Clarification? |  |  |
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I have just bought a DOF kit+single row bearing and noticed some interesting posts about Super Precision bearings.But there was no links to a reasonable price/availabilty.Without that it was impossible to decide if it was a reasonable upgrade.
An expert (not me!) on another Forum posted that surface roughness(Ra) was a more critical factor than just dimensional precision.He also asserted that he would only use an IMS bearing with pressure lubrication on his Porsche.I believe he is the ex-Timken guy that LN used for consulting? So an affirmation of DOF for Pedro ! His reasoning was (roughly becaue I can't find his post now)-that excessive roughness on the surface of the balls would penetrate the oil film that they should ride on.That would cause wear/heat.
If you want to try a very high quality bearing at a reasonable price, I found 20+, ABEC 9 ,NTN6204 2RS ,Yes ABEC9/nine bearings and they have a steel cage ,not phenolic.And yes the balls are steel not ceramic.You would have to remove 1 seal and perhaps 'shave' the open face a little to fit the circlip??? And clean the bearing very,very well after that shave!
Source: "Locatebearings".They are in Palm Desert Ca .Mark quoted $105 each.I have seen that spec bearing for double $.
Call "Mark" at 800 409 3632. But only place your order in writing/Internet ,not verbally over the phone.Carefully check the part number you order/receive to ensure it is ABEC9. A lower ABEC grade 6204 NTN bearing could be found on EBay for $10 ! So ABEC 9 needs to be on the order and the receipt and you need to confirm on the NTN website catalog the correct part number.You don't want to pay $100+ for a $10 bearing!
Only buy via a special Listing they create for you on EBay or Amazon - in case you have a problem with the spec.Google "LocateBearings" first.
I have no affiliation with Locatebearings ,just sharing very obscure info. and asking advice from the Forum experts.
An expert (not me!) on another Forum posted that surface roughness(Ra) was a more critical factor than just dimensional precision.He also asserted that he would only use an IMS bearing with pressure lubrication on his Porsche.I believe he is the ex-Timken guy that LN used for consulting? So an affirmation of DOF for Pedro ! His reasoning was (roughly becaue I can't find his post now)-that excessive roughness on the surface of the balls would penetrate the oil film that they should ride on.That would cause wear/heat.
If you want to try a very high quality bearing at a reasonable price, I found 20+, ABEC 9 ,NTN6204 2RS ,Yes ABEC9/nine bearings and they have a steel cage ,not phenolic.And yes the balls are steel not ceramic.You would have to remove 1 seal and perhaps 'shave' the open face a little to fit the circlip??? And clean the bearing very,very well after that shave!
Source: "Locatebearings".They are in Palm Desert Ca .Mark quoted $105 each.I have seen that spec bearing for double $.
Call "Mark" at 800 409 3632. But only place your order in writing/Internet ,not verbally over the phone.Carefully check the part number you order/receive to ensure it is ABEC9. A lower ABEC grade 6204 NTN bearing could be found on EBay for $10 ! So ABEC 9 needs to be on the order and the receipt and you need to confirm on the NTN website catalog the correct part number.You don't want to pay $100+ for a $10 bearing!
Only buy via a special Listing they create for you on EBay or Amazon - in case you have a problem with the spec.Google "LocateBearings" first.
I have no affiliation with Locatebearings ,just sharing very obscure info. and asking advice from the Forum experts.
In a bearing everything is critical.
But to be sure, surface roughness is of course important. If the bearing runs in oil the oil film between the rolling element and the race becomes very thin -- in some applications less than one micron (0.00003937") -- as it is under very high pressure, in some cases hundreds of thousands of pounds per square inch. At these high pressures the oil acts as a solid and with the high pressure deforms the rolling element and its opposing component's surface. If the surface roughness of the ball/roller or race is too great the film could be broken down and metal to metal contact between the ball/roller and its races will occur.
Might add that in this scenario the condition of the oil becomes quite critical. Particulate matter in the oil is particularly bad as this interferes with the formation of the film of oil. Also, water is bad. Water doesn't have the property (pressure-viscosity coefficient) that lets it form a solid film under high pressure like oil and water in the oil can result in boundary conditions which leads to increase in wear and premature bearing failure.
It is the double barreled issues of particulate matter in the oil and the presence of water in the oil that had me skeptical from the outset of these direct oil feed solutions.
Last, but not least, I just do not get this "try" mentality with Porsche owners so willing to offer up their engines as test beds in the search for a suitable bearing. And "suitable" in the sense that after installation and upon first engine start and some subsequent running the bearing appears to hold together. To accept this as sufficient proof the bearing is a viable replacement is amazing. But I've given up trying to understand this.
But to be sure, surface roughness is of course important. If the bearing runs in oil the oil film between the rolling element and the race becomes very thin -- in some applications less than one micron (0.00003937") -- as it is under very high pressure, in some cases hundreds of thousands of pounds per square inch. At these high pressures the oil acts as a solid and with the high pressure deforms the rolling element and its opposing component's surface. If the surface roughness of the ball/roller or race is too great the film could be broken down and metal to metal contact between the ball/roller and its races will occur.
