Hi Everyone ,
I'm in the process of changing out the block on my 1997 XK8.
Can I reuse the head, connecting rod, and main bolts? If not where is the best place to get new ones?
Thanks,
Jay111

 

117 Views so far but no opinions. I don't like to see any question go unanswered on the forum so let's at least spark some discussion.

In the days of the straight 6 cylinder XK engine with cast iron block and aluminium head, it was regular practice to re-use cylinder head bolts once and put a 'pop' mark on the top of the hex to indicate they had been re-used.

I've gone through JEPC and the printed Workshop Manual for the early XK8 and found no guidance either to re-use or to replace head bolts on the all aluminium V8. My assumption for this is re-use is expected or there would be a warning that head bolts must be replaced.

I've always re-used con rod and main bolts for an overhaul unless there had been a failure.

1. Techs on the forum are likely to have seen any relevant TSB giving the definitive JLR guidance on re-use or replacement.
2. Parts specialists (check with forum Sponsors /Vendors) could say either 'we sell a lot of these' or 'rarely get asked for these'.

I'm off the don my Flame Suit.

Graham

 

As a rule of thumb; Look at the torque spec for the actual bolt. If it is just a specific torque you can reuse it. If it is a specific torque and then a additional degree of turn (ex 90 Nm + 180 degrees) then you should not reuse it, as the actual torque is defined by stretching the bolt.

 

Thank You, much appreciated, this forum has been a big help to me. This is my first XK8 and I'm trying to get it back on the road after a long time sitting because of a dropped valve.
Thanks,
Jay111

 

That reminded of another rule learned long ago. Where a torque setting is given as two figures e.g. Accessory drive belt idler pulley = 53-69 Nm, this is NOT a range. The higher figure is for a new bolt and the lower figure for a used (pre-stretched) bolt.

As were on the topic, here's the torque specifications for the 1999 X100 engine;




Graham

 

The cylinder head procedure I attached to your previous thread contains the information regarding re-use of the head bolts and the torquing sequence. It states that they can be reused twice (step 26). I wouldn't, but ymmv.

The conrod bearing cap bolts are single-use. See attached procedure.

Engine Repair Course Code 168 (in the stickies) gives the bedplate reassembly instructions. The bolts are again single-use.

 

Where is the best place to get new connecting rod bolts? Are they the same as Lincoln LS bolts?
Thanks,
Jay111