This was a conversation online from an older Flathead website that was lost after the owner passed away. We have been getting archived articles from those that use to help with it. So keep in mind this was an archived thread with helpful information. Not a written out and proofed article.

Oilcan Harry: 10/26/2000 – 1/1/1900 12:53:17 PM

I just picked up a 50 flathead for my chopped 26 T coupe project. It`s complete but stuck. Any hints on un-sticking it? I was advised to keep pouring kerosene in the plug holes and be patient. I will be completely rebuilding it.

Bubba: (Sep 19 1999 11:09PM)

Everyone has their own favorite for penetrating oil. Mine is Marvel Mystery Oil, but others (including kerosene) are probably just as good because the real key is soak `em often and have more patience than a bull waiting for a heifer to come out of the barn.

If it is stuck, you can bet the rings are stuck in the pistons and are not going to just come loose. Get the engine out, lay it on a big flat surface, pull all accessories, pan and oil pump. Squirt knock loose, not WD-40 and get the kind that has a petro. base, not the water type, around the bottom of the pistons. Use a large prybar and start working the flywheel back and forth with the starter teeth. when you can turn the crank all the way around, its free. You may also have to pull the timing gear off the cam, if the valves are stuck, they also will keep things from moving.

Lars Brandow (Sep 20 1999 8:05AM)

Put the engine on a Engine stand, and turn the engine so you can fill the cylinder with your favorite oil (50% kerosine50% Diesel) leave for a while maybe days. Then Jim’s way is one way to go. Or take a big piece of wood place it against the piston. And hit it with the biggest hammer you have 🙂

JWL (Sep 20 1999 8:46AM)

I agree to remove engine. I also agree to liberally soak with your favorite mixture. When trying to turn the flywheel, some of the rods will be in tension and some in compression positions depending on the direction of rotation. Observe for those in tension and use a block of wood about the same size as the bore and a good-sized hammer to impact the top of those pistons. Next move the flywheel in the opposite direction so those rods which were in compression are now in a tension mode. Repeat the wood block, heavy hammer action on those in tension. Now go the other way with the flywheel and move back to the original pistons. etc. etc. At first the movement will be exceedingly small, but usually, with enough patience and effort you will get it to turn. I also agree with Jim`s suggestion to remove the cam gear so you know what you are working on. Good luck.

bill (Sep 20 1999 2:36PM)

every time you walk past it while soaking ping it…find a good solid spot where you won’t break anything ang give her a good shot with a maul…the vibrations will do wonders…please do not hurt the puppy with a hole or crack in same perhaps several small pings in several places would be better…

billk (Sep 20 1999 7:08PM)

I had a 50 merc motor that had been in a flood and then sat for a long time. Boy, was it stuck. I didn`t even hope of saving the pistons. If you can get a ridge reamer in the cylinders to get the ridge out, then try to break the pistons, assuming that they are aluminum. You might not even need to remove the ridge if you expect to break them out anyway. Take off a rod cap that is near the top of the stroke. Go at them from the bottom with a length of pipe or steel rod and the BIG hammer. Once they break you can work them out in pieces. It’s no fun but it`ll work.

48 Al: 10/26/2000 – 1/1/1900 4:24:44 PM

I have used PB B`laster for years on stuck engines. this stuff Melts rust. have never used anything better. as in other posts, patience is particularly important if you don’t want to do damage. Al

Frankie Flathead: 10/26/2000 – 1/1/1900 7:53:25 PM

What about soaking the mill in a molasses/water mixture bath. This also dissolves rust. Like you wouldn’t believe. Just strip oil pan/intake/timing cover and remove as many parts as possible. Do not leave any Aluminum parts on the engine. Then degrease the block as best as possible so that the mix is not contaminated. I had a very rusty 8BA that I left in a plastic tub of molasses for 2 1/2 weeks. When removed and hosed off, the engine looked like it had just come out of the foundry and the water jackets were clean enough to eat off!! You can also use the molasses bath to de-rust other project components Finally, the used molasses is also environmentally friendly and will do plants good if poured into the garden!! What else could you ask for?

Sopp: 10/26/2000 – 1/1/1900 10:40:38 PM

What`s the mix ratio of mo` to H2O? This sounds like something I just might try.

Jim Marlett: 10/26/2000 – 1/1/1900 10:49:09 PM

After posting that rather large string of other people`s posts, it is worth mentioning that Red Hamilton of Red`s Headers soaks his flatheads in a barrel of #2(?) diesel before disassembly. I`m sorry I don`t know anything about diesel fuel, but #2 seems to be what I recall. That trick is a little bit beyond my tinkering capacity, but if you`ve got the space and can deal with the waste…

Frankie Flathead: 10/27/2000 – 1/1/1900 4:16:24 AM

Sopp, The ratio I used is 1 part molasses to 4 parts water. Pour in your molasses first, then pour in hot water to dissolve the thick syrupy molasses. If ya got seriously rusted stuff, make the mix a little stronger ie: 3 parts water. Lastly, I Just emptied my drum after using this stuff for over a year, so it works for quite a while!! After a while, it also tends to get a bit whiffy so stash the drum/barrel in a corner of the backyard away from the back door!!!

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