can you reuse bearings

grumpyvette

Administrator
Staff member
"question grumpy?
I have about 500 miles on my new engine since it was rebuilt, I'm swapping it into a new car which requires a new oil pan, so I,m going to inspect the bearings while the oil pans off, I assume if they look ok, I can just reassemble and re-torque the rods and mains as long as I'm careful not to disturb the bearings and everything will be fine provided I find the bearings look good of course, but I'm wondering if I should just replace them all while its apart being inspected?"


NEVER GUESS, DEAL IN PROVEN FACT!
Id get out the plasti-gauge and check clearances, don,t guess , know exactly what your dealing with!
if the clearance falls in spec and the bearings look decent they can be re-used, but its foolish to do so if they look overly dirty, worn or don't have the correct clearances


http://garage.grumpysperformance.co...earances-and-journal-surface.9955/#post-38385

http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/#post-26440
MEASURE CAREFULLY

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when your talking about bearings, technically, all bearings are used once they were installed, in the block, and once the crank shaft rotates,its a good idea to inspect the bearings but if they look like nearly new and the clearances still check out with a bit of plasti-gauge theres no reason to replace them so your bearings having been run have a few miles on them, but should not need replacement, if the clearances were correct and there has been no crud or debris in the oil, to cause problems, naturally having used a good moly assembly lube and a quality oil filter and checking all clearances would help a great deal as would starting any build with a carefully cleaned block, with all the oil passages cleaned but the important thing is the bearing clearances and the condition of those bearings, and maintaining a dependable pressurized oil film that prevents or at least significantly minimizes direct metal on metal contact, between the crank and cam journals and bearing surfaces

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grumpyvette

Administrator
Staff member
Engine Bearing Installation and Fitting Tips

When measuring bearing measurements, they should always be taken at 90-degrees to the parting line to determine the minimum clearance. If measuring the bearing wall thickness, use a special micrometer with a ball anvil to fit the curvature of the bearing ID. The best way to determine bearing clearance is to measure the bearing ID with the bearings installed in the housing and the bolts torqued to the specified assembly torque. Use a dial bore gauge to measure the bearing ID at 90-degrees to the parting line, then subtract shaft size from bearing ID to determine the clearance. If the dial bore gauge is zeroed at the actual diameter of the crankshaft journal to be installed, the dial bore gauge will then read clearance directly and the subtraction calculation can be eliminated. About .001" clearance per inch of shaft diameter is a good rule of thumb. Increasing that by about .0005" will add a little margin of safety when starting out, especially for rods. Example: .001" X 2.100 = .0021" then add .0005", so starting out set clearance at .0026" for a 2.100 shaft.

If clearance adjustments need to be made, use either an extra clearance part for more clearance or an undersize part for less clearance. It is permissible to mix sizes if less than .001" adjustment in clearance is desired. When mixing sizes for a select fitting: a) never mix parts having more than .0005" difference in wall size; b) and always install the thickest wall shell in the upper position if installing a rod bearing or the lower position if installing a main bearing. When working with a reground shaft, always measure assembled bearing ID's first. Next have a shaft sized to produce the desired clearance since there are no extra clearance parts available for undersize shafts.

When measuring a bearing ID or wall thickness, avoid measuring at the parting line. The diagram illustrates there is a parting line relief machined into nearly all bearing shells. This relief is to allow for any mis-match between upper and lower shells due to tolerance differences, or possibly resulting from cap shift or twist during assembly. To determine bearing wall eccentricity or assembled bearing ID ovality, measure at a point at least 3/8" away from the parting line.

When installing any bearing DO NOT ATTEMPT TO POLISH THE BEARING RUNNING SURFACE WITH ANY TYPE OF ABRASIVE PAD OR PAPER. Bearing overlay layers are extremely soft and thin – typically .0005" on high performance parts. These thin layers can easily be damaged or removed by an abrasive media. Because the overlay layer is electroplated, it may exhibit microscopic plating nodules that make it feel slightly rough. The nodules are the same material as the rest of the plated layer and will quickly be flattened by the shaft. Bearing surfaces can be lightly burnished with solvent and a paper towel if desired.

Arriving at the correct choice of a high performance bearing for any given racing application is much like determining what clearance works best. From past experience, our knowledge of the intended usage and common sense can guide us in making an initial choice. Next, we can fine tune the selection process based on those results. The information given here is intended to aid in the initial selection as well as the fine tuning process.

The following table serves as a brief overview of the features included in each of the special Clevite 77® brand high performance bearing series.
bearingchart.jpg



NEVER GUESS, DEAL IN PROVEN FACT!
Id get out the plasti-gauge and check clearances, don,t guess , know exactly what your dealing with!
if the clearance falls in spec and the bearings look decent they can be re-used, but its foolish to do so if they look overly dirty, worn or don't have the correct clearances
lots of moly assembly lube and spraying any potential moving contact surface with moly spray (like bearings ,lifters rockers) and liberal use of moly assembly lube during the break-in process helps reduce wear issues


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pre-spraying all bearing and valve train components with a moly based spray, helps embed micro moly lubricants in the metallic surface micro fissures , a good paste lube like cranes assembly lube over the spray surface helps insure a good lubricant surface coating, that is far stronger than just the ZINC and PHOSPHATES in oil
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CAREFULLY
.. reading links and SUB LINKS is almost mandatory on this web site!
if you want all available useful related info

http://garage.grumpysperformance.co...earances-and-journal-surface.9955/#post-38385

http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/#post-26440

http://garage.grumpysperformance.com/index.php?threads/can-you-reuse-bearings.5544/

http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-68194

http://garage.grumpysperformance.co...tion-of-crank-durring-short-blk-assembly.852/

http://garage.grumpysperformance.com/index.php?threads/assembly-lube-summary.6352/#post-68508

http://garage.grumpysperformance.co...ear-articles-you-need-to-read.282/#post-57371

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these threads have good related info, that you should read thru before starting the block prep, and rotating assembly process

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