Proper torque settings for 12.9 grade main bolts?

[Thuppu]

Pas, do you have experience with JE low tension oil control rings? They feel really suspicious. Have now tested 2 kits of rings. Next I will take all apart and measure everything.

[AndyP]

Pas, do you have experience with JE low tension oil control rings? They feel really suspicious. Have now tested 2 kits of rings. Next I will take all apart and measure everything.

You using JE pistons too? I hope mine is not rings as I really don't want to rebuild the engine again

[Thuppu]

You using JE pistons too? I hope mine is not rings as I really don't want to rebuild the engine again

Yes, and my is definitely letting oil past the rings, but the reason can be the bores.

[Error404]

The more I read about JEs the more I think they are just not suitable for use in a road engine! But I guess they are not designed as such, I am sure in terms of strength & lightness they are great, but I was put off by the seeminlgy massive clearances you need to run with them, hence I went with Wossner (which still use 3 x the clearance of the OE Mahles!)

[SteveH]

So, the stock main bolts(10.9 grade) torque specs are 48ft/lbs. ARP mains 65ft/lbs, but this can bend the main caps and press the clearance to zero.

So I suppose 12.9 grade bolts should be something between these? What would be the ideal sweetspot?

Did you ever get an answer to the correct torque rating for 12.9 grade bolts?

[SteveH]

Looking at this web source, the torque spec for 12.9 grade bolts should be in the 80NM range.

https://www.wtools.com.tw/STANDARD-BOLT-TIGHTENING-TORQUE.shtml

[Thuppu]

Did you ever get an answer to the correct torque rating for 12.9 grade bolts?

I ended up to keep the torque somwhere between the OE- and ARP-bolt settings. Just to keep it safe so the caps dont deform.

[vidar skotheim]

Did you find out about the oil problem ,, i have one engine with new valve guids ,, the dimensions were the sealing sits are to smal so i can turn the sealing with the finger . that engine realy burns oil . mostly filing the ex manifold after it stops ..