Clevite MS429H 77, GM Tri-Metal Main Bearing
Part #: MS429H
List Price: $167.50
Our Price: $102.51
You Save: $64.99
General Motors Clevite H-Series 77, Tri-Metal Main Bearing Set fits the following:
265 CID 4.3L Chevrolet V8 cylinder 1955-1957 (High Performance),
283 CID 4.6L Chevrolet V8 cylinder 1957-1967 (High Performance),
302 CID 5.0L Small Journal Chevrolet V8 cylinder 1967 (High Performance),
327 CID 5.4L Small Journal Chevrolet V8 cylinder 1962-1967 (High Performance).
NOTE ALL: H-Series Performance, Grooved Upper Halves Plain Lower Halves.
Clevite Main Bearing Set part number: MS429H (Standard)
These bearings are identified by a letter H in the part number suffix. Part numbering is based on the same core number as the standard passenger car parts for the same application. These bearings were developed primarily for use in NASCAR type racing, but are suitable for all types of competition engines.
H series bearings have a medium level of eccentricity, high crush, and main bearings have a hardened steel back and thin overlay. These bearings also have enlarged chambers for greater crankshaft fillet clearance and are made without flash plating for better seating. Bearings with .001” extra clearance are available for standard size shafts and carry the suffix HX” (X = extra clearance).
Tri-Metal bearings have significantly greater seizure resistance than bi-metal bearings, by as much as 40%.
Tri-Metal bearings can withstand much higher loads for longer periods of time as compared to bi-metal bearings, over 60% higher.
Embedability & Conformability:
The overlay on a Tri-Metal bearing offers a far more forgiving surface than bi-metal bearings. These features may not be as critical during OE assembly as they once were, but they do offer additional protection that can be extremely beneficial in an engine that is poorly maintained.
Clevite 77’s Tri-Metal bearings not only exceed light vehicle OE durability requirements of 150,000 miles, they also exceed heavy vehicle OE durability requirements of 300,000 miles.
Because the surface layer of a Tri-Metal bearing adds an additional manufacturing step, Clevite regularly hold wall sizes to within .0005” as compared to a bi-metal that can be held to within .0003”. This stack up of tolerances has nothing to do with quality, suitability, or service life.
While the silicon in the bi-metal material does contribute to slightly improved wear resistance as compared to the Babbitt surface layer of a Tri-Metal material, it’s at the direct expense of embedability and conformability.
Note: Not even all tri-metal engine bearings are the same. If you want the strongest engine bearings of the highest quality, ask exclusively for the original Clevite 77 Tri-Metal Engine Bearings.
*Part of a combination interchange requiring multiple parts competitor partsWhen 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 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.