Crank and rod bearing journal sizes standard bearings or turn crank?

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big block

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Ok guys I need some engine experts. Here are my crank journal sizes. Do I need the crank turned or can I use standard bearing sizes? Crank looks pretty good to me.
Engine is a 1978 LA 360
Sizers are
mains
no 1 2.875
no 2 2.7895
no3 2.7915
no 4 rear main 2.7870

rods
no1 2.1055
no2 2.1060
no3 2.1075
no 4 2.1040 I hope someone can direct me in right direction.
Thanks
big block
 
Whoa, that #1 is way out ! bearing are available in .010 steps with a .001 available after a polish. I think #1 is a misprint...maybe 2.7875? 2.81 is stock blueprint so yours looks .030 (edit .020) under already...that about as far as bearings go.
 
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pishta said:
Whoa, that #1 is way out ! bearing are available in .010 steps with a .001 available after a polish. I think #1 is a misprint...maybe 2.7875? 2.81 is stock blueprint so yours looks .030 under already...that about as far as bearings go.
Click to expand...
I,ll go remeasure. Back in a minute or so.
 
Is this just a theoretical question ? "looks pretty good to me "??
Journals also need to be "round". They will wear into oblong dimensions.
Money ?? Just because ? The A-Engine is a link with specs.

A-Engine
I have assembled many Mopar engines. Your questions are not exact enough for a real answer. Bores, crank, rod journals etc..; Are only perfectly round when new. As they wear, they wear in a tapered and/or oblong fashion.
Anyone who does engine/machine work knows this. A standard mic does not measure this.
Engine clearances need to be picky.

 
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I,m Back. Did a little more careful measuring. Made sure I zeored the mike each time.
mains
ni 1 2.7885
no 2 2.7810
n0 3 2.7735
no 4 2,7870
Rods
no 1 2.1020
no 2 2.1020
no 3 2.1025
no 4 2.1025
 
How about crankshaft throws instead of rod journals. Looks good to me means smooth no pits or scratches on the journals.
I asked for experts not nitpickers. I wanted some one who has actually torn an engine do once.
 
Calipers is not the right tool but gets u pretty close. Take the crank to the machine shop and have them check it. As mentioned earlier they go out of round. 9 times out of 10 the machine shop will tell u it needs to be turned. Kim
 
still looks like it (3 of 4 measured) could take a clean .030 cut and new -.030 bearings if your gonna do it. .0015 is blueprint bearing clearance. Number 3 journal looks past due for even a .030 cut though. May not be an issue but it is what it is.
 
First, there are four rod journals, and five mains. Twice you have given measurements for only four mains.
Next: if your measurements are good, you have .030+ mains now, and an odd size rod journal, between .020 and .030 under.
The first thing i would do, i would make sure i could find .040 under main bearings. If you cant, that crank is now a lamp stand.
YES, it sounds like it needs grinding. Best advice you got here...take it to a crank shop, and ask.
(And, no offense, i use a digital caliper for some things too, but a micrometer is the proper tool, and each main needs two measurements, and each rod journal needs four.)
Edit: take a look
at the back side of your bearings, they will tell you what size they are. There will be a part# like xxxx-20 or *** .030 (if you use standard bearings on that crank, you might be lucky to get five pounds of oil pressure. But it will turn over easy.)
 
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