Might add that in this scenario the condition of the oil becomes quite critical. Particulate matter in the oil is particularly bad as this interferes with the formation of the film of oil. Also, water is bad. Water doesn't have the property (pressure-viscosity coefficient) that lets it form a solid film under high pressure like oil and water in the oil can result in boundary conditions which leads to increase in wear and premature bearing failure.
It is the double barreled issues of particulate matter in the oil and the presence of water in the oil that had me skeptical from the outset of these direct oil feed solutions.
Last, but not least, I just do not get this "try" mentality with Porsche owners so willing to offer up their engines as test beds in the search for a suitable bearing. And "suitable" in the sense that after installation and upon first engine start and some subsequent running the bearing appears to hold together. To accept this as sufficient proof the bearing is a viable replacement is amazing. But I've given up trying to understand this.
| Clarification? grant - 9 years ago |
Marc,
Maybe i'm misreading your note, but what about direct oil feed solutions makes oil dirtier or more diluted with water?
Grant
gee-lenahan-at-gee-mail-dot-com
Maybe i'm misreading your note, but what about direct oil feed solutions makes oil dirtier or more diluted with water?
Quote
MarcW
It is the double barreled issues of particulate matter in the oil and the presence of water in the oil that had me skeptical from the outset of these direct oil feed solutions.
Grant
gee-lenahan-at-gee-mail-dot-com
| Re: Clarification? tonyd - 9 years ago |
Ed,
Thanks for taking the time to comment.
I very much appreciate you giving us the benefit of your experience in bearings.
Locatebearings(Mark) did tell me the bearing was not listed .I thought it may be too good to be true - hence all the caveats in my post.
The part that was listed and originaly prompted me to investigate was this:
[www.ebay.com]
and
[www.ebay.com]
Thanks for taking the time to comment.
I very much appreciate you giving us the benefit of your experience in bearings.
Locatebearings(Mark) did tell me the bearing was not listed .I thought it may be too good to be true - hence all the caveats in my post.
The part that was listed and originaly prompted me to investigate was this:
[www.ebay.com]
and
[www.ebay.com]
Dirt gets in the oil naturally as metal is shed from inside the engine. While the filter removes the larger bits (except maybe at cold start when the oil is routed around the filter) the filtering is intended to meet the filtering needs of an engine with no ball/roller bearings. The original IMSB is a sealed unit and is not expected to be lubricated by engine oil. Water in the oil is a byproduct of combustion.
so on a practical basis, most of them are lubricated by oil anyway. I've taken half a dozen out. None had (much or any) grease left.
All were in various stages of "ok"
I'd rather have a well lubricated bearing than a marginally lubricated one, assuming they are both lubricated by the same oil , clean or dirty.
Thanks,
Grant
Grant
gee-lenahan-at-gee-mail-dot-com
All were in various stages of "ok"
I'd rather have a well lubricated bearing than a marginally lubricated one, assuming they are both lubricated by the same oil , clean or dirty.
Thanks,
Grant
Grant
gee-lenahan-at-gee-mail-dot-com
| Well, I do not know about most of them lubed by oil anyway comment. A half a dozen is not a large... MarcW - 9 years ago |
Quote
grant
so on a practical basis, most of them are lubricated by oil anyway. I've taken half a dozen out. None had (much or any) grease left.
All were in various stages of "ok"
I'd rather have a well lubricated bearing than a marginally lubricated one, assuming they are both lubricated by the same oil , clean or dirty.
Thanks,
Grant
sampling size.
I find it a bit perplexing that you found little to no grease left and the bearings were all in various stages of "ok" and this apparently is something to be positive about? To me you finding the bearings missing grease and instead having to rely upon oil and being just "ok" suggests they were suffering from having to rely upon oil for their critical lubrication rather than the grease for which they were designed.
Also, I note the OE bearing was not removed and a duplicate OE bearing installed and monitored. The new bearing and its seals might have held up just fine. Kind of like my Boxster's RMS. The original one leaked and was replaced at 25K miles. The replacement has remained oil tight now for 255K miles.
I too want a well lubed bearing rather than a marginally lubed bearing. Who doesn't? Where I think we will end up disagreeing is just what constitutes a well lubed bearing. I believe the OE bearing as it comes from the factory is well lubed. While a number of bearings have failed for one reason or another, far more of them have not failed. Thus the factory bearing's default lubrication system is pretty darn good. Because of that, I'm not convinced any change to how this bearing is lubed, either just removing the seals and letting God splash on some oil or fitting something that directs oil to the bearing offers better lubrication.
| Please dont twist what i said.... but we are largely in agreement on the facts.... grant - 9 years ago |
" find it a bit perplexing that you found little to no grease left and the bearings were all in various stages of "ok" and this apparently is something to be positive about?"
Not a bit positive, quite alarmed really, just saying what i found. facts.
"they were suffering from having to rely upon oil for their critical lubrication rather than the grease for which they were designed."
