Regrinding crank questions

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ClassicComp
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Regrinding crank questions

Post by ClassicComp » Tue Dec 11, 2018 9:20 pm

Possibly need to have a sbc steel crank 2.480 mains ground down to 2.300.
Will this need to be rehardened?
results speak for themselves
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Re: Regrinding crank questions

Post by Keith Morganstein » Tue Dec 11, 2018 10:30 pm

ClassicComp wrote:
Tue Dec 11, 2018 9:20 pm
Possibly need to have a sbc steel crank 2.480 mains ground down to 2.300.
Will this need to be rehardened?
I’m sure it would be better to have it nitrided, but It’s been done countless times without.
Automotive Machining, cylinder head rebuilding, engine building. Can't seem to quit #-o

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Re: Regrinding crank questions

Post by mag2555 » Wed Dec 12, 2018 6:34 am

That can be a uncontrollable process at times with good depth penatration at some areas of the Crank and only a few thousands in others.
I might look into getting it Cryogenic treated if the added cost is not a factor which would add strength that the Ni treating does not , plus have the added surface ware hardness.

The main thing by far though in terms of strength is to have the regrind put in a nice fat radius at the Crank cheeks and the mod the Main Bearings if need be for clearance.

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Re: Regrinding crank questions

Post by Momus » Wed Dec 12, 2018 7:58 am

Nitride for sure. The journals will be hard and wear resistant and the crank will be in compression giving extra fatigue resistance.

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Re: Regrinding crank questions

Post by Newold1 » Wed Dec 12, 2018 11:54 am

I would talk to someone who is a crankshaft builder and expert grinding and repair shop like Dave at Marine Crankshaft in Santa Ana, California and get the best opinion from an expert that does these things over the years in big quantities and knows what you can do and what will stay together the longest.
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Re: Regrinding crank questions

Post by In-Tech » Wed Dec 12, 2018 11:59 am

^^^^^^^^Yup, Dave gets my vote too.
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Re: Regrinding crank questions

Post by Dave Koehler » Wed Dec 12, 2018 12:51 pm

I have heard no mention of the intended application for this crank.
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Re: Regrinding crank questions

Post by ClassicComp » Wed Dec 12, 2018 1:32 pm

SB2.2 drag engine
results speak for themselves
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Re: Regrinding crank questions

Post by Newold1 » Wed Dec 12, 2018 3:15 pm

If that's your application then I and I am sure others here would recommend chasing down a good used aftermarket racing billet SB2.2 crankshaft . They are quite a few available at decent costs out of track racing team disposal in probably the type of journal size you are talking about.
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ClassicComp
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Re: Regrinding crank questions

Post by ClassicComp » Wed Dec 12, 2018 7:31 pm

2.300 mains 3.625 stroke w/a BBC snout are tough to come across without a contact.
results speak for themselves
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Re: Regrinding crank questions

Post by Dave Koehler » Wed Dec 12, 2018 7:42 pm

So...it's a blower application?
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Re: Regrinding crank questions

Post by ClassicComp » Wed Dec 12, 2018 10:27 pm

Dry sump,ATI dampener jesel drive
results speak for themselves
BobF

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Re: Regrinding crank questions

Post by Dave Koehler » Wed Dec 12, 2018 10:47 pm

FWIW, long before all the hi zoot cranks were available off the shelf like today we would grind the oem Chevy cranks down like you are doing and race on.
No issues to speak of and did not seem like a big deal at the time. Just sayin'
Now we know too much or think we do.
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Re: Regrinding crank questions

Post by ClassicComp » Thu Dec 13, 2018 6:57 am

=D>
results speak for themselves
BobF

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