Series one head studs sizes

the four head studs that were not in coolant are ok all others I just want to replace for peace of mind and I reckon I will save myself pain and suffering down the head back on phase towards it running again so I figure spend now or pay again later…That said I noticed on my two series one engines the head studs are different, one to another all my long studs on one engine have no dowels on them and the other engine has 3 long studs with dowels half way. I noticed on a jag parts place they have a stud on sale for 7.95 that is 12-11/16 with dowel.which I don’t have that size. also on the lifting brackets they were on the left side of engine looking at front, and on other engine they are on the right, but these also seem to be the same brackets with eye hook has my series 3 engine but they are on the right. obviously some are wrong I figured at most they would be on the right side for balance has intake manifold is on the left more weight on the side when lifting maybe I’m in correct. I also notice that other engines has the bracket going across the head…With no eye hook On my series one engine I noticed also it has for bolts with locking tabs holding the cams on and my other engine has just two with wire going through so did they do some production changes in 1972? is there somewhere on this site that’s gives a chart of stud sizes and washers and lifting brackets placements? sure would make things easier. cheers

Hi Sawyer - they did change from wire to locktabs on the cam gears. The 72 I’m working on right now had wires and my 73 had locktabs but I couldn’t tell you when exactly the changeover happened.

As for the studs - it depends on your block number what you’re supposed to have for studs and that’s because of what is under the head bolt for that particular car (lifting eye, spark plug standoff etc…)… I will tell you that from what I’ve seen of the Series 1 7L blocks, the dowels are on the 4 really short ones that don’t go through the water jacket and only one of the long ones that goes through the water jacket. If you’ve got a Series 1 XJ6 with 3 doweled long studs, it probably didn’t come from the factory that way. Here is a pdf of the page in the Series 1 parts manual that shows which part number bolts go with which blocks. Figure out your part numbers and then go to SNG Barratt’s website to look them up. They have the sizes listed in milimeters XJ6 S1 PARTS MANUAL - edited 37.pdf (57.8 KB) You’ll notice that the blocks after 7L1175 have a part number in the 14 studs that there is only one of - that’s the long doweled stud.

What year is your car? I have two 72’s and a 73 I can look at for lifting eye placement etc…

~Mike

RustfreeMike hey thanks for the info I have two 72 and 73 xj6 with the 7L block. Which are both after 7L1175. I know about the small studs with dowels. and believe the 12-7/16 doweled stud came out of the second long stud hole drivers side is that true? the lift brackets are the same has my series 3 xj6 which I thought was wrong for series one. And my brackets were on left side of head I’ve looked at various pics on google and it seems there all in different places. So I’m not sure on that…if you could tell me or send pic that would help and thanks for the info it is much appreciated. My 73 has XJS front brakes and hubs and also has XJS rear which I’m not sure of the difference. and came with the XJS wire spokes. the last owner put in a series 2 transmission the only thing I’m looking into is there is a 4 prong connector tied to the transmission dip stick so not sure where that lives or if the wire harness for series one even has it, I looked for its home but no joy so far.

sorry thats one 72 and one 73.

I gotta go out tomorrow and look at the 73 cause I got 72 on the brain right now since I’m rebuilding the engine. But for that 72 (which is a #3 stud configuration in the pdf I sent) the doweled long stud goes on the exhaust side 2nd one from the front. So first is the little short one then right after that is the doweled long one. That block has the lifting brackets that go from one side to the other and since that bracket is thicker than the lifting eye the stud is approx 13-1/16" long.

I’m about 90% positive the 73 has the later style lifting eyes like the Series 3 - I’ll look tomorrow. I don’t think it makes much difference which side you put those lifting eyes on as long as you use the right length studs.

XJS’s has Powerlock differentials so maybe that’s why they changed it.

The only electrical connector you would have for an original BW Model 12 transmission that would be in a Series 1 would be one or 2 wires for the kickdown solenoid so if that 4 prong connector is in fact from the tranny, the corresponding harness wouldn’t be there in that format.

~Mike

Hi again Sawyer,

I looked at my 73 and it does has the new style lifting eyes like a series 3 - I think they’re original because the head is definitely a Series 1 head. Also I looked at the book, Original Jaguar XJ, which is lousy with pics and every single image of a 4.2 (Series 1,2 and 3) fitted with those new-fangled lifting eyes that bolt only on the intake side of the head, the front eye is under the first and second nut (so short one and long one) and the second is under the 5th and 6th from the front.

Also my 73 engine no. is a #6 configuration in the parts manual (last series 1’s in there). When you look at the part numbers this means that there is one longer short-stud (the one that the first lifting eye goes under) and 3 longer long studs (for the other lifting eye positions). From what I’m seeing, the series 1 blocks that have the new lifting eye don’t have a long doweled stud - only the 4 shorties are doweled.

So basically this all boils down to knowing which block you have and using the right studs for the lifting equipment and washers that you have.

Hope that helps,
~Mike

thanks mike that’s a big help…cheers what colours are your jags and interiors. whats story on your cars did you buy them running sounds like your doing what I’m doing I have rebuilt my 72 engine just waiting on the head… Hey I got into jags about 3 year ago I purchased a 86 series 3 in great shape but head gasket was gone come to find out the head was crack. and of course I ripped out the whole engine and painted the fire walls and redid wiring harnesses. when you have time check out my video my youtube chanel is thesawyer10702. let me know about your cars.

not sure how to send straight to your email is it a PM?