Crankshaft Bolts to Cylinder Torque ?

[Sindako]

Hello .
See Tommorow I will Install The Pistons and crankshaft to my Cylinder block >
everything is good now thank god for that .
But I need to Know The Torque Of These Bolts Shown In the Photo ,
The Bolts That Hold The Crankshaft and conjunctions to the block .

What The The Torque for these Ones .
I have Every Toque I need But I couldn't Find Those ones Torque .

Also In The Bentley Service Manual , The Head Bolts Which Are Torx
30 , Wait 15 minutes then 90 degrees , then while Optimal temp another 90 degrees .

But I've Read Somewhere That it's :
Cylinder Head bolts: 30 then loosen them then 30 then 45 then 65 then 80nm

what should I Do Now ?

[Madhatter]

look in the bentley for main bearing cap bolts. That's what the item you are pointing to actually is, the main bearing cap. All m10, m20 and m30 motors are 60Nm (45 ft/lbs).

The bolts aren't torque to yield "stretch" bolts so they can be reused if you wish, bmw generally recommend replacing them anyway just for safety if you are pulling down and rebuilding the engine.

Both torque settings you posted above for the cylinder head bolts are kind of right, there are two different torque specifications depending on the type of bolt. The hex head style is 40Nm, wait 15 mins, 60Nm, then torque through an additional 25 degrees. The newer torx style is 30Nm, then 90 degrees and 90 degrees.

[jlevie]

Even if you happen to have some, never use the hex head head bolts. They were recalled for separation of the head of the bolts. Madhatter is correct on the main bearing caps, but failed to mention that rod bearing and head bolts are one time use items. Once installed that must be replaced rather than reused.

I recommend bringing the head bolts to initial torque (30NM) and then finishing the installation of the head and everything else before angle torquing. If you find it necessary to pull the head the gasket and bolts can be reused.

[Sindako]

Even if you happen to have some, never use the hex head head bolts. They were recalled for separation of the head of the bolts. Madhatter is correct on the main bearing caps, but failed to mention that rod bearing and head bolts are one time use items. Once installed that must be replaced rather than reused.

I recommend bringing the head bolts to initial torque (30NM) and then finishing the installation of the head and everything else before angle torquing. If you find it necessary to pull the head the gasket and bolts can be reused.

I used The Best head Bolts I have , I have 44 bolts at my garage , I took the best ones with sharp rail and I screwed them using the toque and the angle , and it's fresh and shiny . I followed the directions of the Bentley manual and finished up my build 4 days ago ,
now I just need to put the cables in the bracket with the relays and the Engine harness plug .

Thanks you , Cheers

[Madhatter]

They were new bolts though yeah?

[Sindako]

They were new bolts though yeah?

Nope . But Bolts That are Cleaned and Had Sharp rails , also tested at a Lathe to see if they're still as good as New .

[jlevie]

Nope . But Bolts That are Cleaned and Had Sharp rails , also tested at a Lathe to see if they're still as good as New .

Torque to yield bolts are never "as good as new" once used. The process of installing the bolts takes the material just past the elastic limit so that deformation will occur. The bolt will then hold its clamping force as long as load stays below the elastic limit. The elastic limit of the bolt changes after the first deformation, which means that the bolts can't be reused.

Pull out any re-used rod or head bolts, purchase new ones, and install those using the procedure in the Bentley/TIS.