Gaterman GP-1023 Lifters Long Term Wear

[q1svt]

I don't ever do this, but here goes. After reading all 20 pages of this thread I thought I would put my 2 cents in backed with some REAL data learned from many years of doing this. A few basic points that many have left out. First of all, the center line of the camshaft MUST be 90° to the centerline of the lifter bore. Highly unlikely in these engines. As someone pointed out a few pages back, the bearing (Roller wheel) is not flat, it's crowned. Pushrod angularity will try and "turn" a lifter in it's bore. This effect is almost unmeasurable in some cases, and much more pronounced in others such as applications using offset pushrod seats in the lifter. Unless lofting is occurring the bearing does not skid across the face of the lobe. Ever. I could go on and on.
Someone posted about sending this to a lab for analysis. Only cost a few bucks. OK, here's where it gets real. We've sent countless sets of lifters along with the corresponding camshafts to one of the most well known, best respected metallurgical engineering service laboratories in the world for forensic failure analysis. In every case the findings have been the same. Surface finish incompatibility between the two contact materials, and lubrication failure. Lubrication failure attributed to a breakdown of the boundary layer of the lubrication. Anyone can send these lifters to a lab and get the same results. Only costs $3,500.00 for the full micro hardness, chemical analysis, scanning electron microscopy, energy dispersive spectrometry, failure analysis. Twenty pages of pin diameter posts don't have anything to do with this failure.

Thank's for your contribution to the subject matter here on HTT...
Earlier in this thread and in other threads lifter rotation, side loading of the lifter roller/needle bearings and the HD alignment pin clearances was discussed.  Can you provide any more information as to is impact to lifters, any guidance on proper clearances that should be maintained, etc

[clawdog60]

The lubrication part we should be able to deal with. Surface finish incompatibility,how the he'll we deal with that? Cryogenics?

[Don D]

Why would end users of a product, regardless of the origin, spend money of this magnitude to find a problem such as this? I see this as the manufacturers responsibility.

[BVHOG]

If the surface has zero "skidding" then how does wear occur?

[No Cents]

Why would end users of a product, regardless of the origin, spend money of this magnitude to find a problem such as this? I see this as the manufacturers responsibility.

    with you Don.
is it possible eddiepointdexter works for a lifter manufacture and is speaking of their testing that has been done?   
$3500.00 for testing lifters from a private individual looking for an answer to this problem...would be quite expensive.

Ray

[Don D]

Yes and even if for the sake of discussion if the testing was done the conclusion would likely point to what can be improved with the part the lab was presented not provide a root cause analysis. Now we go back to Reliability Engineering 101 and study all of the mating parts for answers.
When an electrical system is blowing fuses should we focus on the fuse and what may or may not be wrong with the fuse? Similar analogy.

[Admiral Akbar]

Thanks for taking the time to make an informational first post. Firsthand information from someone that has work experience in this field is always welcome. Knowing that rollers are ground with a 23.03" radius crown that you cannot see with your eye across the short distance of the roller width is paramount when trying to get to the root cause of a complicated problem. I hope you will continue to post because we can always use more factual information.

Sorry, Some putz that has no real experience just skewering the Internet..

http://kams.publishpath.com/flat-tappets-roller-followers

http://www.crankshaftcoalition.com/wiki/Lifters

As far as I can tell only flat tappet lifters need a crown.. Just trying to learn here..

Max

[Vic Chichester]

Why would end users of a product, regardless of the origin, spend money of this magnitude to find a problem such as this? I see this as the manufacturers responsibility.

    with you Don.
is it possible eddiepointdexter works for a lifter manufacture and is speaking of their testing that has been done?   
$3500.00 for testing lifters from a private individual looking for an answer to this problem...would be quite expensive.

Ray

There was an Eddie Poindexter that worked at Crane Cams, just may be the same guy.

