| Author |
Message |
    
trapperlon
New member
Username: trapperlon
Post Number: 3
Registered: 06-2011
| | Posted on Monday, June 20, 2011 - 04:01 pm: | 
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Just picked up a 4hp Acadia, but the piston is frozen in the cylinder. An one know of a way to remove it. Any help would be great. |
johnoxley
Member
Username: johnoxley
Post Number: 29
Registered: 04-2010
| | Posted on Monday, June 20, 2011 - 04:48 pm: |
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Hi - see http://www.oldmarineengine.com/history/Acadia/AcadiaSect6HP.htm Careful hitting down on Cast Iron piston as it can fracture. Start penetrating oil immediately and for some time - dismantle cylinder - check bore beneath piston for rust first (remove all) - I would make a puller to draw down connecting rod (do not load extremity of base flange - can fracture) - LP gas warm cylinder to point where spit starts to steam - load up puller - gentle tapping with broomstick down plug hole. If fail, fill top with oil and pump in very thick oil to hydraulic piston as far as exhaust port - keep puller tensioned - once it starts to move, it should continue. |
qwilkin
Advanced Member
Username: qwilkin
Post Number: 39
Registered: 08-2009
| | Posted on Monday, June 20, 2011 - 05:42 pm: |
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I own a blaxland which had not been moved since 1982. I filled the cylinder with Penetrene oil and left it for 3 months , Came back and inch the flywheel and it came free. Patience is required ,
Quinton |
tom_montagu
Member
Username: tom_montagu
Post Number: 13
Registered: 12-2011
| | Posted on Saturday, December 31, 2011 - 02:23 pm: |
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trapperlon; jonoxley is right, hitting cast-iron pistons can lead to irreperable damage (and on old engines often irreplaceable). Trick I learnt from a guy who HAD to free-off a seized and very rare earo engine--heat up some old engine oil in a (old, and check with the wife first) saucepan. Then VERY CAREFULLY pour the oil ontop of the piston---it worked for him because the programme ended with him flying the plane--Just be CAREFUL |
scott_n
Senior Member
Username: scott_n
Post Number: 213
Registered: 02-2008
| | Posted on Sunday, January 01, 2012 - 10:48 am: |
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check out my winter project in the calle thread |
johnny
Senior Member
Username: johnny
Post Number: 433
Registered: 03-2006
| | Posted on Monday, January 09, 2012 - 12:37 pm: |
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Me and my father have removed a few stuck pistons over the years. I can give you some tips that will keep you from breaking your engine in pieces if you want to email me. Just right click on my name and send me a email. Dad is 76 and I'm 50. I started working on the antique engines when I was a teenager. |
matt_morehouse
Senior Member
Username: matt_morehouse
Post Number: 100
Registered: 12-2009
| | Posted on Tuesday, January 10, 2012 - 11:14 am: |
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Pour some Kroil in the cylinder and let sit for a week or so in a warm place.
