Series 3 in a boat bottom end removal

Hi
So the cylinder head is at the engineering company “ Saunders” in the New Forrest near Southampton. For any Brits very good place.
The CH was assessed while I was there, skim, new inlet and exhaust valves, and exhaust guides. With new valves being seated and a hold down kit fitted for good measure. £250 of work and just under £200 for all the parts from SNG.
Now got to flip block over on the stand, and get started on completely dissembling the bottom end.
Have read the manual probably 3 times now, before I attempt this part, was just checking for any tips, tricks, engineering measurements I should be doing pre strip.

Thanks in advance as always.

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Good digital camera or iPhone… Take pictures, lots of pictures from every conceivable angle. When you think you’ve enough photo’s —TAKE MORE!!! Full view shots, close-ups, and any other versions you can think of. Once taken download to a thumb drive. Brain on a stick!!!
You’re sure to have questions later on. The manual isn’t correct for all things but a very handy tool. It’s also set up for RH drive cars for you info! Have more than one reference manual as you’ll find… it helps…
Let us know how you’re progressing (pictures too)…

Enjoy and Happy Trails,

DIck

Saunders are excellent, I’ve been a customer of theirs for 30 years, great service

Adding on what Dick wrote: if you’ve got the manual I’d also shoot pics just in the perspective of the manual’s pictures to enlighten your later use of the manual. Also take pics of things you’ve taken apart such as screws, bolts, rings, spacers etc. I also make annotatios referring to the ROM numbers on different pages of a booklet, write the ROM figure on the top right corner, then tear the top right corner off and put it with all related small parts into separate plastic bags.

Good luck - looks gorgeous by the way!

Jochen

75 XJ6L 4.2 auto (UK spec)

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Bear in mind that you are dealing with two separate issues, Robert; the crankshaft itself and its big end bearings - and the pistons, conrods and their bearings. They are, arguably, all worthy of same scrutiny…:slight_smile:

You may find that all is well, and consider re-using parts - which, pending their state, is not wrong. In which case; it is extremely important that the reused parts goes back exactly where they were. may be worth while to check present tolerances where applicable, to verify ‘state of the union’ - and for practice…?

Frank
xj6 85 Sov Europe (UK/NZ)

Bottom end update



So, with crankshaft pulled this is what I found.!!
All look and feel fine, except the flywheel end main bearing which is not good.
It is badly worn, and well out of shape, as in it does not sit comfortably in its seat, and is very loose.
I’m sure there’s a reason, but currently I’m at a bit miffed by it.
Thanks

Rob

Is there blueing from heat near the saddle on the right side? Too much heat means insufficient oil pressure for the load. The very first thing I would check would be to see if the crank is bent at the rear journal. My number one guess, considering that this was in a boat, presumably a sporting craft, is that the rear main was exposed to a severe continuous imbalance, some external force, like a bent prop, or less likely, something in the V-drive. If you can’t find an external issue, it could have been an oiling problem, although I don’t know why that would not affect all the mains and the rods. That could be a restriction, or perhaps more likely, an internal leak.

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Are you talking about the old bearing shell, Robert - and what about the shell in the cap…? Have you inspected the surface of the crankshaft there for possible signs of anomalies - and measured it for ovality? Any sign of previous assembly misplacing caps - they have to go back in the factory order. All of which to possibly clarify causes…

Being at the rear; the oil passages within crankshaft may be blocked at the rear - removing the blind plugs to assess/clean the passages would be a prudent move. I assume you are planning to replace the bearing shells anyway - but the cause of the rear bearing’s state should be plausibly explained and rectified…

Frank
xj6 85 Sov Europe (UK/NZ)

Could it be that someone used the wrong bearing shell?
The way it sits on the block doesn’t look right… How does the other side look like?

Poor oil suppy to the rear main. Seen in other engines.

Carl

Hi
Mike, this engine is a donor engine from an automatic 1982 VDP with 108k miles on it, and has not been in the boat yet.
It was running when I bought it, not very well, but was running ,just stripping and refreshing everything before it goes in the boat.
Here is a picture of the crankshaft journal, in question, although all of the others are in good condition.

