Get the ARP studs! Some common sense will tell you that the bolt torque is the cause of the failure. It just about takes a five hundred pound Gorilla to get those bolts loose. I have performed many head jobs on the Rover V8 and have done them using studs and stretch bolts. I haven't used a stretch bolt in years because of all the research that has been done proving that they are the reason for the cracking of blocks and liners. The ARP studs aren't much more money and only torque to about 80ft. lbs. as compared to about 200 with the stretch bolts. It's your engine...I know my custom built 4.6 will last more than 100,000 thanks to ARP.

 

If you can avoid resurface - then avoid it.
Makes the compression higher.

Heads are probably just fine as they are.

 

Both heads checked ok within tolerance.
Will check into the ARP studs.
I'm running a tap through all the holes to get them good and clean.
Gaskets that came off were Land Rover branded, don't know if that is good or bad.

 

Don't use a tap, use a thread cleaner. Some taps will cut more material from the block giving you even less load surface (not a desirable condition)

 

Update on head gasket repair, in case anyone is suscribed.
The #1 head bolt (forward of #5 Cylinder) pulled all the threads out in one spiral piece. Installed a Helicoil and hoping for the best. New water pump and thermostat installed. Plan on finishing it tomorrow if no other issues jump up and bite me.

 

It's interesting that the bad cylinder had the stripped bolt.

Seems to support the notion that stretch bolts suck.

Where do you buy the arp stud kit?

 

I never could find an ARP kit for a Rover, they did not show one on their web site. (Or I couldn't find it) Really didn't want to invest another pile of cash into a mod I'm not totally sure about.

I haven't researched this yet, but it appears to me that the amount of torque required to stretch the head bolt 180 deg, is borderline TOO MUCH for a 7/16" bolt in an aluminum block.

 

Did the research on bolt torque for the head bolts. And just as I suspected, the maximum torque for this fastener package is 77 lb.ft.. Suggested value is 54 lb.ft. This is assuming the highest grade aluminum listed in the chart, which I doubt we have in this case.

Sounds like a design problem/flaw to me.

A set of 1/2" -13 bolts would appear to be a better size for the 180 deg stretch bolts. This would allow 118 lb.ft. torque.

 

You can scan eBay for the bolts, I just bought some from a place in Los Angeles for 95 dollars. I believe the studs come in at about 200 dollars.

 

I've read the studs should be torqued to no more than 60 ft/lbs or they might pull out.

But 60 ft/lbs seems to be plenty.

Thanks for the ebay tip. I should have thought of that.