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#875640 03/25/22 3:47 pm
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Hi guys, I’m in need of some advice and ideas please. I have an A65 motor with the pistons frozen bad in the jugs, worst I’ve ever had! They’re at pretty much top of stroke and I’ve tried all three catalysts I have, WD40, PB Blaster and an unknown commercial grade catalyst give to me from a mine equipment refab shop, all with no luck. They’ve been sprayed and soaking for 2 weeks but won’t budge. Open to all ideas as I believe these late model jugs on it are standard bore and, so I’d really like to save them. Any help out there?
Thanks in advance!


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Look up "electrolysis, rust removal", using a battery charger and washing soda for rust removal.


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Stuck “up” is hard.

I saw an old boat restoration programme and they (outdoors)

Heated up engine oil in a can, and poured it into the cylinder.
I assume that the heat shock allowed the oil o penetrate.

The lower the piston is, the more oil you can use and presumably the bigger mass of oil retains heat.

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Originally Posted by breeze1954
.....They’ve been sprayed and soaking for 2 weeks but won’t budge. Open to all ideas......
You're off to a good start with all the soaking. If there's any rust in the tops of the bores, scrape that out.

I would be trying heat next. The idea is, the aluminum pistons will expand more that the iron barrels. Heating up and then cooling down will swell up and then shrink the pistons in the bores helping to unstick them.

If you have an oven you don't mind stinking up, bake the engine at 300 degrees or so for an hour or two.

Keep soaking it with PB Blast or your favorite penetrant.

If you don't want to go the oven route, you could also carefully heat the piston crowns with a torch but temp is harder to control. Go by the 'spit' test.

Heat the piston some, spit on it, and watch what the spit does. If it just sits there, it's not very hot. If it bubbles away, it is around boiling ie 212 degrees. If your loogie hops and pops and dances around, you're hot enough. Do the same to both pistons.

Then, let it cool down cold, even outside overnight, and then try to free it up. Arrange some way to turn the crank back and forth with a big lever. Since it is at or near TDC, any small piston movement will allow the crank to move quite a bit and once it frees a little, continued oil and motion should get it freed up.

If it still won't budge, repeat the process. Best of luck.

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Hello;
with the heat method and lubricants described you would free the pistons.
Pistons material is Aluminum; the jugs are steel so eventually they would release however; may be are the connecting rods etc what you have stuck there

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I've been toying with the idea of using a grease gun to force stuck pistons to move.
That would involve a section of steel flat (probably minimum 3/8" thick) bolted down to the cylinder block, with holes drilled near the bore centres, and tapped to take grease nipples. The hold-down holes would be located off the head using a transfer punch.

In theory, the high pressure grease would be sufficient to move the pistons enough to break the rust bond between the rings and cylinder bore.

Soaking with penetrating oil for quite some time beforehand, along with a few heat cycles would also help.

Having the pistons at TDC is probably the worst possible case, so would require also applying torque to the crankshaft.


Then there's always the brutal approach of drilling the crowns off the pistons and slotting the skirts with a hacksaw blade, but I didn't mention that.

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Come to think of it, how about something like Evapo-Rust?

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Hi guys, still working at it and still stuck. No Reverb it’s the pistons in the jugs. I took the jugs loose right off to make sure where and they can move up and down about 3/8 inch off the cases turning the crank. So far I’ve had them soaking for a couple weeks, used a bit of heat on the pistons then let them cool and been working the crank back and forth. May try some heat on the jugs and a small dead blow on the pistons tomorrow, but I’m done for the day, kinda tired of it for now and don’t want to take a big big hammer to it.
Thanks for the ideas and I’ll keep y’all posted how it goes.


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Originally Posted by Shane in Oz
I've been toying with the idea of using a grease gun to force stuck pistons to move. .........
Derail time:
For ages now, Shane's grease gun idea has been my go to method for forcing frozen pistons out of disc brake calipers. It's messy but works awesome. Never ever thought of using it to free up stuck engines though. It would probably work fine but all that expensive grease. What a mess!

