Looking for opinions. Most break in oils in the market tout their high levels of zinc or other antiwear components. It seems to me the object of breaking in would be to wear faster and develope surfaces even with each other. But than would not high antiwear lower the break in rate? A mystry for me. Hoping wiser minds can explain.
Break in oils
- Thread starter DWC28
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Break-in wear has to be carefully controlled with old -style slider cams. There is a very hard surface treatment but its very thin- gotta knock down the high spots but NOT harm the larger surface area, or the cam may lose some lobes very quickly. The high AW agents help to protect the hardened layer, but the surface high spots still wear down. In fact, the cam should be coated with a special cam break-in grease AND a good AW oil should be used if its a new cam, new lifters, and high performance valve springs.
For an engine without a slider cam, forget the break-in oil. You don't need it. Bearings, roller cams, and rings don't need anything special at all.
For an engine without a slider cam, forget the break-in oil. You don't need it. Bearings, roller cams, and rings don't need anything special at all.
Higher quality machining has essentially eliminated new car break-in and the need for special break-in oil.
Imprecise machining, variable surface finish and poor quality lubricants worked together resulting in the final sizing and polishing of moving parts was done during initial operation.
This is cheap and effective, but a bit of a dice roll. You could end up with perfectly fitting, polished parts with a broad bearing surface. Or you could end up with sloppy parts with rough, uneven bearing surfaces that continue to wear. The more parts, the worse the chances of success and the higher the cost of failure.
People forget that their old work-horse engines are the lucky survivors, when most of the production wore out early.
Fabricating the parts accurately before assembly means that the final surface hardness and finish can be controlled. In many cases a microscopic roughness is desirable to retain an oil film. If this is done throughout the engine, the only break-in needed is the thermal setting of the gasket resins and perhaps thermal stress relief of the metal parts.
Imprecise machining, variable surface finish and poor quality lubricants worked together resulting in the final sizing and polishing of moving parts was done during initial operation.
This is cheap and effective, but a bit of a dice roll. You could end up with perfectly fitting, polished parts with a broad bearing surface. Or you could end up with sloppy parts with rough, uneven bearing surfaces that continue to wear. The more parts, the worse the chances of success and the higher the cost of failure.
People forget that their old work-horse engines are the lucky survivors, when most of the production wore out early.
Fabricating the parts accurately before assembly means that the final surface hardness and finish can be controlled. In many cases a microscopic roughness is desirable to retain an oil film. If this is done throughout the engine, the only break-in needed is the thermal setting of the gasket resins and perhaps thermal stress relief of the metal parts.
Thanks. I understand the concept but am having a hard time grasping the mechanism how the antiwear protects part of the surface but allows others to wear. Sems like normal oil would do a better job.
I should also mention this is not just academic inquiry. Several natural gas converted GM engines are failing camshafts soon after overhaul. With the use of break in oil (many brands seem to work) problem is nearly eliminated. But I still don't grasp the mechanism of how it is working.
Were the cam shafts re-ground?
Is so, it's likely the original hardened surface was machined through leaving an unevenly hardened working surface, with unknown roughness. That's a good combination for odd wear patterns.
Extreme pressure additives can mitigate some of the problem by providing a somewhat slippy metallic wear surface when the oil film fails (slippery enough that the surfaces don't weld together then tear), and the intense heat triggering a chemical reaction that leaves a slightly harder layer of molecules behind.
The description can be written to make it sound like it's building up a fresh bearing surface, but it's really just reducing the damage.
Is so, it's likely the original hardened surface was machined through leaving an unevenly hardened working surface, with unknown roughness. That's a good combination for odd wear patterns.
Extreme pressure additives can mitigate some of the problem by providing a somewhat slippy metallic wear surface when the oil film fails (slippery enough that the surfaces don't weld together then tear), and the intense heat triggering a chemical reaction that leaves a slightly harder layer of molecules behind.
The description can be written to make it sound like it's building up a fresh bearing surface, but it's really just reducing the damage.