It looks worse, in the picture, but I can’t catch my fingernail on anything.

This is the saddle, in question,

Same kind of deal with this bearing,loose in the saddle,
Bearings are STD C30026&30027. Respectively
There seems to be some damage on/near locating tang.
The bottom end I believe has not been apart, the tabs on everything in the bottom end were to neat. ( as in not bent many times).
I haven’t measured anything yet, as it all needs a good clean,I also need to borrow a large micrometer from a friend, I hope the crankshaft is not knackered as it is the tutrified ( hardened) type and cannot be ground.
Couple of pistons had frozen rings, but generally she looks good for a rebuild, other than suspect bearing.

Thanks as always
Rob

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I wonder how those suspected areas will look when cleaned up, Rob - shells may show some wear. Lack of lubrication seems still a valid diagnosis - and crankshaft oil channel is main suspect. The shells are sacrificial, they wear before the journal…

Frank
xj6 85 Sov Europe (UK/NZ)

Especially things like the chain guides and hydraulic tensioner: some repops are badly-made.

All bearings should be replaced.

That crank journal looks bad to me. Are you planning to have it machined to an undersize?

I’d be willing to bet a dollar to a donut, that crank needs to be ground undersize.

Hi
Thanks for comments
All bearings were going to be replaced, my biggest worry is that the crankshaft is classed as HARDENED. Does this mean it cannot be ground and is just a throw away item ?
Or is it that it requires special machining?
It’s a real shame if that’s the case, and my only way of rectifying the situation would be to purchase a new crank ( crazy money ) or
Would a series 2 crank fit?
Another dilemma!,
Thanks
Rob

No. If you remove the thin hardened surface by excessively polishing or grinding at worst you wind up with standard forged steel crankshaft. If you are building engines for the 24 Hours at Lemans, the Daytona 500, or a heavy diesel over-the-road truck, that surface hardness may inhibit the formation of surface stress cracks that could lead to failure. The heat treatment provides some protection under extreme conditions. As a practical matter, the rod bolts will always be the weakest link in any stock IC engine rotating assembly.

I’m curious if the bolt that plugs off the drilling from the main gallery to the rear main journal was correct? Any 1/2"-20 bolt will fit, but something longer than the correct bolt could block the rear main feed.

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I had a 3.4 L engine from an 81 XJ6 rebuilt using the original crank that was reground to 20 thou u/s and fitted with matching bearing shells and it ran really well. I did 10,000 miles before the car was stolen and used in a 'Ram Raid ’ and written off.
It looks to me like the rear main brg was starved of oil at some point. The oil passages in the block or crankshaft can become blocked, especially on a poorly maintained car. I would have the block professionally cleaned after removing all the core plugs and cover plates, and the same for the crankshaft after the regrind.

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Hi
WOW that’s a big relief that the CS can be ground, so, block completely to bits next, all plugs out , checking the bolt on the drilling to the failed main, to see if that was part of the problem.
Thanks very much, good news
I shall push on
Rob

Hi Robert,

After removing the crank I would have a competent machinist mic all the journals. The rear main (or others) may be out of round which may attribute the bearing shell wear. For a proper overhaul all removable plugs are taken out, the crank is boiled out to remove all internal contamination so all the oil passages are clean and unobstructed. The machinist will also check if the crankshaft is bent!
Jaguar used a process they called “Tuffriding”. Tuffriding in industry standard terms is nothing more than Nitriding. It’s the last process a crankshaft goes through, usually found on aircraft or high performance engines (or Jaguar motors), and IMHO worth the extra $$'s. It hardens the journal areas making them less susceptible to damage. If they have to turn the journals undersize I’d have them Nitrided afterwards. The E-type S3 ROM states the crank cannot be ground undersize BUT they sell undersized bearings! S0, YES, it can be turned undersize if required! Jaguar just wanted to sell you a new crankshaft I guess :thinking:
Happy Trails,

Dick