I used to use Marvel Mystery Oil but Kroil works better. The stuff is amazing. |
matt_morehouse
Senior Member
Username: matt_morehouse
Post Number: 101
Registered: 12-2009
| | Posted on Tuesday, January 10, 2012 - 11:17 am: |
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It might take longer than a week. Take a peek with a strong flashlight, if some or most of the Kroil is gone you can be sure it is working, add more Kroil and time. |
speleausmining
Member
Username: speleausmining
Post Number: 18
Registered: 10-2010
| | Posted on Tuesday, January 17, 2012 - 12:03 am: |
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Trick here is patience and perseverence. I doubt anyone who has feed an engine with penetrating oil has ever had a REALLY stuck engine but thats just my experiance. That said theres about as many ways of freeing a stuck engine as their are people who work on them. I would be prety wary of taping from the top with a broomstick. Doing that puts shock on one of the weakest points of the piston (the middle of the crown). Also beware of pushing the piston in, this can work but you can also push it too far and get the rings stuck in the combustion chamber. Do that and your only option is to break the piston out. Best method I have used (successfully) is to soak both sides of the piston with Evapo-rust untill the metal is clean on either side. then fill the cylinder above the piston with Brake Fluid. Let it sit for a couple of weaks. If possible heat the cylinder gently intermitantly during this time. Once it has sat make an adapter out of a plug so you can presurize the cylinder with grease. Also cover the exhaust ports. Then start pumping in grease. Once the Cylinder is presurized leave it that way for a week then up the presure again. keep doing this on and off untill you get movement or fluid starts working past the piston. Once you have brake fluid leaking past the piston your home free, more or less. I have had them fight all the way out to the last 1/4 inch. Longest It ever took me to free one was 8 months like that. |
jb_castagnos
Senior Member
Username: jb_castagnos
Post Number: 647
Registered: 07-2002
| | Posted on Tuesday, January 17, 2012 - 08:05 pm: |
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How do you determine how much pressure you're putting with the grease gun? I had to sleeve a cylinder that had the side blown out of it, barely had enough to recieve the sleeve at the top. Obviously he used too much pressure. |
speleausmining
Member
Username: speleausmining
Post Number: 19
Registered: 10-2010
| | Posted on Tuesday, January 17, 2012 - 09:38 pm: |
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I usually addd a pressure gauge to my adapter to keep an eye on the pressure. I also use a hand opperated grease gun. I have heard of people using a hydralic pump to presurize but that allways made me nervous to think about. The main difference between my method and normal grease presurization is the use of brake fluid to occupy the space in the cylinder and pausing rather then just uping the pressure untill something moves. My method the presurization serves as much to help push brake fluid into the space between the piston and cylinder as to push the piston out. Of course with old engines there is no guarentee, the cylindr walls might be thin, more corroded then you thought, or allready weakened by fractures. Like any "aggresive" method of freeing the piston there is the potential for something to break. |
speleausmining
Member
Username: speleausmining
Post Number: 20
Registered: 10-2010
| | Posted on Tuesday, January 17, 2012 - 09:41 pm: |
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I have rarely had to use much over about 150PSI to get a piston to move using this method. Its as much about sustained pressure over time as it is about brute force. |
silverghost
Member
Username: silverghost
Post Number: 30
Registered: 05-2009
| | Posted on Friday, January 20, 2012 - 03:34 pm: |
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Most auto supply stores carry screw-in spark plug adapters to allow compressed shop air to be charged into an engine cylinder.
After soakng with penetrating oil the compressed air works very well, & safely, to push-on a stuck piston in a cylinder bore without opening-up an engine. |
worth
Member
Username: worth
Post Number: 5
Registered: 12-2011
| | Posted on Friday, January 20, 2012 - 04:32 pm: |
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My understanding is that shops use compressed air in modern automobile engines to keep the valves from falling into the cylinder when replacing valve seals. I'm not sure I would want to pressurize the cylinder of an antique engine with compressed air, since the cylinder could explode if it cracked. Some of previous posters suggested a pressurized liquid, which is much safer since the liquid is incompressible and thus stores no energy to be released in a rupture. |
silverghost
Advanced Member
Username: silverghost
Post Number: 31
Registered: 05-2009
| | Posted on Friday, January 20, 2012 - 07:10 pm: |
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I understand your safety concerns stated above.
But~
If you don't go crazy and pressurize to 100-125 PSI from the start you should be safe.
Start out only at only 5-10 PSI pressure at first.
If you factor in the total surface area of of the piston top at 5-10 psi you are still putting quite a few of foot pounds of force on the piston top.
It may pay to put a robust safety blast continment box or container & padding around the engine and stand far way when adding any air pressure.
I restore Brass Era & Full Classic era autos and this air tecnique has been very successful for me in breaking loose long stuck & siezed early auto & boat engines. |
