High lift camshafts link bar lifter failure
06-26-2011, 12:20 PM
#1
Melting Slicks
Thread Starter
High lift camshafts link bar lifter failure
After 10K miles and approx. 10 hrs of road course use during those miles, my LS7 developed some upper end valve train noise.
I First suspected the CHE rockers as it sounded just like when my Harland Sharp V.1 rockers ( the ones with the bad bearings that were replaced under warranty by them). Ed Doyle @ CHE took VERY good care of me and checked them out after I overnightd them to him. Even though they had MINIMAL wear, he completely rebuilt them and sent them back to me. 1st class customer service all the way!
Because of time restaints, I had to install another set of rockers, so the CHE's are for sale.
After getting that report back, I decided to pull the heads to inspect the lower valve train. What I found was EXCESSIVE wear on the rollers of my Morrel Link Bar lifters ( standard not high RPM)
AND my Comp Cams ground LPE GT-19 camshaft. 227/239 .678/.688 114 LSA. This wear was VERY uneven from intake lobes to exhaust lobes to each individual lifter wheel.
Top end of the motor has very sound components
-LPE heads with Ferrea springs, ti retainers
-Stock Ti intake valves ( PVD coated for durability)
-Delwest custom Ti exhaust vales ( PVD coated for surability)
-Comp Pro Magnum 3/8" pushrods
-Morrel Link Bar lifters
To be truthfull, I loved the GT-19 camshaft. Between the motor build and tuning, the thing almost drove like stock and put down 571/532.
Initially, the springs were suspect, so we tested them while the heads were off (along with the guides and installing new seals). Springs were only down 5% from new when tested cold.
Possible reasons for the carnage...
1) too high of lift used in road race conditions
2) bad core ( low grade material/metalurgy)
3) bad metalurgy/hardening from morrel
4) valve float ( put springs still tested well)
5) lifter rotation in the bore. even though there can be no lateral movement in teh lifter bores, these lifter still have play in the link bar set-up that allows +/- 5 degrees of rotation
6) oil (uneven wear does not support this, nor does the great condition of the camshaft journals and bearings)
I suspected #1, so I inquired with several corvette racers/shops that road race on what they have used successfuly in LS7 applications. Special thanks to Randy at DRM and John at 21st century for all the help. MTI never returned a call when they said they would, even on in stock parts.
Timing played a key role in which cam I went with and ultimately John had one on the shelf that looked the most promissing. He second day'd it out to me and I went with Lunatis Link bar lifters but with the high RPM version because of the wider roller wheel and advertised high RPM abilities.
-LPE claims no failures with GT-19 packages
-Comp says the core was not identified as a bad core in their system
-Morrel was too busy to be bothered and has a set sent in from HKE over 12 months agao with no report back,
Although there is no definate conclusion to this, I'm hoping an advertised higher quality lifter and a lower lift camshaft that has been proven with over 30 hrs of track use in another LS7 keeps this motor running strong for longer than 10K miles
Those with more knowledge than me can look at the pics and decide for yourself..
As a side note, the car ran great yesterday at HP for (4) 30 minute sessions in 90 degree heat. passed everything but the gas pump.
I First suspected the CHE rockers as it sounded just like when my Harland Sharp V.1 rockers ( the ones with the bad bearings that were replaced under warranty by them). Ed Doyle @ CHE took VERY good care of me and checked them out after I overnightd them to him. Even though they had MINIMAL wear, he completely rebuilt them and sent them back to me. 1st class customer service all the way!
Because of time restaints, I had to install another set of rockers, so the CHE's are for sale.
After getting that report back, I decided to pull the heads to inspect the lower valve train. What I found was EXCESSIVE wear on the rollers of my Morrel Link Bar lifters ( standard not high RPM)
AND my Comp Cams ground LPE GT-19 camshaft. 227/239 .678/.688 114 LSA. This wear was VERY uneven from intake lobes to exhaust lobes to each individual lifter wheel.
Top end of the motor has very sound components
-LPE heads with Ferrea springs, ti retainers
-Stock Ti intake valves ( PVD coated for durability)
-Delwest custom Ti exhaust vales ( PVD coated for surability)
-Comp Pro Magnum 3/8" pushrods
-Morrel Link Bar lifters
To be truthfull, I loved the GT-19 camshaft. Between the motor build and tuning, the thing almost drove like stock and put down 571/532.
Initially, the springs were suspect, so we tested them while the heads were off (along with the guides and installing new seals). Springs were only down 5% from new when tested cold.
Possible reasons for the carnage...