Hi. If you go to the Amsoil site and "Search" for G-2881, it has a good graphic of how this works. Let me know if that is what you are looking for.
DJB, they are new camshafts.
Al'z : thanks for the information source. To me it seems to be contradictory. Again it is the higher levels of anti wear allowing critical wear while at the same time preventing wear at non critical areas. Wouldn't low levels of antiwear give quiker wear in the critical area?
Al'z : thanks for the information source. To me it seems to be contradictory. Again it is the higher levels of anti wear allowing critical wear while at the same time preventing wear at non critical areas. Wouldn't low levels of antiwear give quiker wear in the critical area?
Originally Posted By: DWC28
Wouldn't low levels of antiwear give quiker wear in the critical area?
Most of the break-in occurs in the first 15-30 minutes after firing up the engine for the first time, how much faster do you want it?
It needs to be a controlled break-in wherein the surfaces mate without a wipe out, thats where the boundary layer of ZDDP comes into play.
For the small cost of proper break-in lubes and oil why gamble with a catastrophic failure?
Wouldn't low levels of antiwear give quiker wear in the critical area?
Most of the break-in occurs in the first 15-30 minutes after firing up the engine for the first time, how much faster do you want it?
It needs to be a controlled break-in wherein the surfaces mate without a wipe out, thats where the boundary layer of ZDDP comes into play.
For the small cost of proper break-in lubes and oil why gamble with a catastrophic failure?
Originally Posted By: Rock_Hudstone
Originally Posted By: DWC28
Wouldn't low levels of antiwear give quiker wear in the critical area?
Most of the break-in occurs in the first 15-30 minutes after firing up the engine for the first time, how much faster do you want it?
It needs to be a controlled break-in wherein the surfaces mate without a wipe out, thats where the boundary layer of ZDDP comes into play.
For the small cost of proper break-in lubes and oil why gamble with a catastrophic failure?
But your car is basically broken in before it leaves the assembly line, or as it leaves the assembly.
Originally Posted By: DWC28
Wouldn't low levels of antiwear give quiker wear in the critical area?
Most of the break-in occurs in the first 15-30 minutes after firing up the engine for the first time, how much faster do you want it?
It needs to be a controlled break-in wherein the surfaces mate without a wipe out, thats where the boundary layer of ZDDP comes into play.
For the small cost of proper break-in lubes and oil why gamble with a catastrophic failure?
But your car is basically broken in before it leaves the assembly line, or as it leaves the assembly.
Originally Posted By: DWC28
Looking for opinions. Most break in oils in the market tout their high levels of zinc or other antiwear components. It seems to me the object of breaking in would be to wear faster and develope surfaces even with each other. But than would not high antiwear lower the break in rate? A mystry for me. Hoping wiser minds can explain.
At break in, parts DO wear n faster . But this is not a goal, it is because the parts are roughest when new.
We want to minimize galling and spilling - scratching. We want to let parts seat and wear together in the best way possible. Fast and hard is damaging.
Looking for opinions. Most break in oils in the market tout their high levels of zinc or other antiwear components. It seems to me the object of breaking in would be to wear faster and develope surfaces even with each other. But than would not high antiwear lower the break in rate? A mystry for me. Hoping wiser minds can explain.
At break in, parts DO wear n faster . But this is not a goal, it is because the parts are roughest when new.
We want to minimize galling and spilling - scratching. We want to let parts seat and wear together in the best way possible. Fast and hard is damaging.
Thanks to all who have replied. I am still not sure that I understand the logic of high zinc break in. Seems like those claims should apply all the time. That is prevent wear on old engines also. Anyway, I do not get onto here very often and notice that threads die out quickly, so if you arrive late please contribute as I will be back.
No doubt break in requires more additives.
Esp for problematic cam systems.
Untold #s of cams/lifters have been wiped out in an hour because of improper break in grease, oil, or break in technique.
Esp for problematic cam systems.
Untold #s of cams/lifters have been wiped out in an hour because of improper break in grease, oil, or break in technique.
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