These special bearings have a .015" oversize outside diameter for use in Formula Ford 1600 ("Kent/Cortina") engine blocks that have been line-bored. Line boring cleans up misalignment in the main saddles. Ford even used the technique on many new blocks installed in new cars, to prevent scrapping otherwise good blocks. Many of these blocks are still in use today, though the special bearings are becoming harder to find.
Q: How do I know if my block has been line bored?
A: The ID of the main bearing saddles measures 2.286" / 58.07mm in a bored block (2.271" / 57.69mm in a non-bored block). Bored blocks are often (but not always) stamped "015" somewhere on a main bearing web or oil pan rail.
Main bearings are sold in sets of 10 (one set completes one 4-cylinder engine).
| Crankshaft Measurements for Main Bearing Sizes |
|---|
Bearing Size
(Nominal) | Crankshaft Journal
Diameter (inches) | Crankshaft Journal
Diameter (mm) | Bearing Part No. |
|---|
| Standard | 2.125" - 2.126" | 53.983mm - 54.003mm | 1504-STD/15 |
|---|
1st Undersize /
10 Under | 2.115" - 2.116" | 53.729mm - 53.749mm | 1504-010/15 |
|---|
2nd Undersize /
20 Under | 2.105" - 2.106" | 53.475mm - 53.495mm | 1504-020/15 |
|---|
We also offer Standard Main Bearings (Part No. 1502) for use in blocks that have not been line-bored.