[rbabos]

In my view a crowned roll will cause more issues then it suppose to stop.
Ron

[1FSTRK]

According to the Delphi specs they use a roller follower crown radius.
https://delphi.com/shared/pdf/ppd/pwrtrn/gas_vlvlift.pdf

[q1svt]

Thanks for taking the time to make an informational first post. Firsthand information from someone that has work experience in this field is always welcome. Knowing that rollers are ground with a 23.03" radius crown that you cannot see with your eye across the short distance of the roller width is paramount when trying to get to the root cause of a complicated problem. I hope you will continue to post because we can always use more factual information.

Sorry, Some putz that has no real experience just skewering the Internet..

http://kams.publishpath.com/flat-tappets-roller-followers

http://www.crankshaftcoalition.com/wiki/Lifters

As far as I can tell only flat tappet lifters need a crown.. Just trying to learn here..

Max

Max your link goes here:
"The right side of the diagram above shows a cam lobe and roller follower.  Sometimes the roller or both the roller and the pin are crowned.  Across a roller that is 5/8" wide, the amount of crown might be 0.00025"-0.00300".  The purpose of the crown on a roller is to reduce edge loading, and the amount of crown is intended to flatten under load so that the roller is effectively flat during operation. "

[kd]

The roller crown is likely just enough to cause the footprint to shrink on contact under the force of the valve springs and provide the traction that ensures the roller rolls and doesn't skid.  It would be very helpful if lofting or similar events occur.

Just saw the q1svt post and it makes good sense now   

[1FSTRK]

The roller crown is likely just enough to cause the footprint to shrink on contact under the force of the valve springs and provide the traction that ensures the roller rolls and doesn't skid.  It would be very helpful if lofting or similar events occur.

Just saw the q1svt post and it makes good sense now   

You will also notice different max contact stress numbers for different cam materials.
The roller must be fully supported by the lobe.

[Admiral Akbar]

According to the Delphi specs they use a roller follower crown radius.
https://delphi.com/shared/pdf/ppd/pwrtrn/gas_vlvlift.pdf

Thanks..

Max your link goes here:
"The right side of the diagram above shows a cam lobe and roller follower.  Sometimes the roller or both the roller and the pin are crowned.  Across a roller that is 5/8" wide, the amount of crown might be 0.00025"-0.00300".  The purpose of the crown on a roller is to reduce edge loading, and the amount of crown is intended to flatten under load so that the roller is effectively flat during operation. "

Oops  missed it.. I thought they were still talking about flat tappet rollers..

Max

[eddiepoindexter]

Unless lofting is occurring the bearing does not skid across the face of the lobe.

Lubrication failure attributed to a breakdown of the boundary layer of the lubrication.

Aren't these 2 statements contradictory??  If not please explain..


FWIW, The rollers I've seen are flat and not crowned.. They show even contact on the both the lifers and the cams when all is working well.. I suppose there might be enough slop that the contact show up as even but one would think that the patterns would favor the center in that case..

Max

Don't see a contradiction. Should have been more specific, lubrication failure attributed to a chemical breakdown of the boundary layer of the lubricant.

The bearing crown has been addressed.

[eddiepoindexter]

I don't ever do this, but here goes. After reading all 20 pages of this thread I thought I would put my 2 cents in backed with some REAL data learned from many years of doing this. A few basic points that many have left out. First of all, the center line of the camshaft MUST be 90° to the centerline of the lifter bore. Highly unlikely in these engines. As someone pointed out a few pages back, the bearing (Roller wheel) is not flat, it's crowned. Pushrod angularity will try and "turn" a lifter in it's bore. This effect is almost unmeasurable in some cases, and much more pronounced in others such as applications using offset pushrod seats in the lifter. Unless lofting is occurring the bearing does not skid across the face of the lobe. Ever. I could go on and on.
Someone posted about sending this to a lab for analysis. Only cost a few bucks. OK, here's where it gets real. We've sent countless sets of lifters along with the corresponding camshafts to one of the most well known, best respected metallurgical engineering service laboratories in the world for forensic failure analysis. In every case the findings have been the same. Surface finish incompatibility between the two contact materials, and lubrication failure. Lubrication failure attributed to a breakdown of the boundary layer of the lubrication. Anyone can send these lifters to a lab and get the same results. Only costs $3,500.00 for the full micro hardness, chemical analysis, scanning electron microscopy, energy dispersive spectrometry, failure analysis. Twenty pages of pin diameter posts don't have anything to do with this failure.

