Do they have more clamping load then?Well I use my own stronger studs - so yes good idea, more clamping load, but the trouble is the block and the crank path were machined for the old OE unheat- treated bolt , about grade 8. So use a stiffer bolt and you will distort the block more, crushing the crank in it's path.
A similar situation happens at Scholar - they hone liners in blocks and occasionally crank paths, They are honed with their own grade 10.8, 10mm bolt done up to 60lbft. The OE bolt sequence 20Nm + 180+180 is equivalent to 40 NM - about 32lbft
so as I said building problems into the engine.
And as my uncle used to say," midbogglingly stupid"
I assumed the load would be the same since they are not tightened as much and it's just that they stretch less when additional load is put on them - thus the block would not be distorted?
the MLS kit ( ZUA000080 ) which includes the new uprated oil rail. High tensile head bolts are WAM2293SLP. These are grade 10.9 which do not stretch as much as the originals. ( Grade 9.8 ) Once these are torqued into the heavier oil rail....they stay torqued !.
This oil rail is the same as was spec'd for the EU4 engine and is the one for the even newer "ultimate fix" gasket kit mentioned in another post.
So are the head bolts WAM2293SLP.
Only thing with the newer type is the torque settings change.
20Nm then 180 degrees and then 135 degrees instead of the current 20Nm then 180 degrees and then 180 degrees .