first hotrod build

Before you continue, you forgot to open up and smooth the oil drainback holes. See yellow circle.
 

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ok I can open them up, for an under 6000 rpm street engine I did not know it is necessary, this is why I am glad to have all your input.
 
I honestly would not be too much worried about it if you do open them up I would spend some time cleaning and using a magnet to get all the shavings out. That is work in my opinion that should have been done prior to the last hot tank and cleaning.
 
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learning to post pictures
 
Just block off any important holes or passages in the area and have a shop vac running while you are doing the grinding.
Strong magnets in the area will help also.
 
checked crank runout #2 .0007-.001 #3 .0007-.001 #4 .001 book says .002 or less on street engines .0008 or less for racing. does this seem right for a cast scat crank?
 
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IMG_20170728_180548898 (820x606).jpg cam bearing that was removed, worst of the lot. not impressed but all was clean beneath. don't understand the rear bearing with two oil holes and one oil groove.
 
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Yeah. I wondered about that myself. How can that work???
Glad you caught it. Hopefully, no other surprises.
 
ok this is what I keep getting with plastiguage .0015 main bearing clearance. torqued down rotating resistance is 45 inch pounds to start rotation about 25 to keep rotation. I am thinking I am doing something wrong, I would think a scat rotating assembly that they balanced would not be out this much.
 
keep in mind the assembly lube or even oil on the bearing surfaces has a surface shear limit,
that why the crank is harder to start rotating but the required effort to keep it spinning is significantly lower,
your initial effort to twist the crank must break that surface tension on the lube,
once its sheared the lube forms a lubricating layer and metal to metal contact is prevented as the lube forms a barrier layer

bearingwedgea.jpg

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bearingwedgeb.png

http://garage.grumpysperformance.co...tion-of-crank-durring-short-blk-assembly.852/

http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/

http://garage.grumpysperformance.com/index.php?threads/can-i-get-it-polished.9214/

http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-68194

http://garage.grumpysperformance.com/index.php?threads/thrust-bearing-wear.619/

http://garage.grumpysperformance.co...earances-and-journal-surface.9955/#post-38385
 
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