Thanks for taking the time to make an informational first post. Firsthand information from someone that has work experience in this field is always welcome. Knowing that rollers are ground with a 23.03" radius crown that you cannot see with your eye across the short distance of the roller width is paramount when trying to get to the root cause of a complicated problem. I hope you will continue to post because we can always use more factual information.

Not sure about this 23.03" dimension, would need to know what the gauge width is to correctly measure the crown. It's ever so slight, measured out to minutes and seconds. For example, a plotter printout of the crown on a .842" diameter tappet is about eight feet long...

[eddiepoindexter]

I don't ever do this, but here goes. After reading all 20 pages of this thread I thought I would put my 2 cents in backed with some REAL data learned from many years of doing this. A few basic points that many have left out. First of all, the center line of the camshaft MUST be 90° to the centerline of the lifter bore. Highly unlikely in these engines. As someone pointed out a few pages back, the bearing (Roller wheel) is not flat, it's crowned. Pushrod angularity will try and "turn" a lifter in it's bore. This effect is almost unmeasurable in some cases, and much more pronounced in others such as applications using offset pushrod seats in the lifter. Unless lofting is occurring the bearing does not skid across the face of the lobe. Ever. I could go on and on.
Someone posted about sending this to a lab for analysis. Only cost a few bucks. OK, here's where it gets real. We've sent countless sets of lifters along with the corresponding camshafts to one of the most well known, best respected metallurgical engineering service laboratories in the world for forensic failure analysis. In every case the findings have been the same. Surface finish incompatibility between the two contact materials, and lubrication failure. Lubrication failure attributed to a breakdown of the boundary layer of the lubrication. Anyone can send these lifters to a lab and get the same results. Only costs $3,500.00 for the full micro hardness, chemical analysis, scanning electron microscopy, energy dispersive spectrometry, failure analysis. Twenty pages of pin diameter posts don't have anything to do with this failure.

Thank's for your contribution to the subject matter here on HTT...
Earlier in this thread and in other threads lifter rotation, side loading of the lifter roller/needle bearings and the HD alignment pin clearances was discussed.  Can you provide any more information as to is impact to lifters, any guidance on proper clearances that should be maintained, etc

Like to see .0015" / .0025" lifter to lifter bore clearance depending on lifter bore material, so I would think .003" / .004" lifter to pin would be the target.

As for side loading, even the above average engine builder won't be able to get rid of it. Engine architecture, and if nothing else, cost would make this prohibitive. First of all you would need to index the lifter bores so they are perfectly 90° to the centerline of the cams. Once you accomplished this you would need to address pushrod angle along with the rest of the valve train geometry. While in theory this could all be fixed you're pretty much designing and building a different engine at that point. Again, too cost prohibitive.

[eddiepoindexter]

If the surface has zero "skidding" then how does wear occur?

When the boundary layer breaks down it exasperates the surface finish incompatibility issue.

[eddiepoindexter]

Yes and even if for the sake of discussion if the testing was done the conclusion would likely point to what can be improved with the part the lab was presented not provide a root cause analysis. Now we go back to Reliability Engineering 101 and study all of the mating parts for answers.
When an electrical system is blowing fuses should we focus on the fuse and what may or may not be wrong with the fuse? Similar analogy.

Correct. We have a good idea of root cause. The Moco buys/makes a million camshafts. They specify a surface finish for the lobes. Then Eaton/Delphi someone makes millions of lifters for the Moco. Eaton/Delphi whoever buys millions of bearings from Ina or SKF and they specify a surface finish on that bearing that will be compatible. Everything's happy. The problem is we're dealing with aftermarket parts. There is no industry standard. And while they're all real close, tolerances vary from company to company.

[Admiral Akbar]

Unless lofting is occurring the bearing does not skid across the face of the lobe.

Lubrication failure attributed to a breakdown of the boundary layer of the lubrication.

Aren't these 2 statements contradictory??  If not please explain..


