>The machine shop I am using prefers to provide a full 180 degree undercut
>on each side of the journal bearing, as opposed to a 90 degree fillet.
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This is known as full radiusing the journals and on any heavily stressed or
performance crankshaft this is (should be) done. It reduces the likely
hood of a crank failure at the journal by reducing stresses at these
junctures. Even the automobile manufacturers do this as witness on the
Ford 60 deg V6 family. The truck crank on the 2.8 and 2.9, as well as
being forged, have this full radius on all the journals, while the
passenger cars don't. Both engines use the same bearings so that would not
appear to be an issue. Sounds to me like you found a REALLY GOOD machinist
- keep him.
Barry Schwartz (San Diego) bschwart@pacbell.net
72 V6 Spitfire (daily driver)
70 GT6+ (when I don't drive the Spit)
70 Spitfire (long term project)
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