1) too high of lift used in road race conditions
2) bad core ( low grade material/metalurgy)
3) bad metalurgy/hardening from morrel
4) valve float ( put springs still tested well)
5) lifter rotation in the bore. even though there can be no lateral movement in teh lifter bores, these lifter still have play in the link bar set-up that allows +/- 5 degrees of rotation
6) oil (uneven wear does not support this, nor does the great condition of the camshaft journals and bearings)
I suspected #1, so I inquired with several corvette racers/shops that road race on what they have used successfuly in LS7 applications. Special thanks to Randy at DRM and John at 21st century for all the help. MTI never returned a call when they said they would, even on in stock parts.
Timing played a key role in which cam I went with and ultimately John had one on the shelf that looked the most promissing. He second day'd it out to me and I went with Lunatis Link bar lifters but with the high RPM version because of the wider roller wheel and advertised high RPM abilities.
-LPE claims no failures with GT-19 packages
-Comp says the core was not identified as a bad core in their system
-Morrel was too busy to be bothered and has a set sent in from HKE over 12 months agao with no report back,
Although there is no definate conclusion to this, I'm hoping an advertised higher quality lifter and a lower lift camshaft that has been proven with over 30 hrs of track use in another LS7 keeps this motor running strong for longer than 10K miles
Those with more knowledge than me can look at the pics and decide for yourself..
As a side note, the car ran great yesterday at HP for (4) 30 minute sessions in 90 degree heat. passed everything but the gas pump.
Last edited by bowtiguy; 12-31-2011 at 10:41 AM.
06-26-2011, 12:23 PM
#2
Melting Slicks
Thread Starter
and the morrel link bar lifters
Edit: duplicate information.
Last edited by bowtiguy; 12-31-2011 at 10:43 AM. Reason: duplicate info.
06-26-2011, 01:53 PM
#3
I have exactly the sames pics...valve-train instability in my case...solved by matching the correct peripherals.
Did I mention the amount spent twice (at least) for a wrong first OK to go?
Christian
Did I mention the amount spent twice (at least) for a wrong first OK to go?
Christian
06-27-2011, 09:02 AM
#4
Melting Slicks
Thread Starter
Thank God the lift on the cam gets SMALLER when the valve train beats it self up so no other problems.
I guess keeping a good ear what the car sounds like helps too. I have enough miles both on an off track now to know how the car "should" be running at any point and time.
And I almost signed up for the Good Guys auto-x the same day I found the drive train noise.
I guess keeping a good ear what the car sounds like helps too. I have enough miles both on an off track now to know how the car "should" be running at any point and time.
And I almost signed up for the Good Guys auto-x the same day I found the drive train noise.
06-27-2011, 09:35 AM
#5
Safety Car
Can you please detail the symptoms that made you look into the problem to begin with?
I have the same lifters in my new motor. I also have a bit more cam than you as well.
On startup, my car has a top end tick until the oil reaches about 100 degrees. Sometimes, the tick doesn't go away at all, unless I shut down and restart no matter what the oil temp is. We have been blaming an air pocket for the noise, and I have been told this is normal.
Tony
I have the same lifters in my new motor. I also have a bit more cam than you as well.
On startup, my car has a top end tick until the oil reaches about 100 degrees. Sometimes, the tick doesn't go away at all, unless I shut down and restart no matter what the oil temp is. We have been blaming an air pocket for the noise, and I have been told this is normal.
Tony
Last edited by KLLRVET; 06-27-2011 at 11:25 AM.
06-29-2011, 02:51 PM
#6
Melting Slicks
Thread Starter
Can you please detail the symptoms that made you look into the problem to begin with?
I have the same lifters in my new motor. I also have a bit more cam than you as well.
On startup, my car has a top end tick until the oil reaches about 100 degrees. Sometimes, the tick doesn't go away at all, unless I shut down and restart no matter what the oil temp is. We have been blaming an air pocket for the noise, and I have been told this is normal.
Tony
I have the same lifters in my new motor. I also have a bit more cam than you as well.
On startup, my car has a top end tick until the oil reaches about 100 degrees. Sometimes, the tick doesn't go away at all, unless I shut down and restart no matter what the oil temp is. We have been blaming an air pocket for the noise, and I have been told this is normal.
Tony
It happened whether the oil is warm or cold. More noticeable at idle up to about 2K rpm. I could hear it from inside the car with the windows up.
when my harland sharp V.1 rocker bearings went bad, it was more like a squeek.
BTW, air pockets don't "tick" I had a darton liner drop in my first 454 cu in LS7 and the heater box sounded like an aquarium when I turned off the car. #4 liner dropped a thou and compression gas's were making it into the coolant passages.
I hope that helps.
