The Ford Barn - View Single Post - Understanding Crankshaft journal hardness

MikeK · 07-02-2015, 03:19 PM

Brent, If the journals are at 50C Rockwell you are good to go for either babbitt, tri-metal, or Aluminum/Silicon bearings. Harder won't accomplish much. A typical file will be ~62C Rockwell or 700+ Brinell. If you are using AER's latest inserts they are Al/Si and will actually do best on a surface that is not glass-hard! The Silicon in the alloy actually micro-polishes a crank in the 400-500 Brinell range (42C-52C) and gives you the 100K mileage bearing life in today's production engines.

07-02-2015, 03:19 PM	#20
MikeK Senior Member Join Date: May 2010 Location: Windy City Posts: 2,919	Re: Understanding Crankshaft journal hardness Brent, If the journals are at 50C Rockwell you are good to go for either babbitt, tri-metal, or Aluminum/Silicon bearings. Harder won't accomplish much. A typical file will be ~62C Rockwell or 700+ Brinell. If you are using AER's latest inserts they are Al/Si and will actually do best on a surface that is not glass-hard! The Silicon in the alloy actually micro-polishes a crank in the 400-500 Brinell range (42C-52C) and gives you the 100K mileage bearing life in today's production engines.