Like to hear thought on main bearing crush when its out a .0002 loose?

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Re: Like to hear thought on main bearing crush when its out a .0002 loose?

Post by user-23911 »

Maybe I worked it out wrong?
Would anyone here know?
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Re: Like to hear thought on main bearing crush when its out a .0002 loose?

Post by Warp Speed »

joe 90 wrote: Mon Apr 09, 2018 5:25 pm Maybe I worked it out wrong?
Would anyone here know?
It's your story..........
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Re: Like to hear thought on main bearing crush when its out a .0002 loose?

Post by MadBill »

The thermal expansion rate of steel is 7.2 ppm F., so a 3" diameter specimen heated from 32 to 68° F. (0-20° C.) will expand by (7.2 x 3 x 46)/1,000,000, or almost exactly one thous.
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Re: Like to hear thought on main bearing crush when its out a .0002 loose?

Post by NXBOY »

I asked more then one question at first [-X and for the record I was going to run it like it was. I do realize that most people I know just make sure mains are within spec and trust the Bearing company for crush. I should of just said was a tiny bit out of spec and I always thought and read on the big 3 inch mains with fairly high RPMS and nitrous use, you need all the crush you can get. I always in past been fine or had aligned bored and been in the middle of the eight 10 thousandths window it gives. I always thought going to tight side from loose side of spec, would make some difference on holding bearing , understand align honing isn't as good as Boring and will be looser /bigger the worst the bore is out. So sound like alot of you guys are saying close to spec is good enough. I AM NOT worried about .0002 , on the edge of spec would be no difference. Atleast I learned to measure crush and thats better then trusting bearing company.
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Re: Like to hear thought on main bearing crush when its out a .0002 loose?

Post by statsystems »

Run it. If .0002 kills it there is something else wrong.
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Re: Like to hear thought on main bearing crush when its out a .0002 loose?

Post by superpursuit »

statsystems wrote: Wed Apr 11, 2018 6:34 pm Run it. If .0002 kills it there is something else wrong.

I've got to agree with this. :D
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Re: Like to hear thought on main bearing crush when its out a .0002 loose?

Post by gnicholson »

Heres another question: how much does removing and reinstalling a visually perfect used main bearing affect crush? Or put another way ,is it safe to reuse?
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Re: Like to hear thought on main bearing crush when its out a .0002 loose?

Post by pamotorman »

gnicholson wrote: Wed Apr 18, 2018 5:27 pm Heres another question: how much does removing and reinstalling a visually perfect used main bearing affect crush? Or put another way ,is it safe to reuse?
i reused rod bearings if they looked good when doing a re ring and never had a problem
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Re: Like to hear thought on main bearing crush when its out a .0002 loose?

Post by cgarb »

If the bearings look good, and still snap into their respective bores like they should...I reuse them all the time. I had a set of coated bearings I ran on 2 different sets of rings...4 seasons of brackets in my 355. Just started to take the coating off on the last time I pulled it apart so I tossed them.
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Re: Like to hear thought on main bearing crush when its out a .0002 loose?

Post by IDT-572 »

High side is the max allowed factory tolerance. .0002 over that is fine, your talking fly crap in the pepper shaker.

Stock block 460 Fords I build with Chinese 4340 cranks (Scat, Eagle) I always line honed to 3.193 high side. The cranks are ALWAYS big and now the main bore is true and with main oil spec at .0034 to .0036 with a standard bearing, they live no problems.
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