Last edited by bowtiguy; 12-31-2011 at 10:45 AM. Reason: spealing...;-)
06-29-2011, 04:04 PM
#7
Safety Car
I meant an air picket in the lifter, not something like a dropped sleeve.
I'm scared to say,
is what I have heard.... I'll cut open my oil filter when I change the oil this weekend 
I'm scared to say,
It happened whether the oil is warm or cold. More noticeable at idle up to about 2K rpm. I could hear it from inside the car with the windows up.
If I got down on the ground I could hear it from under the car too, almost like it was coming through the block.
If I got down on the ground I could hear it from under the car too, almost like it was coming through the block.
06-29-2011, 06:25 PM
#8
Le Mans Master
I just went thru the same issue with an OEM lifter going bad and taking out a cam lobe (only .581 lift). I've come to the conclusion that there is no really good soln to this as it appears even a $500 set of linked-lifters are prone to the same results. 
I'm questioning if the lifters are oil starved with a stock block; oil passages not designed to entirely reach lifters when increaing cam lift because the lifter is further up into the lifter bore? Sustained high RPM's (road course) would quicken the failure.
My gut feeling is many of those with aftermarket cams will evetually start seeing lifter failure once they log enough miles/hours. Time will tell.
I'm questioning if the lifters are oil starved with a stock block; oil passages not designed to entirely reach lifters when increaing cam lift because the lifter is further up into the lifter bore? Sustained high RPM's (road course) would quicken the failure.
My gut feeling is many of those with aftermarket cams will evetually start seeing lifter failure once they log enough miles/hours. Time will tell.
06-29-2011, 06:36 PM
#9
Safety Car
I would say bad cam or bad lifters or combo of both.But of coarse nobody will replace either piece.But they will sell you another one? I bet the cam is suspect which then tore up the lifters. At least your back to tearing up the road coarse again.
06-30-2011, 09:43 AM
#11
Le Mans Master
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I would take both peices and have them tested to see if the hardness rating is the same between the two. If one is exceptionally harder than the other its going to tear up the other if lubrication is lack luster. I am sure that there are some metallurgy or bearing analysis websites somewhere where you can post these pictures to get an experts opinion on what happened.
I have seen bearing failures like this in paper mills in large load bearing roller bearings. In talking with the bearing representatives I recall him using terms like flaking and spalling. The pictures you displayed looks very much like the failures I saw on the bearings. The lifters rolling over the tops of the cam lobes have similar actions of a bearing other than varying loads as it goes up and down on the lobe profile.
I have seen bearing failures like this in paper mills in large load bearing roller bearings. In talking with the bearing representatives I recall him using terms like flaking and spalling. The pictures you displayed looks very much like the failures I saw on the bearings. The lifters rolling over the tops of the cam lobes have similar actions of a bearing other than varying loads as it goes up and down on the lobe profile.
Last edited by tjwong; 06-30-2011 at 09:47 AM.
07-01-2011, 02:29 PM
#12
Melting Slicks
We see this same problem in Big Block Chevy race motors. Your lifters were worn out. If you grab the roller will find up/down play in it as well as slight hard points when you roll it carefully. The lifters then galled the cam lobes as they skipped across the surface.
Now the big question is why were the lifters worn out at 10K miles. It most likely was poor quality needle bearings but could also be not enough spring pressure and thus hammering the lifter during valve float. I see Isky is now selling roller lifters with bushings vs needle bearings to eliminate the problem. Some of the other manufacturers are now selling larger diameter lifters with larger roller wheels and thus larger bearings. This is a good alternative, but requires bushing the block lifter bores using a BHJ fixture.
Best of luck!
Now the big question is why were the lifters worn out at 10K miles. It most likely was poor quality needle bearings but could also be not enough spring pressure and thus hammering the lifter during valve float. I see Isky is now selling roller lifters with bushings vs needle bearings to eliminate the problem. Some of the other manufacturers are now selling larger diameter lifters with larger roller wheels and thus larger bearings. This is a good alternative, but requires bushing the block lifter bores using a BHJ fixture.
Best of luck!
07-01-2011, 02:31 PM
#13
Melting Slicks
Thread Starter
NO sh*t. neither MFG gave a flying fling. Not that I was looking for free replacements. I just didn't want the same results next go around.
I would take both peices and have them tested to see if the hardness rating is the same between the two. If one is exceptionally harder than the other its going to tear up the other if lubrication is lack luster. I am sure that there are some metallurgy or bearing analysis websites somewhere where you can post these pictures to get an experts opinion on what happened.
I have seen bearing failures like this in paper mills in large load bearing roller bearings. In talking with the bearing representatives I recall him using terms like flaking and spalling. The pictures you displayed looks very much like the failures I saw on the bearings. The lifters rolling over the tops of the cam lobes have similar actions of a bearing other than varying loads as it goes up and down on the lobe profile.
