Not having much luck removing the head bolts. Tried a breaker bar and an impact wrench, but to no avail. Do I need to apply heat?

 

heat is not required. remove from outside in, to center. slide a cheater bar over your 1/2 breaker bar (1" x36" plumbing nipple is what I use). use an impact socket

 

this x100

 

Thanks! For replacement (using ARP studs/nuts), should I use the 100 ft/lb recommended by ARP, or the 15 ft/lb, then 90 degrees and 90 degrees more recommended by LR?

 

Follow arps directions using their lube

 

I personally think the arp recommendations are high on the final torque recommendation. I go by their series of torque to # recommendations, but my final torque was to 88ftlbs.

 

x1 ARP | The Official Web Site follow their instructions which are also on their website.

 

This is one time I DO use a torque wrench Dusty

There ain't no second chances if I screw up

 

these dudes go 60ftlbs, that seems low
2001 Land Rover Discovery II - 4 Wheel Drive & Sport Utility Magazine


all over the place here...20 60 80 seems to be a common group and seems about right
ARP Headgasket Oil Leak - DiscoWeb Message Boards


and on and on, but the arp recommendation takes you to 100ftlbs (unless it has been updated in the last couple years.) that seems awfully high to me, but I'm no bolt/stud engineer.
I think I went 20 40 60 80 overnight 88. same principle just added a stage or 2.


yep arp still has 100...
8. Following the manufacturers recommended torque sequence tighten the nuts in three equal steps to 100 ft lbs with ARP ULTRA-TORQUE FASTENER ASSEMBLY LUBRICANT.

 

Using ARP head bolts for some years on the Vauxhall Caterham, Ford BDA and Pajero heads. The Paj suffers the same issues as the D2 V8 with blown head gaskets albeit an alloy head to iron block but much higher compression ratio, 19.5:1. I would have thought that 'first use' threads could take much more than 90 lb/ft but problem is stretched weakened threads in well used blocks create a different scenario and also embrittlement comes into play. If it were me, I'd go for 3-4 torquing stages on an older block with the thread super lube and after 3 button it up and run the engine up to temp and then a final re-tighten to say 90 lb/ft once cooled down. Alternatively, as Dusty states, let the bolts stretch some overnight and do a final tighten which saves refitting all the rocker covers and intake tat and then stripping it all off again then refitting it all back - tedious or what?

I hate head bolt threaded into alu blocks in any case 'cos they always frick up sooner or later

Source some helicoils or inserts just in case.