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Gaz-2006

Cylinder Liner Protrusion Too Much - What To Do?

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Gaz-2006

Hi all,

 

I have recently rebuilt my engine and had a coolant leak from the head gasket, upon removal of the head I re-checked the cylinder liners protrusion (the liners are the originals for the engine but have been re-honed) and they are about 0.5 mm where the tolerance is a maximum of 0.1 mm with a minimum of 0.03 mm....

 

I was wondering if anyone has encountered this issue before, and how they went about correcting the protrusion to bring it within spec?

 

I would obviously like to avoid stripping pretty much the whole thing down and would like to fix it without removing the pistons and liners from the block.

 

I'm personally thinking along the lines of trying to 'rub down' the liners with progressive use of wet and dry paper to achieve the correct protrusion whilst plugging the bores with blue roll to prevent anything getting into the bores...

 

Any other suggestions are welcome but would also be nice to hear from anyone who has experienced the problem themselves!

 

Best Regards

 

Gary

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Bally

Where was this coolant leak. .005 shouldnt cause that problem.

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Gaz-2006

The coolant leak was all the way around the cylinder head and it was 0.5 not 0.05mm :)

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Gaz-2006

Any ideas?

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lagonda

Seems rather strange IF these are the original liners to your block. When I rebuiilt mine, the worry was too little (but just enough!) protusion. Would have thought most likely a piece of crud preventing proper sealing ... did you scrupulously clean the barrel & block faces where the O ring sits ... this is absolutely essential.

If all else fails & you are absolutely certain the barrels are too tall, the only option will be to measure the difference accurately & get each barrel machined down. You'd nead several million years to rub them down with emery, & then they probably wouldn't be true.

BUT check & double check that you have no alternative ... metal removed can't be added.

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welshpug

get some large washers and bolt the liners down, then re-check the protrusion.

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Emmy Seize
get some large washers and bolt the liners down, then re-check the protrusion.

 

 

 

Did you mean check it, while the liners are clamped down ?

 

You´re not supposed to do that - never not!

 

My guess would also be that the liners do not sit properly in the block, yet.

 

Debris could be one reason, so take the liners out and clean all the surfaces.

 

The "Revue technique" suggests you could also try rotating the liners by half a turn and measure again.

 

A gentle tap (and I mean gentle tap) with a plastic hammer may help as well.

 

Recommended tolerances differ from manual to manual as from engine to engine.

 

The ones I found read 0,08mm to 0,15mm with a variance from liner to liner of 0,05mm.

 

Biggest problem might be the variance between the liners anyway, so if you are sure the liners belong to the block and you don´t find any means of reducing the amount of protrusion, just make sure they are all even and fit the head nevertheless.

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ALEX

As suggested check that the liners are seating properly in the block.

 

I'm unsure of this, but are you supposed to check the potrusion with the liner seals in or out?

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Guest Davva
As suggested check that the liners are seating properly in the block.

 

I'm unsure of this, but are you supposed to check the potrusion with the liner seals in or out?

 

I have read differing advice.

 

1. measure with seals in

2. measure with seals out

3. measure clamped

4. measure unclamped

 

& any permutation of the above (& more).

 

I am sure it can't be that complicated but just nice to know for sure a 100% method!

Edited by Davva

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pug_ham

Liner protrusion should be measured unclamped with no seals fitted.

 

Graham.

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rnotman67
Liner protrusion should be measured unclamped with no seals fitted.

 

Graham.

 

 

I am in the process of rebuilding my Mi16. Had the crank away to get regrind. The blocks sittin on the stand stripped and ready to be cleaned. I've not touched the liners thinking they will be okay...

...Until I read this thread.

 

Where about and how do I measure the liner protusion and seeing as I am here is it wise to just take them out and replace the seal (not sure how easy it is).

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Stu

If the crank is out and the block is on a stand i'd defo do the liner seals, they are pennies mate and the last thing you want is to reassemble it all to find they are leaking.

 

Remove the liner, (noting the position and orientation), clean up the seat(s) and drop it back in. In the absence of anything better use a known good straight steel running across the liner onto the block in the upright position and see how much the liner protrudes the block by getting a shim/feeler gauge in between the block and rule.

 

If its low the block may need machining, if its high the liner needs machining. Make sure the gasket face of the block is immaculate before hand, and that the top of the liner is mint too else it wont be an accurate test.

 

Dont be scared by it mate, it sounds horrible but 90% of the blocks/liners ive come across have been within tolerance. If your feeling particularily adventurous mix and match the liners to get the best protrusion, and rotate them 180 degrees from their original position so that the wear is on the 'back' edge.

