I have had a look back over previous posts but there seems to be a lot of opinions to what is right and wrong !!!!

I'm running a cometic h/gasket and arp stud and nut kit at 20psi boost, when fitted they were torqued to 80ftlb, head and block were skimed. Now at full load the cooling system pressurises and blows past the expansion cap, if drive at low boost it will drive all day long with no abnormal cooling system pressures...i've rechecked the head nuts once cold and they all didn't move when i rechecked the torque...

Would you slacken them one at a time and retorque checking the studs haven't moved (i've paint dotted the tops of the studs to see if they move) and if so what would you torque them to ??? I havent any lub that came with the stud kit !!!

Any experienced opinions please.....

Thanks Guys,

Sean.

 

I'm not at all surprised you were having trouble at 80lbft, head gasket will likely be no better than scrap now though, ie weakened.
They need torquing up to 120lbft, that's what I do it to, using a victor reinz group a Yb 0611, part number now is 27380 00, as this is a fibrous gasket leave at least 4 hours then retorque, or overnight is fine.
It is 100% vital that the studs do NOT bottom in the block, each hole needs clearing/tapping and depth checking, the if necessary trim a few mm from the stud if needed.
The studs have a shoulder that sits in the very small area around the actual hole, this absolutely must sit on the block and not be proud.
The studs just need nipping up with pliers nothing more so they don't move.
Lube the top threads with 10W40, not swimming just damp, the refit etc the head.
tabetha

 

Thanks for the info Tabetha....much appreiciated !!!

 

Will the victor reinz gasket be ok for 32psi boost ???

 

Im on a Grp A gasket peaking @ 2.2 bar and its still holding together.

Im also just on standard headbolts

Steve

 

Depends on turbo, but certainly with t34/38, easy.
tabetha

 

definatly going for this gasket rather than the metal type, mine started lifting at 2 bar after 1k

 

T4..........????

 

Detlef in germany has been running 28psi on a T4, over 40,000 miles(not K's) including days at the ring(he lives 8 miles away), not seen a problem yet.
I know there's quite a few norweigan lads running 500+ on group a as well.
tabetha