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Crankshaft grind down .010?

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Old Mar 7, 2021 | 09:36 PM
  #1  
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Default Crankshaft grind down .010?

Do I have to get the crankshaft Nitride coating after the machine shop grind down .010? My plan is to boost the motor.


Old Mar 7, 2021 | 10:24 PM
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No, I never have.
Old Mar 7, 2021 | 10:36 PM
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Originally Posted by curly
No, I never have.
Thank you. From my reading, the crankshaft has a nitride coating from the factory and shaving the crank down would remove the coating, therefore making the crank weaker.
Old Mar 8, 2021 | 09:45 AM
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Only cranks that are commonly "re-heat treated" after work are aircraft which have to be by law.
Car stuff is commonly heat treated at the factory (Japanese/German stuff ) but it's THIN and not done to the same level as aircraft stuff is.
Having a crank re-treated is EXPENSIVE as most of the shops that do this are doing aircraft of industrial stuff.
I prefer to use factory cranks that have not been ground for my go fast builds but...
I've never seen a recut crank fail because the metal was too soft.
Lots of folks use ground cranks on big HP builds on all brands of manufacture.

More important on a regrind is a gentler (larger) radius on all of the "edges/corners" and high quality work.
On a REALLY serious build this radius can be so large that bearings with a 45 degree clearance cut on the outside edges is some times a requirement.
I haven't seen this on a BP build yet.

In my book having the crankshaft re-balanced is more important than having it re-heat treated.
Old Mar 8, 2021 | 01:46 PM
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Originally Posted by technicalninja
Only cranks that are commonly "re-heat treated" after work are aircraft which have to be by law.
Car stuff is commonly heat treated at the factory (Japanese/German stuff ) but it's THIN and not done to the same level as aircraft stuff is.
Having a crank re-treated is EXPENSIVE as most of the shops that do this are doing aircraft of industrial stuff.
I prefer to use factory cranks that have not been ground for my go fast builds but...
I've never seen a recut crank fail because the metal was too soft.
Lots of folks use ground cranks on big HP builds on all brands of manufacture.

More important on a regrind is a gentler (larger) radius on all of the "edges/corners" and high quality work.
On a REALLY serious build this radius can be so large that bearings with a 45 degree clearance cut on the outside edges is some times a requirement.
I haven't seen this on a BP build yet.

In my book having the crankshaft re-balanced is more important than having it re-heat treated.
thank you for the info
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