Crank won't fit with new Main Bearings.

91BLOWNSC

Registered User
Alright, my engine is in a shop getting put back together, and the new main bearings that I purchased were Standard size for a 3.8L SC'd engine. Now, there trying to put my crank back in, and it fits in the middle 2 mains, but the front and back main bearings do NOT allow any clearance between the crank and bearings themselves. There is NO clearance whatsoever, how can it beat that tight? I do not understand.....
 
Make sure you have the right bearings in the place, if I remember right there are notches on the outside bearings that have to be put in the right place, that or they have to be rotated some way.
 
Also make sure the bearing shells are installed in the right spot. The rear main journal of the crank is .010" undersized. Stick the bearings that are supposed to be there in another spot and the crank will be bound.
 
When I did mine, there's a Sealed Power Part number that puts the same Diameter Mains in the Ford 460 as the 3.8L SC motor. The difference is the 460 Mains are 0.070" wider, which to the eye at first glance, appear to fit nicely, but the width is enough to push up into the radius on the crank journals. My crank fit, but wouldn't turn!! Scared the hell out of me, to say the least, 'cause it was a new crank!!
I was hotter that hell when I found out, but they took care of me and we got the right bearings in, and now all is good.

Just something to check

Good luck!!
-Steve-O
 
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