GM Racing Lifters Failed in New Motor
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GM Racing Lifters Failed in New Motor
These 2 New GM racing lifters (88958689) were removed from a New LS6 motor , A tickng developed about 100 miles after the install so we pulled it to find out why.
The valve lash was set with 7.30 rods, odd because Linginfelter said that 7.4 rod the stock length would be fine, but we found different and on start up everything was quiet and idled good with AFR, Oil pressure, etc. Motor has exceptional power and there were no clearance issues upon inspection.
The cam install was not straight forward, there was little to no clearance between the lobes and the bearing so insertion was very slow. Cam is a GT2-3 new from Linginfelter.
I think either the CAM is no good or the Lifters are detective. There is no physical damage on the CAM, But if the Cam was made wrong could this be the issue? Also these lifter sleeves are scored as a result.
The valve lash was set with 7.30 rods, odd because Linginfelter said that 7.4 rod the stock length would be fine, but we found different and on start up everything was quiet and idled good with AFR, Oil pressure, etc. Motor has exceptional power and there were no clearance issues upon inspection.
The cam install was not straight forward, there was little to no clearance between the lobes and the bearing so insertion was very slow. Cam is a GT2-3 new from Linginfelter.
I think either the CAM is no good or the Lifters are detective. There is no physical damage on the CAM, But if the Cam was made wrong could this be the issue? Also these lifter sleeves are scored as a result.
Last edited by billc5; 04-26-2007 at 08:26 PM.
#3
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Originally Posted by billc5
These 2 New GM racing lifters (88958689) were removed from a New LS6 motor , A tickng developed about 100 miles after the install so we pulled it to find out why.
The valve lash was set with 7.30 rods, odd because Linginfelter said that 7.4 rod the stock length would be fine, but we found different and on start up everything was quiet and idled good with AFR, Oil pressure, etc. Motor has exceptional power and there were no clearance issues upon inspection.
The cam install was not straight forward, there was little to no clearance between the lobes and the bearing so insertion was very slow. Cam is a GT2-3 new from Linginfelter.
I think either the CAM is no good or the Lifters are detective. There is no physical damage on the CAM, But if the Cam was made wrong could this be the issue? Also these lifter sleeves are scored as a result.
The valve lash was set with 7.30 rods, odd because Linginfelter said that 7.4 rod the stock length would be fine, but we found different and on start up everything was quiet and idled good with AFR, Oil pressure, etc. Motor has exceptional power and there were no clearance issues upon inspection.
The cam install was not straight forward, there was little to no clearance between the lobes and the bearing so insertion was very slow. Cam is a GT2-3 new from Linginfelter.
I think either the CAM is no good or the Lifters are detective. There is no physical damage on the CAM, But if the Cam was made wrong could this be the issue? Also these lifter sleeves are scored as a result.
Another possiblilty is improper installation.
#5
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Are those cracks in the photo? Looks like (if they are) they started at the end of the lifter, have you checked to see if there was contact between the lifter body edge and the cam on the lift ramp? This can be a problem with fully enclosed rollers, but on that cam I wouldn't think so as I seem to think it is fairly mild. The lower photo does seem to indicate some type of impact though.
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Heads have to be pulled to get to the lifters and there is no interference with the valves and pistons.
The cam still looks pristine, we inspected every lobe they look perfect.
Lingenfelter said that they had never seen this problem before, in other words they said, Not My Problem and were not interested in talking to the Engine builder.
As far as I know the bores for the lifter in the new block were not tight, upon removal only 2 of the lifters were tight in the bores and they were not like that when installed. Could the alignment of the lifter bores be OFF? How would you check.
This failure is not easy to see by eye!
The rollers are rotating freely like new, there are no impact marks.
The cam still looks pristine, we inspected every lobe they look perfect.
Lingenfelter said that they had never seen this problem before, in other words they said, Not My Problem and were not interested in talking to the Engine builder.
As far as I know the bores for the lifter in the new block were not tight, upon removal only 2 of the lifters were tight in the bores and they were not like that when installed. Could the alignment of the lifter bores be OFF? How would you check.
This failure is not easy to see by eye!
The rollers are rotating freely like new, there are no impact marks.
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At what part of the lifter are these close-up photos taken, at the very bottom? Note the area that looks to have been hit or something, the metal has some compressive plastic deformation.
Also, I know you stated the cam was fine, but in the photo below it sure looks like something hit it. Also, compression and cracking doesn't seem to fit either, cracking is usually the result of a tensile load (Mode I failure). Can you explain the note in the close-up photo, not sure what is meant. It does appear that it might have hit something, which initiated a crack.
Are you running LS6 valve springs?
As a side note, from a design standpoint, that corner looks to be incredibly weak and prone to flex and hence a fatigue failure. This "may" be the root cause of your problem.
Obviously not much help to you, but check the design of the Morel's in this thread:
Morel Photo's
Also, I know you stated the cam was fine, but in the photo below it sure looks like something hit it. Also, compression and cracking doesn't seem to fit either, cracking is usually the result of a tensile load (Mode I failure). Can you explain the note in the close-up photo, not sure what is meant. It does appear that it might have hit something, which initiated a crack.
Are you running LS6 valve springs?
As a side note, from a design standpoint, that corner looks to be incredibly weak and prone to flex and hence a fatigue failure. This "may" be the root cause of your problem.
Obviously not much help to you, but check the design of the Morel's in this thread:
Morel Photo's
Last edited by vettenuts; 04-27-2007 at 07:11 PM.
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I have replaced the picture with the area of the closeup marked.
the loading of the lifter is from the bore which has sheared inward to the center. this could also be described as inadequate bearing strength. Note that we were lucky to pull the lifter before a chunk was lost, see on the side view how the cracks have propagated from the edge and almost connected up the barrel in both lifters.
