And so it begins. Restoration of 1975 XJC

(Eric Feron) #61

Is that bad?
The pistons are ok (and we’re quoted time new for $1500!).
I need to replace at least one liner (cracked). I could then only replace the one liner (cheap), or all of them and go for flanged.

(David Jauch) #62

You get six new liners installed, removal of the old, and fitment as in boring, honing and decking the block (timing cover at the same time!)? I think that is quite okay considering the labor and what garages want for simple work in comparison? Sure is expensive but you want that engine. Specify pistons okay?

(Eric Feron) #63

Yes timing cover will be decked at same time.
Pistons are okay (need new rings I suppose).
I am thinking that if I go for flanged liners I might just as well salvage the original engine block, getting rid of the between-cylinders cracks.

(Frank Andersen) #64

No ‘I suppose’ about it, Eric - it’s peanuts in the scheme of things…

As Paul implies; when reusing pistons, make absolutely sure that the new liners and the old pistons are compatible.

xj6 85 Sov Europe (UK/NZ)

(Pete55Tbird) #65

Good morning Eric, Please allow me to add to all the FREE ADVICE you are receiving about your engine
( keeping in mind how much such advice is worth )
I get from your posts that you are in SF Bay area and you want a driver not a 100% correct restoration.
With that in mind and the fact that shop labor around here is $125/HR and higher consider that the calls
to buy new pistons, go to extremes to make your engine exactly like it was on the day it rolled off the
factory floor today ( even though on the day of manufacture it contained A LOT OF FLAWS ) may not be in your interests.
You asked for imput and advice so you have opened yourself up to a lot of points of view, GOOD.
Now take a time out and figure out a COST vs Benefit of what YOU WANT.
I personally would take a less than perfect reliable driver but as always YOUR MILAGE MAY VERY. Pete

(Paul Wigton) #66

Welll… my FREE advice is based upon having done a helluva lot of professional work: to use old pistons, almost irrespective of how good they MAY be, in new liners is a bit of a false economy.

For the $600-$1000 more for a set of pistons, doing so will result in a better build, and replace a critical component that, if something goes awry with the old pistons, is GOING TO COST a lot more to revisit, than the cost of the pistons.

That’s not about being ‘factory perfect’ (which these engines were damn close to being, in the day), it’s abouta more informed and intelligent rebuild.

(Pete55Tbird) #67

ERIC 3181

Hello again. After getting some blowback I used Google to do a CURSERY SEARCH ( quick not in depth)
and asked about re using pistons. This is from big trucks but I believe it CAN be applied to ANY ENGINE
Why using examined used pistons in a cylinder with liners is FORBIDDEN is way above my pay grade
and I hope other MORE QUALIFIED experts will chime in Pete

(Paul Wigton) #68

Let’s see: big truck pistons are usually run at around 1000-1800 rpm.

Jags run at around 3000-5000… BIG difference in effect on ring land wear, effect on piston ovality.

Apples. Oranges.

(Paul) #69

While it’s of course up to you, viewing those images, you are going to need everything done…including new pistons. It is standard practice with a re-bore most of the time despite what they may look like to you.

With the amount of work that motor requires, whew, it is foolish not to.

There are cracks between each bore?? No, scrap that block.

There is one listed on ebay for around $150.

Better yet, searching your zip code I came across these.
You can get a dead or running S3 for $2k or less these days with patience. Run some tests and check them out. you can get lucky.
Some other guy has one listed there, “Reduced Jaguar XJ6” @$1800 and “another engine” is included … make him an offer of $150 for the "other " motor…

Others too. People can only say no. You’d be surprised what you can get speaking with people and just asking.

Pity you’re not in Dallas, John’s Cars is giving complete xk engines away.

All of that depends on various things I won’t bore everyone with. Caveats apply. However it is a good option with patience and time considering all you are about to spend, one can get a complete running XJ6, and with understanding and luck, a good motor…

As noted, numbers matching are nice, but as a purist, I feel completely overrated as do most others…

Get one of these, strip all the usable parts (which are many) and rebuild the other on the side if you so desire while driving it with the swap motor. Sell the other car or write off.

However, in my mind, cracks between all bores will cost a fortune to remedy and set right and may certainly require far more structurally than mere sleeves. Once again, to me, it is a scrap block.

I think it is foolish to play with it. Get another motor in there and enjoy the damn car, bcs these damn things take time. I have yet to even drive mine after 2 yrs!
My .02
Good luck with whatever you decide.

