XJ40 head bolt torque, dry bolts or wet?

I have a quick question.
I have looked at old list posts on the XJ40 forum on jag-lovers.org and I have found the following information on cylinder head bolt torque:

“The cylinder head must be torque tightened as follows:
Following the sequence shown in Fig 1, tighten the cylinder
head bolts to 59 - 61 Nm.
NOTE: Ensure that the camshaft is still on TDC using the
service Tool 18G1433 (Fig 2).
Then rotate the bolts clockwise in sequence through exactly
90 degrees using Special Tool LST122 or a self-manufactured
tool of the dimensions given in Fig 3.”

What I am wondering is if these torque specifications are for dry bolts and threads (in the block) or if this is a lubricated thread value.
I.E. should I be putting oil or some other lubricant on the threads of the cylinder head bolts prior to torquing them down or not?

I did not lubricate the bolts when I did my head years ago. You are aware that you must use new head bolts and cannot reuse the old ones. IIRC you tighten them to a torque setting and then another 90 degrees. That final set stretches them beyond their elastic limit

Head bolts can be re used twice before they are needed to be replaced, on the first re-use they need to have a centre pop on the head to show that they have already been used once before.

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Good to know Robin. My information was from the original ‘91 FSM. Seems like that was superseded in your bulletin.

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Talk about taking the words (err question) out of my mouth …

I’m putting the head back on my 3.6L tomorrow and I have the same question. I’ve chased the head bolts threads with a tap and I was wondering should I lubricated the new bolts. Even though this is the first time my head has been removed from my '89 I still decided to use new bolts. I cut the heads off two of the old ones to use as an installation guide. The only reason I bought new bolts was … well actually there wasn’t a good reason, I just did it :grinning:

So any official word on lubricating the bolts before torquing them down ??

I don’t recall the FSM requiring it and I’ve never lubricated the threads. I do use neversieze on the shaft of the bolts to minimize problems with head removal later

Unfortunately I gave the eight volume set to a good friend when I left Virginia

Quoted torque settings are for dry, clean threads, no lubricant.

Guys …

My cylinder head went on today :smiley:

I read all the pros and cons online of lubricating head bolts before installation, and the expertise is all over the place ! So I ended up using a little machine oil and then wiping the bolts down. Everything went well.

I agree. The advice is confusing. When I put my head back on last month I used old bolts, oiled the threads, oiled under the bolt head, cranked them down, no worries.