Sometimes I’ll here that voice in my head…It goes like this “stop moaning and get on with it” lol
Don’t let it beat you D
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Core plugs are press fit, (hence not reusable) Demian - using sealant any sealant, or indeed makeshift plugs, are counterproductive. As the coolant system is pressurized sealant may slip…
As for the ‘short’ studs; I suspect Jaguar, when increasing the bore, considered remaining block material insufficient for reliable strength with the short plugs? Or indeed that the earlier ‘short’ stud blocks were cast differently to give sufficient material for strength in critical areas? The ‘conversion’ is not an approved Jaguar repair; that it is possible is unquestionable - but there are no reports on longevity of the modification.
Or indeed if the such makeshifts aimed at one or two studs - not a general conversion?
Frank
xj6 85 Sov Europe (UK/NZ)
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You may access relevant lists for comparisons?
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Frank, I suspect the makeshifts plugs being too small (as he mentioned) are the main problem here and would say that they can’t be perfectly tight in any way but correctly sealed exactly what I‘d have done. There are frost plugs you can tighten, for racing or something.
I believe to have read that the long studs are superior in strength or clamping force and can imagine the block becoming somehow more sturdy. The AJ6 has studs that go all the way through to the main bearings which I believe was said to be way better. Good to know that the short studs would work! (1 stud is loose in mine and the threads are good).
Do they thread in the holes that the studs go through, beimg thicker at the threads, or how does it work?
Good luck, you seem to be doing great!
David
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Hi there
Quick note.
You guys seem to have misunderstood, these plugs i mentioned i installed and are leaking were merely the plastic, temporary 1.5" plugs used to seal the block while filling with the rust killing acid (evaporust)…(and for keeping closed while using penetrating lubricant now.)
Merely didn’t use enough atv on a couple, so they leaked, not allowing liquid to work properly higher up within block.
Caught what leaked within container below. Ordered more. Will be doing again once studs addressed.
Yes, the short studs from earlier cars used are simply threaded within present block pass through stud holes.
One’s initial conceen is that there may be some differences in block structural integrity, but there aren’t apparently.
It is the same as it was before in terms of deck strength/support.
Sure, as is well known, as you say, the modification to long studs aided in focusing clamping pressure, reducing head gasket issues…that was only intent of redesign.
They add no block strength, per se…nor additional strength at the deck…per se…
…as the studs merely pass through freely to the base of block.
They are not fixed at the deck pass through, they pass freely remember.
There is no added rigidity there due to tge long studs, just support, as you say.
It is merely a redistribution of support.
In typical Jaguar fashion, they always tried to perform direct modifications to current designs and cross pollinate with other models to save production costs. This is no different.
It is also good engineering .theoretically.
The earlier 4.2 without pass through studs was only available for short time.
The question i think is how often head gasket issues occurred with this earlier, short stud iteration?
Must have been a problem methinks to have made the design upgrade?
No doubt upgrade to use of wet liners…which I don’t believe the earlier version had. Need to check.
The later design is obviously better, but again, doing this stuff, i am glad i have a plan “D”…just in case.
“Not an approved Jaguar repair”?
When did that ever matter or enter the equation within Jaguar restoration? haha
If so, the motivation behind such a decision is clear.
If all are upgraded to version 2.0, they are not going to support use of version 1.0…
That means little to me, personally. But I absolutely appreciate what you’re saying.
Not intended as a full conversion? …no doubt. Possible?
No records (online) of such a conversion?..true.
Would be an interesting experiment when only other option is “scrapping the block”.
May dig deeper when need arises or when I find time.
Thank you for kind note David.
Was a daunting mountain to begin with, now manageable.
C’est la vie
Just praying the block is not cracked.
Will know what i need when head removed.
As final note, as it is a publicly made comment, here is quick thread within jcna forum by respected fellow too.
http://www.jcna.com/e-type-42-engine-head-studs
Kind regards
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Hi Demian,
I will hoist a Guinness and toast your patience and resolve in trying to get those studs out! Love your idea of closing up the core plugs and filling the block with Evaporust. May the oily gods of Olde-British-Motorcars smile on you.
~Mike
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Hah…thanks for that! Appreciated!
Hope so…
As a fine art painter, restorer, as well as having lived in Italy many years until recently, I suppose I’ve learned patience!
Sounds good…never was a drinker, but how well working on old cars and a cold drink go together?! How did i not discover this earlier?
Thanks again
Ciao babe…
For posterity, snapped a photo showing what i ws referring to regarding bottle caps, etc.
