OLD topic -- S52 main bearing bolt torque

[snaponbob]

Doing Google searches has netted minor confusion. I am in search of the correct torque procedure for S52 main bearing bolts. Frankly, I do not remember how I have done them in the past, as I always "go by the book". However, the "book" has no info. I have read everything from 20nm and 50deg, to 20nm and TWO 90 degree pulls. The first spec results in ~ 45 ft/lbs. Any thoughts?

[FredK]

It should be 20 N-m + 50 degrees.

Your result of 45 lbs-ft is reasonable. The main bearing cap bolts should be M10. A grade 10.9 M10 fastener as these normally are should have a torque value of around 40 lbs-ft for an oiled screw.

[tjm3]

Fred wins.

1_Block Torque Mains_page1.png

[snaponbob]

I don't always trust old data. Why? There are four 6mm bolts in the M50/52 heads that have torque specs of either 22nm or ft/lbs (I forget which). These bolts are in the black pieces that attach to the head behind the VANOS. That much torque is guaranteed to strip before the torque wrench clicks !!. So, THAT'S why I was validing, and I appreciate the responses.