Trouble torqueing v8 heads

[mikec]

Hi guys just fitting my heads at the minute. I was doing the 20nm plus 90 plus 90 system. But I had been told with care you can do 80lbft. So set my torque wrench to 80 so I didn't go above that. So I did the first 90 now I've come to the second 90 the first six all went ok, but from bolt 7 onwards there all hitting the 80 limit without barely turning! Any advice on this? Cheers mike

[need4speed]

tbh ive never bothered with the 90 plus 90 rubbish. Listening to Ray at V8D i did mine at 30lbft then 80lbft. Job done.

[mikec]

tbh ive never bothered with the 90 plus 90 rubbish. Listening to Ray at V8D i did mine at 30lbft then 80lbft. Job done.

Was that with stretch bolts? Think ill have to undo them and try again?

[need4speed]

I NEVER use stretch bolts. Hate 'em. Yes i know the purists will be on quick as a flash saying theres nowt wrong with them etc etc.... My opinion? Chuck em in the bin.

For one thing now that you've stretched them by fitting them, are you now going to trust putting 80lbft into them again?

I use HT cap head bolts from V8D. Though im sure you can get similar from other places. One advantage of bolts like these is the fact that you use them time and time again.

[Ash.Witty]

I used ARP head studs when I rebuilt the top end after boiling my v8, you run the studs down into the ally block and then tighten the nut pulling on the stud. They are better for the block threads as you're not torquing the bolt into a soft metal so there's less chance of pulling or stripping a thread.

Also I have built up a V8 with V8D's ht bolts and washers and they worked a treat but only tightened to 70 ft lbs. where as with the Arp studs I torqued the heads down to 90 ft lbs. because my v8 was turbocharged