PS: I don’t know where Sunnyvale is. Did a quick search only for your zip. Use autotempest."XJ%206"|XJ6)&searchNearby=1"XJ%206"|XJ6)&searchNearby=1

One more. Offer him $1k for it … or less. Perhaps only mk offer for motor? Says he’ll part it out.

(Pete55Tbird) #70

Eric, morning. Since it is raining again ( and nobody here wants any of my free advice ) let me try to
give you some.
First choice, find a decent USED 4.2
Second choice, COST out fixing your old engine ( be realistic ) DESCION is required here.
Change of topix. I posted the link to the TRUCK parts website FOR THE FLOWCHART to decide
if using old pistons in a re-build was GOOD/BAD. This flowchart is helpful. Keep in mind this is for
a diesel engine in a heavy commercial vehicle designed to go 500,000 miles between re-builds
A 20 to 1 or higher compression + a super or turo charger. If this re-build fails the cost is not ONLY
the engine rebuild BUT THE DOWN TIME OF THE TRUCK. Big bucks.
OK, if you use old block and put in new liners they WILL be OVERSIZED and then bored/honed
to WHATEVER pistons YOU decide on.
I still do not know why this is INCORRECT and await imput.
As to the JAGUAR 4.2 being perfect as it was manufactured, that is certainly in the eye of the beholder
Take care Pete

(Paul Wigton) #71

If wanting to keep it “original,” then the cost may be a considered “OK.”

For expediency and to lessen costs, personally I agree: toss it and use a later-style block. They are not rare.

(John) #72

The old block gets wrapped up and put under a workbench… makes everyone happy.

(Paul Wigton) #73

Good middle ground!!!

(Eric Feron) #74

For context, I am now on my second block already.
First one cracked between every cylinder.
Second one cracked liner.
So far, luck or not, it is 100% problems…
I am hesitant to buy yet another engine and still have to deal with the same problem anyway.

Cracks or not, the wise way to go is flanged liners and new pistons, even with a third block… So I might just as well do this with block no.2 (and scrap block no.1).

The cheap option ($2K less than option 1) is to only replace the cracked liner and reuse the pistons (with new rings). That engine reportedly has less than 50k miles on it, it is in phenomenal shape otherwise.

Btw, anyone wants engine parts?? :slight_smile: I have a lot of extra ones :slight_smile: Stromberg carbs anyone?

(Pete55Tbird) #75

Have you considered a 3.8 block?
This is the time to step back and figure COST vs Benefit. How many mile do you plan on getting out
of this.
Context I rebuilt the engine in my 55 Tbird in the 60`s and have put 150,000 miles on it and
now it sits in the garage. Pete

(Paul) #76

I see. . Excuse me. That’s great then.
(Edit: Bad luck indeed. The S3 block AND head however really are best way to go if original in poor shape. Note to self.)
Nevertheless, an option we ALL should keep in mind I think…sigh…
Wished I had in times past.

Engine parts?? Hmm Hmm Hmm…

(Eric Feron) #77

On a facebook group, a guy is refreshing a 85k miles engine.
He simply honed the bores, cleaned the pistons and replace the rings. Plop.

(Pete55Tbird) #78

Eric, Hone , re-ring is normal for a DIY. The guys who urge you to buy new pistons are re–building
for a customer and must warranty the work they do. Easy to justify new pistons in this case.
Or Jaguar purists who for whatever reason just “get carried away by the mystique of it all”
Remember; you did ask. Pete

(Paul Wigton) #79

85 thou, I can see that: FTR, tweety’s pistons had 165,000 miles on them, and they were within spec, as were the bores.

If the pistons in question spec out that good, by all means use them.

Even though it burned oil like a ocean liner, the thing kept running, well! Partly why I rebuilt it: I wanted to see what was causing it to run!!!

Still not sure why…:stuck_out_tongue_winking_eye:

(Frank Andersen) #80

If the pistons are the right dimension for the new liners, Eric - reuse them…

Reusing pistons, with new rings, is after all standard practice if a rebore is not done. And with new liners, properly crosshoned, the bore is as good as - provided the pistons are indeed of the right size…

It is advisable to ensure the pistons go back into the block in their previous positions - like all parts that are being reused…:slight_smile:

One question; have you actually removed the liners to inspect the block? A cracked liner is unusual and may hide another cracked block - which in itself is not that common…

xj6 85 Sov Europe (UK/NZ)