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Siezed Engine Cure?


N.O.S.

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I've got a big old engine to free up - seized through standing, probably just rust in bores.

 

A friend keeps telling me that the best stuff is a can of Coca Cola down each bore, swears he got this from a reliable source.

 

Must say I am very sceptical, mainly because it is water based. :|

 

On the other hand, considering what it does to your insides, it sounds so bizarre it might just be true. :dunno:

 

Is this a CURE-ALL, or a DISASTER COCKTAIL - what do you think?

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Tony,

 

I would have the head off first to see how bad the corrosion is, if not too bad then diesel is good as it has a searching action and is a lubricant. I have had gudgeon pins siezed / rusted, which does not help either. With the head off and a lump of hard wood, you can thump the pistons alternatively to rock it back and forth slightly to break any rust bond on the rings. It may be too badly siexed, like an Austin K2 engine I rebuilt a while back, now that one, I had to take the crank out and really force the pistons down, that one was so bad it definitely needed reboring.

 

Coke contains a mild dose of phosphoric acid, we used to have large tanks of this acid to clean engine components on the overhaul line, it eats any thing like alloy though. Thinking of it, Coke comes in alloy cans so the acid strength must be quite a bit mild :-D

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Yes the acid strength is quite mild in COKE, but I would not leave it in there too long as it will eventually eat away at anything soft etc. I know as I work for them and it eats the machinery at work. :-D

 

 

 

But PLEASE buy loads and kep me in gainful employment ;-)

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There is a vintage car that does the local show circuit that had its engine sitting in a vat of diesel for seven years to free it up :schocked:. It is something like a seven litre four cylinder beast and you can see huge flywheel, it's something approaching three feet across, underneath the car. I think it is American in origin and it sounds awesome but what the make is eludes me at the moment :dunno:

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I would recommend taking the head off and cleaning out the worst of the rust by with a rotary wire brush first (if possible). Coke seemed to loosen up the worst of it, but after a couple of days I filled the bores with diesel and that seemed to do the job.

 

I managed to turn the crank just a fraction, then the after a couple of days i got some more crank movement. I then flipped the block on its side, removed the big end caps and tapped the pistons in an out in out small ammounts, until they came through the top of the block.

 

It helped that when each piston had moved down slightly, I used a glaze buster and hone tool to clean the bore to ease the upward journey of the piston. I took a bout 3 weeks of a little movment at a time to remove all 6 pistons.

 

I am guessing that your engine is large and American?

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Well, the bores are very large, but is a McLaren 2 cylinder 44hp 1940's diesel. It was running until 20 years ago when parked up. Lots of moisture down exhaust but not a lot of water.

 

Followed Lee's link to the last thread on it - looks like my pal Brian was right after all!

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  • 2 weeks later...

when I worked at the museum, we used diesel and time. If we thought the engine was bad we'd take the heads off, as mentioned prior, then pour in diesel and leave, everyday trying to turn the crank with slight pressure. Usually a couple of days did the trick, when the pistons moved, we always seemed to find a ridge of rust where the pistons had been resting.

 

 

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I've been trying to unstick a J60 for the past 2 weeks. I've tried coke, hot oil, diesel, WD40, heat, time, a large hammer and block of wood. So far I have got 3 pistons out (2 came out easily) by removing the head & sump and knocking them out through the top. The other 3 won't budge and it's really starting to annoy me know. It's sat full of diesel at the moment. Any suggestions, or should I just leave it even longer?

 

Incidently the engine looks very good, little wear and the 3 pistons we got out looked almost new. The engine has been drained of oil and has sat a long time, otherwise I think it may have been ok! :shake:

 

Chris

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I've been trying to unstick a J60 for the past 2 weeks. I've tried coke, hot oil, diesel, WD40, heat, time, a large hammer and block of wood. So far I have got 3 pistons out (2 came out easily) by removing the head & sump and knocking them out through the top. The other 3 won't budge and it's really starting to annoy me know. It's sat full of diesel at the moment. Any suggestions, or should I just leave it even longer?

 

Incidently the engine looks very good, little wear and the 3 pistons we got out looked almost new. The engine has been drained of oil and has sat a long time, otherwise I think it may have been ok! :shake:

 

Chris

 

 

Chris,

 

get hold of a 400,000 btu's roofing torch & try heating the block so it expands...

 

width=550 height=278http://www.flameengineering.com/Assets/roofing_images/RT-2.5-20-C.jpg[/img]

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Um, would need very careful application of heat to prevent hot spots. Cast iron can very fragile. At least now you can get a relatively cheap stand off infra red thermometer to check if the heating is uniform. I know Maplins sell them for about £35, can be very useful for checking circulation in radators etc.

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