I have seen bearing failures like this in paper mills in large load bearing roller bearings. In talking with the bearing representatives I recall him using terms like flaking and spalling. The pictures you displayed looks very much like the failures I saw on the bearings. The lifters rolling over the tops of the cam lobes have similar actions of a bearing other than varying loads as it goes up and down on the lobe profile.
Last edited by bowtiguy; 12-31-2011 at 10:46 AM. Reason: I need to proof read more.
07-02-2011, 10:18 AM
#15
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I agree with Vito.......not enough spring pressure to prevent valve float. All it takes is the start of a minute flat spot on a roller - and it's on it way to becoming a flat tappet.....
07-02-2011, 12:22 PM
#17
Melting Slicks
Thread Starter
If thats true, then LPE needs to go back to the drawing board on their "630 hp" package using the GT-19 camshaft and Ferrea spring pack.
Advertised specs are 410# open/ 130# closed. When we tested the "used" springs. they lost less than 10#'s open. closed were still right on the money.
Hopefully my "under .650 lift" cam selection will prove more reliable.
07-13-2011, 04:37 PM
#18
Burning Brakes
I'm sorry to read about your misfortune Bowtie. I agree with Christian, that looks like valve train instability rather than a defective part/metalurgy.
Also for anyone reading the thread who may not know, Lunati, Isky etc lifters are all made by Morel and rebadged under their brand name. No one makes better hydraulic rollers than Morel. It doesn't mean they never have a defect, but I doubt this is one of them in this case.
Curious, did you buy the 5294 equivalent, or the 5850 (both High rpm Morels/Lunatis/Isky, etc)?
Also, the lift on that Lingenfelter cam is borderline too high for stock ls7 rockers (whether they have been bushed or not).
Keeping it under .650 for road racing is a step in the right direction all around.
Who installed and setup your valve train (the first time)? Was it Lingenfelter?
Also for anyone reading the thread who may not know, Lunati, Isky etc lifters are all made by Morel and rebadged under their brand name. No one makes better hydraulic rollers than Morel. It doesn't mean they never have a defect, but I doubt this is one of them in this case.
Curious, did you buy the 5294 equivalent, or the 5850 (both High rpm Morels/Lunatis/Isky, etc)?
Also, the lift on that Lingenfelter cam is borderline too high for stock ls7 rockers (whether they have been bushed or not).
Keeping it under .650 for road racing is a step in the right direction all around.
Who installed and setup your valve train (the first time)? Was it Lingenfelter?
07-13-2011, 05:04 PM
#19
Melting Slicks
Thread Starter
I'm sorry to read about your misfortune Bowtie. I agree with Christian, that looks like valve train instability rather than a defective part/metalurgy.
Also for anyone reading the thread who may not know, Lunati, Isky etc lifters are all made by Morel and rebadged under their brand name. No one makes better hydraulic rollers than Morel. It doesn't mean they never have a defect, but I doubt this is one of them in this case.
Curious, did you buy the 5294 equivalent, or the 5850 (both High rpm Morels/Lunatis/Isky, etc)?
Keeping it under .650 for road racing is a step in the right direction all around.
Who installed and setup your valve train (the first time)? Was it Lingenfelter?
Also for anyone reading the thread who may not know, Lunati, Isky etc lifters are all made by Morel and rebadged under their brand name. No one makes better hydraulic rollers than Morel. It doesn't mean they never have a defect, but I doubt this is one of them in this case.
Curious, did you buy the 5294 equivalent, or the 5850 (both High rpm Morels/Lunatis/Isky, etc)?
Keeping it under .650 for road racing is a step in the right direction all around.
Who installed and setup your valve train (the first time)? Was it Lingenfelter?
My first lifters were Isky (non link-bar) in my 454 cu in LS7. I swapped those in after my Cadillac lifters fell apart (under .650 lift camshaft).
The lifters pictured were the standard Morel linkbars. I put the high RPM ( lunati) version in this go around.
LPE set-up the heads/valvetrain the first time around. Turns out my 7.750 pushrods worked well with the new grind cam. I haven't got it on the rollers yet, but the power is all over the RPM range now.
Last edited by bowtiguy; 07-13-2011 at 05:07 PM.
07-13-2011, 05:19 PM
#20
Melting Slicks
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That looks like my LG cam and stock LS6 rollers. 10+ of the 16 lobes/lifters were damaged, more on some than others. I would loose oil PSI at idle to 0 and gain regular PSI at anything above idle. Tear down found the cam/lifters to be the only failure.