3/4 bit. I used a spade, but whatever…
Will then cut end of bottle off, screw it in, and fill with marvel mystery oil…
FWIW
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Thought provoking thread!
are you sure the block casting is not changed?..will check my sources
yes, this is a good question, good XJ blocks are getting harder to find
iirc, “short stud” blocks are seen as more desirable by Modified Engine builders (but I could be wrong),search archives.
poster Dick Maury from Coventry West, and a few other posters, would likely be able to provide valuable real world information on this topic
One reason I suggested removing the head first, is to ascertain
A) Bore wear…you will be lucky if the engine does not need to be bored…so new pistons
B) Crack…you would be unlucky, but needs new stepped liners (and pistons)
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The strength of stud/bolts only relates to their thickness and material used in them, David - I would ‘think’ there must be some other reason behind Jaguar decisions…?
Certainly, the difference alters the stress direction on the block itself; the ‘long’ studs applies compression to the block material’ - while ‘short’ bolts puts the material under stretch. And while cast iron stands well up to compression - it is not very good against stretching…
Short bolts is a common enough solution in head bolting - but it may then also be related to block construction or block material. The forces involved relates to compression and bore dimension - but are quite considerable.
The same forces also acts on the block via the crankshaft, but independent of the head stud anchoring. But while the studs/bolts are always under tension; the crankshaft load on the block is alternating between compression and tension. And neighbouring bearings, to some extent, is in opposite phases - easing the load…
Block construction is not immaterial - and for a variety of reasons, makers want to use the least possible material, without compromising integrity…
Frank
xj6 85 Sov Europe (UK/NZ)
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Greetings from a fellow Fine Art Painter!
You sure learn patience and perseverance with this craft.
Love your plastic bottles idea!
I am sure you will find the solution.
Bon courage.
Aristides
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That’s what I call “Better living through modern chemistry”.
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Thank you all once again for thoughts.
All genuinely helpful.
Hey Tony, spot on…
I do intend and prefer to remove head first for just those reasons.
My concern is not bore wear as much as finding block crack(s)…
If i see nothing really upsetting or some serious lip at top of cylonder, I’m leaving it for now.
The compression was actually good on all but one, which has a maladjusted valve.
To such a degree that it was visibly blowing out the intake port at turnover.
Leak down on it absolutely confirmed.
Sure there was very faint sound from dipstick tube, but no engine is completely seal proof…there will always be some air passing the rings.
All said, i intend to rebuild head in its entirety and just run her until she dies…
You know, despite all the jaguars I’ve owned, i never once did a compression check on them i realized.
I just enjoyed them as they were. All sounds and feels were good. No smoke, etc.
Ignorance is bliss.
I’ve read of guys here diagnosing a recent problem w compression check for first time upon driving for years to discover they had low compression…i mean really low.
It’s not the be all end all …
And for now as it all really sounded good otherwise, and believe me, i can tell…i just intend to rebuild head now and down the road eventually pull for rebuild when necessary.
Will look into that fellow you mention, thanks…
The only differences are wet liners…and the best blocks are pre 1975 from what I’ve read…until the later s3 from like 1982 on.
The head from s3 is preferred for reasons well documented, although it will make engine idle lumpier.
Also, these earlier long stud blocks were reinforced laterally in comparison to earlier iteration which are perfectly flat, with only 3 plug holes.
I added that link above for that reason.
One can see the thicker, ribbed sides on the block with additional ports as opposed to earlier ones on 420G and E.
And you know, although this design is criticizrd, if system maintained decently it is fine…and superior from what I’ve read.
That the earlier iteration is preferred as you say, comes as a surprise.
But what is more, we should all be thankful to Jaguar engineers for placing a core plug at precisely each stud end…it says a lot.
Each can’t be necessary for casting, though i may be wrong.
Yet i know the Italians or Lotus would never have added such a premeditated convenience.
All in all, although no documented evidence online, i feel comfortable doing it if necessary as a complete modification.
If these create great trouble where it becomes easier to somply grind them down flat, , i will do it.
The exhaust side concerns me more tjan well eroded intake sides as the corrosion goes to the top, from underside where it passes upwards to top of block.
Dunno if i can get a dremel snake grinder up there or if I’ll need to hack em down.
Merci Aristides! Il est bon de savoir qu’il y a un autre artiste ici!
merci beaucoup pour l’encouragement. c’est utile, croyez-le ou non!
I am hoping for the best!
