Crankshaft will not rotate

[VIKING_MECHANIC]

I'm going to get straight to the point: I was installing the crank into my engine I'm rebuilding for my K1500, using new bearings, assembly lube and the main caps in the correct position. I torqued it down to spec in the correct order and it rotated great. No binding or anything. I noticed some imperfections on the counter weights, so I took it out and brought it to the machine shop that did the machining to the block and had them correct the imperfections.

I got it home, installed it in the same way I did the first time; same new bearing since they didn't have any imperfections; lube and caps in same place that they were the first time. Each bearing was re-installed with the original cap when the crank was first installed.

Torqued to spec and now it will not rotate at all, at least not without great effort.

Even the bearings seem in perfect condition and designed very well (King engine bearings).

Did I bend the bearings or crush them just enough that the crank won't rotate by hand when torqued to spec?
The crank rotates freely when bolts are just hand tight and adequate lube on crank and bearings.

Are the bearings just one-time use once torqued down?

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[Madscientist]

Make sure your main caps are all in the correct order and direction. I would unbolt one cap at at time. See of it rotates, if not put it back on and go to the next one. I would be willing to bet one cap in on backwards.

 

[Hipster]

Was it line honed? If so you'll have fresh hash marks to look at. Pull the crank and bearings out, bolt the caps on, get out a strong ass magnifying glass and look at the hone marks at the parting lines to see if they match up. I can be more difficult to see if it wasn't honed.

Shyt happens. I had my girlfriends 10 y/o son get the touchy feely's on a set of maincaps sitting on the bench when I wasn't looking. In my case what was a crank kit turned into a complete disassembly and line boring to get it right.

 

[evilunclegrimace]

The main caps have an arrow stamped/cast in to them indicating the proper orientation. The arrow points to the front of the engine. The caps are also numbered 1 through 4 with 1 being at the front of the block.

Also the bearing locating tabs in the cap must be on the same side as the ones in the block

 

[Hipster]

The main caps have an arrow stamped/cast in to them indicating the proper orientation. The arrow points to the front of the engine. The caps are also numbered 1 through 4 with 1 being at the front of the block.

Also the bearing locating tabs in the cap must be on the same side as the ones in the block

Not all of them have numbers on the caps from factory, Hoss

 

[frito-bandito]

You could also use Plasti-gauge to figure out which bearing/cap has the least clearance.

 

[evilunclegrimace]

Not all of them have numbers on the caps from factory, Hoss

OK Hoss, I been working on these trucks and others for the last 40 plus years and that includes time as a GMC service tech, a Chevrolet tech, a Peterbilt service tech and an International service tech
I have yet to see an engine that did not have the caps numbered from the factory. Caterpillar, Cummins, Detroit Diesel, International/Ford all number their main caps as does Chevrolet/GMC.

The main reason that the caps are numbered in the first place is that when the blocks are cast they must be machined to size which includes line boring and then disassembled so that the rotating assembly can be installed.The numbering of the caps prevents the issue that the OP is having on the assembly line, Hoss.

 

[Hipster]

OK Hoss, I been working on these trucks and others for the last 40 plus years and that includes time as a GMC service tech, a Chevrolet tech, a Peterbilt service tech and an International service tech
I have yet to see an engine that did not have the caps numbered from the factory. Caterpillar, Cummins, Detroit Diesel, International/Ford all number their main caps as does Chevrolet/GMC.

The main reason that the caps are numbered in the first place is that when the blocks are cast they must be machined to size which includes line boring and then disassembled so that the rotating assembly can be installed.The numbering of the caps prevents the issue that the OP is having on the assembly line, Hoss.

There's no engine rebuilding that goes on as a Gm tech at the dealership. They R&R short and long blocks.

If you had tossed Mopar in there I would agree 100% but were not talking about other Oem's we're talking about Gm so you're experience, oh, and mine in that regard is irrelevant.

 

[Hipster]

A 94 block that I have built on the stand

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A 91 block that I have disassembled

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4 caps in 4 positions is still 15 ways to eff this up and eat some bearings and journals

 

[Hipster]

A 94 block that I have built on the stand

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A 91 block that I have disassembled

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4 caps in 4 different positions is 1 right way and still 15 ways to eff this up and lunch some bearings and journals and send metal trough the engine.

No worries, they're all marked, 40 years, um, ok