FWIW, The rollers I've seen are flat and not crowned.. They show even contact on the both the lifers and the cams when all is working well.. I suppose there might be enough slop that the contact show up as even but one would think that the patterns would favor the center in that case..

Max

Don't see a contradiction. Should have been more specific, lubrication failure attributed to a chemical breakdown of the boundary layer of the lubricant.

The bearing crown has been addressed.

Well for a roller, doesn't it have to break through the layer and make contact for it not to slide?  Or is the layer thin enough roller still gets some traction?

Yeah figured out the roller crown..

Max

[Don D]

What is the correct finish and steel properties for a camshaft to be compatible with the rollers?
What API grade, composition, and viscosity of oil would be optimum for use with these lifters?

I understand the explanation to rest of the proposed solutions.
Problem I have seen is excessive side thrust in the bores, evidence scratches on the lifter bodies after very low hours of use. I can't prove it but the noise is a strong evidence that the lifters are lofting and/or launching. So regardless of the brand or materials we are dealing with a similar part to the street mechanical roller used by the car guys, a maintenance item. The best of the lifters and the other items addressed, to the best of cost affordable reality, can extend the life but we still have to get in and check them. How often? I don't know.

[eddiepoindexter]

Why would end users of a product, regardless of the origin, spend money of this magnitude to find a problem such as this? I see this as the manufacturers responsibility.

    with you Don.
is it possible eddiepointdexter works for a lifter manufacture and is speaking of their testing that has been done?   
$3500.00 for testing lifters from a private individual looking for an answer to this problem...would be quite expensive.

Ray

There was an Eddie Poindexter that worked at Crane Cams, just may be the same guy.

There is not now, nor has there ever been an employee of Crane Cams named Eddie Poindexter. 

[eddiepoindexter]

Thanks for taking the time to make an informational first post. Firsthand information from someone that has work experience in this field is always welcome. Knowing that rollers are ground with a 23.03" radius crown that you cannot see with your eye across the short distance of the roller width is paramount when trying to get to the root cause of a complicated problem. I hope you will continue to post because we can always use more factual information.

Sorry, Some putz that has no real experience just skewering the Internet..

http://kams.publishpath.com/flat-tappets-roller-followers

http://www.crankshaftcoalition.com/wiki/Lifters

As far as I can tell only flat tappet lifters need a crown.. Just trying to learn here..

Max

While I may be a putz from time to time, I have been involved in professional motorsports and aftermarket parts manufacturing for 35 years. I learn new things every day. I like to say I know a lot about a whole lot of things, and a whole lot less about a whole lot more.

And I am cheating just a little bit and relying on years and years, a few hundred million cycles at this point, of SpinTron data.

[BVHOG]

If the surface has zero "skidding" then how does wear occur?

When the boundary layer breaks down it exasperates the surface finish incompatibility issue.

Well that certainly is a more plausible answer the the common answer of dirt/contaminants being the cause.  But then again what causes the boundary layer to break down?

[eddiepoindexter]

Unless lofting is occurring the bearing does not skid across the face of the lobe.

Lubrication failure attributed to a breakdown of the boundary layer of the lubrication.

Aren't these 2 statements contradictory??  If not please explain..


FWIW, The rollers I've seen are flat and not crowned.. They show even contact on the both the lifers and the cams when all is working well.. I suppose there might be enough slop that the contact show up as even but one would think that the patterns would favor the center in that case..

Max

Don't see a contradiction. Should have been more specific, lubrication failure attributed to a chemical breakdown of the boundary layer of the lubricant.

The bearing crown has been addressed.

Well for a roller, doesn't it have to break through the layer and make contact for it not to slide?  Or is the layer thin enough roller still gets some traction?

Yeah figured out the roller crown..

Max

The boundary layer is close to microscopic, it's filling in the peaks and valleys of the material. The "flow" in front of the wheel is carrying away most of the heat. When the layer breaks down due to heat, contaminants etc., it stops filling in those peaks and valleys.

A visual indication of lofting will be lines in the wheel running in the same direction of rotation. Think airplane wheel touching the ground on landing. Problem is contaminants in the average street engine will cause the same wear so it's hard to determine. In a race engine much easier.