imperfections in cylinderliner - headgasket issue?

Hi!

I am currently in the process of rebuilding a F136 engine - there is a little notch on top of the cylinderliner exactly under one of the two paths of the headgasket. It also would be very interesting to know how it appeared in first place... As far as i can tell the former headgasket was not leaking... Would you guys recommend to use some kind of sealant ? All the info i found on the internet recommended to use a multilayer steel gasket dry... but iam still not sure in this case

BR

Chris
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Call these guys. They make the best there is. As I recall they make some of the factory stuff for out of production models too.

https://www.cometic.com/

 

this is a better photo of the notch

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thx for the link but unfortunately they don t do modern rari engines

 

Cometic have indeed done some. MLS is typically only used when the deck is totally flat, as in no liner protrusion. Does the F136 have liners that sit out a couple thou? What’s wrong with using an OEM head gasket? I don’t see that imperfection causing issues otherwise

 

i ordered std. headgaskets - just wanted to know if you guys would recommend to use some kind of additive sealing on the notch in the cylinderliner

 

Looking at the whole picture, there is some sort of complete circle around the whole liner. My guess, is this could be related to the machining process of the liner, so not pretty but presumably not a cause of concern.

With so-so gaskets I used to smear a thin coat of Hylomar over the deck, but not on the fire rings themselves. As an alternative to Hylomar, some do use high temp paint for gasket dressing.

As far as you are concerned I just don't see the point of using any such "glue" on this small notch: way to close to the combustion chamber.

 

Thx for your reply - the headgasket has two rings of metal which actually press against the cylinderliner and seal it - but exactly under the inner ring of the headgasket there is this notch - so i am afraid that it won t seal well in this spot - actually there are multiple spots all over the cylinder liners bur this one is by far the most concerning one

that is why i thought of filling the notch with some kind of glue

 

No sealant would hold up at the firing ring anyway. Typically if one is going to put something on the head gasket to supplement things, it's to help seal some of the coolant passages. I have heard old school V12 mechanic stories of even using a tiny bit of yarn to help seal the round cooling passages between the head and gaskets for example, not that I would ever recommend that there. I digress, nothing will nor can help with sealing that high compression area other than the fire ring on the head gasket. Rest assured the firing ring is much wider than the small imperfection you're seeing at the top of the cylinder liner, so I'd run it and rest easy.

 

are you sure that the HG will rest over the majorit of the face of the liner - because you can see on the HG that there are 2 rings that press against the liner - can t tell if the HG seals in between aswell?

 

The only way to tell is to lay the gasket over the liners as it's intended to mount and check. Firing rings are normally .120 or so wide

 

you mean 0.125 inch so 3.xx millimeter? the gap in between the firing ring edges might be around 3 mm - so you mean the HG seals over the entire 3.xx mm or just at the two edges?

 

this

 

I only use Murray Glegg from Australia for my Ferrari head gaskets. Outstanding design and quality. He has also made a custom thickness for me to help tailor the compression ratio.

 

We also use Murray head gasket for the vintage engines exclusively! Great guy and excellent products.

Wade where are you in GA?

 

I’ve only seen Murray’s gaskets for vintage engines, always great. I’ve been using Cometic as well though and they also been great. Cometic can scan any headgasket and print a new one in various thickness grades on Victor Reinz viton head gasket material. I believe the thickness ranges from 1.1mm-2mm. On some engines I use a bit of Aviation sealant at certain areas. No issues to date

 

I live in Sugar Hill, Ga. NE of the big city. The shop is in Norcross just outside the perimeter.

 

This is common, cylinder sleeves are protruding above the engine block, an old HG is leaving an imprint on them, no sealant needed. I can show you many more pictures like this.
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Hi Guys,

after face-milling the heads - i finally bought a straightedge and feelergauge too because i was interested in the flatness of the block - now another question came up - all the cylinderliners look like the one in the attached picture - the have this sloping angel twoards the combustion chamber - is this normal ? if yes - what is the reason for it? if there is a reason for it it would be impossible to face mill the block if ever needed?? - same with the protruding cylinderliners - can somebody fill me in on those design choices.

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No, this is not normal, the top of the sleeve has to be square. Ideally, you'll need to replace them. However, if you'll lay a head gasket over it, you'll see that it's covering just about a half of the width of the sleeve, so technically the new sleeves will not make much of the difference.
The reason for the sleeves to protrude above the deck is to "preload" them when everything is assembled. If they would be same height as the block, they will move, because the head gasket is not solid. Normally sleeves protrude approximately 0.03-0.08mm above the deck, the measurement has to be equal to all the sleeves in each bank of the cylinders.

 

Dear

hi thx for answer - i also don t understand why the liners would look like that - but they all are looking more or less the same - the gap right at the combustion chamber is aprox 0.01mm. if i place the feeler gauge somewhat to the area where the HG actually seals it is considerably less and i can t remove the feelergauge under the straightedge anymore - as far as i have researched the MLS HG should be able to absorb 0.01mm - so i quess i will be fine - i just wonder why they are all looking the same - and if not intended what could have caused the liners to look like that

 

all the liners protrude the block approx 0.02mm

 

do you guys know what material the f430 cylinderliners are - the look like some kind of steel - but the are kinda soft and non magnetic

 

The inner diameter of the sleeve is not covered by the head gasket and exposed to a different thermal and chemical processes. I would say it's a "wear". If you install a new, perfectly square sleeves, after a while they'll be identical to what you have now.
0.02mm is on the lower end of the tolerance.

 

Material is an aluminum alloy with Nikasil coating.