Putting the heads back on

[rturbett]

When putting the head bols in on a 3.9, do you use a sealant on the threads?
My machine shop said if they were blind holes, use a drop of oil, or if they went into the water jacket, use a selant.

Do you reccommend re-torquing the bolts? Or is there somthing in the new gasket design that makes this not needed.

Thanks,
Rob

[57loboy]

The correct bolts are not supposed to be retorqued - ever. use only new bolts. They are stretch bolts and are only good for one use. Follow the torque sequence and values precisely and you'll have no issues. I used a marked socket for the +90deg part...

[rturbett]

I have the new set of head bolts. I was referring to retourqing after installing, not reusing the old bolts.

The engine manual says "6. When all bolts have been tightened, recheck
the torque values." but I had read somewhere about not retorquing, but not sure where.

I do not understand what you mean by +90

Rob

[rturbett]

Okay, so now I decided to read the directions that came with the new head bolts. (sorry if I've lowered the Land Rover gene pool)

I now see the 90 then 90 more. Why wouldn't you just set the correct torque value? Is this a technique that is specific to stretch bolts?

Thanks for your thoughts

[57loboy]

I believe it is a technique specific to the stretch bolts. Getting the right initial clamp by tightening to the specified value and then doing the 90deg and 90deg gets the bolts to the right "net" value by taking advantage of the "stretch" feature. I am not all that knowledgable about the metallurgy behind it, but it's what's called for. On another note, several people have suggested to me (and it's what I did) that one should wait a little bit between bolting them up to the torque value and beginning the 90deg turns. Kind of like, tighten to spec, have a beer, tighten 90deg further, have a beer, tighten final 90deg.... Could be witch doctor/old wives tale, but it makes you think about what you're doing for sure.

[rturbett]

I did the work last night- You are right about waiting a little bit. After I did the first 90, I thought there was no way I would get another 90. After waiting a beer and a bandaid (both for when the wrench slipped) I was able to get the final 90 in. I can see where the drop of oil they recommend on the underside of the head really helps.
Rob