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Originally Posted by Stuart Kirk
Originally Posted by Shane in Oz
I've been toying with the idea of using a grease gun to force stuck pistons to move. .........
Derail time:
For ages now, Shane's grease gun idea has been my go to method for forcing frozen pistons out of disc brake calipers. It's messy but works awesome. Never ever thought of using it to free up stuck engines though. It would probably work fine but all that expensive grease. What a mess!

Even worse derail- grease isn’t that dear, at £40 ($53) for a 12.5 kg pail, delivered. Probably cheaper at your local agric. supplies place.


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Put the head back on, modify spark plugs to take grease gun fittings, push the pistons down with grease.
I like 50/ 50 Acetone / Atf as a rust breaker, it does a clever chemical trick, turning rust into a more brittle compound that lets go easier.
The chemistry is interesting, Acetone reacts with rust ( iron oxide) to give water, CO2 and iron carbide, the iron carbide is extremely brittle and will fail with impact force, the ATF is there to help lubricate. if you cant be bothered with the grease, repeated bathing in the Acetone ATF mix with occasional impact force should break the rings free. Eventually. As with all chemical reactions , heat will speed the process.


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so thats how it works

i had thought the acetone was just a solvent for the atf


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You need to press them out…An automotive damper pulley puller works good..Rig it onto the cylinder using the head bolts..Run the screw down against the piston…A small quantity of thin oil for lube..


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Originally Posted by triton thrasher
Originally Posted by Stuart Kirk
Originally Posted by Shane in Oz
I've been toying with the idea of using a grease gun to force stuck pistons to move. .........
Derail time:
For ages now, Shane's grease gun idea has been my go to method for forcing frozen pistons out of disc brake calipers. It's messy but works awesome. Never ever thought of using it to free up stuck engines though. It would probably work fine but all that expensive grease. What a mess!

Even worse derail- grease isn’t that dear, at £40 ($53) for a 12.5 kg pail, delivered. Probably cheaper at your local agric. supplies place.

You don't have to use grease to fill the combustion chamber or space between the piston and a plate. Fill it up with waste oil (you are going to need to clean it up anyway) and use the grease gun to apply the pressure. try to fill the void as completely as possible to avoid much compressed air.

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I like HilbillyBikes idea, rig up some kind of press that bolts to the cylinder head bolt holes and had a central bolt that can be tightened down onto the piston.

Try not to over-tighten the bolt pressing on the piston for fear of stripping the head bolts.

With the press applying constant pressure to the piston you can then try various combinations of penetrating oil/acetone/PB Blaster/Kroil etc. and also keep cycling the heat over and over. Keep checking the pressure on the piston, you might find the pressure has reduced as the piston has moved slightly.

It might also be worth trying a freezing spray as used by plumbers, this should be sprayed onto the piston crown in the hope that it will shock the components apart.

Using the above methods, something should eventually give, though it may take weeks, so be patient.


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Originally Posted by gunner
...........something should eventually give, though it may take weeks, so be patient.
Some years back I had a rusted up 1940 Lincoln V12 engine block with cast iron pistons I wanted to save. Water had sat in it for years before I acquired it from my dad and the iron pistons and block had almost become one. It took several years of soaking, beating on piston tops with a 5 lb hammer and trying to turn it but it finally freed up. It is in a running car now.

So...... there's hope, just be patient and try not to break anything important.

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Originally Posted by gavin eisler
Put the head back on, modify spark plugs to take grease gun fittings, push the pistons down with grease.
The steel or aluminium flat approach was based on this, but trying to be nicer to the head

Originally Posted by gavin eisler
I like 50/ 50 Acetone / Atf as a rust breaker, it does a clever chemical trick, turning rust into a more brittle compound that lets go easier.
The chemistry is interesting, Acetone reacts with rust ( iron oxide) to give water, CO2 and iron carbide, the iron carbide is extremely brittle and will fail with impact force, the ATF is there to help lubricate. if you cant be bothered with the grease, repeated bathing in the Acetone ATF mix with occasional impact force should break the rings free. Eventually. As with all chemical reactions , heat will speed the process.
It's nice to have an explanation for that brew.

