grinding is done is that it can warp the cam and it will no longer be straight. You also have to go back over every lobe and journal to refinish the surface.
Thread Starter
Joined: Sep 2004
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From: Michigan & Florida
Darth, thanks for chiming in. If I had to guess, I agree it is probably 5150. I don't know what the cam core is for sure because it was called in to Allan Futral, who had CM grind it to his specs; .603" lift I., .608" E., 112° LSA, 232° duration intake, 250° duration exhaust. I have the cam info sheet, I'll see if it specifies material. I've always liked CM cams, too. After all, I did buy 2 of them. Since the cam heels showed no wear, and all 16 measured in at 56-58 RC, EXCEPT the really bad lobe, which measured only 30-32 RC, I believe that cam lobe is not hard enough. This is in an LS7, with 3/8" Trend PRs, .080" wall. Yes, the PRs could be heavier wall. But if that's the case why aren't all the lobes totally trashed, since the springs checked fine?
@grinder11 forgot to say thanks for having the springs tested and posting the results. Also thanks for keeping us updated.
With your testing, I think at this point, it may have been just that lobe that didn't get heat treated properly.
I would like to point out for the record that is not something Cam Motion has control over. The heat treating is done by the company they buy the core blanks from.
I know your not putting them down. You are just trying to collect information and figure out what happened. Just point that out for any outsider that may be reading this thread whom may not know or understand that fact.
With your testing, I think at this point, it may have been just that lobe that didn't get heat treated properly.
I would like to point out for the record that is not something Cam Motion has control over. The heat treating is done by the company they buy the core blanks from.
I know your not putting them down. You are just trying to collect information and figure out what happened. Just point that out for any outsider that may be reading this thread whom may not know or understand that fact.
Thread Starter
Joined: Sep 2004
Posts: 3,207
Likes: 1,610
From: Michigan & Florida
Also, I did check the lobes with a 1"-2" outside micrometer. The wear measured between .005"-.007" deep. Hard to get an exact reading due to the lobes being asymmetrical, I believe. I am confident in all my measurements, however. I guess we can't say with 100% certainty that the lobe failed/was too soft. But there are a few arrows pointing that way. As everyone here knows, anyone can make a bad cam. I will also say with a lot of confidence that this problem happened in the last 3,000-4,000 miles. Because I have a powerful rare earth magnetic drain plug. Nothing much on it before. This time when I drained the oil, the plug was full of metallic powder at least 5/16 long!!!
Thread Starter
Joined: Sep 2004
Posts: 3,207
Likes: 1,610
From: Michigan & Florida
You guys are very welcome. Tony deserves a huge shout out, too. I spent $20 sending him the springs, but he took his valuable time checking all 16. He also checked at both the recommended 1.800 installed height, and the installed height I set up, which was 1.750"-1.760". Time consuming. He said at 1.800 the weakest one was 149lbs. At my installed height, the weakest came in at 164lbs. seat, 420+lbs over the nose. Amazing the springs lasted 50,000+ miles!! I know I sure got hung out to dry by some guys here. All I asked for was some CM cam guys to post up!! I've been called bored to having psychological issues, ferchrissakes!! My lifter preload was around .090", set up by a pro shop. In post 14 here , I clearly stated I ran LS7 lifters. One guy here kept insisting I was running Johnson lifters! Most of those guys have strangely disappeared. I took a lot of my time doing the hardness testing, sending the springs to Tony, etc. Hell, I had to dig those springs out of my garage garbage can, and clean them up. Not much incentive to try and contribute factual info, I must say. 1FastBrick, thank you for being appreciative of what Tony and I did....
Last edited by grinder11; Aug 19, 2024 at 05:03 PM.
The Cores are heat treated in batches Prior to grinding. I am sure you already know that.
The problem with Nitrating or any any type of hardening process AFTER the grinding is done is that it can warp the cam and it will no longer be straight. You also have to go back over every lobe and journal to refinish the surface.
The problem with Nitrating or any any type of hardening process AFTER the grinding is done is that it can warp the cam and it will no longer be straight. You also have to go back over every lobe and journal to refinish the surface.