Remove liners or not.

[tyang]

Hi Guys,

In a discussion I had with Francois a few months ago, we talked about Vintage V-12 cylinder liners. His opinion is never remove the liners from an old V-12 unless it's absolutely necessary. Francois explained that in the 70s, when he was head mechanic for NART, "The Old Man" (in this case, Chinetti) warned Francois against pulling the liners out of a race car to prepare it for a race. Chinetti claimed that the engine would never be the same, but Francois, being young and stubborne, removed them anyway. The Old Man turned out to be right, as Francois could never get that engine to perform like it did when it was untouched.

It seems that I've heard modern shops make it routine to pull and replace the liners on vintage V-12s, and was wondering if anyone else believes this unecessary, and perhaps even detrimental to its original potential? With modern machining and precision, it would seem that many of these variables could be removed, but is there something else that is not so obvious? This is perhaps a difference between the old timers and the new Ferrari mechanics?

Tom

[xs10shl]

In my limited experience, I've never had the liners replaced so long as they were undamaged. I cant speak as to potential performance gains or losses.

[fest]

OPINION TIME!

I have pondered this dilmena myself-
the Engine job I did was nowhwere to this extent (depth)
but I do wonder what I would do if it was my Engine (and $) on the line

I would advocate removal of the Liners

it would be much too risky IMHO
not to remove and re-seal the Liners
when performing a complete re-build
not to mention the heartbreak of a leak occuring
after re-building the engine 100%

the leak may not have been there before
but if the liner gets jostled, like during boring, honing, etc
or just plain dis-assembly, re-assembly, re-torque, etc
a leak may very well be propagated

I have heard that this is a 'common' problem
on the Daytona, i.e. leaks at the bottom of the liner over time
(where it seals to the block)
but don't have any first hand experience with those
I DO know of a 400 that developed this problem
(shortly after the car was purchased, unfortuneatley for the buyer)

the difference between us and the 'old timers'
is about 40 years or so-
back then it might have been unnecessary
to mess with the liners
as the engines were relatively new at the time

but now 30-40 years have elapsed
and with dissimilar metals in direct contact so long
in the presence of coolant in a charged state
(what is that called, dielectric corrosion)
deterioration is inevitable

this I HAVE seen first hand on my Engine
on the (steel) tubes that the oil passes through in
the coolant passage in the (aluminum) Block
on it's way to and from the Oil Filter;
I was tempted to pull and re-seal these
(indeed the manual indicated as such)
as I observed evidence of corrosion
but as I was not performing a complete re-build
I was afraid of complications setting in

maybe like most other aspects of restoration
it is best addressed on a case-by-case basis
if the areas in question showed absolutely NO evidence of corrosion
I might be talked into leaving them in-situ

one might also pressure test the Block
before re-assembly to see if there is any evidence of seepage
at the junctures where the Liners are seated into the Block

another thought is that it would be impossible to 'Deck' the Block
with the liners in place, and making sure the surfaces are perfectly flat
is one of the keys to a successful re-build
also, the amount that the Liners 'stand proud' of the Block
is of key importance in good sealing of the Heads
this is impossible to adjust without removal of the Liners
both factors support the removal of the Liners

all this said,
it is still hard to disregard the voice of (that much) experience
perhaps the liners are best left in place unless absolutely necessary

a difficult dilemna, to be sure
one that I am glad I am not facing presently

AKB
nothin yet
(workin on it)

[Rudy van Daalen Wetters]

Two Ferrari mechanics that I have had dealings with both advocated not removing the liners. Both claim it is somewhat like opening Pandora's box and better off leaving them be unless absolutely necessary.

Rudy van Daalen Wetters
1963 GTE s/n 4001
1966 330 GT s/n 8705

[daffy]

The monent you take out the liners they are not round anymore.
Up to 15-25 oo/mm out of diameter will be the result.
If you need to drill to fit oversice pistons always keep the liners in the block when drilling.(you will need spesial equipment)
Rule 1 : never remove the liners in a colombo engine.

I was personally in Maranello two years ago and asked questions abouth this.

Dag

[Bryan P]

we have decided not to remove the liners from the 500 Mondial's Lampredi motor; mostly for fear of breaking an irreplacable crankcase during the operation.

I know that Brian B performs this operation w/ special tools/long moment bars, etc.; maybe he will weigh in here.

[David Booth]

I don't have an answer to this one, simply another log for the fire.

On my aborted 128F rebuild, one of the very first (and as it turned out, ONLY) things that Jens Paulsen, a well-known rebuilder did, was to remove the liners, even though he reported to me at the time that their condition wasn't too bad. I believe he intended to replace all of them. I sort of caught my breath when I heard this, because of the persistent Conventional Wisdom about not removing the liners unless absolutely necessary. But I remember thinking, "..he's the pro, I guess I'll just go with the program..".

At Tom's Monterey party, I was talking with Tom Meadows about potentially completing the rebuild myself, and he of course immediately said, "...don't pull the liners.." before I even brought it up.

I'd be interested to hear Zac's and Tom S's experience in this area.

[tyang]

It's good to hear that most people agree with not removing the liners, but I'm sure they can be removed without problems, especially when it HAS to be done.

Tom

[whturner]

My Mechanic (was ALGARs V-12 specialist) was strongly against pulling liners unless absolutely necessary. He claimed the problem was getting a good seal again at the bottom. His attitude was the traditional "If it ain't broke, don't fix it".
And you should have more performance - if you bore the cylinder sleeves, you increase the bore. But you no longer have a 250 or 330 GT.

Cheers
Warren

[Stephanm]

Removing the liners isn't needed unless absolutely necessary. When I have pulled liners in the past I use loctite bearing retainer for installing the new one which seals any gaps and keeps the liner in place.
As far as "decking" the engine block, this is a big no-no as well as shaving the head. These engines are "wiggly" enough to where .010 out will work as long as you have a good head gasket. Yes, the liners should be proud .002-3 but if the engine has not been messed with don't fool around with with it.(again, unless absolutely necessary).

[tim]

Greetings... When I did the engine on the Big Yellow Taxi, we found 2 cracked liners. There is a procedure in the book on heating the block for removal of the liners. The engine shop was across the alley from a kiln maker and they got together on the procedure. After replacing the 2 bad liners, the macinist wasn't happy with the location of the other 10 and went back through the heating process again, removed all the liners, cleaned and replaced them to his satisfaction. He felt the heating process allowed the unremoved liners to move just a bit so if you do it, it's an all or nothing job. As to sealing, there were no seals nor evidence of sealant. There was some evidence of collant incursion maybe halfway down between the block and the part of the liner that mates with the block but no sign of anything ever reaching the bottom end. I suppose if you had everything all nice and clean, you could use some wicking grade locktite once everything is in place but it doesn't seem neccessary. Tim