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Guest Davva
Liner protrusion should be measured unclamped with no seals fitted.

 

Graham.

 

Hi Graham, many thanks for the prompt reply. 'Murphy's Law', we have another 'wee' issue, which is slight corrision on the liner mating surface in the block.

 

DSC04919_small.JPG

 

but nothing like as bad as some of the pictures I have seen on the forum.

 

Some forum members say they have used a thin smear of Automotive Silicone sealant on the mating surface.

 

One workshop we spoke to said he would try something like

 

www.lab-metal.co.uk but is there a 'recommended' solution?

 

Cheers

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rnotman67

Magic cheers Stu. What should the liner protrusion be when it comes to measuring?

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Stu

If i remember correctly its 0.03 to 0.10mm, with a max difference of 0.05mm between liners for 8v engines and 0.02 for 16v engines.

 

If you do search bud im sure its been covered before, you might even find my post on the subject recently!

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Gaz-2006

Got to love Peugeot's!..

 

I have now been forced to use the block from my spare engine which is still not in great condition erosion wise, and about 30-40 thou/1mm needs to be removed from the cylinder liner seat to get it to seal properly, and also the block surface to get the protrusion correct. This is going to send my compression ratio through the roof considering i already had 1.2mm removed from the cylinder head! next question - my standard headgasket thickness is 1.25 mm, I know the motor factors do a 1.5mm gasket, but I will be looking at a 1.75 - 2.00 mm gasket now to bring my compression ratio back within check.

 

Any ideas on that?

 

Gary

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Mikey S
Got to love Peugeot's!..

 

I have now been forced to use the block from my spare engine which is still not in great condition erosion wise, and about 30-40 thou/1mm needs to be removed from the cylinder liner seat to get it to seal properly, and also the block surface to get the protrusion correct. This is going to send my compression ratio through the roof considering i already had 1.2mm removed from the cylinder head! next question - my standard headgasket thickness is 1.25 mm, I know the motor factors do a 1.5mm gasket, but I will be looking at a 1.75 - 2.00 mm gasket now to bring my compression ratio back within check.

 

Any ideas on that?

 

Gary

 

i doubt very much you will be able to get a standard gasket @ 2mm thickness. maybe a solid copper gasket?

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Gaz-2006

I was thinking of that, however i am on a very tight lead time and need a gasket this week/very early next week as the car needs to go to donington for its first test on 7th December!

 

Anybody had a copper gasket made up before and any idea who would be able to do this for me ?

 

Any leads much appreciated as I'm getting worried about being able to make my deadline now!

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Gaz-2006

If i have removed 1.2 mm from the head, and also decked the block by 1mm.. does anybody have similar experience of removing that much material from the head and block, an idea of high the compression ratio will actually be, and whether it will run without pinking on a fairly standard 1.6 8v.. I need to act fast to get this engine back together and I was thinking that if i increased the gasket thickness by 0.25 of a mm from the standard thickness of 1.25mm up to 1.5mm then that will JUST bring me within spec..

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Guest Davva
http://www.ferriday.co.uk/copper/copper.shtml

heard good things about these guys. :wacko:

 

I got this connection too:

 

Yes, we do 1.6 or 2mm compressed thickness gaskets. They can be made out of standard composite material, which is designed to cope with compression ratios up to 25:1, and even more ir you are 'ringing' the tops of the liners. We also use reinforced composite material, which is designed to whithstand 30:1 and over compression ratios, as well as cope with all sorts of known forced induction, additional fuel modifications, etc.

 

This would be a one of gasket, and I would need a pattern for it (old gasket is quite sufficient).

 

the price, depending on your choice of material and thickness will be £65-£85.

 

You can contact me on 07981965648 to discuss all the details.

 

Regards,

 

 

 

Director @ RS Gaskets

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M@tt

JUst a few of my thoughts on the subject, i could be way off however i can understand the liner protusion not being enough (ie the liners wearing into the block) but i'm struggling to understand why/how it would be too much.

 

For what its worth i would be very tempted to whip the pistons and liners out and have a clean up of the mating surfaces between the liner and the block, you'll probably find there's loads of hardened crap between the 2 which is pushing your measurements out, especially if the liners have been unsettled previously(maybe during a previous HG change). If you've already got the engine and head off it's a pretty quick job, you'll just need some new O ring seals. I'd have a bash at that first rather than the forking out for an expensive one off headgasket.

 

I think it's got to be something fairly simple as i dont think the engine would have made it out the factory if it had that sort of problem, assuming its all still the original internals.

 

Matt

Edited by M@tt

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