stock forged cranks, undercut fillets?

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pishta

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Did the 273 or 340 forged cranks have undercut fillets? I know cast cranks have this feature and the aftermarket forged units don't as it is a 'potential stress riser'. Seems if so, it would be a simple way to ID a stock forged crank at a swap meet for the untrained eye.
 
How about the 318 cranks and anyone got some pics to share?
 
Yes. Fillets cast or steel
Raised is aftermarket sometimes described as "radiused journal"
Thanks , explains same bearing number used on both cast and forged cranks. When you cut a rod journal .030, this is still there?> How deep are they?
 
Thanks , explains same bearing number used on both cast and forged cranks. When you cut a rod journal .030, this is still there?> How deep are they?
Yes, they are still there... barely.That's only .015 off the journals surface.
 
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Here's one of a modified 360 to go in a 318, rod journal under cut still visible, but the mains now have a radius, under cut is gone.
100_1984-jpg.jpg
 
guys
they are not "undercut"
they are rolled under extremely high pressure, compressing the metal
really undercut with a tool or grinder would really weaken
rolled are tough and the deformation goes deeper than the depression
what matters is still there
aftermarket grinders do not have the big tooling to roll fillets IMHO rolled fillets are better than ground
It takes a big radius
 
guys
they are not "undercut"
they are rolled under extremely high pressure, compressing the metal
really undercut with a tool or grinder would really weaken
rolled are tough and the deformation goes deeper than the depression
what matters is still there
aftermarket grinders do not have the big tooling to roll fillets IMHO rolled fillets are better than ground
It takes a big radius
Here's one of a modified 360 to go in a 318, rod journal under cut still visible, but the mains now have a radius, under cut is gone.View attachment 1715306055

Wyrmrider's got the terminology right! That's how it is.

The only who said "under cut"
 
Yeah, me bad, poor wording on my part. Only using the term in the header post.
 
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NO problem
lots degenerate MOPAR "under cut" fillets and try and sell a radius fillet aftermarket crank
I call out the BS
 
guys
they are not "undercut"
they are rolled under extremely high pressure, compressing the metal
really undercut with a tool or grinder would really weaken
rolled are tough and the deformation goes deeper than the depression
what matters is still there
aftermarket grinders do not have the big tooling to roll fillets IMHO rolled fillets are better than ground
It takes a big radius
I had no idea that was the case... Many thanks wyrm.
 
Words have meanings but often we get caught up in the latest new descrptions of old terminology...does that make sense?

I was often schooled on using proper terminology by my GM Training School instructor John Porter. That was 50 years ago but he always asked "how can you order the correct parts for a job when you don't know what the parts are named"?

Made sense even then. We are all guilty of doing this...

Carry on.
 
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