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How to un-seize an engine

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New Dexter
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How to un-seize an engine

Post by New Dexter » Sat Sep 23, 2017 11:02 am

Could anyone recommend a cocktail to put into there bores of an engine to un-seize it? I have heard of people using diesel or a cocktail based upon that. I have access to some red diesel.

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Re: How to un-seize an engine

Post by John-B » Sat Sep 23, 2017 12:20 pm

Read this topic as Big A'l had the same problem and eventually resorted to a large hammer. Various liquids were tried, like Coca Cola.

Two Pistons that stubbornly refuse to move, I have soaked them with Diesel, for Two months, heated them with a blow lamp, soaked them in WD40, and almost anything I could think of.
I have even resorted to placing a hard round piece of timber into the bore so that it rested on the Piston Crown, and given them a beating with a Two pound Lump Hammer, and they still resolutely refuse to budge.
Morning, Chaps, well I tried the " Wood & Sledge Hammer" method, and only succeeded in shattering the wood, without even slightly moving either Piston ! ! .
Time to get angry šŸ˜” so I found a suitable piece of thick plate, and a nice longish piece of Bronze Bar, and then gave the "Buggers" what for.
Even then, it still took some time to persuade them to give in, ...

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Re: How to un-seize an engine

Post by JT7196 » Sat Sep 23, 2017 4:59 pm

Exactly !!! 8-)
The LA11 (1444cc) Engine will probably be up for sale soon, I do not need it, as I have recently completely overhauled mine.
It will of course need to be reconditioned, but where else is one going to find an 80 year old Engine that has a Bore size of only + 0.020" oversize.
If you are interested, contact me here in the first instance.

Cheers A'l 8-) 8-)

New Dexter
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Re: How to un-seize an engine

Post by New Dexter » Sat Sep 23, 2017 5:04 pm

I did read Al's postings about his problems un-seizing his Lanchester engine but that one had had the head removed. I have an engine that's complete but which appears to be stuck. I was proposing to remove the spark plugs and pour something down the holes. I could use Plusgas but I think I would need almost a couple of pints to be successful.
Is it just rings rusting to the bores or is there something else involved?

Big Col
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Re: How to un-seize an engine

Post by Big Col » Sat Sep 23, 2017 5:38 pm

I think Diesel would be a good start for the first week or so if you don't want to strip bits off. I imagine that the initial movement will still need a strong bar though.
Are you are thinking about getting it turning over so you can start it up?
The thing to watch for there is if the rings crack when you do get it moving that you don't score the bores and then have lots of blue smoke as a consequence and then needing a rebore anyway.
I may be slow but Iā€™m rough as well !

New Dexter
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Re: How to un-seize an engine

Post by New Dexter » Sat Sep 23, 2017 6:31 pm

Thank you for the warning Colin. I was hoping to be able to turn it over on the starter before being bold enough to start it. Just to ensure it was free would be nice.

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Re: How to un-seize an engine

Post by Sydsmith » Sat Sep 23, 2017 10:09 pm

Freeing a seized engine depends on how or why it became seized. The remedies so far proposed assume there is a problem with the pistons stuck in the bore.

Other reasons can be big end, small end or main bearing seizure, so it can be a top or bottom end problem and forcing the engine round could cause huge damage to the crank or bores.

Unless the reason for the seizure is known it would be wise to at least remove the head and sump to inspect the engine before any more damage is done.

If the engine is known to be rusted, paraffin will often loosen rusty bores. Syd

Stan Thomas
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Re: How to un-seize an engine

Post by Stan Thomas » Sat Sep 30, 2017 9:18 am

Simply seeking to "un-seize" the engine is no engineering solution - for as everyone advocates - you don't know why its seized - or for that matter if it is a broken and jamed component.

Chances are though that it will be pistons and bores if the engine has just stood, although just feeing them off is no long-term answer unless your looking to just off-load the engine on Ebay etc.

Assuming the engine is out of the car, its no big shakes to remove the head and base chamber (or "sump" on any other engine than a Daimler) then remove the crank. You then have six pistons in the block with dangley rods which can be treated and removed individually.

Just a few hours work.

Come back to me if you need to hone the bores.

Keep us posted.


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