What kind of damage did you try fixing? and what did you use?
Why not try to give the head a light surfacing in that area? If its only a couple of thou then so long as the indent is removed the head would take up any deviation.
I used a high temp, hi-metal solids, meant for metal repairs. Itâs been long enough ago I cannot recall the brand.
It was a Datsun 1200, so R&Ring a head was a couple hour job⌠not quite the same on the Jag.
Do what ya will, but a quick cut of 2-3 thou wonât affect anything, and itâll be correct. Youâd have to do both sides, though.
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Thanks! I am weighing my options and getting the heads surfaced is was my gut tells me but at the same time I think I can get away with this repair. Oh well iâll let you guys know what I end up doing.
I would definitely surface the head, itâs a lot of work to re do.
You only have to do the damaged side.
Yea thats what I am leaning towards. As for doing only one side, wouldnât that screw with the engine having one side be a slightly higher compression ratio than the other? if they have to take off more than 0.003 then I would want to both sides right?
IMO .003â the engine wouldnât see it. If you were talking bigger figures, and I mean bigger, then yes.
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Q: Can a machine shop do .003"? I thought there was a minimum depth cut, something like .010". Try cutting anything smaller and the tool just skips around on the surface. But Iâd like to defer to the experienced machinists here.
Aluminium would be fine as you would be aware itâs a softish material.
(Retired toolmaker)
Ok after some more digging I have found that I am going to need a valve job done as well as resurfacing both heads. Today I took the rods and pistons out and to my pleasant surprise even though the bearings are heavily worn the crankshaft rod journals seem to be in great shape, just a very quick at-home polish to get the oil stains off and it will look good as new⌠obviously still going to measure all the journals to make sure they are all still within specs, but they are such good condition that I would highly doubt any damage/wear has occurred. I also fiddled with the famous chain tensioner which was much easier to work on than I had anticipated, but maybe that is because I have the engine on a stand completely stripped down 
. I have included some pictures of it for anyone that wants/needs more reference as to what it looks like. Mine was HEAVILY worn I am surprised that it didnât snap when I retracted it or when it was in service! Anyways thatâs what I am up to in these interesting times, sorry for the long post!
Ok I have a few questions, How do I know if I have A or B grade cylinder liners? and I know that Jaguar does not give a spec for +/- for wear but how much can you actually get away with?
anyone know? I need to know if I need to get new liners or not.
Standard rule for wear is if you can feel a ring ridge with your fingernail, you need to bore or replace liners.
And is that at the bottom of the bore 90 degrees from the thrust direction?
I always took it to mean at the top of the bore and in any direction. If you can feel a ring ridge at all, time to rebore or replace liners.
Ok so I took some measurements a few days ago before I realized that the A and B grade liners were one or there other not dependant on the cylinder bank, but regardless here are the measurements with a dial bore gauge and it seems that there is some decent wear and a some are out of round by a little more than I would like to see, BUT there is absolutely no ring ridge at the top of the liners but there is one at the bottom. but some of that looks like it might be carbon/oil/gunk buildup and its only 90 degrees from the thrust direction. Here are the measurements that I took, keep in mind Iâm a noob at using a dial bore indicator, so some measurements may be inaccurate +/- 0.0005 or more. Side note I measured these form the center of the bore but I just went and checked them at the top and bottom and there is little to no difference in the measurement, which means very little cylinder taper 
Ok very good news, the ridge at the bottom of the bores 90 degrees from the thrust direction are almost entirely hardened carbon/oil sludge buildup some vigorous brushing with a nylon brush and some acetone and its all gone! there is still a little bit of a ridge but you cant even feel it with your finger nail. So itâs looking like Iâll probably just re use these liners and pistons (which all measured exactly the same).
Pretty much every later V12 we have stripped (and we have stripped quite a few) have these factory machined chamfers.
William - have you removed the liners from the block? Excuse me please if you have already mentioned yes or no!
Cheers,
Neville
I have yet to remove them from the block, but that is on the agenda after the crank and oil pump come out and get checked. And no I have not mentioned it yet so no worries
Ok some more progress, and some more good news. I checked the crank over and it is well within spec on all main and rod journals! The surface finish is also still very smooth on all journals so a light polish with 2500 grit should do nicely, or I might just leave it alone. I also found out that I have a one piece rear main seal that appears to have never leaked and is great condition. I am going to replace it anyways though.