Crankshaft journal radius

[Dave1]

What is the recommended radius for the ends of the bearing journals when grinding. I have a coupe of cranks on hand, it seems the last fellows that ground had different ideas.

Dave

[Kerry]

Usually what the grinder does, he is not going to change any angles of his stone for just one T crank if it differs from what he is using. ie, scat cranks have a larger radius and usually have to scrape the babbitt some to clear.

[t-time]

The 1926 Ford print shows the main journals 5/64-1/8 radius and rod journals 7/64-9/64 radius. The larger the radius the stronger and less chance of cracks developing.

[J and M Machine]

We try and keep them as big as possible. At least 3/32"
Problem is after 100 years and bad machine shops most often nothing left.
BTW: since everyone else is advertising now on the forum:
https://www.jandm-machine.com/grinding.html

[Dave1]

Gotcha, thanks