Bingo. Oil - the very oil you were warning against. My point is that you have two choices:
1. insufficient dirty oil via splash, or
2. sufficient dirty oil via stream feed
I choose #2. You seem to choose #1.
Finally, you said: "I believe the OE bearing as it comes from the factory is well lubed"
And 6/6 times the factory lube was gone. Good sample, no, but if you flip a fiar coin 6 times, what's the chance of getting 6 heads, eh?
1/64. Possibly fair, no doubt. But a small possibility.
And yea, there is too much panic about IMS. And too many false cases (one of which i debunked with pics right here, one of the 6).
And, as i noted, all 6 were "ok". I cant measure them. I cant predict the future. I am simply admitting they were not obviously goners yet.
Anyway, i understand your original point. Assuming that there is lots of grease int he joint bathing it in dirty oil may not be a good thing. True. except i never seem to find the grease part.
Grant
Grant
gee-lenahan-at-gee-mail-dot-com
Not a bit positive, quite alarmed really, just saying what i found. facts.
"they were suffering from having to rely upon oil for their critical lubrication rather than the grease for which they were designed."
Bingo. Oil - the very oil you were warning against. My point is that you have two choices:
1. insufficient dirty oil via splash, or
2. sufficient dirty oil via stream feed
I choose #2. You seem to choose #1.
Finally, you said: "I believe the OE bearing as it comes from the factory is well lubed"
And 6/6 times the factory lube was gone. Good sample, no, but if you flip a fiar coin 6 times, what's the chance of getting 6 heads, eh?
1/64. Possibly fair, no doubt. But a small possibility.
And yea, there is too much panic about IMS. And too many false cases (one of which i debunked with pics right here, one of the 6).
And, as i noted, all 6 were "ok". I cant measure them. I cant predict the future. I am simply admitting they were not obviously goners yet.
Anyway, i understand your original point. Assuming that there is lots of grease int he joint bathing it in dirty oil may not be a good thing. True. except i never seem to find the grease part.
Grant
Grant
gee-lenahan-at-gee-mail-dot-com
Hi,
I looked at the Locate Bearings web site. They do not list a NTN 6204 RS ABEC 9 bearing. Neither does the NTN web site. NTN doesn't even list a 204 size bearing in ABEC 9 tolerances. 6204 RS: This would be a sealed ABEC 9 bearing. I'm not aware of any manufacturer making a sealed ABEC 9 bearing. ABEC 9 bearings are typically angular contact and must have a thrust load or be used as a preloaded pair. Not practical on the IMS
BEWARE!
Ed B
Bearing engineer
I looked at the Locate Bearings web site. They do not list a NTN 6204 RS ABEC 9 bearing. Neither does the NTN web site. NTN doesn't even list a 204 size bearing in ABEC 9 tolerances. 6204 RS: This would be a sealed ABEC 9 bearing. I'm not aware of any manufacturer making a sealed ABEC 9 bearing. ABEC 9 bearings are typically angular contact and must have a thrust load or be used as a preloaded pair. Not practical on the IMS
BEWARE!
Ed B
Bearing engineer
Ed,
Thanks for taking the time to comment.
I very much appreciate you giving us the benefit of your experience in bearings.
Locatebearings(Mark) did tell me the bearing was not listed .I thought it may be too good to be true - hence all the caveats in my post.
The part that was listed and originaly prompted me to investigate was this:
[www.ebay.com]
and
[www.ebay.com]
Edited 1 time(s). Last edit at 11/08/2014 02:13PM by tonyd. (view changes)
Thanks for taking the time to comment.
I very much appreciate you giving us the benefit of your experience in bearings.
Locatebearings(Mark) did tell me the bearing was not listed .I thought it may be too good to be true - hence all the caveats in my post.
The part that was listed and originaly prompted me to investigate was this:
[www.ebay.com]
and
[www.ebay.com]
Edited 1 time(s). Last edit at 11/08/2014 02:13PM by tonyd. (view changes)
Hi,
I'm off jury for a couple of weeks so I've got a little more time.
i'm a little surprised to see an ABEC 5 bearing with seals. Seals have rubbing contact which create debris. Not good for a high precision bearing.
Grease is made of oil and a thickener, usually a sodium or lithium soap, clay or teflon. Oil is the lubricant, not the thickener. There are some highly refined greases for instrument bearings but you won't find them in off the shelf bearings.
Modern automotive oil filters are very good and can remove very small particles. Grease, by definition, is a semi solid fatty substance.
Filtered oil is my choice.
Ed B
I'm off jury for a couple of weeks so I've got a little more time.
i'm a little surprised to see an ABEC 5 bearing with seals. Seals have rubbing contact which create debris. Not good for a high precision bearing.
Grease is made of oil and a thickener, usually a sodium or lithium soap, clay or teflon. Oil is the lubricant, not the thickener. There are some highly refined greases for instrument bearings but you won't find them in off the shelf bearings.
Modern automotive oil filters are very good and can remove very small particles. Grease, by definition, is a semi solid fatty substance.
Filtered oil is my choice.
Ed B
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