Crankshaft Main Bearings - 1thou under


ACL Race Series crankshaft main bearing shell set to fit Ford crossflow, pre-crossflow, Lotus Twin Cam and BDA engines.

These bearings are 1thou under, please see the table below with measurements in inches and millimetres to see if these bearings will suit your crankshaft. 

These crankshaft main bearings are sold in a set. One set completes one 4-cylinder engine.

We have the following sizes available:


- 1thou under (0.001")

- 10thou under (0.010")

- 20thou under (0.020")

We suggest checking that you are installing the correct bearing size by using plastigauge prior to final assembly.

Crankshaft measurements for big end bearing sizes

Bearing size (nominal) Crankshaft journal diameter (inches) Crankshaft journal diameter (mm)
2.125" - 2.126"
53.983mm - 54.003mm
10th under 2.115" - 2.116" 53.729mm - 53.749mm
20th under 2.105" - 2.106" 53.475mm - 53.495mm


Please note that once the packaging is open, we won't accept any returns/refunds for these items.

Free shipping Australia-wide on all orders over $150.

Free shipping to New Zealand on all orders over $200.