help for a frenchie

[matuva]

I was looking a the torque thread and found following values :

Crankshaft:

• 
  Bearing Cap 12mm Inner Bolts:
  Make Two Passes--55 (75)
  Final Pass--90* more

• Bearing Cap 12mm Outer Bolts:
  Make Two Passes--48 (65)
  Final Pass--90* more

• Bearing Cap 10mm Outer Bolts:
  Single Pass--30 (40)

This is not clear for me. Which ones are the 12mm outer bolts, the inner, and the 10mm outer bolts

Wich ones are the ones for the connecting rods and for the bearings on block ?

You may say I should find when the oil pan will be down, but I waan a get sure I get all torque informations before I swap the crankshaft.

Thanks for your help...

 

[qwomack]

The way I read it is they are all for the main bearing caps. The 12mm outer bolts are for the early blocks and the 10mm outer bolts are for later blocks. All blocks have 12mm inner bolts. Does this make sense? Also, it is a 4 bolt main block, hence the outer and inner bolts.

 

[mitchedo]

Those specs are all for the main bearings. The old blocks have 12 mm bolts at all 20 positions. The newer blocks with the oil squirters have 10 mm bolts at the outer position on 2, 3, and 4.

From the torque sticky: Connecting Rod Nuts--48 (65)

 

[matuva]

Thanks a lot guys. More clear now.
Mitchedo, thanks for the Rod nut, I missed this one :thumbsup:

 

[Missy Good Wench]

I noticed the specs on the main bolts quoted as adding an extra 1/4 turn after torque was reached

The mains are not a TTY bolt. The specs right from the GM shop manual shows (12mm bolts) 100 outer bolts and 110 inner bolts.

These do not get the extra 1/4 turn.

Doing so will seriously over torque these bolts.

The bottom end of these engines are touchy anyway so dont complicate things with too much bolt torque.

Best

MGW

MGW

 

[matuva]

mmm, wrong stickies so ? :shocked:

 

[matuva]

So, on the mains, last turn 90° or not?

 

[Mezmorized]

That build is going on 4 years?

 

[NVW]

So, on the mains, last turn 90° or not?

Not according to Missy in post #5, I would follow her advise Al.

 

[matuva]

Yup sure Leo, will do.

Anybody can confirm torque spec for the 10mm outer bolts? Single Pass--30 ft/lb (40N/m) ?

 

[NVW]

My Haynes manual says 110 ft/lbs inner and 100 ft/lbs outer. No mention of 12mm or 10 mm bolts.

 

[matuva]

Hmmm, that's odd, not sure a 10mm bolt can handle as much torque than a 12mm can.

 

[matuva]

I think I found it : http://www.torkspec.com/torkspecme.aspx?KI=12-6.5L-396ci-V8

so if I'm right, the 10mm bolt must be torqued single pass to 80ft/lb

 

[matuva]

Sorry, was reading too fast and confused head bolts with mains ones

The interesting point is that according to this chart, head bolts go in one pass at 80ft/lb, instead of 2 passes @ 55ft/lb + 1/4 turn more...

 

[NVW]

I agree 100 ft/lbs would be high for a 10mm bolt so it must be for a 12mm.

Check the site you linked to, the only 80ft/lb torque setting I saw was for the cyl. heads. I think those specs are for the gas engine as there is mention of 2 bolt mains.

http://www.thetruckstop.us/forum/showthread.php?612-Torque-Specs I think you already read this as it says 30 ft/lbs for the 10mm outer bolts.

 

[matuva]

Yes, I saw that, and this time I think it's a bit weak for mains bolt...:skep:

 

[matuva]

Bet that if head bolts can be torqued at 80, the 10 mm mains bolt can too, but I'm afraid of cracking mains...

 

[NVW]

Lots of members here have rebuilt these engine, probably best to wait for an accurate reply.

 

[matuva]

One more find, but still for the 1988-1996 engines, nothing for 1997 and on http://www.mrwrench.com/1988-1996GeneralmotorsChevroletGMC62L-65LDieselTorquespecs.html

 

[matuva]

Finally, it looks like the 10mm outer bolts are to be torqued at 30 ft/lb : http://www.dieselplace.com/forum/showpost.php?p=1386710&postcount=3