Originally Posted by Hillbilly bike
You need to press them out…An automotive damper pulley puller works good..Rig it onto the cylinder using the head bolts..Run the screw down against the piston…A small quantity of thin oil for lube..
That's a nice approach. Mechanical rather than hydraulic. Machined discs of steel or aluminium to act as piston protectors might be an enhancement.

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Originally Posted by Hillbilly bike
You need to press them out…An automotive damper pulley puller works good..Rig it onto the cylinder using the head bolts..Run the screw down against the piston…A small quantity of thin oil for lube..

Last evening after another day of some heat and soaking I rearranged a robust puller into a press and tried Hillbilly bike’s idea (really good idea). But even with enough pressure to make me worry about stripping or snapping the head bolts I could get no movement on the pistons at all. So today I’m going to put the head back on and fill the cambers with the Acetone / ATF mix (my hip got to hurting too bad to do it last night, but that’s another story). I’m just going to leave it to soak for a few days or weeks adding more mix as needed each day, and thanks Gavin for the interesting explanation of the mixture. I’ll let y’all know how it goes when I go back at it and thanks again everyone for all the ideas and help.

Last edited by breeze1954; 03/27/22 12:01 pm.

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I would seriously consider sacrificing the pistons.
It will probably need a rebore and new pistobs if the bore has rusted


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...if you do not have the pistons stuck but the steel rings to the jugs (steel too) you have 3 rings per piston so about 6mm (2mm x 3 rings) of surface stuck in each piston.
I do not see how the acetone would remove all that corrosion.
The problem with a powerful method is the neck and eye of the connecting rod; that could be internally damaged; not perceived at simple observation and if they are aluminum like Triumph´s, no magnaflux test will aid so that is a big concern (if you do not put new rods)
If you put new ones; just like Andy is saying, you can go with more drastic methods and remove then.
-If the corrosion is big besides the rings, you will need to go 1 or 2 measures in the over bore

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Originally Posted by reverb
The problem with a powerful method is the neck and eye of the connecting rod; that could be internally damaged; not perceived at simple observation
I think either the hydraulic or mechanical approach should be alright, provided the cylinder isn't bolted down to the crankcase. There should be downward force on the piston and upward force on the cylinder, but very little force on the connecting rods.

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Originally Posted by Stuart Kirk
Originally Posted by gunner
...........something should eventually give, though it may take weeks, so be patient.
Some years back I had a rusted up 1940 Lincoln V12 engine block with cast iron pistons I wanted to save. Water had sat in it for years before I acquired it from my dad and the iron pistons and block had almost become one. It took several years of soaking, beating on piston tops with a 5 lb hammer and trying to turn it but it finally freed up. It is in a running car now.

So...... there's hope, just be patient and try not to break anything important.


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Hi All,
20 odd years ago I went to press out the pistons from a Triumph 5T, they were really stuck
I had tried all the release tricks to no avail
I made up a steel plate to bolt to the head studs and a pair of grease jacks to apply pressure to the pistons
I got the pistons to move after drilling down the sides of the pistons to break the hold of the rings
BUT
Once the piston ring areas reached the plain part of the cylinder below the fins the cylinder split around the circumference

So I would recommend scrapping the pistons to save the cylinder

John

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Originally Posted by chaterlea25
Hi All,
20 odd years ago I went to press out the pistons from a Triumph 5T, they were really stuck
I had tried all the release tricks to no avail
I made up a steel plate to bolt to the head studs and a pair of grease jacks to apply pressure to the pistons
I got the pistons to move after drilling down the sides of the pistons to break the hold of the rings
BUT
Once the piston ring areas reached the plain part of the cylinder below the fins the cylinder split around the circumference

So I would recommend scrapping the pistons to save the cylinder

John


Exactly my sentiments too, why waste time and resorces mucking about, A65 pistons are fairly common too so I really wouldn't worry about the pistons. Barrels are becoming harder and harder to find in decent condition. Especially late ones.


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I once spent a lot of time and effort to get the pistons unstuck from a vintage Chevy engine and “destroying” the pistons was the only way….But the rust pit damage to the cylinders was beyond sensible repair…


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