Reply With QuoteI know they make bearings for Chevrolets, both SBC and BBC where you can turn down a crank to .040 rods and mains. They are more common in Mexico where the rebuild engines for ever.
If you need to have a crankshaft turned what's the maximum you can remove...
v-drive
I know they make bearings for Chevrolets, both SBC and BBC where you can turn down a crank to .040 rods and mains. They are more common in Mexico where the rebuild engines for ever.
Pretty open question but generally whatever size you can find bearings for. Generally .010, .020 and .030. There are some .040 for some motors tho.
Ok now this brings up another question, how much can you remove from the crank before it weakens it??. Don't know how many times I been told that anything under .010/.010 is looking for trouble and I was nuts to even think about it, but yet I've run .020/.030 on a factory crank 7500+r's and never had a problem??. I don't know but to me .030's less material shouldn't make that much difference in strenght I would think???, what ya think have I just been kucky???
Well one thing that can help is by putting an aftermarket size radius on the corners of the journals. That is one thing that is not often spelled out to many newcomers. The edge of the journals is where they usually start to crack, and by having a big radius it removes the sharp corner therefore increasing the cranks resistance to cracking. Then again Art, you already knew that.
Paul
Well one thing that can help is by putting an aftermarket size radius on the corners of the journals. That is one thing that is not often spelled out to many newcomers. The edge of the journals is where they usually start to crack, and by having a big radius it removes the sharp corner therefore increasing the cranks resistance to cracking. Then again Art, you already knew that.
Paul
I consider that standard procedure on any high performance application!..
Ok now this brings up another question, how much can you remove from the crank before it weakens it??. Don't know how many times I been told that anything under .010/.010 is looking for trouble and I was nuts to even think about it, but yet I've run .020/.030 on a factory crank 7500+r's and never had a problem??. I don't know but to me .030's less material shouldn't make that much difference in strenght I would think???, what ya think have I just been kucky???
Do you have the crank nitriding re-done when cutting down this far?
Ok now this brings up another question, how much can you remove from the crank before it weakens it??. Don't know how many times I been told that anything under .010/.010 is looking for trouble and I was nuts to even think about it, but yet I've run .020/.030 on a factory crank 7500+r's and never had a problem??. I don't know but to me .030's less material shouldn't make that much difference in strenght I would think???, what ya think have I just been kucky???
Back in the 80's class was called super modified. I took the rod journals from the stock 2.200 down to a 283 chevy size which is 2.00 on a GM 427 steel crank, then I also drilled a 1/2" hole through the rod journals, large radius, .250 long alum rods, drag race only turned it 8800 to 9200 many times no problems...
Do you have the crank nitriding re-done when cutting down this far?
I have on some and on some I didn't, no problems either way though!.
Yes the radius is most important. On rod journals I have turned them clear down to the old small block chevy size of 2.000 as did many of the Pro stock racers did and never had a problem. That's .200 down. Lot of guys did 2.100 (small block 350 size) and still do today.
The mains...that is where my concern would be. I've run a lot of .030 but it always bugged me. .010 doesn't bother me. But when we look at the really small amount .030 is I guess it should not bug us. But since the BBC dies by the mains I think that is why we get concerned with any material removed from the mains.
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