What is a typical main bearing clearance specification?
As a rule of thumb, main bearing clearance should be targeted between 0.0025- and 0.0020-inch for most street and street/strip engines.
What is an undersized main bearing?
An undersized bearing has extra material thickness on the inside of the bearing facing the crankshaft journal. Undersized bearings are used when a crankshaft has been machined or ground undersize. Oversize bearings have more material on the outside facing the bearing housing bore.
What is an undersized bearing used for?
Undersized bearings are used to accommodate a smaller sized journal than a standard sized bearing. Sometimes, if a journal is damaged or excessively worn, it is machined smaller so that the damaged surface can be removed and a fresh surface made for a new bearing.
How many main bearings does a V8 have?
Some V8 engines have five main bearings, with one crank pin between each pair of adjacent main bearings. Most straight-5 engines have six main bearings, to help counter the essential imbalance of this design.
What are oversize bearings?
An oversized bearing is one that fits into a larger hole in the engine block, into the hole created by bolting the main caps to the engine block. This gets all of the mean bearings into perfect alignment, increasing bearing life and decreasing vibration and stress on the crank.
What is the difference between oversized and undersized bearings?
An undersized bearing has extra material thickness on the inside of the bearing facing the crankshaft journal. Oversize bearings have more material on the outside facing the bearing housing bore. Oversized bearings are used when the block has been machined or line bored oversized.
Do I need undersized main bearings?
An undersized bearing has extra material thickness on the inside of the bearing facing the crankshaft journal. Undersized bearings are used when a crankshaft has been machined or ground undersize….UNDERSIZE & OVERSIZE ENGINE BEARINGS.
| Part No. | 8N8926 |
|---|---|
| Size | 0.010″ US (0.25MM) UNDERSIZE |
| Description | BEARING MAIN |
| Application | 1140, 1145, 3208 |