The closeups do not show any impact from the lobe on the lifter and there is no evidence of impact on the lobe.
Fatigue maybe, but these failed almost immediately.
The area that looks whacked is actually a chunk that spalled off, in compression the material will start to pop pieces off were the load is applied, there is demonstrable inward displacement, towards the center, (the thinnest part of the skirt is pushed in) and the cracks are opened on the outside radius and closed on the inside.
Let me know if this answers your question.
the loading of the lifter is from the bore which has sheared inward to the center. this could also be described as inadequate bearing strength. Note that we were lucky to pull the lifter before a chunk was lost, see on the side view how the cracks have propagated from the edge and almost connected up the barrel in both lifters.
The closeups do not show any impact from the lobe on the lifter and there is no evidence of impact on the lobe.
Fatigue maybe, but these failed almost immediately.
The area that looks whacked is actually a chunk that spalled off, in compression the material will start to pop pieces off were the load is applied, there is demonstrable inward displacement, towards the center, (the thinnest part of the skirt is pushed in) and the cracks are opened on the outside radius and closed on the inside.
Let me know if this answers your question.
#14
It looks like from the close up that the edges where rolled over from dropping them or some sort of impact. I'm not saying this happened inside the motor. Aren't these hardened fairly hard? I'm thinking they got damaged somehow in the manufacturing process before they was even sent for the grinding operation.
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Boy, I sure hate to see this, as I just put a set of these in along with a T.R. cam and Patriot 243's. Did so as a matter of insurance as my thinking was that these were better, stronger, lighter design than the stockers. Mine has less than 100 miles on the combo, so I guess I'll just keep a careful ear to the engine...
Would be interested to hear SDPC's response to this...
Would be interested to hear SDPC's response to this...
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Looks like impact cracking from hitting the edge of the lifter hole.
A bigger cam pushes the lifter sideways against the hole with more force.
Think of the lifter as a lever, the cam as the force and the edge of the lifter hole the fulcrum point.
I replaced my LS6 lifters with ones (RHOADS) that had a larger contact area with the hole (shrouded roller) like you show, but I left in the stock cam.
If you will notice, the edges are angled and not flush on the shroud not like the one you show, so it doesn't fulcrum on the hole edge.
The stock lifter has no shroud.
Stock LS6 lifter is at the right.
A bigger cam pushes the lifter sideways against the hole with more force.
Think of the lifter as a lever, the cam as the force and the edge of the lifter hole the fulcrum point.
I replaced my LS6 lifters with ones (RHOADS) that had a larger contact area with the hole (shrouded roller) like you show, but I left in the stock cam.
If you will notice, the edges are angled and not flush on the shroud not like the one you show, so it doesn't fulcrum on the hole edge.
The stock lifter has no shroud.
Stock LS6 lifter is at the right.
Last edited by heavymetals; 04-28-2007 at 05:10 PM.
#17
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Originally Posted by billc5
I have replaced the picture with the area of the closeup marked.
the loading of the lifter is from the bore which has sheared inward to the center. this could also be described as inadequate bearing strength. Note that we were lucky to pull the lifter before a chunk was lost, see on the side view how the cracks have propagated from the edge and almost connected up the barrel in both lifters.
The closeups do not show any impact from the lobe on the lifter and there is no evidence of impact on the lobe.
Fatigue maybe, but these failed almost immediately.
The area that looks whacked is actually a chunk that spalled off, in compression the material will start to pop pieces off were the load is applied, there is demonstrable inward displacement, towards the center, (the thinnest part of the skirt is pushed in) and the cracks are opened on the outside radius and closed on the inside.
Let me know if this answers your question.
the loading of the lifter is from the bore which has sheared inward to the center. this could also be described as inadequate bearing strength. Note that we were lucky to pull the lifter before a chunk was lost, see on the side view how the cracks have propagated from the edge and almost connected up the barrel in both lifters.
The closeups do not show any impact from the lobe on the lifter and there is no evidence of impact on the lobe.
Fatigue maybe, but these failed almost immediately.
The area that looks whacked is actually a chunk that spalled off, in compression the material will start to pop pieces off were the load is applied, there is demonstrable inward displacement, towards the center, (the thinnest part of the skirt is pushed in) and the cracks are opened on the outside radius and closed on the inside.
Let me know if this answers your question.
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These were installed with good clearance and then failed after several hours running, I removed them with vice-grips, (my engine builder couldn't remove them he would have never thought to use vice-grips on the new GM Racing Lifters)therefor I should think there was no prior impact, the edges are typical of all the new lifters.
We have to do more investigation on the status of the bores, but I would say at this point they will survive.
We have to do more investigation on the status of the bores, but I would say at this point they will survive.
Originally Posted by Red99C5
It looks like from the close up that the edges where rolled over from dropping them or some sort of impact. I'm not saying this happened inside the motor. Aren't these hardened fairly hard? I'm thinking they got damaged somehow in the manufacturing process before they was even sent for the grinding operation.
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Originally Posted by Old SStroker
What did the Lingenfelter folks say when you asked them about your problems? You did contact them before posting this, right?
Another possiblilty is improper installation.
Another possiblilty is improper installation.
Please tell us how the skirt of a lifter and specifically 2 out of 16 Brand New Lifters could suffer failure from the hands of the installer? given the evidence of the photographs presented.
I would think that the mode of failure is in the design or the material or in the manufacturing process. The skirts at the failure location are only 0.020" thick. So could the oil pressure between the bore and Lifter reach 2000psi? perhaps someone in the advanced section could tell us as this type of question is not appropriate in that section?