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i did find blurb in the archives, apparently re-studding the top of the block (with at least one short stud) has been done by a few fellows (or they found it upon stripping down the motor)
altho it is not ideal, I cant see why it wouldnt work, in the instance of one or two badly damaged lower stud holes
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The main concern of the compression test is evenness between cylinders, Demian - gross unevenness definitely means some action is required. General low compression may be caused by other factors than wear - it may be a procedural thing…
Good luck with your progress - it is well deserved…
Frank
xj6 85 Sov Europe (UK/NZ)
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Usually a bad valve for some cause - a ‘wet’ test will usually confirm or reject that possibility, but only a head off inspection can really confirm suspicions…
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You know, at this stage of the game, or rather if i had the opportunity and time, space, gear, HELP!..
…replacing all as a complete conversion to short studs would be something i would really want to experiment. If these studs become some nightmare, i honestly don’t mind trying it.
And my instincts ( or perfectionism) seem to tell me it would be better to replace all(?) if it’s done.
While I’m not an engineer, those alternate forces replacing only a couple, seems like it would create an issue.
As final note, it would actually also free up space between those siamesed bores, aiding in coolant flow.
Will be a bit until i get back to it. Away now, setup the plastic caps, but not yet filled with marvel mystery oil etc…
Want a lot of setting time, another attempt at corrosion removal, application of penetrating lubricant etc before even considering attempting.
Kind regards, and thank you all for taking time and thoughts.
Will definitely update this thread fwiw.
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Bodging it with ‘all short’ bolts is not ‘perfectionism’, Demian…
The possible issues with one or two short bolts will not go away with ‘all short’…
Frank
xj6 85 Sov Europe (UK/NZ)
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You should get a cross section and look at the forces that might be involved: if there’s a wall around the stud there won’t be any asymmetry and I believe the only issue I could see (provided clamping forces between long and short are somewhat close) is that the forces are not taken up all around.
But anyways Jaguar must have had some reason to change to the what I imagine to be much more complicated and more expensive long studs. But I wouldn’t call it bodging if you replaced one or more as a repair with a design that Jaguar also used! And it is the neatest solution one could come up with in my book. Besides that it would be great if it worked as ‘advertised’. That would make head work a lot easier on the mind… and I somehow like the short studs. Time to read up on long stud benefits.
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Well I thought I would make a quick update fwiw.
It looks good!
Whew.
No corrosion at the head or block…
Surfaces clean…nothing bizarre.
Came apart properly.
Gotta love the tech now. Not available when i was doing this last.
Detailed hi res flash photos taken revealed no block cracks or cylinder scoring, etc.
Everything looks normal.
Been paranoid about cracks…
Of course more to analyze, but it looks good.
So thankful, if not surprised to be honest.
Anyway, snapped some photos i thought I’d add for those searching in the future as I’ve never found any.
Not wishing to reinvent wheel either as there is info available in archuves, but some notes to those doing it first time…
It seems like binding is inevitable.
Have small blocks and sheets of wood handy.
Despite efforts mine bound at front, as example.
May have been stuck stud crud.
I continued to pour goop down stud holes, but it still bound at front right corner, even placing bottle jack at front it strangely torsioned the rear completely upwards.
Anyway, remember aluminum is soft.
These surfaces are paramount.
Remove plugs and rotating clockwise turn engine to Top Dead Center.
Stick rags down front beneath sprockets.
Remove locking wire and tie them with a zip tie at center.
Also, i recommend not playing around, just remove the camshafts to recess valves.
You’re certainly going to need to replace cam bearings anyway.
You don’t want to bend valves.
Also, when an end comes up always use blocks of wood to keep it propped up.
Should an end come up above studs as mine did, insert sheet of wood. You don’t want those studs gouging the head surface as you’re manipulating the jacks, letting it up and down and around etc…
Eventually you’ll get it and the head will rest at the top of studs to remove.
I’m not a heavy guy, athletic, so i can hop in there and pull it off like a redneck, but get a friend and you both can get it out.
Cover alk w blankets etc…
Anyway, last image as i covered it for night awaiting friend for help next day.
Looks like cathedral … Appropriate i thought. 
Anyway, fwiw
Kind regards
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Great post. Layers of an onion I tell you. I purchased a $400.00 Series 3 that was a no runner. got it going. Then as I poked around, I discovered a bunch of stuff that needs immediate attention. I too have a Series 1 that I want to be working on, but I’ve got this S-3 that I’m fixing for my daughter if she wants it. If not, then off to a happy home.
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Also check that the dist rotor points to #6, frontmost, cylinder, Demian - when head is replaced #6 becomes the cylinder ready to fire…
Frank
xj6 85 Sov Europe (UK/NZ)
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