Dear all,

Our adventure with Jaguar XJS, 5.3, x12 continue ;-)
After clarifying the problem with timing and advice from Greg Francis ,
we decided to clear the pistons with ultrasonic bath.
During removal of the pistons one of cylinder liners pop-up very easy and we
can not see any seal, sealant or gasket between liners and engine block. It is very strange for us.
We don't have previous experience with such engines...
So, the question is how to install them back. Just return back on place ?
Pictures attached
Thanks in advance!
BR
Stan

 

Stan,

See here:

https://forums.jag-lovers.com/t/v12-...iners/129162/5

Paul

 

Yep,

The liners are sealed to the block at the base ridge. The liners are "proud" of the deck face, (yes I forget the measurement, BUT 0.003" rings a very dim bell). Originally Hylomar, then the head fitment "crushed" the liners to the ledge, thus preventing coolant entering the oil.

When the head/s are removed, liner clamps "should be" fitted, which prevents this as the pistons are removed.installed.

I use Hi Temp RTV, and a 2mm bead is all, fit the liners, clamp them down, and do whatever it is you want to do.

Its that simple.

 

Hello Grant,
Thanks for prompt reply.
Another issue, should We remove all liners and seal them all ?
I can see your silicon Hi Temp RTV is up to 650 F (~ 350 C).
The guys from another threat suggesting Loctite 518 (it is up to 150 C ~ 300 F).
At first glance I can't find RTV in Bulgaria, Loctite is everywhere.
What is your opinion ?
BR
Stan

 

Stan,

That 518 is fine, just I had Loctite RTV on the shelf, so waste not. Now JB Weld has taken over the RTV sales down here, with an awesome range. Pity OI have no engines needing attention, HA.

I would do all 12, if one has moved the integrity of the others is in doubt in my opinion. A hell of a lot of work later if one leaks.

 

Because there was no clamp to secure the liners, you cannot be sure that none of the others have lifted.
That sealing between liner and block is essential to prevent coolant leaking into the crankcase.
Trouble is that some of those liners will just pop out with little effort, as you found out.
Others can take a massive force, think of tons, to get out of the block.
In theory those liners are slip fit into the bores of the block, and they probably were when first assembled.
However, over 30, 40, 50 years of engine life there can be oil creep up the slip fit gaps and turn into very, very sticky tar.
There is a large area of tar to resist extraction of the liner, hence the tons of force.
It is an oddity some liners pop out easily, others do not, but I found that on 3 V12s I rebuilt.

You could use a feeler gauge to check any gaps between liner lip and bore seat. Not 100% reliable, probably 95%.
You could use a good straight edge across the liner top surface and see if it sits too proud above the machined top surface of the block.
Grant said he thinks there should be 3 thou of "proudness". That sounds about right.
Bulgaria being metric, 3 thou is 0.003 ins.
Loctite 518 is what I used for sealing, and many others do the same.

 

Stan,
I have presumed too much again. Old age, so apologies.

The liner protrusion of the top deck is NOT critical, and NOT adjustable in the true meaning of that word. As long as the liners are "JUST" proud is all you can get. I had one engine where 5A sat flush, no good, so I swapped liners around until I was happier.

REMEMBER:
This engine was developed etc in 1954, shelved, and reworked in teh late 1960's for the Series 1 XJ and the S3 E Type.
What did they have for sealing back in 1954, NOT MUCH. I dont remember, I was only 4 at that time.
Hylomar was only ever a Gasket Dressing, and did its job very well.
Today, we have all sorts of new, flash, sealants, some better, some maybe not.
The crush of the liners between the head and lower deck is HUGE, and they simply DO NOT leak.

Like yours, one has moved, so play it safer, and seal them all, clamp them down while you do other tasks, and move on.

Moving liners around is of no concern. You are replacing the rings, and possibly honing the liners anyway.
Also, those liners are HARD, whatever they are mode of, I would expect you to still see the Factory hone marks on them all.

 

Hello, Just one big concern please, Assuming your using a engine stand. could you fit a 2 by four at the front to support the engine please. A friend of mine was building a V-12. The weld broke at the engine stand head and now is still missing his feet.

Thank you.

Larry Louton

 

I highly recommend using a board of some sort for support unless you have a super robust stand- particularly after you put the heads on. I just pull it off when rotating the engine as I’m supporting the front anyway.