Slipped liners

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Mc Tool
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Slipped liners

Post by Mc Tool »

I have acquired a 3.9 block ,actually whole engine in bits ( serp motor with dizzy ) ,are there any tell tale signs of slipped liners that one might see on a bare block . Supposed only 60,000kms but I suspect it did most of that on one oil change , funny uneven wear patterns on some bearing shells , and it lookie like some of the ex valves have been kissing the pistons . I just dont want to prep the block to find it has wonky liners . I plan to polish all the visable (while in car ) parts of the block , heads and manifold/plenum .


I wish I was young again , Id be heaps smarter than the first time

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ChrisJC
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Re: Slipped liners

Post by ChrisJC »

You should be able to see if a liner has slipped - if it is not dead flush with the deck.

However, that is not the main problem with these blocks. The real issue is that they crack behind the liner, and allow water to seep from the water jacket, through the crack, and up to the top where they come over the top of the liner and into the combustion area.

The test is a pressure test of the block, ideally hot.

Chris.
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Series IIA 4.6 V8
R/R P38 4.6 V8

Mc Tool
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Re: Slipped liners

Post by Mc Tool »

Thanks Chris . I may have dodged the bullet, as whilst mostly in bits and uncleaned there is no sign of there being any water in the oil . Im just a bit suss as to why this motor was taken out of service, kinda hoping the donor vehicle was totalled . It definatley hasnt been well serviced . 🙂
Just had a thought ,I wonder if there would be anything to see by shoving my flexi camera in thru the frost plug holes .🕵️😀
I wish I was young again , Id be heaps smarter than the first time

SuperV8
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Re: Slipped liners

Post by SuperV8 »

Mc Tool wrote:
Wed Jul 21, 2021 6:22 pm
Thanks Chris . I may have dodged the bullet, as whilst mostly in bits and uncleaned there is no sign of there being any water in the oil . Im just a bit suss as to why this motor was taken out of service, kinda hoping the donor vehicle was totalled . It definatley hasnt been well serviced . 🙂
Just had a thought ,I wonder if there would be anything to see by shoving my flexi camera in thru the frost plug holes .🕵️😀
The coolant could also end up in the combustion chamber so you may not see and oil contamination.
The combustion chamber may look 'steam cleaned' compared to the other none leaking cylinders - may not I suppose if it's only a small leak.
My 4.6 had 3x leaking from a hot pressure test, but by all accounts the 4.0 and 4.6 were worse for this.
Dax Rush 4.6 supercharged V8 MSII

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ChrisJC
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Re: Slipped liners

Post by ChrisJC »

As stated, the oil does not go into the water.

The usual story is that the engine starts to use water, so the garage says the head gasket must have gone, so they get changed.

The problem remains.

The gasket gets done again.

The car gets scrapped!

If the vehicle history has got head gasket replacements, then be very suspicious!

I took some photos of a cracked block that I had here:

http://www.cowdery.org.uk/cracks.php

For all of my engines, I got top hat liners fitted as a matter of course. Expensive, but solves it for good!

Chris.
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Series IIA 4.6 V8
R/R P38 4.6 V8

Thunderchief
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Re: Slipped liners

Post by Thunderchief »

I suspect that slipped liners will be caused mostly by overheating. In my time I've owned cars, tractors, vans, lorries, excavators, generators, the list goes on, if they are serviced regularly and the cooling system is kept in good order and they are never allowed to overheat, even the engines with a bad reputation are generally fine. Keep in mind aluminium has a higher coefficient of expansion than iron/steel, the hotter your ally block gets, the looser the liner will become, the more likely it will be to slip. If you heat an ally block up to not a very high temperature, iron liners will literally fall out under gravity.

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