Ran into an issue with installing my crank...

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(posted from my build thread)

Alright guys, I'm in need of some serious help...

I have been working on putting everything back together (mostly getting the crank in) and I ran into a serious issue.

I torqued in all of the mains to 30 ft/lbs (full torque is 45-52) and I was going to spin the crank just to make sure that everything was moving smoothly. Note: I have not installed the pistons yet - just the crank. When I went to spin the crank it would not rotate. Now when I took everything apart the crank would spin smoothly with the old bearings in it and everything. However, now it would not spin anywhere close to "freely" - I had to put over 100 ft/lbs to get it to move.

So, please help me out. I ordered what I thought were standard main bearings from Advance Auto - I told them standard and the part number on the box indicates that it isn't oversized.

For reference the part is Sealed Power MFG# 7285M

It seems like the only reason the crank would resist this much would be if the bearings were oversized.

Any help with this issue is greatly appreciated!

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Does anybody know if Nissan would put in 0.50mm UNDERSIZED bearings in from the factory?

I ask because I just measured the bearing diameter (installed and tightened) and compared it to the crank journal diameter and had the following measurements:

Main Bearing = 59.62 mmCrank Journal = 60.1 mm

Going by this in order to get a clearance of .020mm - .046mm (factory spec) I would have to purchase .50mm undersized (or thinner than standard) bearings. That is if in fact I received the properly sized bearings in the first place - which I am unable to find out anyway of telling besides the packaging which has no indication of being oversized or under (and I ordered standard)

[480sx]

No, nissan would never put an undersized crank from the factory. Ever. You might have a crank that has had a regrind, therefore has oversized bearings. You might want to take it to a machine shop and double check. Expensive ish were talking here, its worth the ~100 bucks to check everything out professionally.

You need to go find a plastigauge dealer and buy some. Check all your clearances, also, check to make sure the plastigauge isnt compressed unevenly, indicating that one side is tighter than the other, or your cranks warped.

Also, i believe that the torque spec is 50 NM not foot pounds for the main girdle bolts. Remember, the whole Jap world and most Euro cars doesnt use foot pounds as a standard. The same is true with the nissan FSM.. They list ft pounds in some places but pretty much always go with NM as their first number.

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Well, I went and pulled my replacement bearings out and found that they said 0.25 on them (my assumption being that they were oversized bearings)

I also looked at the old bearings and noticed that they were in fact the original bearings (or at least Nissan replacements) because they are Nissan bearings and were STD size.

So, I took the oversized bearings back and will have standard bearings tomorrow. However I am still unsure if they will fit but I will find out tomorrow.

[driftiteasy0113]

i would say check to see if you put all your bearings in the right way. if any are in wrong it will cause it not to rotate freely.